Weather

396 
fxus62 kmhx 281440 
afdmhx 


Area forecast discussion 
National Weather Service Newport/Morehead City NC 
1040 am EDT Thursday Aug 28 2008 


Synopsis... 
a front with tropical moisture will move slowly north across the 
region today as the remnants of Fay pass by to the northwest and 
dissipate. A lingering area of weak low pressure will remain 
across North Carolina Friday and Saturday and produce scattered 
afternoon and evening showers and thunderstorms. A cold front will 
cross the region Sunday. High pressure from the north will build 
over the state on Monday through Wednesday. 


&& 


Near term /until 6 PM this evening/... 
forecast on track so only minor tweaks this morning...mainly to bump 
up temperatures just a couple degrees and adjust sky cover mainly SW part 
with a bit of a drier slot moving over that area and temperatures already 
in the l80s. Moisture remains abundant with dewpoints in the 70s 
with southeast flow and weak boundary/remnants of Fay northwest of area. Best 
850mb moist Theta-E advection and deepest moisture is over NE half and 
expected to remain there through afternoon so have kept highest likely 
probability of precipitation there and good chance SW. With heating and tropical air mass over 
the area expect precipitation coverage to increase through the day much of 
area though. Additionally...will have upper support with WV imagery 
showing diffluent flow aloft over area between upper ridge axis just 
offshore and troughing inland. 


Vwp and model forecast soundings indicate impressive directional 
shear although the magnitude of the shear is weak. Nonetheless there 
has been rotation in cells early this morning and with a low local 
environment and increasing low level instability with heating 
there will be a small potential for brief tornadoes. Another concern 
will be local poor drainage/low lying area flooding with precipitable water values 
remaining around 2". Expecting rainfall amounts of around 1 inch 
in most locations with much higher local amounts. Will carry 
likely probability of precipitation into this evening. Forecast highs will follow the 
warmer MOS due to better southerly flow today. 




&& 


Short term /6 PM this evening through Saturday/... 
precipitation coverage should decrease after midnight but lingering 
boundary and still moist airmass warrants chance probability of precipitation late. 


A weakness in the height fields will remain across the middle 
Atlantic-southeast states through Saturday as the middle level center of Fay 
becomes an open wave over the eastern Great Lakes. At the surface 
a weak boundary will persist over the area with a chance of 
afternoon/evening showers and storms Friday and Saturday. Probability of precipitation 
will decrease from around 40 Friday to 20-30 on Saturday. Highs 
will be in the middle to upper 80s Friday and around 90 Saturday 
with more sunshine expected. 


&& 


Long term /Saturday night through Wednesday/... 
a very strong upper ridge is forecast to develop over the lower 
lakes late this weekend as blocky upper pattern develops. The 
resulting strong surface anticyclone over the NE states will push 
a front and deeper moisture well south of the area Saturday night 
or early Sunday. Will hang onto slight chance probability of precipitation through Sunday 
due to residual moisture and heating but then we can expect a 
prolonged period Monday through Wednesday with dry and warm 
conditions as high pressure dominates. 


&& 


Aviation /14z Thursday through Monday/... 
scattered rain showers with isolate thunderstorms and rain will be likely this afternoon with lingering Fay 
moisture still over the area. The rain showers complicated conditions 
overnight with periods of IFR followed by VFR as the showers moved 
in and out. For today the low clouds will lift late morning...but 
looking at MVFR conditions for at least late morning/middle day given 
additional shower activity this after. Can't rule out showers 
tonight...but coverage will be less than observed overnight. 


For the rest of the weekend...look for scattered thunderstorms and rain activity 
mainly in the after with predominant VFR conditions. 


&& 


Marine... 
winds have increased over northern waters with tighter pressure gradient 
(although some of current gustiness to around 25 knots is due to 
convective activity) and forecast on track. No change to Small Craft Advisory...winds and 
seas will be marginal Oregon Inlet to hat inlet but outer portions 
likely to see higher conditions. 


Rip currents... 
southeast swell around 11 seconds combined with light to moderate onshore 
flow and a high astronomical tide cycle will bring a high rip 
current risk to the beaches north of Hatteras and a moderate 
threat elsewhere. 


&& 


Mhx watches/warnings/advisories... 
NC...none. 
Marine...Small Craft Advisory until 8 PM EDT this evening for amz150- 
152-154. 


&& 


$$ 
Synopsis...jme 
near term...mcw 
short term...jme 
long term...jme 
aviation...sj/jbm 
marine...jbm