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Area Forecast Discussion (AFD)

Issued by Charleston, SC (CHS)

                            
000
FXUS62 KCHS 230119
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
919 PM EDT Fri Mar 22 2019

.SYNOPSIS...
A dry cold front will drop through the region tonight. High
pressure will build over the region this weekend. Low pressure
is expected to move across the region on Monday night through
Tuesday night. High pressure will then rebuild. 

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
No major changes were made for the evening update. 

A dry cold front currently moving slowly south across North
Carolina will drop through the forecast area early Saturday.
Post-frontal cold air advection is forecast to be rather weak 
and mostly confined to 925 hPa and below. While the boundary
layer could decouple in a few inland areas after sunset, a weak
westerly flow will persist before shifting northwest to north
after FROPA. Lows will range from the lower 40s inland to the
to around 50 at the beaches and Downtown Charleston.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
Surface high pressure will build over the region on Saturday and 
will slide of the Carolina coast on Sunday. Saturday and Sunday, 
daytime temperatures will peak around 70 with morning lows in the 
40s. The center of low pressure will track rapidly east across the 
Ohio River Valley and mid Appalachians on Monday. A cold front 
associated with the low is expected to slide across the foothills 
and Piedmont of the Carolinas by Monday afternoon. Temperatures on 
Monday in advance of the front are forecast to warm into the upper 
70s with dewpoints in the mid to upper 50s. GFS CAPE values may 
surge to around 500 J/kg Monday afternoon and evening. I will keep a 
mention of SCHC for thunderstorms.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A series of shortwaves will move through the area Monday night 
through Tuesday night while a backdoor cold front slowly sinks 
south through the area. We currently have the highest rain 
chances on Tuesday as this coincides with the front dropping 
through the area and the strongest PVA aloft. Cool high pressure
will affect the area through Wednesday before weakening and 
shifting east, allowing for a warming trend late next week.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
VFR.

Extended Aviation Outlook: Flight restrictions possible Monday 
night through Tuesday night.

&&

.MARINE...
This Evening through Tonight: West winds should gradually turn west-
southwest this evening as dry high pressure extends over the waters. 
In general, winds should top out in the 15-20 kt range while seas 
are no higher than 3-4 ft. A dry cold front is then expected to 
approach from the northwest, then shift over the coastal waters 
after midnight. Winds are expected to remain elevated (15-20 kt) 
post fropa, but will likely turn northwest after midnight, then 
north across South Carolina waters approaching daybreak Saturday.

Extended Marine: High pressure will build over the marine zones on 
Saturday and will slide east on Sunday, yielding winds generally 
below 15 kts. Seas are expected to range between 1 to 3 ft. A cold 
front will approach the region on Monday, sliding across the region 
Monday night into Tuesday morning. In the wake of the front, gusty 
NE winds are expected across the marine zones. Small Craft Advisory 
conditions may begin on Tuesday and remain through Wednesday. High 
pressure is expected to build across the region on Thursday, 
resulting in decreasing winds. Seas on Thursday may remain at or 
above Small Craft Advisory criteria.

&&

.FIRE WEATHER...
Saturday through Sunday: Critical or near-critical relative 
humidity values are likely to persist.

&&

.EQUIPMENT...
The KCLX radar is inoperative. Parts are on order and repairs are 
expected to occur on Monday.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...None.

&&

$$