Intense tropical cyclones (maximum wind speed greater than 131 miles per hour) are one of the most devastating natural disasters in the world due to torrential rains, flooding, destructive winds and coastal storm surges. New public impact research co-authored by a University of Hawaiʻi at Mānoa atmospheric scientist revealed that since the 1980s, category 4 and 5 hurricanes (equivalent to intense tropical cyclones) have been arriving three to four days earlier with each passing decade of climate change. The findings were published in .

“When intense tropical cyclones occur earlier than usual, they cause unexpected problems for communities,” said Pao-Shin Chu, atmospheric sciences professor in the 东精影业 Mānoa and Hawaiʻi State Climatologist. “Moreover, the earlier advance of these storms will overlap with other weather systems, for example local thunderstorms or seasonal summer monsoon rainfall, and can produce compounding extreme events and strain the emergency response.”

Changes in many characteristics of severe hurricanes under a warming climate, for example, the number, intensity and lifespan, are fairly well-studied. However, little is known about changes in the seasonal cycle of these events.

Using satellite data, historical tropical cyclone tracks, NOAA rainfall records and various statistical methods, Chu and co-authors found that there has been a significant shift of these intense tropical cyclones from autumn to summer months since the 1980s in most tropical oceans. The effect was particularly observed in the eastern North Pacific off the coast of Mexico, where most hurricanes near Hawaiʻi come from; the western North Pacific; the South Pacific; the Gulf of Mexico; and the Atlantic coast of Florida and the Caribbean.

“It was surprising to consistently see earlier arrivals when we independently assessed satellite data and conventional ground-based observations of intense tropical cyclones,” said Chu.

Extreme rainfall, flooding

In August 2017, for example, Hurricane Harvey, a category 4 hurricane, made landfall on Texas and Louisiana and inflicted catastrophic flooding and more than 100 deaths. Hurricane Lane is another example. Lane was a category 5 hurricane and occurred in August 2018. Lane brought very high rainfall and fire to Hawaiʻi Island and fire to Maui.

The potential for simultaneous occurrence with other high-impact weather events should be a serious concern for the society.

Using simulations from high-resolution climate models, the team detected warmer oceanic conditions developed earlier, which favored the earlier onset of intense tropical cyclones. Further, they found that the ocean warming was primarily driven by greenhouse gasses in the atmosphere.

“In a future with high carbon dioxide emissions, the earlier shifting trend is projected to be amplified,” said Chu.

In South China and the Gulf of Mexico, the earlier onset of intense tropical cyclones contributes significantly to an earlier onset of extreme rainfall.

“Given the seasonal advance of intense tropical cyclones, as shown in this study, the potential for simultaneous occurrence with other high-impact weather events should be a serious concern for the society,” said Chu. “Understanding potential changes in hurricane activity in response to global warming is important for disaster prevention, resource management and community preparedness.”

–By Marcie Grabowski

The University of Hawaiʻi at Mānoa (DPS) is kicking off the school year with a variety of free online safety workshops to help students and employees stay safe on campus. These training sessions include Active Shooter Awareness and Response, Hurricane Preparedness, and Conflict Resolution and De-escalation training.

Training sessions

• Active Shooter Awareness and Response (75 min): Provides information on various active shooter scenarios, what you can do to keep yourself safe, and what to expect when police and DPS respond. This training uses concepts from the Department of Homeland Security鈥檚 Run-Hide-Fight program.
• Hurricane Preparedness (75 min): Learn about how to prepare for a hurricane in Hawaiʻi, including tips for preparing an emergency kit, what to do when a hurricane is approaching, and how to find a local shelter or shelter-in-place.
• Conflict Resolution and De-escalation (75 minutes): Learn about precipitating factors to conflict, signs of agitation, and discuss verbal and nonverbal de-escalation techniques. In addition, we discuss how to end the de-escalation process, and what to do when de-escalation isn鈥檛 possible. Recommended for faculty and staff.
• Safety and Wellness (1 hour): Learn about services offered by DPS, discuss safety tips for both on and off-campus, learn about common crime prevention measures that can be taken to increase safety on campus, and engage with DPS staff to have your safety questions answered.

