From 135 mph wind gusts on Hawaiʻi Island to 62 inches of rainfall on Maui, a recent Kona low system brought weather conditions usually reserved for major hurricanes to the state. These extreme totals were captured by the University of ±á²¹·É²¹¾±ʻ¾±â€™s Hawaiʻi Mesonet, a weather monitoring system that is mapping localized threats across areas that previously had no data available. ¶«¾«Ó°Òµâ€™s Hawaiʻi Climate Data Portal team created a report on the storm.

Alongside immense flooding, the storm brought destructive winds. The Hawaiʻi Mesonet station at Kaiāulu Puʻuwaʻawaʻa on Hawaiʻi Island recorded a maximum wind gust of 135.4 mph. Winds were briefly sustained at speeds equivalent to a Category 2 hurricane, averaging 105 mph over a 15-minute period.

Maui was hit the hardest, with peak rainfall totals reaching 62 inches in localized regions. Hawaiʻi Island also saw heavy precipitation, with areas recording 16–32 inches, and isolated spots also nearing 62 inches. Both Kauaʻi and Oʻahu recorded maximum totals ranging 16–32 inches. Molokaʻi and Lānaʻi experienced peak amounts 4–16 inches.

The upper elevations of Haleakalā experienced the most extreme rainfall, with 33.2 inches falling during the 24-hr period beginning March 13 at 8:30 a.m., nearly double the highest 24-hr rainfall previously recorded there. That amount is much greater than the NOAA‘s official estimate of 19.7 inches in 24 hours for the 1000-year storm (the rainfall amount with a 0.1% chance of being equalled or exceeded in any given year). Rainfall was even higher at the Kuiki Hawaiʻi Mesonet station on the east rim of Haleakalā crater with 36 inches falling in 24 hours beginning at 6 p.m. on March 13. This amount exceeded the NOAA 24-hr 1000-year extreme rainfall estimate of 28.5 inches.

“Before the project began, Hawaiʻi was one of only 20 states without a comprehensive statewide weather monitoring system, meaning we previously had no access to information in many of these areas,” said Tom Giambelluca, Hawaiʻi Mesonet project lead, and former director of the ¶«¾«Ó°Òµ Water Resources Research Center. “Now, the system is constantly collecting data on rainfall, soil moisture, and other weather variables that can tell us in real time if an area is highly susceptible to fires or flooding, which ultimately allows us to be as prepared as possible”

To make this information accessible, ¶«¾«Ó°Òµ launched a real-time weather dashboard offering public access to live weather data from more than 70 monitoring stations currently active across the state. The dashboard updates data every 15 minutes, allowing users to view current, localized conditions including temperature, rainfall, wind, humidity, solar radiation and soil moisture. This creates one of the most comprehensive and timely weather resources available in Hawaiʻi.

In 2025, Hawaiʻi experienced its second–driest year in more than a century, alongside persistently above average temperatures throughout the year—a stark reality detailed in the inaugural . Published by the , this first-of-its-kind report uses plain language, along with easy-to-interpret maps and figures, to summarize statewide rainfall, temperature, and drought conditions over the past year.

The report is designed to connect communities, resource managers, and policymakers with the climate data behind what many experienced firsthand, providing essential information to support climate preparedness and long-term planning across the islands.

This report reflects decades of effort to monitor Hawaiʻi’s climate and conduct high-level scientific research, paired with more than eight years of collaboration by a team of climate and data scientists to develop an expanding suite of high-quality climate maps and decision support tools. These maps are hosted on the Hawaiʻi Climate Data Portal (HCDP) and, for the first time, make it possible to summarize climate conditions consistently across the entire state.

“Throughout 2025, we heard people across the state talking about just how hot and dry the year felt,” said Ryan Longman, director of the Hawaiʻi Climate Data Portal. “Now we have the data to show what people were experiencing on the ground. We hope this type of reporting helps connect residents to their own lived experiences with Hawaiʻi’s climate and gives communities the information they need to plan for what’s ahead.”

The report is accompanied by a detailed, interactive website that allows users to explore the same climate information for individual islands and even for specific ahupuaÊ»a or watersheds. Together, the report and website provide a clear picture of what many residents across Hawaiʻi experienced firsthand in 2025.

Highlights from the report

• 2025 was the second driest year in Hawaiʻi’s 106-year record, with statewide rainfall averaging just 42 inches—about 20 inches below the 30-year average.
• Maui experienced its driest year on record, while Hawaiʻi Island recorded its second driest year.
• Rainfall was below average for 11 out of 12 months, and August ranked as the driest August in the past 35 years.
• Statewide, 2025 ranked as the sixth warmest year on record, averaging 0.8°F warmer than normal. For Maui and Kauaʻi, it was the third warmest year since 1990.
• Drought conditions were widespread and severe. By the end of the year, 65% of the state was classified as abnormally dry or worse, and all of Molokaʻi experienced dry conditions. The most intense drought occurred in February, when 56% of HawaiÊ»i was in severe drought or worse.

Future data collection to expand

Looking ahead, the establishment of the Hawaiʻi Mesonet is expected to further improve the quality and detail of future reports by expanding on-the-ground climate observations. This report marks the first in a new annual series, to be released at the start of each year and refined and expanded over time as Hawaiʻi’s climate data and monitoring networks continue to grow.

The report also announced the launch of monthly climate update summaries, expected later this spring, which will send the latest information on rainfall, temperature and drought directly to subscribers’ inboxes, with a focus on the parts of the island chain that matter most to the individual subscribers.

“The goal of the monthly climate summaries is to provide an early signal of emerging rainfall and drought conditions,” said Longman. “By delivering site-specific information at the scales people actually work at, these updates can support more proactive planning and decision-making.”

The report was compiled by the Hawaiʻi Climate Data Portal and Hawaiʻi Mesonet teams. Funding was provided by the National Science Foundation, the State of Hawaiʻi Commission on Water Resource Management, and the U.S. Geological Survey Pacific Islands Climate Adaptation Science Center.

