Weather

826 
fxus61 klwx 061906 
afdlwx 


Area forecast discussion 
National Weather Service Baltimore Maryland/Washington District of Columbia 
306 PM EDT Monday Oct 6 2008 


Synopsis... 
high pressure will build south into the middle Atlantic through middle 
week. The next storm system will approach the region from the 
west...bringing a return of unsettled conditions late in the week 
and possibly into the first part of the weekend. 


&& 


Near term /until 6 am Tuesday morning/... 
middle to high clouds continue to clear this evening as wedge of 
high pressure builds from the north. Main forecast challenge is 
overnight low temperature and the potential for frost. The 18z MOS 
have come in warmer than previous runs. Looks likes lowest 
temperatures would be across the northern tier as well as some of 
the higher elevations out west. Will expand the area of patchy 
frost to incorporate the Potomac Highlands and along the Allegheny 
Front. 


&& 


Short term /6 am Tuesday morning through 6 PM Tuesday/... 
high pressure will dominate for Tuesday...bringing clear skies and 
cool temperatures. Temperatures will probably be similar to 
Monday...only in the middle to upper 60s. 


&& 


Long term /Tuesday night through Monday/... 
high pressure at the surface moves off the middle Atlantic coast 
Tuesday night into Wednesday...allowing a return southerly flow to 
develop. This will increase surface dewpoints on Wednesday. 
Southwest flow aloft will be in place ahead of an upper low over the 
Tennessee Valley. This will start to increase moisture in the middle 
and upper levels Wednesday...with precipitable waters increasing 
above one inch. This will mean an increase in clouds by 
Wednesday...but any rain should remain outside of the County Warning Area through 
the daylight hours on Wednesday. 


During the end of the week...there remains disagreement among the 
models/ensembles with respect to how an upper low may affect our 
County Warning Area. Models have the upper low pretty far south in the southeast 
Continental U.S. Initially. The 12z GFS tracks it north through the middle 
Atlantic through Friday...while the 00z European model (ecmwf) is slower than the GFS 
and fills it off the southeast coast over the weekend. 


Believe the 12z GFS may be too fast...but have leaned more toward 
its track. This would bring chances of rain into the County Warning Area in the 
Thursday to Friday time frame...especially Friday. 


Over the weekend...based on the GFS track conditions would improve. 
But there remains some question as to whether any moisture could 
wrap back around on Saturday...plus there are the timing/track 
issues of the low itself. Have allowed for slight chance probability of precipitation on 
Saturday...with dry conditions on Sunday. New day 7...Monday...will 
also be dry as high pressure is expected to build into the region. 


&& 


Aviation /19z Monday through Saturday/... 
the middle and high clouds that have persisted most of the morning into 
the afternoon will continue to diminish...leaving mostly clear skies 
overnight. Light and variable winds will become north-northeast Tuesday but 
still less than 10 knots. 


High pressure over the area Tuesday night moves east of the coast on 
Wednesday. Low pressure will approach the region toward the end of 
the week. 


&& 


Marine... 
pressure gradient tightens tonight as high pressure builds from the 
north. Will continue current Small Craft Advisory this evening and 
overnight. High pressure nearly overhead on Tuesday...so winds 10 
knots or less over the waters. 


High pressure over the area Tuesday night moves east of the coast on 
Wednesday. Low pressure may help to instigate gusty winds by Friday 
which could fall into Small Craft Advisory criteria. 


&& 


Lwx watches/warnings/advisories... 
District of Columbia...none. 
Maryland...none. 
Virginia...none. 
WV...none. 
Marine...Small Craft Advisory until 6 am EDT Tuesday for anz530>537. 


&& 


$$ 
Synopsis...peloquin 
near term...sar 
short term...sar 
long term...peloquin 
aviation...sar/peloquin 
marine...sar/peloquin