Area Forecast Discussion
Issued by NWS Charleston, SC

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000
FXUS62 KCHS 310448
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1248 AM EDT FRI JUL 31 2015

.SYNOPSIS...
A WEAK PRESSURE PATTERN WILL PERSIST TONIGHT. A WEAK COLD FRONT
WILL STALL OVER THE REGION FRIDAY INTO EARLY NEXT WEEK. ATLANTIC
HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION BY THE MIDDLE
OF NEXT WEEK. AN INLAND TROUGH WILL THEN DEVELOP BY LATE WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
A WEAK FRONT SITUATED TO THE NORTHWEST WILL PUSH TOWARD THE AREA
AND PROVIDE BROAD LOW LEVEL CONVERGENCE. THIS SHOULD BE SUFFICIENT
TO MAINTAIN A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE
FORECAST THROUGH THE OVERNIGHT HOURS FOR WHAT COULD BE CONTINUAL
NOCTURNAL DEVELOPMENT. COVERAGE AND INTENSITY IS EXPECTED TO BE
LIMITED THOUGH AND MAINLY CONFINED TO THE ADJACENT WATERS.
TEMPERATURES WILL BE SIMILAR TO LAST NIGHT...GENERALLY IN THE MID
TO UPPER 70S...WITH ISOLATED LOW 70S POSSIBLE WELL INLAND.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...A WEAK COLD FRONT NEAR INTERIOR PORTIONS OF SOUTHEAST SC/GA
WILL SHIFT NORTH AND WEST AS DAYTIME HEATING OCCURS AND THE SEA
BREEZE KICKS IN. EXPECT HIGHER THAN NORMAL RAIN CHANCES DUE TO THESE
FEATURES ALONG WITH PLENTIFUL MOISTURE CHARACTERIZED BY UNUSUALLY
HIGH PWAT VALUES NEAR 2.25 INCHES. SUCH HIGH MOISTURE LEVELS AND
LIGHT WIND FIELDS COULD LEAD TO LOCALLY HEAVY RAINFALL WITH THE
STRONGER STORMS. ALSO...SOME STORMS COULD PRODUCE WET MICROBURSTS
CAPABLE OF PRODUCING DAMAGING WINDS. HIGHS GENERALLY IN THE LOWER
90S BUT SOME MID 90S ARE POSSIBLE INLAND. SHOWERS AND
THUNDERSTORMS WILL DIMINISH FRIDAY NIGHT BUT POSSIBLY NOT
COMPLETELY AS THE WEAK FRONT/TROUGH LINGERS OVER THE AREA.

SATURDAY/SUNDAY...12Z/30 MODELS...ESPECIALLY THE GFS AND ECMWF...IN
A BIT BETTER AGREEMENT INDICATING TROUGHING/DEEPER MOISTURE
LINGERING...MAINLY SOUTH AND EAST PORTIONS. THUS SHOULD SEE HIGHER
THAN NORMAL RAIN COVERAGE...ESPECIALLY COASTAL SC/SOUTHEAST GA.
GIVEN THE UNCERTAINTY WE DID NOT MAKE MUCH CHANGE TO THIS PERIOD.
TEMPS NEAR TO SLIGHTLY ABOVE NORMAL.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE REMNANTS OF THE STATIONARY FRONT WILL GRADUALLY DISSIPATE EARLY
NEXT WEEK...AND THE BAND OF DEEPEST MOISTURE SHOULD PUSH JUST OFF
THE COAST. THEN...ATLANTIC HIGH PRESSURE IS EXPECTED TO EXPAND INTO
THE REGION THROUGH MIDWEEK. THUS...AFTERNOON/EVENING POPS REMAIN
SLIGHTLY ABOVE NORMAL MONDAY...THEN DIURNAL POPS DIMINISH TUESDAY
THROUGH THURSDAY. BY LATE WEEK...A TROUGH OF LOW PRESSURE COULD
DEVELOP INLAND...AND DEPENDING ON THE POSITION OF THE TROUGH A
SOMEWHAT MORE ACTIVE CONVECTIVE REGIME COULD DEVELOP. OTHERWISE...
THIS PATTERN SHOULD SUPPORT NORMAL TO ABOVE NORMAL TEMPERATURES.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE EXPECTED TO PREVAIL OUTSIDE OF CONVECTION THROUGH
06Z SATURDAY. SHOWERS AND THUNDERSTORMS BECOME LIKELY ACROSS THE
AREA THIS AFTERNOON AND HAVE MAINTAINED MENTIONS OF VCTS/CB IN
THE TAF/S AT THIS TIME. SOME OF SHOWERS AND STORMS COULD PRODUCE
LOCALLY HEAVY DOWNPOURS WHICH MAY BRIEFLY RESTRICT VSBYS LATER
TODAY IN THE COASTAL CORRIDOR.

