Looks like an active weather day in the northeast tomorrow as a big severe wind event looks to take place during the afternoon and evening. Central and southern New York, and perhaps southern Vermont may get in on the action as the threat for damaging wind develops.
Here's the setup, a warm front will move northward into the northeast and stall out through central and southern New York. This front will be the "tracks" for a series of waves of low pressure centers to ride along. One rather potent wave of low pressure looks to trek along the front during Thursday afternoon which will be enough to push the front a little north into southern New England. That low will cause a line of rain and thunderstorms to develop. Just how far north that front moves will determine where the stronger thunderstorms will be.
The Storm Prediction Center in Norman, OK monitors the entire nation for severe weather in the 1-5 day timeframe. They rank the coverage and intensity of storms on a 3 level scale, slight/moderate/high risk. Most spotty severe weather days will be put in a slight risk (such as this past Monday for our area), while a high risk will be a widespread severe weather outbreak (often large, long lived tornadoes and widespread damage anticipated). In the middle, lives the moderate risk. While it may not sound too bad, "only moderate", moderate risk areas are rather rare to be issued. On Thursday, the SPC has put much of central NY, western New England, back through Pennsylvania in a moderate risk. This mean that the potential for a rather significant severe weather event is there based on current forecast models. The biggest threat coming on Thursday will likely be wind damage. In fact, the SPC alluded to the possibility of a derecho forming through central/southern NY and into western New England. A derecho is a large segment of thunderstorms that produce damaging winds. A few tornadoes may also spin up as this line of storms presses through the Ohio River Valley to southern New England, mainly from 2pm to 8pm. The potential is there for widespread damage and power outages (and of course, travel delays). Here's the outlook as of Wednesday night.
For the latest SPC outlook, check in with their website here.
If a derecho does develop tomorrow in the northeast/southern New England, it would be a rarity. The derecho climo info says that derechos only occur in the NY state and southern New England, on average, once every 2 years or so.
Most recently, a high impact derecho occurred in the mid atlantic and Delmarva region on June 29th of this year. Here were all the damage reports from that day (each blue dot represents wind gusts of at least 60mph and each black dot is over 75 mph!). According to the Washington Post, this derecho event was "one of the most destructive complexes of thunderstorms in memory swept through the entire D.C. area. Packing wind gusts of 60-80 mph, the storm produced extensive damage, downing hundreds of trees, and leaving more than 1 million area-residents without power" (read full article here).
While most of the action should stay southwest of our immediate viewing area, some of southern Vermont may get clipped with the severe storms. If so, be sure to keep with Fox 44 and ABC 22 for local impacts. Be sure to tune in to ABC 22 News at 6, 7, and 11pm and Fox 44 News at 10pm. Or in the morning on ABC 22 from 5-7am and on Fox 44 from 7-9am.