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Henri Is Expected To Bring Wind & Heavy Rain/Flood Impacts To Western & Central Mass Sun & Sun Night

Tropical Storm Henri is gaining strength and is likely to become a hurricane as soon as this evening. It is expected that Henri will move into a very favorable environment for strengthening tonight, Saturday and Saturday night. This favorable environment includes low wind shear and very warm waters of the Gulf Stream. I think it’s quite possible that Henri could strengthen into a 100 to 110 mph hurricane at some point on Saturday and Saturday night as it heads northward and crosses the Gulf Stream. In fact, it’s also possible that Henri could peak at 115 or 120 mph on Saturday night. As we get into Sunday, Henri will exit the very warm ocean waters of the Gulf Stream and enter some water temperatures that are in the mid 70s. This means that Henri will likely weaken as it moves northward towards Long Island and Southern New England. How much it weakens before landfall will depend on how long it stays over the 75 Degree or so ocean waters just south of Southern New England. At this point, I think fairly steady weakening is likely on Sunday and Henri will probably make landfall as something like a 75 to 85 mph hurricane late Sunday afternoon. As for a forecast track, it is now extremely likely that Henri will make landfall somewhere on Long Island and Southern New England late Sunday afternoon and Sunday evening. Where exactly is going to depend on how much an upper level trough of low pressure to the west and southwest of Henri captures it. An early capture like some of the guidance seems to be trending towards would mean Henri would turn more to the north-northwest and northwest and make landfall first in central or even western Long Island with a second landfall occurring somewhere between the central and southwestern Connecticut coastline and right over New York City. If this happens, then wind would become the bigger issue rather than rain across Western Mass and parts of Central Mass with wind gusts of over 60 mph possible Sunday afternoon and Sunday night. On the other hand, if the trough captures Henri a little later, it would mean a landfall along the Rhode Island coastline or on Cape Cod. This type of track would lead to a serious heavy rain event with flash flooding across all of Western and Central Mass with most of the wind issues occurring across Eastern Mass and the Cape/Islands. This means that while a landfall looks very likely rather than a miss, there is still some uncertainty as to where exactly the center will cross the coastline. Either way, the timeline of landfall currently looks to be about late afternoon Sunday as a 75 to 85 mph hurricane. Forecast Impacts Across Southern New England: Wind: The strongest winds will occur to the east of where the center moves. At the very least, I expect hurricane force winds along coastal parts of southeastern Connecticut and coastal Rhode Island, as well as across the Cape and the Islands during Sunday afternoon and Sunday evening. Tropical storm force winds with gusts of up to 55 to 65 mph are expected as far north as the Mass Pike in Central Mass and across all of Eastern Mass during Sunday afternoon and Sunday night. If the track of the storm shifts westward and comes ashore in central or western Connecticut, then the threat of wind gusts of up to 55 to 65 mph would increase across Western Mass as well. I advise everyone across Western and Central Mass, as well as across the rest of Southern New England to be ready, at least, for downed trees with power outages. The ground is super saturated and thus the tree roots are weakened because of it. This means any strong winds will more easily push over trees. Also, the wind direction will be from a southeasterly direction, which trees are not used to and thus they are more susceptible to being blown over. Rain & Flash Flooding: The highest rainfall totals are expected on the western side of the storm track and this potentially means that Western Mass and parts of Central Mass may see 4 to 8 inches of total rainfall with locally much higher totals possible. What really concerns me is that Henri is expected to be a very slow moving storm, which is highly unusual for New England tropical systems. This means that I’m very concerned that Henri may end up raining itself out over us over a 2 to 3 day period leading to some extremely high rain totals. This means that flash flooding and even major flash flooding is likely across Western Mass and parts of Central Mass. Should the track of Henri shift further west, then we could see a much less heavy rainfall threat and more of a wind threat from Henri. Storm Surge Flooding & Marine Impacts: The onshore wind flow is likely to lead to moderate to even severe coastal flooding across eastern Mass, the Cape and along the entire south coast of New England. If you live in a storm surge/coastal flooding evacuation zone and are asked to evacuate, please do so. Tornado Threat: There is the possibility for a few spin up tornadoes as Henri makes landfall on Sunday afternoon and Sunday evening, especially across Central and Eastern Mass. Depending on how long Henri lingers over our area, the tornado threat could last into Monday across the entire area. I highly encourage everyone across Southern New England to be ready for the impacts from Henri. You have the rest of today and all day Saturday to prepare for potential flooding and the possibility of downed trees and power outages. I continue to closely watch Henri and I promise that I'll be with you every step of the way to guide you through this storm.

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