336 
fxus62 kilm 220521 
afdilm 


Area forecast discussion 
National Weather Service Wilmington NC 
1221 am EST Sat Nov 22 2008 


Synopsis... 
Arctic high pressure will build across the area through the 
weekend bringing very dry and unseasonably cold temperatures. 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 /overnight/... 
as of 9 PM Friday...the daytime cumulus dissipated before sunset 
and clear skies should continue overnight. Low pressure bombing 
out a few hundred miles east of the Virginia Eastern Shore will 
keep northwest winds blowing all night. If it weren't for these 
surface winds at 5-12 miles per hour...we would have a night of widespread 
lows in the teens to deal with as 1000 feet temperatures fall to 26 
degrees f. With residual cold advection keeping temperature 
profiles reasonably steep and the wind continuing we are looking 
for lower 20s inland and middle 20s at the coast. This is unchanged 
from previous forecasts. 


&& 


Short term /Saturday through Sunday night/... 
as of 3 PM Friday...a modified Arctic airmass will settle across the 
area through the period. The coldest of air will be waning Sat 
morning as 800 mb temperatures recover from -8 to -12 at the start of the day 
to around zero during the afternoon. If we mix out to about 3 
kft...highs Sat afternoon despite bright sunshine will only manage 
lower to middle 40s. Another day of readings 10 to 12 degree below normal. 
Winds will be lighter on Sat than on Friday...and so for some it might 
feel a little more comfortable. Dewpoints will drop into the 10 to 
15 degree range Sat with perhaps briefly some single numbers owing to 
the very dry airmass. Minimum relative humidities near 25 percent 
are expected. A jet streak and accompanying short wave embedded in 
west-northwest flow will move across the area overnight Sat. Some middle and high 
clouds will invade the sky Sat evening. Column too dry to support 
anything other than perhaps virga. These clouds may serve to 
interrupt what will otherwise be an ideal night for radiational 
cooling. Will forecast coldest temperatures in areas where radiational 
cooling is known to maximize. 


Record lows for: November 23rd 


Ilm: 23 degree set in 1981 
cre: 24 degree set in 1949 
flo: 24 degree set in 1976 




Modified Arctic high pressure will crest overhead Sat night and sun 
and will not be so quick to move high pressure off the coast Sun 
night. Any morning cloudiness early sun will give way to sunny skies 
once again and will carry these clear skies through Sun night... 
delaying any increasing high clouds until after sunrise Monday. Airmass 
will continue to modify and so will continue to forecast 
temperatures approaching normal levels...but still falling 10 to 15 
degree shy of climatological normals...so still chilly for later Nov. 


&& 


Long term /Monday through Friday/... 
as of 3 PM Friday...the extended forecast will feature one chance 
for rain with the cold and dry pattern prevailing for the most part. 
A strong shortwave will ride the ridge late this weekend and tap 
into a bit of Gulf of Mexico moisture Monday and Tuesday. This will 
push a front into the area late Monday and early Tuesday. Models are 
in good agreement on the better lift/dynamics moving to the north as 
phasing of a couple of short waves occurs...establishing an East 
Coast trough for the remainder of the period. Will maintain the 
slight chance probability of precipitation for Monday and early Tuesday. 


The latest temperature guidance remains consistent with a brief 
warm-up Monday preceding the front with a return to cooler than 
average for Tuesday through the remainder of the forecast. 


&& 


Aviation /05z 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 9 PM Friday...cold advection continues tonight as gusty 
northwest winds spill out over the coastal waters. Gusts at The 
Frying Pan Shoals buoy have periodically read 35 knots all evening. 
Cooler water temperatures closer to the coast imply gusts are more 
in the 25-30 knots range within 20 miles of shore. No significant 
changes are needed for the overnight forecast...Small Craft Advisory 
conditions continue through around daybreak Saturday. 


Short term /Saturday through Sunday night/... 
as of 3 PM Friday...winds and seas will continue to abate during Sat 
and this trend will persist through the period as modified Arctic 
high pressure crests overhead. North-northwest winds will slowly veer to north 
during sun and may become light and variable late in day sun and Sun 
night. Conditions may be near exercise caution levels Sat 
morning...before falling well below such levels by Sat afternoon. 


Long term /Monday through Wednesday/... 
as of 3 PM Friday...the period begins with a decent southwest flow 
ahead of the front Monday although remaining below flag 
criteria...basically around 20 knots. Winds will veer quickly to 
northwest in the wake of the front Tuesday and Wednesday. Cold air 
advection does not appear to be as strong as the past couple of 
events and winds may very well remain just under small craft 
criteria...too early to tell at this point. A mostly offshore wind 
component will keep the higher seas well outside of 20 nautical 
miles as well. 


&& 


Ilm watches/warnings/advisories... 
SC...none. 
NC...none. 
Marine...Small Craft Advisory until 7 am EST this morning for amz250- 
252-254-256. 


&& 


$$ 


Synopsis...rek 
near term...Ras 
aviation...rek/dl