A new tool developed by University of Hawaiʻi researchers allows anyone in the state to generate custom, site-specific climate reports to support decisions related to drought, wildfire and land management—a major step forward in Hawaiʻi’s climate resilience efforts.

The was unveiled at a May 2025 meeting of the Hawaiʻi Climate Data Portal (HCDP) User Group, which drew lawmakers, emergency managers and wildfire officials. The new system lets users select or draw an area of interest, enter basic details and receive a tailored climate portfolio by email. It is free to use and portfolios are generated and delivered in less than an hour.

“We used to generate these portfolios one at a time, but the demand for them was so great that we decided to automate the entire process,” said Ryan Longman, lead researcher on the HCDP project and the ¶«¾«Ó°Òµ consortium director of the .

The tool is part of the larger project, which is working to transform how the state tracks weather, drought and wildfire risk using advanced climate modeling, real-time data systems and artificial intelligence. Change Hawaiʻi is part of the Established Program to Stimulate Competitive Research or .

Real-time dashboard

At the meeting, researchers also rolled out a newly developed, open-source dashboard for the Hawaiʻi Mesonet—a growing network of 110 weather monitoring stations statewide, 66 of which are now operational. Each station collects 21 environmental variables and generates more than a million data points daily that feed into predictive models for wildfire and drought.

• Read more about the dashboard on ¶«¾«Ó°Òµ News

“This dashboard puts real-time data at the fingertips of the people who need it most,” said Tom Giambelluca, Hawaiʻi Mesonet project lead, Change Hawaiʻi co-principal investigator and former director of the at ¶«¾«Ó°Òµ. “High-quality data has never been easier to access, and future applications with the data are limitless.”

Wildfire system

The team has developed daily wildfire probability maps and forecasts statewide through the use of optimized machine learning models for more accurate fire behavior forecasting and drought assessment. The user-friendly, real-time data is accessed through the HCDP, which is publicly available. Read more on ¶«¾«Ó°Òµ News.

The goal is to provide early warning to fire managers, emergency responders and landowners so they can deploy resources, issue public advisories and reduce risks through more informed planning. This wildfire system can identify critical wildfire ignition factors, including relative humidity, temperature, rainfall, normalized difference vegetation index (components of wildfire fuel) and land cover.

Future efforts will leverage robust cyberinfrastructure, advanced data visualization, and innovative AI and machine learning applications, including computer vision and edge AI systems, to create a more resilient Hawaiʻi.

A new real-time dashboard launched by the University of Hawaiʻi at ²ÑÄå²Ô´Ç²¹ offers public access to live weather data from nearly 70 monitoring stations across the state, marking a major milestone in the Hawaiʻi Mesonet project. The launch coincides with Wildfire Awareness Month and represents a pivotal moment in the effort to make climate data available to the public.

Hawaiʻi’s diverse geography and microclimates present unique challenges that require precise monitoring to accurately capture weather events. Annual rainfall in parts of Maui, for example, can vary by more than 140 inches within a single mile. The Hawaiʻi Mesonet’s data has the potential to inform planning and decision-making in emergency management, agriculture, water resource, conservation and many other sectors.

Developed by an interdisciplinary team of scientists at ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹ and the Hawaiʻi Department of Land and Natural Resources, the project aims to deploy 100 high-tech weather stations to provide critical data for forecasting, disaster response and improving climate resilience. The dashboard is expected to play a critical role in supporting wildfire and flood early warning systems, particularly as climate-related disasters are expected to become more frequent and severe.

• Access the dashboard

The dashboard allows users to view current weather conditions at stations spanning the Hawaiian Islands, including temperature, rainfall, wind, humidity, solar radiation and soil moisture. The real-time data is updated every 15 minutes, creating one of the most comprehensive and timely weather data resources available in the state.

“This dashboard represents years of effort to build a system that’s tailored to Hawaiʻi’s unique needs,” said Tom Giambelluca, Hawaiʻi Mesonet project lead, long-time professor in the , and former director of the ¶«¾«Ó°Òµ (WRRC) “It’s not just about data—it’s about giving our communities the tools to adapt and respond.”

The launch comes as federal agencies such as the National Weather Service and NOAA face data removal and staffing cuts under the Trump administration. With gaps in data availability growing, the Hawaiʻi Mesonet system is poised to become a key source of reliable, localized weather intelligence.

Data from the system is stored in Hawaiʻi Climate Data Portal (HCDP), which is available to the public and is used to create recently launched new wildfire risk maps and other climate maps. The HCDP pulls data from multiple sources, including the Hawaiʻi Mesonet and as well as other federal datasets.

“The real concern is that most of these federal datasets will no longer be available in the near future—making the Hawaiʻi Mesonet and the HCDP the sole resource for real time weather and climate information in the state,” Pacific Islands Climate Adaptation Science Center University Consortium Director Ryan Longman said. “A big uncertainty is how the state will fill critical funding gaps left by the federal government to support these important efforts.”

For more information, visit the Hawaiʻi Mesonet website.

The University of Hawaiʻi at ²ÑÄå²Ô´Ç²¹ hosted the from March 15 to 23, bringing together 32 students and 19 instructors from 16 countries. The program provided an immersive learning experience focused on El Niño-Southern Oscillation (ENSO), a climate pattern that influences global weather.

This year marks the 50th anniversary of key milestones in ENSO research, including the work of Klaus Wyrtki, the late renowned oceanographer from ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹. His groundbreaking studies helped shape modern understanding of El Niño and its impacts on weather patterns worldwide.

• Related ¶«¾«Ó°Òµ News story: Hawaiʻi State Legislature honors late oceanographer Klaus Wyrtki, March 19, 2025

Over the nine-day program, participants engaged in morning lectures covering ENSO fundamentals, followed by student-led discussions on influential scientific papers. Afternoons featured student presentations, hands-on training and collaborative research projects. The curriculum provided participants a more thorough look at ENSO through real-world data analysis, modeling techniques and forecasting methods.

