As more humid air continues to flow into the East early today, we're going
to be watching a cool front closely during the next 24-36 hours... This
front is currently located in the Great Lakes, and it probably will not reach southeastern New York State to Fairfield County and southern New
England until tomorrow (Friday) evening... But nonetheless, this is going to be one of the key
components in our forecast over the next few days... There will be intervals of clouds and sun
today, with most temperatures reaching the mid and upper-80s this afternoon... Showers and a
couple of thunderstorms will be developing across the northern and central Appalachians this
afternoon, and these should tend to drift a bit to the south and east this afternoon and this
evening... So, after a couple of "uneventful" days that have lacked any rainfall, we should see
some activity appearing on the regional radar mosaic this afternoon and early tonight...
But, as we've been saying now for the past couple of days, it appears that the showers and
thunderstorms which will be flaring up later today will "only be the beginning" of what should be a
pretty active weather pattern... Some of the suburbs of Westchester and Fairflield County could have local rainfall
amounts of up to an inch or two this afternoon and early tonight... However, later tomorrow,
tomorrow night and Saturday, the regional radar mosaic should have numerous showers and
heavier thunderstorms on it in the bigger cities located along the I-95 corridor... As a low pressure
system forms along the front out in the Ohio Valley today, it will be poised to move into western
portions of New York and Pennsylvania tomorrow afternoon... And, the very warm and moist air
located out ahead of it will be getting tapped by both this low pressure system and a slow-moving
cool front that will be trailing behind it... And, if there's enough sunshine tomorrow, and
temperatures do manage to reach the upper-80s and lower-90s like we're expecting, there could be
a few strong or severe thunderstorms which will be erupting in mid-Atlantic states... Much like we
were saying yesterday, the greatest threat for wind gusts in excess of 50 miles per hour and
torrential downpours tomorrow afternoon will be across much of Pennsylvania, Maryland,
Delaware and western parts of New Jersey... After that, what remains of this outbreak of strong
thunderstorms will probably cause rain heavy enough to produce flash flooding in the Tri-State
Area and across much of southern and central New England from tomorrow night into Saturday...
The global models are starting to reach more of a consensus on the timing of the worst of this
weather, and these would imply that there should be a 12-hour window in cities like Philadelphia,
Baltimore, Washington, D.C. and Allentown, PA where the heaviest rain will occur between 3 p.m.
tomorrow and 3 a.m. on Saturday... Meanwhile, for New York City to Greenwich, New Haven, much of Long Island and in
southeastern New England, the heaviest rain should take place between 8 p.m. tomorrow and 8 a.
m. on Saturday before it starts to wind down...
Precipitable water values are going to be quite high tomorrow, tomorrow night and early Saturday, with
some of the guidance indicating that a vertically integrated column of air could produce up to two inches of
rainfall... We believe that a general 1-2 inches of rain, with locally higher amounts of up to 3 inches, is a
pretty safe call for the entire Tri-State Area tomorrow, especially in Westchester and Fairfield County, tomorrow night and into Saturday...
After the low pressure system and its attending cool front manage to move off shore on Sunday, it will turn
out mostly sunny and nicer with lowering humidity... Temperatures should be running mostly in the mid-80s
on Sunday and Monday, and then we'll have some other opportunities to get rain Tuesday and/or
Wednesday of next week... Have a good day!!!