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FXUS61 KBGM 211741

Area Forecast Discussion
National Weather Service Binghamton NY
141 PM EDT Sun Jul 21 2019

A cold frontal boundary will move through today bringing in 
cooler weather by Monday. An area of low pressure will move 
along the cold front to bring our area another round of showers 
Monday and Monday night. High pressure with drier weather 
builds into the region for the middle of the week.


1030 am update...
Only minor changes made to the forecast to incorporate latest
visible satellite imagery and latest surface observations.
Forecast remains basically the same.

Previous Discussion...
Some scattered showers and thunderstorms have moved into 
Steuben county. However, these have struggled to push eastward 
but a few of them are making it toward Bradford county PA and 
the Elmira area as of just after sunrise. Will maintain a slight
to low chance of thunderstorms this morning across the Southern
Tier and far northern PA for the ongoing showers and 


A cold frontal boundary will move into the region bringing with it 
cooler and less humid air. However, this front is still likely to be 
located north of the Southern Tier of NY and NE PA through the day. 
Ahead of the front more hot and humid conditions are expected. 
Modeled boundary layer temperatures do indicate another day of 90-95 
for highs across the Southern Tier and NE PA. 

While, dewpoints come down some today it will still be humid 
enough for heat index values from around 90 in the Southern Tier
to 100-105 in the Wyoming valley and Pike county PA. Heat 
headlines will remain the same from the previous forecast 
update. Take precautions if you have to be out in the heat. 
Further north, welcomed cooler values in the 80's are expected 
today for highs. 

As for thunderstorm chances, inhibition will be in place throughout 
most of the day south of the front which will limit thunderstorm 
development. However, lift along the front should be able to 
overcome the inhibition enough for the formation of scattered 
thunderstorms across NE PA. with the hot and humid airmass CAPE 
values of around 2,000 J/KG are likely by late in the day with steep 
low level lapse rates and mid-level dry air. All of these suggest a 
potential for wet microbursts of gusty winds with any storms. High 
PW values should result in some heavy downpours with any storms as 

Mesoscale modeling is keying in on the Scranton and Wilkes 
Barre areas around mid to late afternoon for the initial 
scattered storms to form. Enough shear (30 kts 0-6KM bulk shear 
modeled) may allow these thunderstorms to organize into a 
complex as they depart NE PA by evening. Further north across 
most of NY, the less humid airmass behind the front should 
prevent anything more than an isolated shower or two after the 
morning clouds burn off.


The cold front gets just south of the region but slows and stalls to 
our south in response to an area of low pressure in the Ohio Valley. 
Right now it appears that showers and thunder from this feature 
should hold off until Monday. The less humid airmass will allow lows 
tonight to slip into the 60's for many locations.



A few lingering showers are possible early Tuesday as the front
continues to move east. In the afternoon, some instability is
created as the upper trough swings through allowing the heating
to develop a few showers. Late in the day and overnight, loss 
of heating will bring any light convection to an end.

Upper trough moves east on Wednesday with the axis over the
eastern NY border. There is the risk of isolated showers over
eastern NY during peak heating but most of the area will be dry. 

Temperatures both day will be a few degrees below normal with
the northwest flow and upper trough. 



Much of the long term features a building surface ridge and
northwest flow aloft under a broad trough. This will result in
near normal temperatures and the outside chance of a shower as a
result of some limited daytime instability. By saturday, the
upper trough relaxes a bit and the upper flow becomes more
zonal. However, surface ridge remains in place so forecast
should remain dry. 


VFR conditions expected through at least 06Z tonight with
potentially a few scattered TS into ne PA this afternoon.
Otherwise, quiet weather prior to the next batch of rain showers
moving in Monday morning along with MVFR cigs as well.

Winds already sustained around 10 to 15 knots and gusts 15 to 25
kt out of the west. Winds become light and variable this evening
and then calm later tonight...remaining variable through Monday


Monday afternoon through Monday night...Rain and restrictions 
likely as wave of low pressure moves up along front just to our 
southeast. Embedded thunder possible as well.

Tuesday through Friday...Mainly VFR other than valley fog for 
KELM in the predawn hours.


PA...Excessive Heat Warning until 8 PM EDT this evening for PAZ044-



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