Special Weather Statement, NWS Charleston, SC

Area Forecast Discussion
National Weather Service Charleston SC
154 PM EDT WED JUL 20 2016

.SYNOPSIS...
A weakening cold front will slowly sag south through Thursday
before dissipating. Atlantic high pressure will gradually rebuild
through early next week while and inland trough prevails.

&&

.NEAR TERM /THROUGH TONIGHT/...
Rest of Today: A weak cold front is approaching from the north.
Surface maps have it located across central SC early this
afternoon. This front will continue to shift southward and weaken
over the next few hours. In the upper levels, a shortwave will
round the western half of a trough that is located off the New
England coast, extending downward and off the NC coast. This
shortwave will weaken as it passes north of our area over the next
few hours. The combination of these along with a developing sea
breeze will allow showers and thunderstorms to develop this
afternoon. SBCAPEs near 3,000 J/kg and PWATs near 1.75-2" suggest
there is plenty of energy and moisture for the storms to utilize.
Shear is not overly impressive and light low and mid level winds
suggest slow storm motions, which could lead to locally heavy
rainfall and the potential for localized flooding. With DCAPEs
near 1,000 J/kg, some severe storms with damaging wind gusts are
possible.

Tonight: Shower/thunderstorms coverage and intensity will diminish
in the evening with mainly dry conditions overnight as the weak
cold front pushes into and possibly through the area. Some fog
could develop, especially in areas that pick up rain and see
clouds clear out. Lows mainly in the mid 70s inland and closer to
80 at the coast.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
The massive upper ridge covering much of the country will expand
to the east Thursday through Saturday. By Friday this ridge will
effectively dominate the entire continental United States. The
best chance for rain is expected on Thursday as some residual
upper shortwave energy drops through the area and a weak surface
front drifts into our southern zones. Between the front, upper
vorticity, and the sea breeze, isolated to scattered showers and
thunderstorms are possible just about anywhere though southeast GA
late in the afternoon seems most favorable. Drier mid level air
will filter in from the north late in the day so little is
expected Thursday night.

Friday through Saturday, as the upper ridge strengthens,
temperatures will soar into the mid/upper 90s. We show pops less
than 15 percent on Friday since the subsidence and drier low-level
air look sufficient to quash most convection despite a modest sea
breeze. We included a slight chance of thunderstorms on Saturday,
mainly across southeast GA, where low-level moisture will begin to
recover during the afternoon. Heat indices both days could
approach 110F in some spots, though the prevalent values will be
105-109F.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
The upper ridge over the CONUS will break down on Sunday but
another ridge will build over the western Atlantic and extend to
the west. Ample low-level moisture and daily sea breezes will
support isolated to scattered afternoon/evening showers and
thunderstorms Sunday through Tuesday. Rain chances may be slightly
less on Wednesday as the upper ridge expands farther west. High
temps will mainly be in the middle to occasionally upper 90s.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
18Z TAFs: A cold front approaching from the north and the sea
breeze will generate showers and thunderstorms this afternoon and
early evening. We have VCTS for both KCHS and KSAV through early
this evening. Brief flight restrictions are possible resulting
from any TSRA that directly impacts either terminal. TEMPO groups
may need to be added in future TAF amendments, once storms start
to develop on radar. Convection will decrease late this evening.
However, MVFR is possible in low stratus and/or fog that may
develop late tonight and around daybreak. But model variations are
too high to include this in the current TAFs.

Extended Aviation Outlook: Brief flight restrictions are possible
with showers/thunderstorms each afternoon though chances are a bit
lower Friday and Saturday.

&&

.MARINE...
Today and Tonight...Winds will mainly be south to southwest 15
knots or less ahead of a weak backdoor cold front approaching from
the north today and then moving south into or even possibly
through the local waters tonight. After the frontal passage winds
will shift to the northwest and even north, especially across the
SC waters. Seas mainly 1-3 feet, highest toward the Gulf Stream.