“This year’s ENSO Winter School was an incredible opportunity for students to engage directly with leading researchers and gain hands-on experience in ENSO science,” said Christina Karamperidou, chair of the school’s scientific organizing committee, and professor and associate department chair in ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹â€™s . “Seeing participants from around the world collaborate and deepen their understanding of climate variability was truly inspiring. By hosting this vibrant community of scientists and future research leaders, the University of Hawaiʻi at ²ÑÄå²Ô´Ç²¹ reinforces its reputation as a central hub for cutting-edge ENSO research.”

“Participating in the ENSO Winter School has not only deepened my understanding of the El Niño-Southern Oscillation but also broadened my perspective on nature and its dynamics, as well as strengthened my professional network,” said Roger Manay-Torres from the Instituto Geofísico del Perú. “This experience has been incredibly valuable, both academically and professionally, and it has far exceeded my expectations.”

Regina R. Rodrigues, a professor of physical oceanography at the Federal University of Santa Catarina in Brazil was one of the lecturers, and talked about ENSO’s impacts on weather extremes, etc.

“It was a great experience to spend more than a week with students, earlier career researchers and many of the most prominent experts on ENSO,” Rodrigues said. “I learned more about past ENSO from paleoclimate records and about future ENSO from climate projections.”

Jérôme Vialard, a senior scientist at Institut de Recherche pour le Développement in Paris, added, “I have worked on ENSO for almost 30 years, but found the lectures of other instructors useful. Some refreshed my memory, and some taught me new things on topics I know less about, such as paleo-climate or machine learning.”

The school was supported by ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹â€™s , International and U.S. CLIVAR, IAPSO/IUGG, CIMAR and the Inter-American Institute for Global Change Research.

To strengthen ±á²¹·É²¹¾±ʻ¾±â€™s flood and wildfire early warning systems and improve the state’s response to natural disasters and climate change impacts, a team of researchers at the University of Hawaiʻi at Mānoa, in partnership with the Hawaiʻi Department of Land and Natural Resources (DLNR), is installing an advanced network of 100 weather monitoring stations across the state to enhance weather and climate monitoring and forecasting. The data collected can also be used for water resource management, agriculture, ranching, ecosystem and cultural resource protection and more.

The 61st weather station of the system, called , was installed next to a Honolulu Board of Water Supply reservoir on the top of Mariner’s Ridge in Hawaiʻi Kai in December 2024. The system is already providing real time data that is also available to the public through an easy-access web interface. Once the remaining 39 stations are deployed over the next two years, the Hawaiʻi Mesonet will fill a critical gap for Hawaiʻi. According to Tom Giambelluca, project lead for the Hawaiʻi Mesonet, “Before the project began, Hawaiʻi was one of only 20 stations without a comprehensive statewide weather monitoring system.”

“It’s about being able to be as prepared as possible, especially when you consider recent events like the devastating Los Angeles wildfires and the terrible Lahaina fire here at home,” said Giambelluca, a long-time professor in the Geography and Environment Department, and former director of the ¶«¾«Ó°Òµ (WRRC). “For instance, the system that is constantly collecting data on soil moisture can tell us in real time if an area is highly susceptible to fires or flooding. This same data collected over time can be used by farmers and ranchers.”

Hawaiʻi‘s unique landscape

Building a network like this is all the more important in Hawaiʻi as the state’s unique landscape and climate patterns create significant variability in temperature, rainfall and other factors. For example, annual rainfall in West Maui can differ by more than 140 inches within one mile, requiring precise and localized data to inform decision-making.

The network requires approximately $600,000 annually for operations, maintenance and data management. Currently, the NOAA National Mesonet Program covers 40% of the cost. The program is seeking additional state funding from the legislature for the DLNR Commission on Water Resource Management to support the ¶«¾«Ó°Òµ program. Hawaiʻi State Rep. Linda Ichiyama says she is a supporter.

“The Hawaiʻi Mesonet represents a critical investment in the safety, resilience and sustainability of our island communities,” said Ichiyama. “This advanced weather monitoring system will empower us to make informed decisions in the face of increasingly severe weather events and climate challenges, like we are seeing in Los Angeles now. Supporting this initiative ensures that Hawaiʻi is better equipped to protect our communities, manage our natural resources, and plan for a more resilient future.”

Real-time insights

Each station is equipped with cutting-edge sensors that measure rainfall, air temperature, humidity, wind speed and direction, air pressure, solar radiation and soil conditions at multiple depths. Sensors scan every second, recording averages and statistics every five minutes. Data is transmitted every 15 minutes, ensuring real-time insights for weather forecasting, emergency management, water resource planning and more. The data captured by the Hawaiʻi Mesonet is publicly available on the ¶«¾«Ó°Òµ Hawaiʻi Climate Data Portal.

“The network spans the whole archipelago, so we are able to get information in places that previously we had no access to,” said Ryan Longman, ¶«¾«Ó°Òµ Pacific Islands Climate Adaptation Science Center consortium program director. “We can monitor and analyze weather phenomena such as extreme winds and heavy rainfall events, with much more accuracy now than we had in the past. We are also using the data to create climate maps that can give us high resolution information anywhere and those maps are already being used by a range of stakeholders. Ranchers, resource managers, water managers are all using those maps to get information on the ground at site specific locations even in places where a mesonet station doesn’t exist.”

The Hawaiʻi Mesonet has secured more than $1.5 million in funding for equipment from the National Science Foundation, with additional contributions from the Honolulu Board of Water Supply and state funding to the DLNR Hawaiʻi Commission on Water Resources Management. Installation costs are supported by WRRC and the ¶«¾«Ó°Òµ .

For more information about the Hawaiʻi Mesonet, visit .

