911 
fxus61 klwx 230854 
afdlwx 


Area forecast discussion 
National Weather Service Baltimore Maryland/Washington District of Columbia 
354 am EST sun Nov 23 2008 


Synopsis... 
high pressure over the middle Atlantic today will move off the East 
Coast tonight. A cold front will move across the area Monday night. 
Upper level low pressure will remain over the northeast portion of 
the United States through the week...as high pressure at the 
surface gradually builds into the region toward the end of the 
week. 


&& 


Near term /until 6 PM this evening/... 
high pressure at the surface covers the County Warning Area early this 
morning...although the high has been dirtied up due to middle to high 
clouds moving through in west to northwest flow aloft. Clouds may be 
preventing the temperatures from dropping as low as they otherwise 
would...but its still cold out there. Early morning minimums will be 
in the 20s...even some teens west of the Blue Ridge. 


Based on infrared satellite imagery...will contend with some middle to 
high clouds to start this morning...but models indicate less cloud 
cover later this morning into this afternoon before clouds roll back 
in tonight. 


High pressure drifts off the Bay late in the day...so the surface 
wind from the west will swing around to the southwest and then south 
by days end. The Arctic air mass will have modified some...so high 
temperatures will be a little warmer than yesterday yet still below 
normal. The air wont have as much as a bite either with less wind 
than yesterday. 


&& 


Short term /6 PM this evening through 6 am Monday/... 
warm advection starts up tonight. This will support increasing 
clouds after midnight ahead of a trough over the Midwest. Despite 
the increase in clouds...theres one more cold night in store where 
most areas will have mins in the 20s...except perhaps in downtown 
DC/Baltimore. 


&& 


Long term /Monday through Saturday/... 
closed 500 mb low forecast over northwestern Ontario Monday morning will drop southeastward 
early in the week and help reinforce eastern US trough during the week. 
This system is expected to meander across the northern middle Atlantic through 
the end of the work week before weakening next weekend. At the 
surface...strong srly flow will bring primarily rain ahead of a strong 
cold front late Monday before it clears the area early Tuesday morning. Although 
rain is expected to be main precipitation type...point forecast soundings from 
the GFS/WRF-nmm12g and NAM models across Highland County and Skyline 
drive indicate a short period of freezing rain/ice pellets before surface temperatures warm 
all above freezing. Am confident that there will be no snow not at 
least until winds become wrly and front clears the area early Tuesday. 
Even if precipitation were to be other that rain any accumulation would 
be minimal. 


Lake enhanced snow showers will then pick up Tuesday and Wednesday as low-level 
winds strenghten. 00z GFS and European models now show another storm 
system impacting the area next Sat. They both indicate this to be a 
rain event too. 


&& 


Aviation /09z Sunday through Thursday/... 
high pressure moves across the middle Atlantic today...promoting winds 
to shift from the west to start today to the southwest or south 
later today and tonight. High clouds /20k feet/ will move across the 
terminals this morning and again after midnight tonight. 
Otherwise...visual flight rules through tonight. 


IFR conditions developing late Monday afternoon with MDT 
rain...then improving to VFR after rain exits the area after 06z 
Tuesday. Gusty west winds Tue-Wed. 


&& 


Marine... 
high pressure moves east of the Bay later today. This will mean a 
shift in wind from the west to the south. Gradient is weak this 
afternoon...but southerly flow will start to enhance winds up the 
Bay overnight into the 10 to 15 knots range. 


Small Craft Advisory conditions returning Monday afternoon and likely to 
persist into Wednesday. 


&& 


Lwx watches/warnings/advisories... 
District of Columbia...none. 
Maryland...none. 
Virginia...none. 
WV...none. 
Marine...Small Craft Advisory from 12 PM to 6 PM EST Monday for 
anz530>537. 


&& 


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