Some of the most common and severe flooding in New York State occurs in the spring when rain falls on melting snow. With the large and in some cases record amounts of snowfall in New York this year, coupled with the extreme cold that kept it from melting until early spring, there was a lot of liquid equivalent available to rush into our rivers and streams. Triggered by heavy rainfall in late March and early April, large portions of the state were faced with flood watches and warnings as well as inundation. Anywhere from 1 to 3 inches of rain fell on already saturated ground in Central and Western New York swelling creeks and inundating low lying areas and causing roads to be temporarily closed.

This all pales in comparison to what was experienced by the state of Hawaii. In early March, around the same time as the flooding that impacted upstate New York, flooding in Hawaii forced thousands of people to evacuate their homes and resulted in hundreds of rescues. While all the Hawaiian Islands were impacted, Oahu and Maui were the hardest hit. Over 400 homes were destroyed and overall damage is estimated at over $1 billion. Weeks later, many people are still displaced. The University of Hawaii estimated that nearly 2 trillion gallons of water inundated Hawaii during this time. That is enough to fill 3 million Olympic-sized swimming pools.

The cause of this flooding in Hawaii was the result of a Kona low. A Kona low storm is the name for a subtropical weather system characterized by wind and rain from the south or southwest. While Kona lows are common in Hawaii, storms of this scale, in particular back-to-back storms, are not typical. Climate Change, however, is making them increasingly common.

The first storm struck between March 10-16, bringing record rainfall and flash flood warnings across the islands. Wind gusts of over 135 mph were experienced and 62 inches of rain fell on the island of Maui during this period. The storm triggered not just flooding but landslides and power outages impacting more than 100,000 people. Extreme weather conditions continued through the week and between March 19-23, yet another Kona low storm moved across the islands dumping an additional 61 inches of water on already extremely saturated ground. Several records were broken. The Ka’ala weather station recorded 22 inches, the highest two-day average for that station. This included 19.67 inches in a single 24-hour period. During the same period, the nearby Kalahe’e Ridge station recorded 9.75 inches of rain in 24 hours.

Beyond the damaged roads, bridges, and buildings, massive agricultural damage occurred. It is estimated that only 3% of Hawaiian farmers have federal crop insurance. Any damages from lost crops will have to be paid out of pocket by farmers who do not have crop insurance.

Additionally, the flood waters carried untreated sewage, herbicide and pesticide runoff from farms, and other industrial pollutants across the landscape and down to the beaches. Even water not contaminated with man-made pollutants can cause a problem. Sediment saturated water can damage or kill coral reefs outright or over an extended period of time by darkening the water and keeping needed sunlight from reaching the reefs. This has a cascading effect. Many species of fish and other aquatic organisms rely upon coral reefs for habitat. Without this habitat these species, many of them threatened or endangered, cannot survive.

Hawaii also suffered (and continues to suffer) serious economic losses. The storms hit major beach areas including the north and south shores of Honolulu, West Maui, Molokai and the Big Island (Hawaii) during a period when many schools are out on spring break and tourists flock to the state’s bars and beaches. According to the Hawaii Department of Business, Economic Development and Tourism, the state lost $300 million in revenue because of the storms. Even in parts of the state that were relatively unscathed, perception that the entire island chain was devastated resulted in cancellations for hotel rooms, flights, and excursions. Hawaii, which was still struggling to regain visitor numbers to pre-pandemic levels, was just starting to see an upward trend in those numbers when the storms hit. All of this comes just three years after the 2023 Hawaii wildfires that killed 102 people, destroyed 2,200 buildings, and caused nearly $6 billion in damages.

While New York State is not impacted by Kona lows, it is impacted by a number of weather events including hurricanes, nor’easters, and atmospheric rivers. Rain on snowmelt events have also historically resulted in high levels of flooding and are not necessarily the result of a distinct metalogical event. While there is likely nothing that could have prepared the State of Hawaii from such extreme back-to-back storms all of us can use this as a learning opportunity to stress emergency management, resilience, and mitigation in a world with increasing extreme weather events.