What a night last night with Tsunami warnings being issued for Hawaii after a massive earthquake off the Western Canadian coast! I’m starting to think the Myans are on to something with the whole world ending in December.
So it begins. The effects of Sandy are already being felt in the Lehigh Valley and Suburbs of Philadelphia. Light rain has been falling since roughly 7am in Allentown while the wind has been steadily increasing through the morning and has been consistent out of the NE. Expect deteriorating conditions through Sunday, Monday and into the early morning hours of Tuesday with the worst of the storm expected to strike the area in the evening hours Monday.
Sandy is beginning to show signs of strengthening, with pressure down to 951mb (Normal Sea Level pressure is 1013mb) and dropping! Winds are still assumed to be at hurricane force on the south western quadrant but these are satellite estimates, hurricane hunter aircraft have not measured any hurricane force winds in the areas surrounding the eye. Much of the strengthening is now becoming more due to baroclinic (temperature gradient) processes rather than tropical, what this means is that the storm is starting to transition into a hybrid monster. Jet energy is currently located in the lower Mississippi valley and is continuing to propagate towards Sandy.
Sandy is still forecast to make landfall somewhere on the New Jersey coast late Monday night. It must continually be noted however, that for communities inland, landfall should not be the focus of attention; this storm is enormous and will have a large impact regardless of where the center hits the mainland first.
Upper level energy is located over the Southeast US and should reach the storm sometime in the next 24 hours. Vorticity is one way to locate the high energy in the upper levels and in the map below you will see an area of high vorticity coming around the trough and meeting up with Sandy. At this point, the low will rapidly deepen while making the final approach toward the New Jersey coast.
Landfall is forecast to be in the vicinity of Atlantic City which will drive a strong storm surge at locations to the north. Snooki better batten down the hatches, Seaside heights could experience some of the worst in terms the impact from this storm. New York Harbor could see record surge as Sandy makes her presence felt on Monday/Tuesday flooding low lying areas in Manhattan and Staten Island. Communities along the long island sound in Connecticut and Long Island need to pay close attention as well with strong winds from the NE driving water down the sound. Flooding could be much more severe than with Irene last August.
Creeks and small river flooding can be expected as rainfall amounts top 4 inches in many areas. Rain will continue to fall on and off through Thursday with the heaviest rainfall anticipated for Monday night. Currently the Delaware river does not look like it will reach flood stage but locations such as the Perkiomen creek could go over its banks. As previously mentioned street flooding will be a big issue as leaves clog the storm drains.
When preparing emergency plans for a city, this is a type of storm they plan for, high winds could blow out windows on skyscrapers, water will be pushing up from the south into the Harbor and water will be driven down the long island sound. I expect subway service to be shut down in some areas, while the airports will cancel flights starting tonight.
At 7pm this evening MTA Busses and trains will stop service in NYC.
Philadelphia, Lehigh Valley, and Suburbs
Power outages will be an enormous problem in the suburbs. Most trees still have leaves and with winds gusting to 60mph and steady in the upper 30’s and even low 40’s I expect massive damage to trees and the power grid. In the city proper, street flooding will cause many municipalities to close roadways. Rainfall amounts will be int he 4-6 inch range. Do not be surprised to hear reports of ears popping when the low passes over the area.