804 
fxus62 kmhx 231521 
afdmhx 


Area forecast discussion 
National Weather Service Newport/Morehead City NC 
1013 am EST Monday Nov 23 2009 


Synopsis... 
low pressure will move NE near or just offshore the Outer Banks today...then 
lift north of the area tonight. High pressure will build over the area Tuesday 
and Wednesday. A cold front will approach from the west Wednesday night and move 
across the area later Thursday. Low pressure will develop along the front 
offshore of the coast Thursday night and deepen as it lifts north Friday. 
High pressure builds into the area next weekend. 


&& 


Near term /until 6 PM this evening/... 
as of 10 am Monday...low pressure to the S will lift north/NE and is 
expected to move near or just offshore the obx later today. 
Deeper moisture and best lift have shifted to the north and east however 
with the low expected to move up the coast still expect chance to 
likely probability of precipitation most of the day. Most of the County Warning Area is currently in a 
precipitation void though so have backed off on probability of precipitation in the very near 
term...then think more precipitation will be possible later this afternoon as 
convergence increases north of surface low...and 850waa over 
shallow/cooler NE surface flow continues inland especially northern counties. Both 
NAM/GFS show some weak instability spreading through the Outer Banks 
and adjacent waters later today ahead of low so continued isolated thunderstorms and rain for 
imd CST today. Temperatures tricky as depends on how far inland southeast to S 
winds develop with low track along the CST. Inland areas will keep 
NE winds and shld stay in the upper 50s to lower 60s. Along the 
central and southern Outer Banks appears 65 to 70 will rule. 


&& 


Short term /6 PM this evening through Wednesday/... 
as of 145 am Monday...appears bulk of the measurable rain will be 
lifting NE of region by around 00z this evening. Low levels will 
remain saturated so maintained previous forecast of areas of drizzle/fog 
overnight. Kept some drizzle into Tuesday morning per saturated low 
levels...later shifts may have to extend drizzle out into Tuesday night. 
Went closer to NAM for temperatures as expect overcast skies with moisture 
trapped below inversion...highs mainly 55 to 60. Dont see many 
break in clouds through Wednesday as low clouds will linger into at least 
first part of Wednesday then expect more middle level clouds later Wednesday with 
upper trf approaching from the west. Added slight pop imd CST late Wednesday 
afternoon per models showing some light quantitative precipitation forecast. With clouds think highs Wednesday 
will be mainly in the lower 60s. 


&& 


Long term /Wednesday night through Sunday/... 
as of 230 PM Sunday...a solution closer to the operational European model (ecmwf) 
continues to be preferred for the system to affect the area on 
Thanksgiving. A southern stream surface low should pass close enough to 
the coast to provide the area with decent precipitation chances (esp near the 
coast) later Wednesday night and through Thanksgiving. This system should 
move out fairly quickly as a strong northern stream short wave 
follows closely on its heels Thursday night. Development of a deep East 
Coast trough signals dry and cool weather going into next weekend. 


&& 


Aviation /15z Monday through Friday/... 
as of 10 am Monday...consensus of all the aviation guidance is 
for primarily LIFR/IFR conditions through Tuesday and possibly into 
Wednesday. The majority of the drizzle/-ra will hug interior 
portions until later this afternoon as the low offshore moves east. The 
rain and low clouds will then spread more east. IFR conditions will 
remain as low level remain saturated in north/NE flow...mainly in 
clouds. At times ceilings may rise to MVFR but but will forecast 
primarily IFR through the period. By Wednesday another coastal low will 
develop and showers will move back into the region late and into 
Thursday...followed by a strong cold front Friday. 


&& 


Marine... 
as of 1015 am Monday...will continue advisories for the southern 
waters through 21z as wave watch is running low vs observed 
conditions. The Swan holds on to 6 feet seas south of Ocracoke Inlet 
through this afternoon. The models are poorly initialized with the 
weak low currently off the coast. The NAM/GFS are too fast and north 
with this system...so have adjusted forecast based primarily on the RUC. 
This solution keeps the winds NE with the exception of Hatteras 
south briefly. Speeds are also weaker than model guidance...so have 
dropped scec for sounds. The seas however across all coastal waters 
continue to hover around the 6 feet mark so will keep Small Craft Advisory going though 
not with 20-25kt winds. The latest Swan model run builds seas back 
to 6+ feet Tuesday afternoon/Tuesday night but would like to see 
another model run before buying into this so will keep conditions 
below advisory levels as forecast Tuesday. 


Developing low pressure will track NE along or just inland from 
the NC coast today...then move NE of the waters tonight. High 
pressure will build over the waters Tuesday into Wednesday. The 
GFS appears too fast moving the low through the area so will use 
the NAM-12 which briefly turns winds around to the south today. 
Looks like winds speeds peaked Sunday evening with all of the wind 
guidance forecasting winds 20 knots or less through Thursday. Another 
low is forecast to develop off the NC coast Wednesday night and 
and Thursday as a strong cold front moves through the area. Strong Small Craft Advisory 
conditions are certain to develop behind the front Thursday night 
and Friday as very cold air pours into the region. The forecast 
for Tuesday night through Wednesday night will have conditions 
below advisory levels but as noted above the latest wave guidance 
is indicating that seas may reach 6 feet. 


&& 


Mhx watches/warnings/advisories... 
NC...none. 
Marine...Small Craft Advisory until 4 am EST Tuesday for amz150-152-154. 
Small Craft Advisory until 4 PM EST this afternoon for amz156- 
158. 


&& 


$$ 
Synopsis...rf 
near term...rf/mw 
short term...rf 
long term...btc 
aviation...jme/sj 
marine...jme/sj 

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