171 
fxus61 kphi 211931 
afdphi 


Area forecast discussion 
National Weather Service Mount Holly New Jersey 
331 PM EDT Thursday Aug 21 2008 


Synopsis... 
high pressure will remain off the East Coast tonight through the 
weekend. Low pressure will move across southern Canada late this 
weekend and cause a cold front to cross our area Monday. 


&& 


Near term /through tonight/... 
high pressure will remain off the East Coast tonight. Skies will 
generally be clear with temperatures slightly below normal for 
late August. Decided to go partly cloudy across the Delaware-Maryland-Virginia and 
southern New Jersey since moisture may begin to increase in the return 
flow and a gently upslope may create some cloudiness. 


&& 


Short term /Friday through Sunday/... 
fair weather will continue into the short term period as the 
surface high off the coast remains in control. Temperatures will 
generally be Cloe to normal with middle 80s by day and middle to upper 
60s by night. A gradual increase in humidity is expected as winds 
turn S to southeast. 


&& 


Long term /Sunday night through Thursday/... 
there are only two periods during the extended period when there 
are chances for rain across our forecast area. The first is on 
Monday when a trough advancing across Canada sends a cold front 
across our area. This trough/front set up look very much like the 
one we had earlier this week, when we had only scant rainfall 
across the area. It was mainly an exchange of humid air for dry 
air. 


The second chance for rain will happen at the end of the forecast 
period (thursday) when the tropical air mass and lingering 
remnants of Fay move northward across our area. Models this far 
out show greatly varying solutions, so chance probability of precipitation are in there 
for now. 


&& 


Aviation /18z Thursday through Tuesday/... 
clear/mostly clear skies and light winds are expected tonight into 
tomorrow. So in short, VFR conditions are forecast through the 
period(fri/18z). 


The only potential issue tonight discussed amongst ourselves and 
adjacent offices was stratus/fog. But as noted above, we just don't 
think it's going to happen. The onshore flow is quite light up 
through 800 mb. Besides being light, the trajectory is poor and the 
fetch is limited. Plus the weak cold air advection the region will 
experience tonight will preclude any big jump in moisture. So, we 
just don't see the dewpoint depressions closing up real tight 
overnight. 


Outlook... 
high pressure will remain in control of the weather for much of this 
week. The next cold front is expected early next week. 


&& 


Marine... 
no big changes to note over the past twelve hours. Models continue 
with the high pressure theme throughout the weekend. There will be a 
wind shift, from southeast to southwest through the forecast period 
as the high moves off the coast. But winds will remain on the 
lighter side. With the light winds, the seas are also expected to 
behave. Thus, no headlines were needed with this package. 


Later in the period, a cold front may approach from the west Sunday 
night into Monday. With the approach and subsequent frontal passage 
we could see a slight increase in winds and seas. But at this time, 
we still don't see Small Craft Advisory conditions. 


&& 


Phi watches/warnings/advisories... 
PA...none. 
New Jersey...none. 
Delaware...none. 
Maryland...none. 
Marine...none. 


&& 


$$ 
Synopsis...O'Hara 
near term...O'Hara 
short term...O'Hara 
long term...O'Hara 
aviation...kruzdlo 
marine...kruzdlo