by Meteorologist Steven DiMartino
When most people think of hurricane season, they typically think of crashing waves and strong winds battering some beach town along the New Jersey shore or on Long Island. The threat for locations further inland is rarely considered.
Naturally, the impacts on the coast from even a tropical storm would be significant for the region with a storm surge enhancing coastal flooding and strong winds creating wind damage and power outages. One of the most devastating aspects of a tropical low pressure system is the storm surge which kills more people than other other factor. In fact, the Nation Hurricane Center has found that most deaths occur due to the storm surge. Of course this factor is also enhanced by the fact that there has been a 32% increase in population in this vulnerable coastal locations, which enhances the threat even more so.
So if you live away from the coast, why would a tropical low pressure system be any more of a threat than a rainy day from a Nor’easter? The answer is in the rainfall.
All one has to do is look back to Hurricane Irene on August 28, 2011. Irene was one of the most devastating storms to hit the region before another storm a year laster called Sandy. While the storm surge from Irene, which made landfall as a hurricane (unlike Sandy) in Little Egg Inlet, just north of Atlantic City, New Jersey was impressive at 3 to 5 feet, the primary impact was the heavy rainfall where over 11 inches of rain was recorded throughout the region. The fact that the region already had a wet Spring and early Summer meant that the ground was already saturated which lead to more flash flooding.
Hurricane Irene was an important lesson as locations away from the coast can have significant impacts from tropical low pressure systems as Irene produced massive flash flooding in the Passaic and Hudson River Valleys.
RAINFALL IS A REGION WIDE THREAT:
A primary concern that this meteorologist has for this upcoming season is the heavy rainfall threat beyond just an actual land fall of a tropical low pressure system. One factor where I think the region is at significant threat is flash flooding throughout the region. Rainfall amounts throughout the region now are near to above normal, much like what was seen in 2011.
When a tropical low pressure system makes landfall on the Gulf Coast either as a Tropical Depression, Tropical Storm, or Hurricane; everyone in the Philadelphia and New York City metropolitan areas should still keep a careful eye on the evolution of the storm over the Southeastern United States. The reason why the population in the Northern Mid Atlantic and New England need to be wary of landfalling tropical low pressure systems on the Gulf Coast and Southeast coast is due to the upper level wind pattern that is developing. Clearly, the theme this Summer, as forecasted by NY NJ PA Weather, is that a trough will be a predominant feature over the Central Plains and Eastern United States. This trough will be positioned such that a southwesterly wind component will be in place from the eastern Gulf of Mexico to New England, which will draw any tropical moisture up the East Coast of the United States. Combine this factor, with a slow moving cold front pressing towards the coast, and the environment for significant rainfall has the potential to be maximized.
Typically, when a tropical low pressure system impacts the region, the western side of the low pressure system tends to be drier, but the flash flooding threat is still present. The potential for several rainfall threats of two to five inches of rain at a clip from a remnant low pressure system can lead to region wide flash flooding that can cause millions of dollars of damage through the Summer and into the Fall. This pattern needs to be monitored carefully.
So when a tropical low pressure system makes landfall over the Southeast, keep up to data with NY NJ PA Weather because the threat for heavy rainfall is still a significant threat. You can count on NY NJ PA Weather to keep you up to date on tropical and all other weather threats.