To view dates and times, or register for a session, please visit the . All training sessions listed above are provided to any group by request. You can request a session through the Workshops and Training Sessions page.

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鈥檚 . “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.

东精影业 resources:

All members of the 东精影业 community are urged to sign up for 东精影业 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 东精影业 campuses will be posted on the emergency information webpage, as well as on social media:

Global warming will intensify landfalling tropical cyclones of a category three or higher in the Indian and Pacific Oceans, while suppressing the formation of weaker events. In Hawaiʻi, model simulations show a doubling of the risk of landfalling tropical cyclones, if CO2 concentrations double. That鈥檚 according to a study published in and co-authored by Malte Stuecker, assistant professor of in the University of Hawaiʻi at Mānoa School of Ocean and Earth Science and Technology (SOEST).

Tropical cyclones, including typhoons and hurricanes, are the most fatal and costliest weather disasters on our planet. But how tropical cyclones will change in response to global warming has long remained a mystery.

To address this question, scientists for more than two decades have used the world鈥檚 largest supercomputers to run climate model simulations that show important aspects of these destructive storms. However, until recently the computing power has been insufficient to capture both atmospheric details and resolve the full interaction with the ocean on a global scale.

A team of scientists, led by researchers at South Korea鈥檚 Institute for Basic Science (IBS) Center for Climate Physics (ICCP) at Pusan National University, recently completed one of the most computing-intensive and detailed global warming simulations to date using the supercomputer Aleph at IBS. The global climate model records small-scale atmospheric and oceanic processes with unprecedented resolution. The model also more accurately simulates ocean temperature than the previous generation of climate models.

“This improvement was important for a realistic simulation of typhoons in the Indian and Pacific Ocean,” said Jung-Eun Chu, lead author of the study and a project leader at the ICCP.

Hawaiʻi ocean temperatures fuel tropical cyclones

While tropical cyclone numbers are simulated to decrease in the deep tropics, the situation is slightly different for Hawaiʻi, which is located at the edge of the tropics. Hawaiʻi is typically protected from tropical cyclones due strong northeasterly trade winds that flow in the opposite direction than the westerly winds aloft in the upper atmosphere. This so-called “vertical wind shear” normally tears tropical cyclones apart that approach the islands. In response to climate change, this wind shear is simulated to weaken and ocean temperatures are projected to warm near Hawaiʻi—fueling tropical cyclones.

“Our new model simulations show an approximate doubling of the risk of landfalling tropical cyclones in Hawaiʻi if CO2 concentrations are doubled” said Stuecker. “Importantly, the impacts of landfalling tropical cyclones will be much more severe due to higher rainfall and increasing sea level. Flood risk and storm surge will be much intensified in coastal areas.”

For more information see .

—By Marcie Grabowski

About lives in a coastal area. In Hawaiʻi, nearly everyone is vulnerable to the effects of tropical storms and hurricanes. Tropical cyclones, regionally known as hurricanes or typhoons, have been moving across ocean basins faster since 1982, according to a study led by University of Hawaiʻi at Mānoa researchers, published in .

The study, led by Sung-Hun Kim, a post-doctoral researcher in the 东精影业 Mānoa (SOEST) at the time of the work, also determined the North Atlantic region has experienced an increase in the frequency of hurricanes and that tropical cyclone activity has shifted toward the poles in the Pacific and Atlantic Oceans.

The researchers, including Pao-Shin Chu, an professor in SOEST, focused on tropical cyclones since 1982, when modern, reliable satellite data became available. They assessed the frequency and locations of storms and trends in tropical cyclone movement speed鈥攈ow quickly a storm moves forward鈥攇lobally and regionally in each ocean basin.

“For people in Hawaiʻi, the threat of hurricanes is always there every year,” said Chu. “If hurricanes move faster, they would pose danger to coastal communities and emergency managers because they would have less time to prepare for evacuation and other measures.”

The study suggests the reason for the observed changes is a combination of natural variations and human-induced climate change. The researchers continue to study the trends and connections between climate variability and tropical cyclone activity.

