From a forecast perspective, the flooding event was spot on. The National Weather Service was sounding the alarm days in advance that the remnants of Hurricane Ida was going to be a huge problem for parts of the Northeast, including New York City. The National Weather Service - New York City put out an urgent message on Monday August 30th stating that remnants of Ida would produce heavy rainfall on Wednesday and Thursday. The message called for 3 to 5 inches of rain “with locally higher amounts possible.” That same alert also said, “This rainfall combined with antecedent conditions may lead to flash flooding.” Earlier this week, I even spent the first part of my Satellite Meteorology class at the University of Georgia dissecting the flood potential for the Northeast while Ida was still in the Southeast. I don’t claim to have all of the answers in this discussion, but there are three big messaging challenges that need to be considered.
This flooding event was caused by the interaction of Ida’s deep tropical moisture and a stationary front draped across the Mid-Atlantic and Northeast. Urban impervious surfaces are also an unsung aspect of many catastrophic flooding disasters. Flash flooding is not just a function of what falls from the sky. The vast and ever-expanding parking lots, pavements, and roadways accelerate the runoff cycle of the water cycle we all learned about in 4th grade. As I told my students this week, a firehouse of moisture is in place and there is a lifting mechanism - a recipe for disaster. And in this case, the urban landscape of New York City did not help. Ok, so the hydrometeorological set-up was pretty obvious. The National Weather Service even issued rare Flash Flood Emergencies during the event. Do people understand what a NWS Flash Flood Emergency means?
Definition of a Flash Flood Emergency
NWS
My colleague Dave Jones, founder and president of StormCenter Communications, Inc, raised this very question on social media. This event represented the first time that the National Weather Service - New York City had issued this type of warning. They even tweeted, “To be clear... this particular warning for NYC is the second time we've ever issued a Flash Flood Emergency (It's the first one for NYC).” The first Flash Flood Emergency for the area had been issued an hour prior to the Tweet for parts of northeastern New Jersey. According to the National Weather Service, a flash flood emergency is issued for, “exceedingly rare situations when a severe threat to human life and catastrophic damage from a flash flood is happening or will happen soon.” Earlier this summer, Jonathan Erdman wrote a piece at Weather.com entitled, “Why You Should Never Ignore a Flash Flood Emergency Issued by the National Weather Service.” Erdman also lays out the triggering criteria for such a warning. To Dave Jones point, the National Weather Service only started using the terminology in 2014. Candidly, the public already responds to flood warnings differently than hurricanes, blizzards, or tornadoes.
NEW YORK, NY - SEPTEMBER 02: Commuters walk into a flooded 3rd Avenue / 149th st subway station and ... [+]
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Which leads me to the second challenge. The prospect of flooding, in my professional option, doesn’t garner the same response level from the public, media, or stakeholders as a named hurricane, tornado or Nor’easter. If you think back to Hurricane Sandy, there was significant debate about whether to keep warning on it as a hurricane even as the storm transitioned to a “regular” extratropical cyclone. The weather-risks were going to be the same, but the discussion illustrated that some officials understood that people pay attention to named hurricanes.
My colleague Brian McNoldy at the University of Miami made an excellent point. He tweeted, “If 32 inches of snow is forecast for NYC (for example), they’d probably close things in advance and stage resources for the aftermath. But when there’s a forecast for extreme rainfall, ignore it until it happens?” His point echoes some things that I argued in a recent Forbes piece about messaging extreme rainfall and flooding. McNodly went on to ask why it matters if the water is frozen and ended by refuting the narrative that this was a “surprise.” He wrote, “ Maybe the EXACT placement of the heaviest amount was not known, but you don’t often see that pink “HIGH” risk cover so much area a whole day in advance.”
NEW YORK, NY - FEBRUARY 09: Pedestrians walk in the snow and wind in Manhattan on February 9, 2017 ... [+]
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Another challenge is the “rise of the Weather Apps.” Don’t get me wrong, Apps can be useful for general weather forecasts and guidance, but I personally do not rely on them for a rapidly, evolving extreme weather event of any kind. Yet, the public is increasingly conditioned to look at the little sun or rain icons to make decisions about the weather. My colleague Dr. Jonathan Gourley, a hydrometeorologist at the National Severe Storms Lab, tweeted, “Could it be over-reliance on non-NOAA sources of weather information such as apps that provide hyperlocal (yet often inaccurate) information down to the minute?” Virtually every meteorologist by now has heard, “But my app said...” Daniel Swain is a trusted source on weather and climate. The expert, who is affiliated with the University of California - Los Angeles (UCLA), echoed Gurley’s concern. He tweeted, “I think this is a bigger part of the problem than a lot of folks realize, and it is incredibly aggravating since the “last mile” forecast communication issue is critically important.”
I will give my University of Georgia colleague Professor Janet Frick the last word. She is a psychology professor who also pays close attention to extreme weather events. Frick also understands behavior and aspects of human decision-making. Frick tweeted, “I think the phone weather App is a big part of it. And not enough people enabling emergency alerts through more reliable weather sources.” She closed by noting that the fix may need to be at local levels and involve realigning systems.
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