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fxus61 kakq 301117 
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Area forecast discussion 
National Weather Service Wakefield Virginia 
717 am EDT Sat Aug 30 2008 


Synopsis... 
a front will approach the area from the west later today and move 
through by early Sunday morning. High pressure slowly builds down 
from the north throughout the day Sunday and remains north of the 
area through at least middle week. 


&& 


Near term /until 6 PM this evening/... 
fog and -dz the main story Erly this am and went ahead and added 
areas of dense fog with some places reduced to under a half mile. 
Have sent out a Nowcast since dense fog is not widespread enough to 
issue a dfa at this time. 


Weak surface low currently over the Eastern Shore will shift offshore 
this morning while a front mvs towards the area. With drier air over 
the area today compared to last several days (pw's are close to 1.5 
inches rather than 2 inches or more)...think that just low end 
chance probability of precipitation are sufficient for this aftn/evng. Especially since there 
really isn't any one feature prognosticated to move over the area today 
that would enhance convection. 


Enough breaks in the clouds throughout the day should allow temperatures to 
get up to if not a degree or two above what we saw yesterday...so 
went with highs in the middle to upper 80s with a few spots reaching the 
90 degree mark. 


&& 


Short term /6 PM this evening through Monday/... 
probability of precipitation will continue into the overnight hours as front mvs through the 
area. Moisture will again be the somewhat-limiting factor however 
so slight chance probability of precipitation north to low-end chance probability of precipitation south planned. 
Front should move off the coast by around sunrise on Sunday but 
models in good agreement with hanging dry air up in northern 
portions of our area throughout the day on Sunday as the high shifts 
into the New England states and stalls. Will continue 20% probability of precipitation north 
to 30% south until Sunday evening after which all probability of precipitation are dropped with 
ridge pushing further eastward and surface high becoming better 
established into the middle Atlantic region. 


High pressure just north of the area on Monday will keep things dry 
and slightly cooler with easterly flow. Highs in the middle to upper 80s 
except lower 80s near the coast. 


&& 


Long term /Monday night through Friday/... 
generally quiet weather expected during the extended period as high 
pressure surface/aloft prevails over area. GFS and European model (ecmwf) both in very 
good agreement through extended period with this scenario...and 
made mainly cosmetic changes to HPC guidance. Temperatures expected to 
be a couple degrees warmer Thursday and Friday...and have adjusted 
previous forecast closer to HPC guidance. Also lowered min temperatures 
Tuesday morning and Wednesday morning...as feel guidance too warm...given 
light winds and clear skies. Next significant weather concerns 
look to be after extended period...and will be dependent upon the 
long-term future of Gustav/Hanna. 


&& 


Aviation /11z Saturday through Wednesday/... 
many locations across the area currently affected by fog this 
morning. Ric/sby/kphf/kecg either currently blw mfvr...or 
expected to drop over the next few hours. All terminals will rise back 
to VFR late this morning. Scattered showers and thunderstorms will 
develop across the region this afternoon...hard to nail down timing of 
showers...but included a few cumulonimbus groups for later this afternoon in several 
of the tafs. 


A cold front will cross the region tonight...but it appears 
front will weak and slow so that fog may again be an issue tonight. 
As winds decouple early and very moist conds will continue with dew 
points in the upper 60s to around 70. 


Front is slow to drop south over NC on sun...so locations in southern 
Virginia/NC may see continued chances for showers sun/Sun night. High pressure 
builds back into the region for early next week...bringing a return 
to more quiet/VFR conds. 


&& 


Marine... 
waters appear to be fairly quiet...at least through the first half of 
this Holiday weekend. Models predicting the surge behind the cold 
front tonight to remain blw Small Craft Advisory criteria...but wouldn't be 
completely surprised if the Small Craft Advisory flag is raised for minimal gusts for 
a brief period Sun morning. (Do not feel particuraly confident in 
this at this time.) 


Otherwise...periods increase later on Sunday as distant southeast swell 
from Tropical Storm Hanna reaches our waters. A small craft advsy 
for 4 to 5 feet seas for later on sun/early Monday looks like a 
possibility. 


&& 


Akq watches/warnings/advisories... 
Maryland...none. 
NC...none. 
Virginia...none. 
Marine...none. 


&& 


$$ 
Synopsis...jym 
near term...ccw/jym 
short term...jym 
long term...worse 
aviation...smf 
marine...smf