In a significant development for climate research and management, the Hawaiʻi Climate Data Portal (HCDP) is set to expand its reach to additional Pacific islands, and provide more data to help decisionmakers. Launched in 2022, the free online portal developed by researchers from the University of Hawaiʻi and the East-West Center is expected to catalyze new research initiatives and inform policy decisions to mitigate climate risks and safeguard natural and human systems.

A major enhancement to the HCDP is the integration of data from the Hawaiʻi Mesonet, which plans to establish 100 new climate stations across the state over the next two years. Similar efforts are underway in American Samoa, and funding is being sought for a mesonet in Guam.

“The Hawaiʻi Mesonet is filling critical gaps in our understanding of climate in Hawaiʻi. Improving monitoring across the Pacific is a goal we are working towards, one station at a time,” said Tom Giambelluca, ¶«¾«Ó°Òµ Water Resource Research Center director.

The HCDP‘s recent inclusion in the Bulletin of the American Meteorological Society underscores its importance in streamlining access to climate information. The HCDP team plans to leverage decades of work developing the portal and expand its utility and function to serve other regions in the Pacific.

User friendly, comprehensive datasets

The user-friendly interface and comprehensive datasets make the HCDP an invaluable resource for improving awareness and facilitating collaboration across sectors. Recent updates feature new gridded surfaces, such as seasonal land cover and daily rainfall and humidity maps.

“Accessing high-quality climate data for Hawaiʻi has never been easier,” said Ryan Longman, East-West Center Oceania researcher. “This means greater opportunities for research, community outreach, and developing decision support tools to aid resource managers.”

Federal agencies increasingly leverage HCDP data for various applications:

• The U.S. Department of Agriculture Risk Management Agency uses the data for an insurance product for ranchers in Hawaiʻi.
• The National Oceanic and Atmospheric Administration produces a monthly state-of-climate report.
• The U.S. Geological Survey develops models to track avian malaria using HCDP‘s gridded products.

Since its launch on March 3, 2022, more than 45,000 unique users have accessed more than 20 million HCDP files. Upcoming developments include mapping hourly wind speed and solar radiation and creating tools for wildfire risk assessment and drought forecasting.

Rainfall estimations on Oʻahu can be more accurate by combining Hawaiʻi’s two main types of rainfall observations, radar and rain gauge, according to a study by University of Hawaiʻi at ²ÑÄå²Ô´Ç²¹ researchers. Current observations are based on one or the other, where specific weather stations are checked (rain gauge), or weather radars are observed to view patterns. The study is an effort to better understand Hawaiʻi’s complex weather patterns and hydrological consequences.

Like most of the world, Hawaiʻi is experiencing more extreme weather, yet often lacks adequate data. By bridging the gap between radar and gauge data, experts can now gain a better understanding of the complex rainfall patterns in mountainous tropical areas across the state, as well as the inherent uncertainties associated with various storm types and structures when simulating streamflow.

The new dataset, which stemmed from combining radar and rain gauge data, also creates better synergy across disciplines. Meteorologists and hydrologists can deepen their understanding, leading to more accurate assessments of flash flood risks, urban planners can test their plans and products against rainfall data, and emergency responders can be more prepared for natural disasters.

“The significance of this research is not only for its immediate benefit to resource managers, weather forecasters and emergency managers, but also for its potential to jumpstart new scientific advances in atmospheric and water sciences,” said Thomas Giambelluca, director of the ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹ .

The study, “,” was published in the Journal of Hydrometeorology. It was conducted by in the ’ and the in the .

Better preparation, resilience

Radar rainfall observation provides rain rate over a large spatial area within a specific time frame (~every five minutes) but struggles with accuracy, while rain gauges provide “ground truth” values (information from direct observation and measurement), but only measures at limited point locations.

Recognizing the need to combine these two observation types to collect more accurate data, the ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹ researchers built off of (hourly rainfall data available ), and merged the two main types of rainfall observations to create a detailed hourly gridded rainfall dataset for Oʻahu. This incorporation of two data sources is also known as kriging with external drift (KED), allowing the researchers to refine rainfall values estimated only by a single instrument.

“With this developed and validated KED method, we are advancing Hawaiʻi’s capacity to better prepare and build resilience when facing climate extremes,” said Yinphan Tsang, co-author of the study and principal investigator of the Tsang Stream Lab.

This research offers valuable insights into the performance of the KED method across various storm types, such as tropical cyclones, cold fronts, upper-level troughs and Kona lows, to accurately estimate rainfall in these scenarios for flood forecasting and impact applications.

“The validated KED hourly rainfall dataset is an especially valuable tool for ongoing research on extreme weather impacts and water resources in Hawaiʻi,” said Giambelluca.

The effects of climate change are no longer far-off threats and are now contributing factors to many of today’s disasters, often exacerbating the frequency of wildfires, heat waves and flooding, and the intensity of rainfall during hurricanes and storms. These unprecedented weather events have triggered a global urgency to prioritize research-based initiatives to understand, predict, mitigate and reverse the impacts of climate change.

The at the University of Hawaiʻi at ²ÑÄå²Ô´Ç²¹ has earned both national and international acclaim for its research and is a part of the renowned . In a field often dominated by men, three distinguished female faculty are further elevating the department’s research and prestige, making atmospheric waves in climate modeling and cloud microphysics.

Enhancing global climate models

Professor Christina Karamperidou’s research focuses on El Niño-Southern Oscillation (ENSO), which is the primary factor affecting variability in water temperature, rainfall and wind strength in the Pacific.

One of the methods Karamperidou uses to study ENSO is to synthesize climate model simulations with paleoclimate data, much of which is gathered from ancient, preserved material such as coral skeletons, shells or lake sediment, which can indicate past temperature and rainfall across the Pacific. Using paleoclimate ENSO records from the Holocene (the past 12,000 years) along with climate model simulations, Karamperidou and her team can study the climate mechanisms behind the ENSO phenomenon—its predictability, impacts and how its characteristics may change under the influence of natural or anthropogenic climate change.

