218 
fxus61 kctp 141156 
afdctp 


Area forecast discussion 
National Weather Service State College PA 
756 am EDT sun Mar 14 2010 


Synopsis... 
a strong low pressure system along the coast will dominate our 
weather through at least Monday. Winds and rains will diminish as 
the low slides slowly southeast of Cape Cod Sunday into early 
Monday. A ridge should build in providing a quiet period of 
weather through most of the coming week before another storm 
system approaches next weekend. 


&& 


Near term /through tonight/... 
steadiest and heaviest precipitation has now lifted north of the 
region with open cellular and bright banding signatures present 
throughout central PA and brief moderate rain showers. Extent of 
flooding from an areal perspective has not been great...but the 
areas where concerns were high for snowmelt and rainfall (laurels) 
certainly materialized in Somerset County. For the remainder of 
the overnight and morning...not expecting any new areas of 
flooding and have opted to cancel the Flood Watch early. 


Low pressure center over east central Virginia may spread some 
moderate rain shower activity into the south this morning...but 
these are moving at a good clip and should not rain heavily over 
any one area for any length of time 


Model soundings remain marginally cold enough over the northwest mountains for a 
bit of lingering wet snow. Additional wet accums should be less 
than one inch. 


As previously mentioned...as the 500 hpa low passes to our south... 
middle- level lapse rates steepen significantly. Thus kept chance of 
thunder in the afternoon. Best lapse rates in the 850-500 hpa 
layer. 


&& 


Short term /Monday/... 
the 500 mb low center tracks off the middle Atlantic coast tonight and 
will do an offshore loop before eventually settling southeastward 
by Monday night. This will keep cyclonic flow and steep lapse 
rates across the region with the threat of showers at any time... 
mixed with wet snowflakes over the higher elevations. 


&& 


Long term /Monday night through Saturday/... 
upper low centered to the east on Monday will keep mention of showers 
in forecast mainly during the day...with lessening chances into 
Monday night. Region will begin to dry out...though some mainstem 
rivers will still be running high on Monday. 


Tuesday begins a run of drier weather that will last until the 
weekend. Broad ridge builds over upper Midwest with weak waves 
sliding through. This will bring cool and dry Canadian air to PA. 


Next chance for precipitation looks to be next weekend as trough 
approaches from the west. Models differ on strength and 
timing...but could see some scattered showers encroach as soon as 
Sat...but likely later as temperatures moderate. 


&& 


Aviation /12z Sunday through Thursday/... 
a major East Coast storm will keep IFR and MVFR conditions 
across the area today...with widespread rain...and some 
wet snow early on across the northwest mts. It will be another 
windy day. 


Conditions should improve by late Tuesday. VFR conditions 
should prevail after this into next weekend. Still a lot 
of spread in model soluations out in time...but some hints 
that we could see zonal flow for a first time in a long 
time. This would cut back the amount of stormy weather we 
have seen since last Summer. 


Note...winds at jst have problems. Still windy across the 
area...given strong easterly flow. 


Outlook... 
Monday...IFR and MVFR. 
Tuesday...becoming VFR late. 
Wed-Thu...VFR. 


&& 


Hydrology... 
still some small bands of moderate to heavy rain across the 
western portion of central PA. General Flood Warning for portions 
of south central PA...along with several river flood warnings 
in effect. Looking at 2 points at moderate flood. 


&& 


Ctp watches/warnings/advisories... 
none. 


&& 


$$ 
Synopsis...devoir 
near term...devoir 
short term...devoir 
long term...rxr 
aviation...Martin 
hydrology...Martin