–By Marcie Grabowski

Located within the most isolated archipelago in the world, Hawaiʻi is critically dependent on a clean, ample supply of fresh water. led by University of Hawaiʻi at Mānoa scientists indicates that rain brought to the islands by hurricanes and Kona storms can often be the most important precipitation for re-supplying groundwater in many regions of Oʻahu.

“The majority of 贬补飞补颈ʻ颈鈥檚 freshwater comes from groundwater,” said Daniel Dores, lead author and groundwater and geothermal researcher in the 东精影业 Mānoa (SOEST). “In this study, we investigated the relationship between trade wind showers, major rainfall events like Kona storms, and groundwater.”

Dores and a team of scientists from SOEST and the Hawaiʻi Department of Health collected rainfall around Oʻahu and analyzed the stable isotopes of rainwater, chemical signatures in the water molecules. They compared the chemical signatures in rainwater to those of groundwater to determine the source of water in the aquifers鈥攅vent-based rainfall or trade wind-related rain.

“Because windward and mauka showers are so common, it is easy to assume that is the main source of our drinking water,” said Dores. “Also, large rainfall events such as Kona storms result in significant runoff into the oceans. However, our research found that a lot of the rain from Kona storms makes it into our groundwater aquifers and is an important source of our drinking water.”

Hawaiʻi is experiencing substantial weather patterns, and precipitation events could become more extreme. Co-authors will continue researching to understand more about local and regional groundwater recharge and water quality.

“By better understanding how our groundwater is impacted by these extreme precipitation events, we can better protect the resource itself,” said Dores.

–By Marcie Grabowski

Hurricane Lane was an impactful event for the Hawaiian Islands. In August 2018, over a four-day period, Hawaiʻi Island received an average of 17 inches of rainfall, with a four-day single-station maximum of 57 inches, making Hurricane Lane the wettest tropical cyclone ever recorded in Hawaiʻi. , led by University of Hawaiʻi at Mānoa researchers, details the compounding hazards—fire and rain—produced by the storm.

“In this study, we document what we believe to be the first instance of a hurricane causing both heavy rainfall and contributing to multiple instances of fire simultaneously,” said Alison Nugent, lead author of the study and assistant professor of in 东精影业 惭ā苍辞补鈥檚 (SOEST).

A team of 东精影业 Mānoa and East-West Center scientists analyzed multiple aspects of the storm鈥檚 meteorology and climatology, the environmental conditions leading up to the storm, and documented the associated societal impacts.

They found that land-use characteristics and preceding moisture conditions exacerbated fire hazards, and both fire and rain severity were influenced by the hurricane environment and local topographic features. Conditions at the edge of the storm resulted in dry windy weather conducive to fire, while closer to the storm center, the incredibly moist atmosphere lifted by 贬补飞补颈ʻ颈鈥檚 mountains brought intense, long-lasting rainfall. The simultaneous occurrence of rain-driven flooding and landslides, strong winds and multiple fires complicated the emergency response.

贬补飞补颈ʻ颈鈥檚 vulnerability

The vulnerability of a population in any given location to the impacts of tropical cyclone hazards is determined by a multitude of interacting factors. Biophysical aspects include distance inland from the coast, terrain slope, coastal ecosystem integrity and land surface cover. Socioeconomic factors include infrastructure quality, the availability of early warning systems, and capacity for evacuation and emergency response.

“The surprising thing about Hurricane Lane was that, despite never making landfall, the storm caused considerable damage and disruptions across the state from two rather contradictory things: fire and rain,” said Nugent. “Severe flooding on the windward side of Hawaiʻi Island built over several days, and multiple fires initiated on the leeward sides of Maui and Oʻahu within hours of each other. Hurricane Lane is one of only three documented cases of hurricanes influencing wildland fire risk in real-time.”

Ryan Longman with the East-West Center; Clay Trauernicht, Matthew Lucas, Henry Diaz and Thomas Giambelluca with 东精影业 Mānoa are also co-authors on the study. This work was partially supported through the National Science Foundation EPSCoR project, ʻIke Wai.

For more see .

—By Marcie Grabowski

The Honolulu Forecast Office predicted a quieter 2020 hurricane season with two to six tropical cyclones in the Central Pacific region.