“Coming out of a longer [three-year] La Niña (cooling of sea surface temperatures), most models currently predict a big El Niño for the end of this year, which could lead to potentially more tropical Pacific cyclones, and altered rainfall patterns in our islands and around the world,” said Karamperidou who recently received the Early Career Scientist Award from the International Union of Geodesy and Geophysics. “Improving our understanding of ENSO mechanisms through our studies of modern and past climates allows us to improve ENSO representation in global climate model simulations to help reduce uncertainties and improve accuracy of El Niño prediction and future climate projections.”

Understanding clouds

One of the most uncertain and complex Earth systems represented in climate models is clouds and the aerosols that they form on. Studying the fundamental structure and processes involved in clouds and aerosols not only allows scientists to better parameterize them in models, but also improves our understanding of the atmosphere and weather patterns.

Associate Professor Alison Nugent studies orographic precipitation, how mountain topography induces or modifies precipitation. Breaking down cloud microphysics, Nugent explained, “In one cubic centimeter—the size of a sugar cube—a cloud has 100 cloud droplets. In a polluted atmosphere, it can have many more times that in the same volume. The size and number of cloud droplets is important for their relationship to precipitation and to radiation. For example, a cloud with many small cloud droplets will be brighter and reflect more radiation, and may take longer to precipitate than a cloud with fewer, large droplets.”

Nugent recently received a National Science Foundation Faculty Early Career Development award that will allow her team to investigate the role of wind, waves and other atmospheric and oceanic properties that influence the production of sea salt aerosols in coastal environments on three Pacific islands. Nugent also helped to secure funding to install 84 climate stations throughout the state.

Broadening horizons in atmospheric sciences

Another researcher making major strides is Associate Professor Jennifer Griswold, the atmospheric sciences department’s first female chair. Since becoming chair in 2021, she has spearheaded a national initiative locally for the past few years called Expand Your Horizons–Hawaiʻi, an annual STEM conference for young women in sixth to eighth grades to encourage and support young girls’ enthusiasm in STEM careers.

Prior to joining ¶«¾«Ó°Òµ, she helped build the first Phase Doppler Interferometer (PDI) and data processing program, a breakthrough innovation and process that significantly improved the study of cloud structures and properties. Now used at several institutions, the PDI measures cloud droplet size and velocity for each spherical droplet. It also records the arrival time of the droplet to determine clustering and turbulence.

Griswold’s research continues to focus on improving the understanding of physical and dynamical processes governing global cloud aerosol precipitation interactions, from volcanic activity, biomass burning and even changes in anthropogenic aerosol levels during the COVID-19 pandemic shutdown.

“Atmospheric sciences, especially climate and seasonal forecasting, is a data-intensive field and the most important and applied research areas going forward,” said Griswold. “Almost all industries will be impacted by climate change, and knowing how and when things will change can positively or negatively impact a business, community or individuals.”

For more, . Noelo is ¶«¾«Ó°Òµâ€™s research magazine from the .

Improved weather and climate forecasting using machine learning and artificial intelligence is the focus of a new project. Results are expected to have a major impact in Hawaiʻi and other tropical climate areas around the world.

Associate Professor Peter Sadowski from the in the earned a five-year, $424,293 CAREER grant from the (NSF). CAREER grants are designed to support early-career faculty to serve as academic role models in research and education.

“One of the risks of climate change for Hawaiʻi is extreme weather events, and current scientific models are poor at estimating these risks,” Sadowski said. “This project will provide a completely new approach modeling these risks, using the latest advancements in AI (artificial intelligence).”

Sadowski’s project will develop machine-learning methods to predict the risk of adverse weather and climate events. AI will be used to develop new data-driven computational methods for modeling risk and apply these methods to weather applications.

In particular, these models will be applied to forecasting solar irradiance and precipitation, two areas that are particularly important for tropical islands such as the Hawaiian Islands. Estimating the risk of rapid changes in solar power generation is necessary for managing energy grids that are seeing a rapid increase in variable renewable sources, and floods claim hundreds of lives and billions in property damage each year in the U.S. alone.

Artificial intelligence methods have greatly improved translating text into predictions using images and video. A key development is the ability to learn probabilistic models of images and video. The research will leverage existing data from numerical simulations of atmospheric variables, observations from satellites and ground-based weather station data from the . The machine-learning methods developed by this project will complement existing physics-based weather prediction models by providing location-specific forecasts with increased speed, higher resolution and probabilistic accuracy.

Fostering the next generation

This research will be paired with an educational outreach program that includes a summer data science course for high school students and a workshop to share data science teaching materials with Hawaiʻi’s K–12 teachers.

Forecasters with the National Oceanic and Atmospheric Administration’s (NOAA) Central Pacific Hurricane Center said the Hawaiʻi region could see fewer than normal cyclones for the upcoming hurricane season. The forecast released on May 18, predicted two to four tropical cyclones compared to four to five in a normal season.

It is important to note that the forecast is for the number of storms in the region but not specifically for landfall to the state.

“This year we are predicting less activity in the Central Pacific region compared to normal seasons,” said Matthew Rosencrans, NOAA’s lead seasonal hurricane forecaster at the Climate Prediction Center. “The ongoing La Niña is likely to cause strong vertical wind shear making it more difficult for hurricanes to develop or move into the Central Pacific Ocean.”

Hurricane season in Hawaiʻi occurs roughly between June 1 and November 30. The Hawaiʻi Emergency Management Agency has a .

The University of Hawaiʻi encourages all students and employees to prepare for the season before storms approach, when the lines at stores can be overwhelming. ¶«¾«Ó°Òµ community members are invited to participate in the that are held over the summer.

¶«¾«Ó°Òµ resources:

All members of the ¶«¾«Ó°Òµ community are urged to sign up for ¶«¾«Ó°Òµ Alert to receive emergency text alerts. If you have already signed up, log in to ensure that contact information is up-to-date.

There is also the and app ( | ) with updated information.

