192 
fxus62 kilm 220813 
afdilm 


Area forecast discussion 
National Weather Service Wilmington NC 
313 am EST Sat Nov 22 2008 


Synopsis... 
Arctic high pressure will settle over the southeast through the 
weekend with very dry and unseasonably cold conditions. The only chance 
for measurable rainfall will come Monday afternoon into Monday 
night as a cold front crosses the area. Dry high pressure will 
follow Tuesday through Friday...with temperatures remaining below 
normal. 


&& 


Near term /through tonight/... 
as of 3 am Saturday...strong northerly flow continues with 
modified Canadian high pressure to our west centered over southern 
Illinois. Deep 500 mb trough in process of swinging offshore this 
morning as high pressure moves steadily eastward. As it does...the 
present northerly gradient and attendant cold air advection will begin to weaken so 
that winds this afternoon and overnight will not be as strong as 
what we saw on Friday. High is expected to move overhead by Sunday 
morning with winds going calm after sunset. Normally this would lead 
to ideal radiating conditions...but Sunday morning a vigorous 500 mb 
shortwave and a slug of moisture up around 600 mb will combine to 
thicken cloud cover over the County Warning Area. If it was not for this damper to 
radiative cooling...we could see temperatures even lower than what 
we will experience this morning. Still...it will be quite cold...up 
to 20 degrees below normal...with temperatures ranging from the low 
20s inland to upper 20s at the beaches. Went with model consensus 
for mins as they were all in very good accord. For maximum temperatures today 
leaned towards the recently better performing and slightly warmer 
GFS/FWC which give US upper 40s about everywhere. This will be very 
similar to fridays maximum temperatures and fits in better with expected Hight 
rises County Warning Area wide this afternoon. 


&& 


Short term /Sunday through Monday night/... 
as of 3 am Saturday...Ridge settling overhead on Sunday with 1034 
mb surface high. Therefore expecting dry weather with light winds and 
temperatures modifying up to middle 50s most places. Atmosphere should 
decouple Sun night under clear skies and calm winds with temperatures 
reaching around freezing. 


Center of high shifts off shore on Monday with a return flow of 
warmer and moister air moving into local area. Should see an 
increase in clouds in a warmer southerly flow with a low level jet up to 30 to 
40 kts out of the SW. Expect a warm and breezy day with temperatures 
reaching into the 60s in a brief warm up. The best chance of pcp will 
come on Monday afternoon through Monday night ahead of the approaching cold 
front as pcp water values reach up near an inch. Moisture feed shuts 
off as winds shift around the the west and eventually northwest as front 
moves through some time Monday night into Tuesday morning. 


&& 


Long term /Tuesday through Friday/... 
as of 3 am Saturday...the long term period will be marked with 
several dry and cool days as high pressure builds in behind the cold 
front Tuesday through Friday. Pcp water values will remain less than a 
quarter of an inch through the extended. Local area will remain at 
the base of a longer wave trough at middle levels with flow maintaining 
a more west to northwest component through the period. A cold surge 
will knock temperatures back down below climatology Tuesday and will remain 
below normal through Friday. Latest guidance keeps 850 temperatures below 0 
c through early Friday. Overall expect maximum temperatures a good 5 degrees 
below normal reaching the middle to upper 50s most places with temperatures at 
night falling to within a few degrees of freezing. Pressure pattern 
becomes a little messier toward the end of the week with next 
possibility of any rain as we head into next weekend. 


&& 


Aviation /06z Saturday through Wednesday/... 
VFR. No changes to the previous set of tafs. Winds diminish a bit 
overnight with a moderate temperature inversion setting up. 
Continued northwest flow on Saturday. Winds will likely go 
variable toward the end of the forecast period as the center of 
high pressure moves overhead. 


Outlook through Wednesday...VFR. Possible showers Monday night as a 
weak cold front passes through. 


&& 


Marine... 
near term /through tonight/... 
as of 3 am Saturday...presently vigorous northerly flow will 
gradually weaken today and tonight as high pressure now centered 
over southern Illinois moves eastward over the waters. Did extend 
current Small Craft Advisory a few hours this morning mainly for 
winds. Buoy observation show seas have been on a downward trend and are now 
just barely within Small Craft Advisory criteria. Winds will go light by this 
afternoon with seas dropping below 3 feet overnight. 


Short term /Sunday through Monday night/... 
as of 3 am Saturday...gradient will weaken on Sunday as high 
pressure moves eastward settling over the southeast. Therefore winds 
will become very light and seas will decrease through Sunday 
remaining less than 2 feet through Monday morning. By Monday afternoon 
a return flow sets up as the center of the high shifts off shore. 
Winds will become on shore and increase out of the S-SW through the 
day in a tightened gradient flow as a cold front approaches. Winds 
should increase into the 20 to 25 knots range by evening ahead of cold 
front pushing seas up to just above small craft criteria mainly in 
the outer waters. Winds will continue to veer around to the west and 
eventually northwest with frontal passage some time Monday night into Tuesday 
morning. 


Long term /Tuesday through Wednesday/... 
as of 3 am Saturday...winds will continue to veer around to the west 
and eventually northwest with frontal passage heading into Tuesday morning. 
Winds will become off shore and decent cold surge behind front will 
hold seas up in the off shore waters through Tuesday morning. Seas 
will decrease through Tuesday in the near shore waters in an off 
shore flow. Seas will decrease into the 2 to 4 feet range by Tuesday 
afternoon and will decrease slightly more through middle week as high 
pressure ridges in. 




&& 


Ilm watches/warnings/advisories... 
SC...none. 
NC...none. 
Marine...Small Craft Advisory until 9 am EST this morning for amz250- 
252-254-256. 


&& 


$$ 
Synopsis...rgz 
near term...rek 
short term...rgz 
long term...rgz 
aviation...rek/dl 

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