Forecasters predict this season will have a 75 percent chance of being a lower than normal season. The cyclones include tropical depressions, tropical storms and hurricanes.

Hurricane season in Hawaiʻi occurs roughly between June 1 and November 30. Now is the time to prepare yourself and your loved ones for the possibility of storms affecting the islands.

If you would like to learn more about what you can do to prepare for a hurricane, the University of Hawaiʻi at Mānoa Department of Public Safety (DPS) is offering via Zoom in June and July. Hosted by DPS Emergency Management Coordinator Jimmy Lagunero, the session covers:

• Hawaiʻi Watch and Warning systems
• Tips for preparing an emergency kit
• What to do when a hurricane is coming
• How to find a local hurricane shelter or shelter-in-place
• COVID-19 considerations and how they may affect hurricane preparation
• Resources and information about local and government agencies

This training is open to 东精影业 employees and students from all 10 campuses. Space is limited, so those who are interested should sign up soon. Find more information about training workshops offered by .

More resources

The Hawaiʻi Emergency Management Agency has pages with great tips and resources:

All members of the 东精影业 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.

There is also the Pacific Disaster Center鈥檚 desktop version and app () with updated information. Notifications affecting 东精影业 campuses will be posted on the emergency information webpage, as well as on social media:

• 东精影业 emergency information website

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鈥檚 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鈥檚 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:

东精影业 resources:

All members of the 东精影业 community are urged to sign up for 东精影业 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鈥檚 Disaster Alert and app () with updated information.

Notifications affecting 东精影业 campuses will be posted on the emergency information webpage, as well as on social media:

东精影业 emergency information website

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

As the climate changes over the coming decades, the northward shift of hurricanes toward the Hawaiian Islands will increase the chance of landfall and pose severe flood risks to populations and infrastructure along the coast and further inland, says a recent study led by researchers at the (SOEST).

Tropical cyclones are usually weakened or deflected to the south when approaching the Hawaiian Islands, due to the high-pressure system to the northeast, strong wind shear and relatively low sea-surface temperature in surrounding waters.

But by synthesizing information from computer models for climate change, hurricane formation and intensity, storm surge and waves, lead author , ocean wave model systems specialist in the (ORE) at SOEST, and co-authors estimated future vulnerability to combined effects of sea-level rise and closer hurricane approach.

Assessing impacts of critical storms

“Of the nearly 2,500 future scenarios in our study, we selected 24 critical storm events that track near the islands to assess the probability of coastal flooding and created detailed flood maps with 100-, 200- and 500-year return periods,” said Li. “With high tide and the projected sea-level rise, the modeling results from a direct landfall of an Iniki-like hurricane on the south shore of Oʻahu showed extensive inundation of downtown Honolulu and Waikīkī. Other hurricanes passing near Oʻahu can also produce severe surge and high surf, causing coastal flooding.”

“The findings of our study were not a surprise,” added , senior author on the study and professor in ORE. “Our recent experience with increasing number of storms tracking closer to the islands—Hurricane Guillermo in 2015, Hurricanes Celia, Darby and Lester in 2016, and Hurricanes Lane and Olivia in 2018—has already confirmed the change of hurricane patterns. The damage caused by Hurricanes Lane and Olivia underscores the importance and urgency of coastal storm hazards mitigation. This research should draw attention from state and federal agencies.”

Planning for the future

Coastal infrastructures and buildings planned or designed today will generally have a service life, that is, a period of time during which they are useful, through the end of 21st century. This study has shown climate change can potentially increase the severity of natural hazards within that time period, thereby reducing the reliability or safety of structures in the future.

“The inundation maps from this study will help assess the types of buildings and structures in the areas of Honolulu that would be exposed to increased flood risks,”said Li. “This has significant implications for engineering practice and land-use planning. If climate change effects are factored into design requirements through new regulations, an economic incentive is created for responding to climate change in planning, siting and construction of structures. This investment in increased resilience will offset the economic consequences of inadequate performance, loss due to damage, loss of marketability or even failures of safety.”

Cheung said, “We would like to seek opportunities to implement this approach in other strategic locations and extend the inundation mapping from urban Honolulu to other populated coastal communities.”

—By Marcie Grabowski