Preview of NWS' New Version of Forecast
This preview is not operational and should not be used for support decisions.

Area Forecast Discussion (AFD)

Issued by Charleston, SC (CHS)

                            
000
FXUS62 KCHS 151940
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
340 PM EDT Sat Jun 15 2019

.SYNOPSIS...
Atlantic high pressure will prevail into next weekend. An
inland surface trough will develop early week and will persist
over the Southeast into next weekend. 

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
The mid-levels will consist of semi-zonal flow overhead. At the
surface, high pressure will move further offshore, allowing a
weak trough to form overhead or nearby our area. This will cause
clouds and dew points to gradually increase overnight. Though, dry
weather will prevail. With all of this factored in, lows will 
be a few degrees below normal, but much warmer than they were
last night.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Sunday through Tuesday: As high pressure consolidates offshore, our 
brief interlude of unusually dry/cool weather will transition to 
more typical heat and humidity, accompanied by greater chances for 
diurnal showers/thunderstorms. 

Sunday, after a cool start temperatures should recover into the 
upper 80s to lower 90s at most locations inland from the beaches. 
Onshore flow will push dewpoints into the lower 70s close to the 
coast/behind the sea breeze, but inland dewpoint should remain in 
the 60s. As the sea breeze pushes inland, guidance suggests that a 
few showers/thunderstorms will develop/dissipate, particularly 
across southeast Georgia. However, a persistent capping inversion 
around 700 mb suggests that coverage of convection should remain 
sparse, and potential for brief/pulse severe thunderstorms should 
remain low. 

Monday and Tuesday, dewpoints in the 70s will become more 
widespread, and PWAT values will increase into the 1.75 to 2 inch 
range. This environment will support greater coverage of convection, 
especially as the sea breeze pushes inland during the 
afternoon/evening hours. For now, maximum inland PoPs are capped at 
45 to 50 percent, but locally greater PoPs could eventually be 
required. Also, the potential for isolated/brief pulse severe 
thunderstorms with damaging wet microbursts will be greater as 
compared with the Thursday through Sunday time frame.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
A mid level short wave over the mountains Tuesday night is forecast 
to dampen and shift off the GA/SC coast late Wednesday. Faster flow 
aloft and a series of mid level short waves will shift over the 
southeast states Thursday and Friday. The end of the week should 
feature higher chances for showers and tstms. Dependent on the 
timing of a significant upper disturbance Thursday/Friday, we could 
see a potential for organized convection and perhaps a risk for 
severe weather at some point. We will need a bit more model 
consolidation before we begin to highlight a possible window with 
any certainty. The region may see a bit more upper ridging to start 
off next weekend. Temps each day will be above climo for the most 
part.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
18Z TAFs: VFR.

Extended Aviation Outlook: VFR through Wednesday. Brief flight 
restrictions are possible in afternoon showers/thunderstorms 
beginning early next week.

&&

.MARINE...
Tonight: High pressure shifting further offshore should allow a
weak trough to form overhead or nearby. Winds will be from the 
SE this evening, veering to the SSE or S by daybreak Sunday and 
easing. Seas will be 1-2 ft within 20 nm and 2-3 ft for the 
outer GA waters.

Sunday and beyond: South to southeast flow will generally remain 
light, mainly less than 15 knots, to end the weekend. Then, between 
high pressure centered offshore and a trough of low pressure 
developing inland, winds will veer to south/southwest and will 
increase in speed during the upcoming week. Winds of 15-20 knots 
will become more common, especially with the afternoon sea breeze 
near the coast and during periods of nocturnal surging, and gusts to 
25 knots cannot be ruled out, especially overnight around midweek. 
Seas of 1 to 3 ft through Tuesday will build to 3-5 ft mid to 
late week.

&&

.TIDES/COASTAL FLOODING...
With the upcoming full moon and onshore winds, minor coastal 
flooding is possible along parts of the southeast South Carolina
coast (mainly for downtown Charleston) with the high tide this 
evening and again Sunday evening.

&&

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

&&

$$
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
TIDES/COASTAL FLOODING...