Hawaiʻi created a great one-stop resource for disasters in the .

Notifications affecting ¶«¾«Ó°Òµ campuses will be posted on the emergency information webpage, as well as on social media:

June 1 kicks off hurricane season. The recently released its annual forecast for the season. They anticipate two to five tropical cyclones for the Central Pacific region.

While the forecast is lower than last year, it is important to prepare now.

“As we have experienced in previous hurricane seasons, it only takes one direct hit, or even a close call, to have a major impact on daily life here in the Hawaiian Islands,” said Chris Brenchley, director of National Oceanic and Atmospheric Administration’s . “Take time to prepare now. Make a preparedness plan so that you and your family stay healthy and safe.”

Hurricane season in Hawaiʻi occurs roughly between June 1 and November 30.

The Hawaiʻi Emergency Management Agency has a page with .

University of Hawaiʻi community members can take part in virtual Hurricane Preparedness Workshops throughout the summer. Visit the site to register.

¶«¾«Ó°Òµ resources:

All members of the ¶«¾«Ó°Òµ community are urged to sign up for ¶«¾«Ó°Òµ Alert to receive emergency text alerts. If you have already signed up, log in to ensure that contact information is up-to-date.

There is also the Disaster Alert desktop version and app ( | ) with updated information.

Hawaiʻi created a great one-stop resource for disasters in the .

Notifications affecting ¶«¾«Ó°Òµ campuses will be posted on the emergency information webpage, as well as on social media:

Recent wildfires ravaging the West Coast highlight the importance of preparation and understanding the threat everywhere, including Hawaiʻi. A team at the University of Hawaiʻi at Mānoa will work to improve assessment and communication of unique wildland fire risk the state faces.

The ¶«¾«Ó°Òµ Mānoa (WRRC), the (College of Tropical Agriculture and Human Resources), and the (College of Engineering) secured nearly $1 million in funding for the project. The grant is from the Federal Emergency Management Agency (FEMA) through partnership and cooperation with the Hawaiʻi Emergency Management Agency (HI-EMA) and ¶«¾«Ó°Òµ Mānoa.

The project will develop a high-resolution fire risk index for Hawaiʻi using spatial data on historical fire occurrence, climate, vegetation and the built environment. The end-product will be a daily map of fire risk for the state published online that uses real-time climate products produced by WRRC and the ¶«¾«Ó°Òµ-based ʻIke Wai program. This work will be led by Sayed Bateni (principal investigator), associate professor in civil and environmental engineering and WRRC, Clay Trauernicht (co-principal investigator), extension specialist in ecosystem fire in the , and Tom Giambelluca (co-principal investigator), director of WRRC.

“The incredible diversity of climate types and vegetation in Hawaiʻi means that the standard fire prediction tools used on the mainland simply don’t work for us. This effort will use climate products developed for Hawaiʻi and integrate local knowledge of forecasters and fire responders to validate and interpret the final product,” said Trauernicht.

Developing comprehensive fire-risk alert system

Beyond mapping daily fire risk, WRRC and ¶«¾«Ó°Òµ will work with the National Weather Service and federal, state and county emergency responders to integrate the maps into the current Red Flag Warning System and agency readiness plans. The only fire-risk alert system actively in place is the by the National Weather Service.

However, because the system is based on a single weather station, red flag warnings may not represent conditions across the state or a red flag may not be declared despite high risk conditions elsewhere. For example, no red flags were declared during any of the multiple, record-breaking large fires on Maui in 2019 due to different rainfall patterns over Honolulu. The project will also use the fire-risk index to examine the historical frequency of fire-risk conditions across the state and work with the non-profit to educate land managers, planners and the general public about how the products can inform proactive risk reduction efforts.

“As our constant brush fires present new challenges to us during both hurricane season and a pandemic, HI-EMA’s hazard mitigation program grant program is critical in getting the proper funding to battle these threats,” said HI-EMA Administrator Luke Meyers.

Fires cost in land skyrockets over years

Wildland fire is a persistent and increasing threat across Hawaiʻi and places significant burden on federal, state and county emergency management agencies. The annual area burned has increased by 300% across all four counties of Hawaiʻi within the past several decades, such that fires often burn a greater proportion of Hawaiʻi land area than many states in the Western U.S. Fire-risk warning is especially critical in Hawaiʻi both due to the vulnerability of populated areas and natural resources to fire impacts and because the majority of wildland fire ignitions are caused accidentally by people.

Global warming is approaching a tipping point during this century that could reawaken an ancient climate pattern similar to El Niño in the Indian Ocean, by scientists at the , the University of Arizona and the University of Texas at Austin.

If that tipping point comes to pass, floods, storms and drought are likely to worsen and become more regular, disproportionately affecting populations most vulnerable to climate change in the region.

The study presented computer simulations of climate change during the second half of the century which showed that global warming could disturb the Indian Ocean’s surface temperatures, causing them to rise and fall each year much more steeply than they do today. The seesaw pattern is strikingly similar to El Niño, a climate phenomenon that occurs in the Pacific Ocean and affects weather globally.

“Although paleo evidence suggested that this Indian Ocean El Niño occurred during the last glacial time under much colder conditions than today’s climate, climate models simulate its reawakening under much warmer climate owing to favorable changes of atmospheric and oceanic circulations in the Indian Ocean,” said Fei Fei Jin, co-author and professor of at the (SOEST).

According to the research, if current global warming trends continue, an Indian Ocean El Niño could emerge as early as 2050.

Today, the Indian Ocean experiences very slight year-to-year climate swings because the prevailing winds blow gently from west to east, keeping ocean conditions stable. According to the simulations, global warming could reverse the direction of these winds, destabilizing the ocean and tipping the climate into swings of warming and cooling akin to the El Niño and La Niña climate phenomena in the Pacific Ocean.

For more see the .

—By Marcie Grabowski

The National Weather Service Honolulu Forecast Office today released its and now is the time to start preparing for the upcoming months.

