At the time of writing, Tropical Storm Lala is approaching the Big Island of Hawaii. The National Hurricane Center is still forecasting the storm to briefly become a hurricane. In fact, it may have reached that status by the time you read this article. As Lala approaches, an important conversation about hurricane risk communication has emerged in the semantic “weeds” of the meteorological community about landfall. It’s an important discussion, so let’s dig in.
Lala’s Status As Of Early Saturday Morning
As I wrote yesterday, “if” Lala reaches hurricane status and makes landfall, it will be the first time in 34 years that a hurricane has made an “official” landfall in Hawaii. I will circle back to this point in a moment. Let’s review the most recent information on Lala from NHC forecasters.
As of 2 am HST, Tropical Storm Lala was moving west-northwestward at 13 miles per her. It had maximum sustained winds of 65 miles per hour. By Saturday afternoon local time, Lala is expected to reach hurricane strength according to forecasters. Hurricane warnings have been issued for Hawaii County, and Tropical Storm Warnings are in effect for Maui County, Molokai, Kahoolawe, Oahu, and Kauai County.
On its current projected track, the center of Lala will be near the South Point of the Big Island of Hawaii by Saturday afternoon and will move just south of the smaller islands on Sunday. “Steady strengthening is forecast, and Lala is expected to
become a hurricane as it approaches the Big Island later today,” according to NHC. “A wind gust to 61 mph (98 km/h) was recently measured at Pu’u Mali on the northern slope of Mauna Kea on the Big Island of Hawaii,” continued NOAA forecasters. That’s not surprising as higher elevations experience more extreme wind and rainfall conditions.
Interestingly, the Big Island may disrupt the storm structure or intensity. That could certainly prevent it from reaching full hurricane status, or once it does, weaken it back to a tropical storm. It is expected to regain hurricane strength again once it passes the islands.
Landfall Or Impact?
It is absolutely correct to say that “official landfalls” are rare in Hawaii. Noted hurricane chaser Josh Morgerman even referred to them as “unicorns” in a public Facebook post. Any headline that said such landfalls are rare is not misinformation. Hurricanes are not dots or lines on a map. They are large weather systems with impacts that extend well beyond the center of the storm. As such, Hawaii has been “impacted” by tropical storms, Kona storms or hurricanes in recent years.
NOAA defines landfall as, “The intersection of the surface center of a tropical cyclone with a coastline.” They also warn that, “Because the strongest winds in a tropical cyclone are not located precisely at the center, it is possible for a cyclone’s strongest winds to be experienced over land even if landfall does not occur.” Even if Lala doesn’t make landfall ”officially,” the islands will be on the “dirty side” of the center and will experience extreme winds, rainfall, storm surge, swales, and mudslides.
Forecasters expect between 1 to 2 feet of rainfall on the Big Island and up to a foot of rain is possible in Maui. Even 4 to 6 inch amounts across the island chain will be dangerous and could cause mudslides and life-threatening flooding. Storm surge, swells and large waves will also be significant hazards irrespective of landfall.
Some experts argue that focusing on frequency of landfall in headlines “clouds” the risk messaging. I respectfully disagree. Two or three things can be true at the same time. The provocative (and accurate) headline can draw attention in order to convey risks associated with the storm whether it makes landfall or not. I have spent my career as a scientist. I know scholars can focus on the technical details of messaging. Often the public doesn’t care about details that we do as scientists. They just want the “so what?” and impacts on them.
The meteorology community operates on inertia. We use a lot of things that are often confusing to the public but are meaningful to us. Let’s make a list:
- Watch vs warning
- The cone of uncertainty
- The Saffir-Simpson Wind scale
- The risk categories for severe weather
- Percent chance of rain
- Polygons.
I could go on and on. My point here is that science communication to the public requires a compromise on messaging while maintaining integrity. “Landfall” has technical meaning for meteorologists and the climatological record. However, impacts are what matters to emergency managers, first responders, and decisionmakers.
I have argued that we need to communicate the full suite of hurricane hazards rather than focusing so heavily on winds. Is it time to provide more context around “landfall” communication too? To their credit, colleagues at the National Hurricane Center have continued to modify its warning language and graphics. For example, the cone graphic, “A depiction of all land-based (coastal and inland) tropical storm and hurricane watches and warnings in effect for the continental United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands,” according to NOAA.
Let’s keep talking.