Area forecast discussion 
National Weather Service State College PA 
1128 PM EDT Sat may 25 2013 


Synopsis... 
a deep upper low over southern New England will continue to move 
slowly northeast on Sunday. High pressure will build southeast out 
of the Great Lakes Sunday into Memorial Day ensuring cool but fair 
weather. Temperatures will be below normal into Memorial Day... 
but will moderate to above normal by middle week. 


&& 


Near term /until 6 am Sunday morning/... 
evening infrared loop showing western periphery of stratocu deck associated 
with upper low just skirting Sullivan County. However...as low 
pulls further away...expect even Sullivan Colorado to become clear 
overnight. 


Although the gusty winds will subside somewhat overnight...a 
tight pressure gradient will remain over the area...keeping an active 
northwest breeze through the night. Therefore...expect little chance of any 
frost and temperatures will be slow to fall due to the resulting mixing. 


Current observation are around 10f degree warmer than last evening and winds 
just as strong...so confidence in a widespread freeze across the 
West Mountains is waning a bit. Latest hi-res NAM...lamp guidance and 
sref/gefs...indicate the best chance of a freeze will be over the 
highest terrain of the West Mountains...with little chance across the mountains 
north of ipt. Have therefore cancelled the warning for North Clinton and 
Tioga Colorado eastward. 


&& 


Short term /6 am Sunday morning through 6 PM Sunday/... 
Sunday looks like a bright day over the area as the surface high 
noses in from the northwest. Pressure gradient relaxes and temperatures aloft 
moderate...as upper low slowly pulls further away. Still expect 
Sunday to be a breezy day...as deepening blyr causes allows gusts 
near 20kts to mix to the surface by afternoon. Ens mean 850 temperatures around 4c 
should support high temperatures in the 60s under sunny skies. 


&& 


Long term /Sunday night through Saturday/... 
high pressure building over region Sunday night will bring another 
chilly night. The light winds under the surface high may result in 
some of the lowest temperatures of this cool snap with frost and/or 
freeze warnings possibly needed...especially along over the Allegheny 
plateau. Dry weather continues into Memorial Day as temperatures rebound 
nicely to within a couple degrees of normal. 


Warm front drifts across PA Tuesday into Wednesday...bringing with it our 
weekly best...albeit still low chance for thunderstorms. Though just about 
all locations will remain rain-free a vast majority of the time. 
Best chance for a tstorm on Wednesday will be north of a line from kbfd- 
kipt- krdg. This warm front will also mark the beginning of much 
milder weather for the remainder of the extended forecast. Lows by 
Wednesday morning will be in the 50s...with highs pushing above normal into 
the upper 70s to middle 80s on Wednesday. A gradual warming trend continues 
into late week as warmer air spreads in around the top of the 
subtropical ridge from the west/southwest...bringing highs in the 
80s for all by Friday as 850mb temperatures warm to around +16c. A 
downside will be with central PA located on the southern edge of 
the westerlies/northern edge of the subtropical ridge...we will 
become vulnerable to upstream mesoscale convective system development as rising humidity 
also begins to make inroads to the region once again. 


Differences persist in the timing of any convective development 
late week and into the weekend...but with a surge in middle level 
temperatures by late week and weak cap on edge of ridge...each day will 
bring a low chance for isolated/scattered showers/tstms. Chances for more 
widespread rain increase late in the weekend heading into early 
next week as pattern becomes more progressive...pushing the trough 
over upper Midwest toward the East Coast. 


&& 


Aviation /04z Sunday through Thursday/... 
no major changes made to the 03z tafs. 


Mainly clear skies overnight into Memorial Day. VFR conditions 
will prevail...given very dry air in place. 


With the loss of heating...the gusty northwest wind will gradually 
diminish. 


Sunday will once again see a gusty northwest wind redeveloping. Expect 
winds gusting to 15-25 miles per hour by middle to late morning. 


Expect more in the way of showers and storms possible later Tuesday 
into Wednesday...as a warm front moves NE across the region. 


Thursday should be dry and very warm...as the warm front is north of 
central PA. 


Outlook... 


Monday...VFR. 


Tue-Wed...mainly VFR...but scattered thunderstorm impacts possible. 


Thursday...mainly VFR. Some fog and haze possible early. 


&& 


Fire weather... 
with diminishing winds...red flag criteria will diminish this 
evening. 


Sunday looks like a repeat of today with low rh's and gusty winds. 


&& 


Ctp watches/warnings/advisories... 
freeze warning until 8 am EDT Sunday for paz004>006-010-011- 
017-024-033. 


&& 


$$ 
Synopsis...la corte/Martin 
near term...Fitzgerald 
short term...Fitzgerald/la corte 
long term...rxr 
aviation...Martin 
fire weather...Fitzgerald