563 
fxus62 kcae 211144 
afdcae 
area forecast discussion 
National Weather Service Columbia SC 
644 am EST Sat Nov 21 2009 


Synopsis... 
high pressure over the region today will weaken tonight. Low 
pressure will move east along the Gulf Coast tonight and spread 
rain to the area Sunday and Sunday night. The low will begin to 
move away Monday and the chances of rain will decrease. High 
pressure will build in Monday night and Tuesday. 


&& 


Near term /until 6 PM this evening/... 
high pressure will move east and clouds will increase from the 
south as a low pressure area moves toward the region. Conditions 
will remain dry today. 


&& 


Short term /6 PM this evening through Monday/... 
an approaching low pressure area will spread clouds and rain over 
the region late tonight and Sunday. The rain will continue Sunday 
night. The low will move offshore and away Monday decrease the 
chances of rain. The rain should be gone late in the day Monday. 
Cool temperatures are expected with Sunday highs in the lower 50s 
and Monday highs in the lower 60s. Quantitative precipitation forecast amounts should be around 
one inch. 


&& 


Long term /Monday night through Friday/... 
in good agreement with long range models bringing long wave trough 
pattern back to the east. This should increase northwest wind flow 
at the surface as a couple of dry cold fronts sweep through the 
region. This will also give the area cooler temperatures. Highs in 
the middle 60s Tuesday and Wednesday cool to near 60 Thanksgiving 
day and black Friday. Overnight lows in the 40s start of period 
lower to the 30s by Friday morning. 


&& 


Aviation /12z Saturday through Thursday/... 


Plenty of middle/high level clouds continue to spread northeastward in advance 
of an approaching Gulf low this morning. This has inhibited much of 
the fog formation with most sites reporting VFR conditions. 


Although cloudiness will continue to gradually thicken and lower 
throughout the forecast period...expect VFR conditions to persist 
through 12z Sunday morning. Both NAM/GFS look to hold off any 
precipitation...especially across the csra until around/just after 12. For now 
will not mention any precipitation in forecasts. 




Extended aviation outlook...widespread MVFR or IFR conditions will 
likely occur late Sunday...Sunday night and into Monday. Conditions 
associated with an area of low pressure that is expected to move 
northeastward from the Gulf of Mexico through the early portion of 
the extended outlook. 


&& 


Cae watches/warnings/advisories... 
SC...none. 
Georgia...none. 


&& 


$$