Thursday through Monday: On Thursday, winds will briefly be
northeast to east behind a weak cold front before reverting to
southerly late in the day. Atlantic high pressure will gradually
rebuild late week into the weekend, persisting well into next
week. This will result in a typical summertime pattern over the
waters with occasional surges, primarily along the coast each
afternoon with the sea breeze and over the nearshore Atlantic
waters at night due to nocturnal jetting.

&&

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

&&

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...JRL
AVIATION...
MARINE...

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHARLESTON SC
345 AM EDT WED JUL 20 2016

AMZ330-350-352-354-374-GAZ087-088-099>101-114>119-137>141-SCZ040-
042>045-047>052-210900-
CHARLESTON HARBOR-
WATERS FROM SOUTH SANTEE RIVER TO EDISTO BEACH SC OUT 20 NM-
WATERS FROM EDISTO BEACH SC TO SAVANNAH GA OUT 20 NM-
WATERS FROM SAVANNAH GA TO ALTAMAHA SOUND GA OUT 20 NM...INCLUDING
GRAYS REEF NATIONAL MARINE SANCTUARY-
WATERS FROM SAVANNAH GA TO ALTAMAHA SOUND GA EXTENDING FROM 20 TO
60 NM-JENKINS-SCREVEN-CANDLER-BULLOCH-EFFINGHAM-TATTNALL-EVANS-
INLAND BRYAN-COASTAL BRYAN-INLAND CHATHAM-COASTAL CHATHAM-LONG-
INLAND LIBERTY-COASTAL LIBERTY-INLAND MCINTOSH-COASTAL MCINTOSH-
ALLENDALE-HAMPTON-INLAND COLLETON-DORCHESTER-INLAND BERKELEY-
INLAND JASPER-BEAUFORT-COASTAL COLLETON-CHARLESTON-COASTAL JASPER-
TIDAL BERKELEY-
345 AM EDT WED JUL 20 2016

THIS HAZARDOUS WEATHER OUTLOOK IS FOR ATLANTIC COASTAL
WATERS...SOUTHEAST GEORGIA AND SOUTHEAST SOUTH CAROLINA.

.DAY ONE...TODAY AND TONIGHT.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY.

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ASSISTANCE IS NOT ANTICIPATED AT THIS TIME.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE CHARLESTON SC
217 PM EDT WED JUL 20 2016

SCZ040-201900-
ALLENDALE SC-
217 PM EDT WED JUL 20 2016

...STRONG THUNDERSTORMS WILL IMPACT PORTIONS OF ALLENDALE COUNTY
UNTIL 300 PM EDT...

AT 217 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM NEAR SEIGLING...OR 7 MILES NORTH OF ALLENDALE...
MOVING SOUTHWEST AT 10 MPH.

  HAZARD...STRONG WINDS 45 TO 55 MPH AND UP TO PENNY SIZED HAIL.

  IMPACT...EXPECT MINOR DAMAGE TO TREE LIMBS AND BLOWING AROUND OF
           LIGHT...UNSECURED OBJECTS. MINOR HAIL DAMAGE TO PLANTS...
           TREES AND CROPS IS POSSIBLE. DAMAGE TO WINDSHIELDS IS
           UNLIKELY.

SOME LOCATIONS IN THE PATH OF THIS STORM INCLUDE...
ALLENDALE...FAIRFAX...SYCAMORE...ULMER...SEIGLING...MARTIN...MILLETT
AND BARTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REPORT DAMAGE DIRECTLY TO THE CHARLESTON NATIONAL WEATHER SERVICE AT
1-888-383-2024 WHEN IT IS SAFE TO DO SO. YOU CAN ALSO EMAIL YOUR
REPORT TO NWS.CHARLESTONSC@NOAA.GOV.

&&

LAT...LON 3311 8137 3311 8122 3304 8115 3278 8142
      3284 8142 3285 8146 3287 8145 3288 8148
      3290 8147 3296 8151 3301 8149 3306 8156
      3305 8157 3310 8161 3316 8154
TIME...MOT...LOC 1817Z 059DEG 7KT 3311 8133