745 
fxus61 kakq 180824 
afdakq 


Area forecast discussion 
National Weather Service Wakefield Virginia 
424 am EDT Thursday Mar 18 2010 


Synopsis... 
weak low pressure will track off the coastal Carolinas today and 
tonight...as high pressure remains to our north. The low moves 
well off the coast on Friday...as high pressure becomes centered 
over the Carolinas. Dry and warm weather will prevail Friday and 
Saturday. A cold front will push through the region late Sunday 
into Monday. 


&& 


Near term /until 6 PM this evening/... 
currently...surface low pressure is deepening off the SC coast...with 
middle/upper level system centered over SC/southeast Georgia. Plenty of middle to high 
level moisture has made its way northward into akq County Warning Area...and have bumped 
up sky cover this morning to mostly cloudy for much of southern Virginia and NE 
NC. Bufr soundings show a deep layer of dry air below 650-700 mb...so 
msbl precipitation looks unlikely (radar looks more impressive than 
reality). Will need to watch for a few sprinkles or -shra in NE 
NC...but have kept forecast dry for now. These clouds combining west/ a 
strengthening NE low level flow off the cold Atlantic waters will keep 
temperatures cooler over southeast Virginia/NE NC...highs only in the upper 50s NC Outer 
Banks...and Lower/Middle 60s over much of interior NE NC. Farther north and 
west...where skies should show a trend for decrsg cloudiness later 
today...highs should be able to reach into the upper 60s to lower 70s 
(most sunshine will occur over northern sections). 


&& 


Short term /6 PM this evening through Saturday/... 
low pressure tracks slowly NE in vicinity of Gulf Stream tonight...model trends 
look a bit slower...so expect the clouds/moisture to linger over southeast 
zones Thursday night/Erly Friday am. Have bumped up cloud cover and min temperatures 
over southeast Virginia/NE NC for Thursday night. Otherwise...surface hi pressure will build in 
from the SW on Friday...and all areas (even southeast zones) should become 
sunny by middle morning hours Friday. High temperatures Friday a touch warmer than 
today...along/W of I-95 will gnly be in the lower 70s (w/ a few 
areas flirting west/ middle 70s?). still cooler over southeast Virginia/NE NC and the 
Eastern Shore...gnly in the middle/upper 60s. 


Sat...surface high becomes centered off the southeast coast as upper ridging 
aligns over the East Coast. We'll see a return flow from the south-southwest...W/ continued 
sunny to mostly sunny skies. Hi temperatures into the middle 70s xcptd for 
much of interior Virginia/NC (though 60s at the immediate cst). 


&& 


Long term /Saturday night through Wednesday/... 
being that Mar.Apr is the most changeable time of yr across the the 
region...decided to make a few changes to the Erly portion of the 
extended forecast. Slower trends in the models have continued...even 
the faster GFS solution suggests most if not all of Sunday daytime 
period will be dry...so have scaled back to only 20% probability of precipitation in the 
afternoon for eastern zones...and only 30% for most of the remainder of 
zones (and this is after 20z/late aftn). Raised temperatures sun a few 
degrees as well...most areas should get into the Lower/Middle 70s 
except along the immediate coast. 


Best chances for precipitation look to occur Sun night west/ the initial 
front (not expecting convective chances to be too high so have pulled 
thunder wording for now). With a more southerly and slower track 
to the upper system have now lingered 20-30% probability of precipitation over northern and eastern 
zones through all of Monday...(and if trends hold the probability of precipitation may 
need to be raised more for Monday/Monday evening). 


Extended period of high pressure/upper ridging then builds in behind the 
front...with downslope (w) flow aloft allowing for mainly dry weather 
Tue/Wed...and temperatures recovering to near/just above normal by 
midweek. Look for highs generally in the 50s and 60s Tuesday...recovering 
into the M/u60s to near 70 by Wednesday. Seasonable early morning lows generally 
in the 30s to near 40. 


&& 


Aviation /08z Thursday through Monday/... 
high/middle level cloudiness from southern stream systm have ovrsprd region past 
several hours. Radar loop indctg precipitation echoes as far north as central NC coast 
but air at lvr levels remains to dry for precipitation to reach grnd. So expect 
VFR cndtns to continue across forecast area this forecast prd with cloud deck at or above 12k 
feet. Kecg may actually see virga next 4-8 hours as low moves further NE. 


The next weather system now a bit slower...with any precipitation / lower cloud threat 
not expeceted until sun nite/Mon. 


&& 


Marine... 
high prs over the waters today will keep north-NE winds below 15 knots. Seas still 
at or above 5 feet out near 20 nm with nearshore seas coming down a bit...spclly 
over the northern coastal waters. 


Low prs moving NE along the Carolina coast will increases NE flow across 
southern waters beginning this afternoon and continuing through Friday. In order to provide 
a bit of wiggle room for the winds with the coastal systm...decided to 
change the Small Craft Advisory for hazardous seas back to just a regular Small Craft Advisory. Seas 
across northern coastal waters prognosticated to slowly fall below 5 feet this evening. Seas 
stay at or above 5 feet across southern waters through Friday due to nearly flow around departing 
low. 


Latest European model (ecmwf) continues to slow next weather systm. Cdfrt apprchs from the west 
late sun nite/Mon. Prefrontal S flow turning west-northwest behind the front 
Monday aftrn/Tue. 


&& 


Akq watches/warnings/advisories... 
Maryland...none. 
NC...none. 
Virginia...none. 
Marine...Small Craft Advisory until 2 am EDT Friday for anz652-654. 
Small Craft Advisory until 6 PM EDT Friday for anz656-658. 
Small Craft Advisory until 7 PM EDT this evening for anz650. 


&& 


$$ 
Synopsis...lkb 
near term...lkb 
short term...lkb 
long term...mam/lkb 
aviation...mpr 
marine...mpr