Forecasters predict this season will have a 70 percent chance of being a higher than normal season with the likelihood of five to eight tropical cyclones in the Central Pacific. These include tropical depressions, tropical storms and hurricanes.

“This outlook reflects the forecast for El Niño to likely continue through the hurricane season. Also, ocean temperatures in the main hurricane formation region are expected to remain above-average, and vertical wind shear is predicted to be weaker-than-average,” said Gerry Bell, NOAA’s lead seasonal hurricane forecaster at the Climate Prediction Center, which collaborated on this outlook. Bell added, “All of these conditions point to an above-normal season.”

Hurricane season in Hawaiʻi occurs roughly between June 1 and November 30.

Last year, Hurricane Lane dumped up to 50 inches of rain and caused damage to parts of Hawaiʻi Island and Maui. University of Hawaiʻi campuses were forced to close.

“As we prepare for another active hurricane season in the central Pacific, we urge everyone to have an emergency plan now, so that you are ready for the devastating impacts that a tropical cyclone could bring to the State of Hawaiʻi,” said Chris Brenchley, director of NOAA’s Central Pacific Hurricane Center. “It is essential that you know where and how to get official information, even in the event of a power failure, and that you have your emergency supply kit ready well before any storms threaten.”

The Hawaiʻi Emergency Management Agency has great tips and resources:

¶«¾«Ó°Òµ resources:

All members of the ¶«¾«Ó°Òµ community are urged to sign up for ¶«¾«Ó°Òµ Alert to receive emergency text alerts. If you have already signed up, log in to ensure that contact information is up-to-date.

There is the Pacific Disaster Center’s Disaster Alert and app () with updated information.

Notifications affecting ¶«¾«Ó°Òµ campuses will be posted on the emergency information webpage, as well as on social media:

¶«¾«Ó°Òµ emergency information website

Individual campus websites will provide campus-specific information during an emergency.

Weather stations on Earth’s surface are easy to install. But how do meteorologists know what the weather is like 6 to 12 miles above their heads? Knowing the state of the upper atmosphere is vital for forecasting weather on the ground. To obtain this information, weather balloons are launched twice a day in almost 900 locations worldwide.

students in Assistant Professor atmospheric science class launch a weather balloon each semester to learn the process first hand. The balloon floated up to about 13.5 miles (10 kilometers) above the Earth.

The helium balloon has an instrument package attached, which measures temperature, pressure and humidity as it rises through the atmosphere. The instruments send back data to a ground receiver. The location of the balloon, wind speed and wind direction with altitude can also be observed.

“We want the students to be able to see the connection between what we learn in the classroom and how it applies to the real science of data gathering,” Nugent said. “I believe such an experience is worth a thousand lectures.”

Nugent has the students use the dataset to learn how to calculate various atmospheric indices, such as the lifting condensation level (cloud base), convective available potential energy (energy available for convection) and other measures of atmospheric energy and stability.

&±ô»å±ç³Ü´Ç;°Â±ð’v±ð been trying to understand all of these different variables in class and we always used data given to us,” ¶«¾«Ó°Òµ Mānoa student Maarten Molenaar said. “Now we’re going to use our own data and make connections to what we see in the sky right above us.”

“It was really exciting,” ¶«¾«Ó°Òµ Mānoa student Eleanore Law said. “We’re seeing all the data pile in. It is cool to see life happening in action.”

Nugent splashed into the public spotlight when she helped break down this summer’s Hurricane Lane on local TV news for hours to help viewers better understand the science behind what was happening.

• Related ¶«¾«Ó°Òµ News story: ¶«¾«Ó°Òµ atmospheric scientists share hurricane expertise, August 28, 2018

The region known as the U.S.-affiliated Pacific Islands is no stranger to variable weather and climate. One of its dominant weather influencers is the El Niño-Southern Oscillation (ENSO), an alternating pattern of abnormally warm and cool ocean temperatures in the tropical Pacific. ENSO can cause drought-like conditions in the southwest Pacific that persist for 3–4 seasons, as well as frequent cyclones and storms.

Given the region’s regular bombardment of extreme events, U.S.-affiliated Pacific Islands decision-makers need accurate predictions from climate models. However, modeling errors can limit the reliability of forecasts.

Now, a researcher from the at the is leading a project to identify those errors. Supported by a $508,000 grant from the NOAA Research Modeling, Analysis, Predictions and Projections (MAPP) Program, Senior Researcher and his team will develop tools, known as diagnostics, to pinpoint where and how errors begin, to help scientists determine how to improve their models.

“Identifying and improving processes in climate models that lead to reliable forecasts of droughts and tropical storms well in advance will allow policy makers ample time to plan and mitigate situations during extreme events,” said Annamalai. “These events have significant impacts on water resources and agriculture, defense-related operations, forest fires, air traffic and more.”

Just like a doctor diagnosing why a patient is feeling unwell, these tools will help climate modelers determine why their models are not performing well.

“Our diagnostics will be user accessible, flexible and adaptable such that they can be transitioned to any group of evaluations during model development,” said Annamalai.

Annamalai’s research will build on results from his MAPP-funded project that is ending this year. That project focused on understanding processes that shape unusual ENSO-related precipitation during the winter season, using diagnostics.

He and his team found that model errors in predicting abnormal precipitation are strongly tied to the models’ ability to represent how moisture is distributed in a certain part of the atmosphere and how the interaction between radiation and clouds are represented. This new project’s diagnostics will address those model errors in representing moisture, clouds and their interaction with radiation in the atmosphere.

Specific project outcomes will include a set of metrics that will help scientists quantify how accurately their models represent ENSO-related impacts and identify sources of model errors that reveal deficiencies to help inform model improvement decisions.

Project collaborators include Yi Ming, head of the Atmospheric Physics and Climate Group at NOAA‘s Geophysical Fluid Dynamics Laboratory; Richard Neale, project scientist at the National Center for Atmospheric Research; and Gill Martin, science manager at the United Kingdom Met Office, Hadley Center.

