Weather

320 
fxus62 kilm 280552 
afdilm 


Area forecast discussion 
National Weather Service Wilmington NC 
152 am EDT Thursday Aug 28 2008 


Synopsis... 
a weak front will remain stalled across eastern North Carolina in 
the vicinity of Surf City overnight...and slowly drift northward out 
of the area through Friday as the remnant circulation of Fay 
moves north by northeastward across the Ohio River valley. A cold 
front will move southeast across the area Saturday 
night...followed by high pressure building from the north Sunday 
through Wednesday. 


&& 


Near term /until 6 am this morning/... 
as of 9 PM Wednesday...best dynamics and instability now north of 
the area. Per latest surface analysis...an east to west lying surface cold 
front is situated across or just north of the ilm County Warning Area. Best thunderstorm 
activity and better potential for severe weather lies north of the 
frontal boundary. Plenty of moisture lies across the area per latest 
precipitable water analysis at or just over 2 inches. Still just 
enough instability and weak impulse rotating aloft that is aiding 
convection firing back up across the SC portions of the ilm County Warning Area. 
This may continue up to or a few hours after midnight. Latest min 
temperatures will need to be increased by 2 to 4 degrees. Much of it based 
on last nites min temperature readings across the ilm County Warning Area. 


&& 


Short term /6 am this morning through Friday night/... 
as of 3 PM Wednesday...stationary frontal boundary is expected to 
be north of the County Warning Area Thursday...and become more diffuse through 
Friday. Drier air... mainly above 700 mb...will begin to wrap 
around Fay remnant low which will be lifting across the Ohio River 
valley during this time. With the infusion of drier air and the 
expectation that the frontal boundary will be north of the 
area...will carry only low chance probability of precipitation on Thursday. By Friday...a 
500 mb trough axis will drift overhead and may help to fire off an 
isolated shower or thunderstorm. 


Maximum temperatures should climb back towards climatology during the period. Prefer 
mav guidance over NAM for Thursday. Mav may be too warm for Friday 
and will blend with cooler Eta model/NAM MOS. Lows will bottom out in the 
lower 70s each night. 


&& 


Long term /Saturday through Wednesday/... 
as of 3 PM Wednesday...the overall forecast philosophy remains the 
same for the extended although the trends have changed a bit. The 
eastern Carolinas are expected to be on the east side of a 500mb 
ridge that will allow a cold front to move across the area from the 
north by Sunday morning. 


HPC had trended back on probability of precipitation associated with the front although the 
operational GFS still shows a decent area of Omega for Sunday 
afternoon through distributed up through about 400mb. Trimmed back 
probability of precipitation slightly to split the difference between HPC and the more 
bullish operational GFS. Followed the drying trend a little closer 
for Monday through Wednesday as time heights are very dry and even 
if the boundary is close enough to provide an impetus for 
convection...the coverage should be isolated. 


Regarding temperatures...things trended a degree or two warmer 
across the board so no big changes there. Still looks like Saturday 
will be the warmest day with readings slightly above climatology 
trending down slowly to near seasonal through the middle of next 
week. 


&& 


Aviation /06z Thursday through Monday/... 
low level of free convection and just enough instability allowing for isolated shower 
activity...but this action is unlikely to impact any of the 
terminals. Low clouds have scattered out enough to improve 
conditions to VFR but will it last? Model guidance hits the 
fog/stratus hardest at kflo...but believe that klbt will see a 
greater impact due to proximity to the boundary and antecedent 
precipitation. Will take both solidly into IFR for a couple hours around 
daybreak. 


Should be enough residual moisture Thursday morning for some sea 
breeze convection. Convection should fire fairly early...best 
chance 15-17z coastal terminals but lesser coverage means that 
vcsh/thunderstorms in the vicinity should cover it. 


Outlook Thursday evening through Monday...chance for fog/stratus 
Friday morning. Otherwise isolated thunderstorms through Sunday. 
High pressure builds in Monday. 


&& 


Marine... 
near term /through 6 am Thursday/... 
as of 9pm Wednesday...as the surface front makes its way northward like 
a snail...winds over the waters will slowly veer to the south and 
southwest. Remnants of Fay well inland and northwest of the area 
waters...has caused the surface pressure gradient to tighten. This has 
resulted in wind speeds increasing to 10 to 15 knots...the hiest thats 
occurred since last weekend. The southeast ground swell of the past 
several days has trended lower in overall height but nevertheless 
continues to be a local influence. This southeast swell will mix with this 
short period wind wave...and result in seas basically around 3 feet 
overnight into Thursday. 


Short term /Thursday through Friday night/... 
as of 3 PM Wednesday...surface winds are expected to be out of 
the south-southwest throughout the period as a weak surface trough 
lingers across the inland Carolinas. A weak pressure gradient will 
result in seas generally 1 to 3 feet. Chance of organized convection 
will be low...however widely scattered activity may development 
inland and drift off the coast during the afternoons. 


Long term /Saturday through Sunday/... 
as of 3 PM Wednesday...the big story will be the wind shift across 
the waters from south/southeast to east/northeast as high pressure 
builds on in the wake of the boundary. Low level winds through 850mb 
not that impressive...basically below 10 knots so the magnitudes 
should be of little concern. Any swell that may be generated by the 
development of invest al95 will still be well offshore...leaving 
wind waves on their own...with 2-4 feet throughout. 


&& 


Ilm watches/warnings/advisories... 
SC...none. 
NC...none. 
Marine...none. 


&& 


$$ 


Aviation...Ras/dl