EXTENDED AVIATION OUTLOOK...MOSTLY VFR. MAINLY AFTERNOON/EVENING
SHOWERS AND THUNDERSTORMS WILL IMPACT THE TERMS...ESPECIALLY THROUGH
THE WEEKEND.

&&

.MARINE...
OVERNIGHT...THE VERY QUIET PATTERN WILL CONTINUE AS THE OFFSHORE
LOW WEAKENS AND LIFTS OUT TO THE NORTHEAST THROUGH THE OVERNIGHT.
AS IT DOES AND THE INLAND FRONTAL ZONE PUSHES IN...PREVAILING LOW
LEVEL FLOW WILL BECOME MORE SOUTHWESTERLY WITH TIME. THERE WILL BE
MORE GRADIENT THAN WE HAVE SEEN IN PREVIOUS NIGHTS...AND SPEEDS
WILL BE SOLIDLY INTO THE 10-15 KT RANGE WITHIN 20 NM AND A SOLID
15 KT BEYOND IN THE EARLY MORNING HOURS. SEAS WILL CONTINUE TO BE
AROUND 2 FT WITHIN 20 NM AND UP TO 3 FT BEYOND. WE BUMPED POPS
UP INTO CHANCE RANGES IN THE MIDNIGHT UPDATE FOR THE COASTAL
WATERS PACKAGE.

FRIDAY THROUGH TUESDAY...AS A COLD FRONT APPROACHES THEN STALLS
OVER THE REGION...S/SW WINDS WILL PREVAIL MUCH OF THE TIME. THE
SEA BREEZE CIRCULATION WILL CAUSE WINDS TO BACK TO THE S/SE AND
INCREASE IN SPEED EACH AFTERNOON...AND NOCTURNAL SURGES OF
SOUTH/SOUTHWEST WINDS COULD OCCUR EACH NIGHT. THIS REGIME WILL BE
DISRUPTED BY THE LATE NIGHT/EARLY MORNING LAND BREEZE...WHEN
LIGHTEST WINDS/ BOUNDARIES COULD SUPPORT WATERSPOUTS...AND BY
THUNDERSTORMS WHICH WILL PERIODICALLY CROSS THE WATERS. OUTSIDE
THESE EXCEPTIONS... HIGHEST WINDS SHOULD REMAIN CAPPED AT 15-20
KNOTS...ALTHOUGH THE PROBABILITY FOR SMALL CRAFT ADVISORY GUSTS TO
25 KT WILL INCREASE DURING THE NIGHTTIME EARLY NEXT WEEK. SEAS
WILL REMAIN 2-4 FT MUCH OF THE TIME...ALTHOUGH PERIODS OF 4-5 FT
SEAS ARE POSSIBLE AT NIGHT ESPECIALLY LATE WEEKEND INTO EARLY NEXT
WEEK.

&&

.TIDES/COASTAL FLOODING...
ELEVATED HIGH TIDE LEVELS WILL CONTINUE FRIDAY THROUGH THE
UPCOMING WEEKEND THANKS TO THE UPCOMING PERIGEAN SPRING TIDE.
SHALLOW COASTAL FLOODING IS LIKELY INTO EARLY NEXT WEEK ESPECIALLY
DURING EACH EVENING HIGH TIDE. WILL CONTINUE TO HIGHLIGHT THE
SHALLOW COASTAL FLOOD THREAT WITHIN THE HAZARDOUS WEATHER OUTLOOK.
ALSO OF NOTE...THERE IS A CHANCE THAT HEAVY RAIN COULD COINCIDE
WITH THE ELEVATED HIGH TIDES. IF THIS OCCURS...MORE SERIOUS
LOCALIZED FLOODING COULD OCCUR...PARTICULARLY IN DOWNTOWN
CHARLESTON.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...RJB
LONG TERM...SPR
AVIATION...
MARINE...BSH
TIDES/COASTAL FLOODING...



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