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Area forecast discussion 
National Weather Service Greenville-Spartanburg SC 
124 PM EDT Friday Mar 19 2010 


Synopsis... 
weak but warmer high pressure will remain over our region through 
Saturday...before moving off the Carolina coast. A cold front is 
expected to cross the western Carolinas and northeast Georgia from 
the west late Sunday with an upper level low passing over on Monday. 
High pressure will again be the main influence from Tuesday through 
Thursday. 


&& 


Near term /through tonight/... 
as of 11 am...gorgeous day with sunny skies and above normal temperatures. 
Tweaked hourly T/TD/wind grids to reflect trends in observation. Bumped maximum 
temperatures up per 12z mav (based on 12z ffc/gso low level thicknesses)... 
resulting in highs in the upper 60s mountain valleys to middle 70s along I-85 
corridor. 


Previous discussion... 
deep layered ridging and dry air to develop and linger atop the 
region today providing sunshine and warm temperatures...about 
2 or 3 categories above climatology. Upper ridge axis prognosticated to 
translate to the coast by 12 UTC Saturday...but any moisture 
developing within the return flow expected to remain west 
of the County warning forecast area. Good radiational cooling conds to result in a 
30 degree f diurnal range for Saturday morning mins. 


&& 


Short term /Saturday through Monday/... 
as of 345 am Friday...fair and warm weather will continue on 
Saturday. High clouds will begin to increase during the afternoon. 
However...highs will be around 10 degrees above normal. 


Latest models show some slowing of the movement of the next system 
across the area. Have used a model blend with timing which does 
capture the slower timing. The upper low that approaches the region 
on Sunday is fairly compact. It/S a strong feature...just not very 
broad. This limits the extent of the moisture transport out of the 
Gulf. Dry air will also work around the low from the southwest 
Sunday evening. While there will still be a good frontal band out 
ahead of the low...these limiting factors will hold down on the 
amount of precipitation that falls across the region. Most places will 
certainly measure with this event...but the only place that looks to 
even approach an inch of rain will be over the southern NC mountains where 
several hours of upslope flow will enhance rainfall amounts. 
However...with the slower movement...only chance pop will be needed 
east of I-26. 


The frontal band will push slowly through the region Sunday night. All 
areas see likely pop during the evening...with chance pop west of I-26 
after midnight. Models show some weak instability and strong shear 
with the front. Although widespread severe storms are unlikely...will 
have to watch this system closely as isolated severe could develop. 
Models all show the upper low farther south...bringing a cold pool 
right across the County warning forecast area late Sun night through Monday. There will be some 
lingering chance pop across the I-77 corridor Monday morning...then dry 
Monday afternoon. Chance pop lingers across the mountains through the day. Even 
with the cold pool moving across the area...it looks like any snow 
accums will be limited to the northern mountains and above 3500 feet elsewhere. 


&& 


Long term /Monday night through Thursday/... 
as of 400 am Friday...the upper low moves across the area Monday night 
then east Tuesday. Some precipitation may spill out of the mountains across NC Monday 
night...with chance pop near the Tennessee border. Precipitation tapers off across the 
mountains Tuesday afternoon. Temperatures remain cold enough for snow at the higher 
elevations and possibly mixing in near daybreak in the valleys. 
However...any accums will still be limited to the northern mountains and 
higher elevations. Temperatures look to be slightly warmer outside of the 
mountains Monday night with clouds lingering and winds high enough to keep 
things slightly mixed. Have removed frost wording. Highs Tuesday near to 
slightly above normal. 


Ridging surface and aloft move over Wednesday bringing dry weather and above 
normal temperatures. Zonal flow allows the next system to approach from the 
west Thursday. Models have slowed this system as well...therefore have kept 
pop limited to slight chance. Temperatures drop a few degrees...but remain 
above normal. 


&& 


Aviation /18z Friday through Wednesday/... 
at kclt...VFR with no restrictions next 24 hours. Light northwest winds 
still expected to shift to SW around 21z and remain light. 


Elsewhere...winds less than 8 kts and mostly clear conditions 
expected through the period. 


Outlook...VFR is expected through Saturday night. A cold front will 
bring restrictions with a line of showers and thunderstorms Sunday 
into Sunday night. Lingering rain/snow showers in the mountains and gusty 
southwesterly/westerly winds over the Piedmont expected on Monday. 


&& 


Gsp watches/warnings/advisories... 
Georgia...none. 
NC...none. 
SC...none. 


&& 


$$ 
Synopsis...rwh 
near term...Ark/csh 
short term...rwh 
long term...rwh 
aviation...Arkansas