Weather

466 
fxus62 krah 281852 
afdrah 


Area forecast discussion 
National Weather Service Raleigh NC 
250 PM EDT Thursday Aug 28 2008 


Synopsis... 
a surface trough coupled with a moist air mass will result in 
scattered showers and thunderstorms each afternoon through 
Sunday. 


&& 


Near term /through tonight/... 
as of 230 PM... 


Moist and moderately unstable air mass continues to reside over a 
large swath of central NC. Most of the scattered convection through 
1830z has occurred over the northern coastal plain. A weak upper 
level trough seen in water vapor imagery may provide enough lift to 
initiate additional convection farther west over the 
Piedmont...especially near a temperature discontinuity area that 
exists between rdu and gso. Main threat from convection will be from 
slow moving heavy downpours that may lead to localized flooding. 


While middle/upper levels of atmosphere have dried out significantly 
since last night. Air mass below 8000ft still very moist. Partial 
clearing this evening may lead to the development of widespread fog. 
Due to recent spat of heavy rain...potential for areas of dense fog 
to develop. Confidence not high enough to issue a dense fog advisory 
at this time but will mention areas of dense fog in forecast text. 
Min temperatures basically in the 65-70 degree range. 


&& 


Short term /Friday through Saturday night/... 
as of 240 am... 


Broad middle and upper level trough weakens for Friday and 
Saturday... but enough moisture persists to keep small rain 
chances in the forecast...mainly afternoons. Afternoon highs 
above normal at 85 to 90. Morning lows 65 to 70. 


&& 


Long term /Sunday through Wednesday/... 
as of 315 am Thursday... 


A lingering chance of showers mainly in the south Sunday... 
otherwise high pressure will build into the area Sunday bringing 
drier air in from the north... spreading south by Monday. Dry 
conditions should prevail through midweek. Highs will be in the middle 
to upper 80s. Lows will be in the 60s. 


&& 


Aviation /18z Thursday through Tuesday/... 
as of 150 PM Thursday... 


Low ceilings slowly lifting in the northwest Piedmont at 18z. Possibility 
that ceilings in the low IFR/LIFR category will persist for an 
extended period of time. Otherwise...a moist and moderately unstable 
air mass will interact with a nearly stationary surface boundary 
across central NC to trigger scattered convection. Most of the 
storms will occur along and east of I-95. With loss of 
heating...storms will gradually diminish. 


While the middle and upper levels of atmosphere have dried out 
sufficiently...plenty of low level moisture persist. Indications are 
that clouds may dissipate enough this evening to allow widespread 
fog to develop with the potential for large areas of dense fog. Have 
hit the fog pretty hard at most taf sites. The exception is The 
Triad where int and gso may see visibilities remain above a mile due 
to persistent stratus deck. 


Appears that fog and associated low stratus will lift and dissipate 
around 14z as drier air aloft mixes down toward surface. 


Will continue to see a chance of convection each afternoon Friday 
through Sunday as surface trough and marginally moist air mass 
lingers over the region. High pressure nosing south Monday should 
lead to an extended period of VFR conditions. 


&& 


Rah watches/warnings/advisories... 
none. 


&& 


$$ 
Synopsis...wss 
near term...wss 
short term... 
long term... 
aviation...wss