—By Rachel Lentz

All University of Hawaiʻi campuses and System offices on Oʻahu and Kauaʻi will be closed from Thursday through Sunday. All ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹ athletic events scheduled for Thursday and Friday are cancelled. A decision on athletic events scheduled for Saturday and Sunday will be made depending upon weather conditions and facility availability. Residence halls at ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹ and ¶«¾«Ó°Òµ Hilo will remain open for student residents. All employees who have been designated as disaster response workers or have been directed to report to work or remain at work due to operational needs, must still report to work.

At this time, the ¶«¾«Ó°Òµ campuses on Hawaiʻi Island, Maui, Molokaʻi and ³¢Äå²Ô²¹ʻ¾± remain closed until further notice.

The State of Hawaiʻi announced today (August 22) that all state government offices and facilities on Oʻahu and Kauaʻi will be closed, starting Thursday, August 23, because of Hurricane Lane, a category 4 storm currently on track to move dangerously close the islands.

Hurricane Lane could make landfall on any or multiple islands, and may bring strong winds, heavy rains, flooding, high surf and storm surges. All students, faculty and staff are asked to keep informed of the latest developments and prepare for the possibility of the need to shelter in place or move to a public shelter. Prepare yourself and your families for the potential effects of the storm. Officials recommend a 14-day emergency supply.

• More on Hurricane Lane on ¶«¾«Ó°Òµ News

Students in residence halls will continue to receive more specific communications and instructions from their respective student housing office. However, please do not hesitate to contact them with any questions or concerns at ¶«¾«Ó°Òµ ²ÑÄå²Ô´Ç²¹: vcs@hawaii.edu and ¶«¾«Ó°Òµ Hilo (808) 932-7403.

Please follow the , other official agencies and local media for the latest weather news.

All members of the ¶«¾«Ó°Òµ community are urged to sign up for to receive emergency text alerts. If you have already signed up, log in to ensure that your contact information is up-to-date:

Notifications affecting ¶«¾«Ó°Òµ campuses will be posted on the Emergency Information webpage, as well as on social media:

• ¶«¾«Ó°Òµ emergency information website

Please stay informed and updated:

, published by an international team of climate scientists in the journal Nature, isolates key mechanisms that cause El Niño to differ from one event to the next. The team found that the complexity and irregular occurrence of El Niño and La Niña events can be traced back to the co-existence of two coupled atmosphere-ocean oscillations, with different spatial characteristics and different frequencies.

This new understanding will help researchers determine whether to expect shifts of El Niño characteristics as the global climate changes.

“Our study reveals that there is a hidden structure in the seemingly chaotic and unpredictable occurrence of El Niño events,” said lead author Axel Timmermann, director of the Institute for Basic Science Center for Climate Physics at Pusan National University and a former professor at the (SOEST).

“Finally we can attribute the observed complexity of the most powerful natural climate engine to the co-existence of two oscillatory states of the underlying mathematical equations,” said , the SOEST professor of who led the development of the new mathematical framework for El Niño complexity presented in the study.

More on El Niño

El Niño events are characterized by an unusual warming of the central to eastern equatorial Pacific Ocean, which can last up to one year. On average El Niño events lead to a drying of Southeastern Asia and the Western tropical Pacific while enhancing rainfall near the eastern Pacific shores, in countries such as Ecuador and Peru. El Niño’s “ripple effects” are not only found in the atmosphere, but also in ocean currents, ecosystems, the occurrence of natural disasters, global markets and national economies.

Climate scientists have long recognized that not every El Niño is alike. Some are weak, others are strong. Some occur in the Central Pacific, others in the east. These differences will determine which areas will be hit hardest by climatic extremes and which ones will be spared. Predicting El Niño events accurately requires a deeper understanding of its diversity or as some scientists call it—its “flavors.”

To clarify the origin of El Niño diversity, a group of 40 climate scientists from 11 countries teamed up to search for the hidden “blueprint.” Using a computer simulation of El Niño events, the team ran numerous scenarios with small tweaks to the temperature, wind and ocean conditions.

They found that Eastern Pacific El Niño events are characterized by a return time of three to seven years, whereas Central Pacific events tend to recur on average every two to three years. The different character of these modes is determined by how strongly the atmosphere and ocean interact with each other. In the observations however, the co-existing Eastern and Central Pacific warm–cold swings are far from periodic.

The tropical Pacific climate systems requires additional excitation, either through random weather events or through atmospheric circulation changes induced by temperature changes in the Indian and Atlantic Oceans.

These interactions are an important source for El Niño irregularity, and limit how far ahead Tropical Pacific climate anomalies can be predicted.

—By Marcie Grabowski

The (PacIOOS) at the has been awarded nearly $500,000 in grant funding to enhance public safety through atmospheric and wave forecasts for the Pacific Island territories of Guam, Commonwealth of the Northern Mariana Islands (CNMI) and American Samoa.

During the three-year project funded by the U.S. Department of the Interior Office of Insular Affairs’ Technical Assistance Program, PacIOOS will improve and validate the existing suite of atmospheric forecasts for the three territories. It will also develop new high-resolution wave forecasts for Saipan, Tinian and Rota in the CNMI and for the Manuʻa Islands in American Samoa.

Impacts from the most recent tropical cyclones in American Samoa and typhoons in Guam and CNMI are stark reminders of the importance of near-term wind, rain and wave forecasts for these island communities. Providing ‘s National Weather Service field offices with additional tools increases forecasting capabilities and results in more accurate forecasts, advisories and warnings for residents and visitors of Guam, CNMI and American Samoa.

“We are extremely grateful for the support from the Office of Insular Affairs to improve PacIOOS‘ forecasts for the territories,” said Director Melissa Iwamoto. “Reliable forecasts are essential to empower insular communities to make proactive decisions. Increased preparedness helps increase public safety.”

For more information on the grant, .

—By Fiona Langenberger