285 
fxus61 kakq 030757 
afdakq 


Area forecast discussion 
National Weather Service Wakefield Virginia 
257 am EST Wednesday Dec 3 2008 


Synopsis... 
high pressure passes across the region today...then moves offshore 
tonight and Thursday morning. The next cold front crosses the area 
Thursday afternoon and evening...with high pressure building back 
over the middle Atlantic region Friday into the weekend. 


&& 


Near term /through today/... 
pesky cloudiness (cigs around 5kft) gradually dcrsg over the lower Maryland eastern shr 
at this time. Otherwise...a cold start to today (wdsprd temperatures in the 20s...to 
m30s). Deep layered dry air mass (as indctd by satellite and model tsxns) west/ low level 
flow turning mr south-southwest by midday/afternoon hours. Today is 1st day of warming 
trend...W/ 850 mb temperatures rising above 0 degrees...to average +4 degrees c by lt 
afternoon hours. Hi temperatures expeceted to be from the u40s to l50s. 


&& 


Short term /tonight through Friday/... 
hi pressure slides offshr tonight through Thursday morning. Low level flow gradually incrss 
from the SW. Cirrus from the west reaches the region...but xpctg mainly sky clear 
overnight. Warmest day of the weak Thursday...W/ SW winds avgg 10-20 
miles per hour...mixed layer to about 875-900mb...and ptntl for near 20-25 knots (fm 
that lvl) to reach surface in the afternoon hours. Cold front approaches from the 
northwest...have gone west/ gradual increases in cloudiness from northwest to southeast throughout forecast area into the 
afternoon/evening hours. Sufficient low level dry layer and weakening mlvl forcing 
prevent going west/ probability of precipitation any higher than 20%. Cloudiness to be slow to decreases 
across southeast sections of forecast area Thursday night/early Friday. Much colder Friday behind the fnt 
after period of moderate low level cold air advection. 850 mb temperatures fall to -2 to -4 degrees during Friday. 


Low temperatures in the 30s (ery low in the u20s expeceted in vicinity of sby)...then 
rdgs rise into the 50s to l60s during Thursday. Low temperatures in the 30s to 
around 40 Thursday night...then hi temperatures only in the l/m40s Friday. 


&& 


Long term /Friday night through Tuesday/... 
sharping of trough aloft through the Midwest Friday night...then to the 
east CST lt Sat into sun...leads to period of incrsd cloudiness. Models hvg 
trouble west/ any surface coastal low pressure development Sat night/early sun in vicinity of 
mdatlc CST. The combination of the jet maximum/h70-50 trough for continued 
mention of a slght chance of -ra and/or flurries Sat night...and possible 
rw/SW...especially NE 1/3rd of forecast area...on sun. As northwest flow develops on sun behind 
departing trough aloft/any surface low pressure...another decent punch of 
cold...Canadian air expeceted by late sun as temperatures at night spill into 
the upper teens/20s inland...near 30 immediate coast. More of a 
westerly flow aloft develops allows for a moderation in temperatures into 
the middle week. Another system prognosticated to move towards the region (tue 
night- wed). 


&& 


Aviation /08z Wednesday through Sunday/... 
VFR conditions to continue through at least the next 24 hours. West winds 
will become SW this afternoon and then S this evening around an area 
of high pressure that will move off the North Carolina coast later today. 


A cold front will approach the region during the day Thursday...then 
move through Thursday night into early Friday. Winds will increase as the 
front moves closer on Thursday...with gusts to around 20 knots likely at 
all terminals. Moisture with the front looks scarce and precipitation is 
only expected to be very light...in the form of sprinkles/light rain 
or virga. NAM and GFS bufr soundings continue to forecast a period of 
MVFR ceilings during frontal passage. High pressure will then build back in on Friday 
through Sat...with the next frontal system approaching by sun. 


&& 


Marine... 
high pressure will move over the coastal waters today...then to the 
east tonight as a cold front approaches from the northwest. S/SW winds will 
increase beginning late this evening as the gradient between the 
high offshore of the mid-Atlantic...and low pressure located over 
interior southern Ontario/Quebec tightens. Raised Small Craft Advisory flags over ches Bay 
late this evening as gusts to 20 knots are expected...with Small Craft Advisory conds 
beginning over the coastal waters from Fenwick Island Delaware S to Cape 
Charles Light Virginia...and for the Currituck Sound early Thursday am through 
Thursday afternoon. 


Will then have a brief lull in headlines Thursday evening/night...although 
models forecast increasing northwest winds/seas behind the cold front by early 
Friday. Winds then decrease late Friday into Sat as high pressure 
stretches across the area from the SW. Winds/seas will ramp up again 
on sun as the next frontal system approaches from the northwest. 


&& 


Akq watches/warnings/advisories... 
Maryland...none. 
NC...none. 
Virginia...none. 
Marine...Small Craft Advisory from 10 PM this evening to 6 PM EST 
Thursday for anz630>632. 
Small Craft Advisory from 10 am to 6 PM EST Thursday for 
anz633. 
Small Craft Advisory from 7 am to 6 PM EST Thursday for anz650- 
652-654. 


&& 


$$ 
Synopsis...alb 
near term...alb 
short term...alb 
long term...alb/ccw 
aviation...jrl 
marine...jrl