465 
fxus61 kpbz 201534 
afdpbz 


Area forecast discussion 
National Weather Service Pittsburgh PA 
1134 am EDT Sat Mar 20 2010 


Synopsis... 
a cold front will approach the region tonight and stall across the 
region. Low pressure will move from the Tennessee Valley Monday 
to off the New England coast Wednesday bringing showers and cooler 
temperatures. 


&& 


Near term /through tonight/... 
for the late morning update...have bumped up afternoon high 
temperatures by 3 to 5 degrees in most locations. Southwest flow 
right above the surface is bringing warmer air into the 
region...and have bumped up Morgantown to an even 70 degrees. 
Still expect that cold front across the eastern Great Lakes will 
slowly drift southeast...but it appears that the front may stay 
far enough to the north that no showers may move in tonight. Will 
wait for all of the 12z guidance to come in before making any 
major changes to tonight/S forecast. 


&& 


Short term /Sunday through Monday night/... 
temperatures will remain above normal Sunday as surface low with 
southern stream storm system streams moisture northeast along 
front ahead of closed low aloft. As upper low and surface low 
transition to Middle Atlantic States widespread showers will be 
across County Warning Area through Monday night. By Monday on backside of system 
cooler air will move into region with temperatures back toward 
normal. 


&& 


Long term /Tuesday through Friday/... 
leftover showers in wrap around moisture for Tuesday. High 
pressure coming from the Midwest should provide dry conditions 
across the upper Ohio Valley Wednesday. Then a low pressure system 
coming from the southwestern U.S. May spread rain showers to the 
upper Ohio Valley Thursday and Friday. 


Forecast temperatures Wednesday through Friday close to blend of 
GFS MOS and HPC guidance...which shows a possible cool down with the 
trailing upper low passage next weekend. 


&& 


Aviation /16z Saturday through Wednesday/... 
VFR conditions will continue through the taf period. A weak frontal 
boundary will push southward across the region tonight... bringing 
ceilings around 4000 to 6000 feet and widely scattered showers. 
Southwest surface winds at 5 to 10 knots will become northeast behind 
the front this evening. 


A low pressure system moving northeast from Arkansas is forecast to 
spread scattered MVFR rain showers across the upper Ohio Valley 
after daybreak on Sunday. MVFR conditions will be more prevalent 
Sunday night into daytime Tuesday as the coverage of rain showers 
increases. Periods of IFR are possible Monday. 


High pressure building in from the Midwest should bring a return to 
VFR weather by Wednesday. 


&& 


Pbz watches/warnings/advisories... 
Maryland...none. 
Ohio...none. 
PA...none. 
WV...none. 


&& 


$$