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000
FXUS62 KCHS 050826
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
426 AM EDT THU MAY 5 2016

.SYNOPSIS...
HIGH PRESSURE WILL EXPAND INTO THE AREA LATE FRIDAY THEN SHIFT
SOUTH OF THE REGION OVER THE WEEKEND. ATLANTIC HIGH PRESSURE WILL
THEN PREVAIL THROUGH THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...A COLD FRONT APPROACHING FROM THE NORTHWEST
IS FORECASTED TO PASS THROUGH OUR REGION AROUND DAYBREAK. THIS
FRONT IS DRY...SO ONLY SOME CLOUDS ARE EXPECTED...BUT NO
PRECIPITATION.

TODAY...WEAK LOW PRESSURE OFF OF THE OUTER BANKS OF NORTH
CAROLINA WILL DRIFT TO THE NORTHEAST. MEANWHILE A LARGE TROUGH
WILL HOVER OVER THE EAST COAST WHILE AN UPPER LEVEL LOW MOVES
SOUTH...SETTLING OVER THE CAROLINAS BY LATE IN THE DAY. THE
NORTHERN THIRD OF OUR AREA WILL BE UNDER THE SOUTHERN PERIPHERY OF
THE UPPER LEVEL LOW. THERE WILL BE OCCASIONAL WEAK VORT LOBES THAT
ROTATE ACROSS OUR THE AREA...GENERATING DECENT FORCING. DESPITE
THE FORCING THERE IS LIMITED MOISTURE IN THE ATMOSPHERE...PWATS
ARE ONLY AROUND 0.6 INCHES. THIS WILL LIMIT CONVECTIVE POTENTIAL.
WE MAINTAINED SLIGHT CHANCE POPS FOR THE NORTHERN THIRD OF OUR
AREA...MAINLY FOR LIGHT SHOWERS. A STRAY THUNDERSTORM IS NOT OUT
OF THE THE QUESTION LATE THIS AFTERNOON. BUT IT WILL BE DIFFICULT
FOR ONE TO DEVELOP DUE TO THE LACK OF MOISTURE AND BECAUSE
INSTABILITY IS MEAGER. AS FOR TEMPERATURES...WESTERLY WINDS AT THE
SURFACE AND NORTHWESTERLY ALOFT WILL AID IN COLD AIR ADVECTION
ACROSS OUT AREA. THIS WILL LEAD TO MUCH COOLER THAN NORMAL
TEMPERATURES...TOPPING OUT IN THE LOWER TO MID 70S ACROSS MOST
AREAS. A LARGE PRESSURE GRADIENT WILL ALSO LEAD TO BREEZY
CONDITIONS THIS AFTERNOON WITH 15 TO 20 MPH SUSTAINED WINDS AND
GUSTS OF 25 TO 30 MPH POSSIBLE.

TONIGHT...THE PRESSURE GRADIENT WILL DECREASE...ALLOWING WINDS TO
EASE. BUT CONTINUED WEST/NORTHWEST FLOW AND MOSTLY CLEAR SKIES
WILL ALLOW TEMPERATURES TO SETTLE TO LEVELS THAT ARE STILL BELOW
NORMAL FOR THIS TIME OF YEAR. LOWS WILL BE CHILLY...IN THE UPPER
40S ACROSS THE INTERIOR AND THE LOWER 50S ALONG THE COAST.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
ON FRIDAY...THE DEEP AND COMPLEX UPPER TROUGH/CUT-OFF WILL PERSIST
BEFORE THE BASE OF THE TROUGH MOVES OFFSHORE ON FRIDAY NIGHT. ONLY
SCATTERED CLOUDS EARLY FRIDAY WILL EXPAND AND BECOME BROKEN ACROSS
THE REGION FRIDAY AFTERNOON AS DIURNAL HEATING IN THE BOUNDARY LAYER
RESULTS IN STEEP LOW LEVEL LAPSE RATES DESPITE SURFACE HIGHS ONLY
REACHING THE LOWER TO MID 70S. MID LEVELS WILL ALSO FEATURE COLD AIR
ALOFT WITH 500-700 MB LAPSE RATES NEAR -7.5C AND 500 MB TEMPS CLOSE
TO -23C. MODELS INDICATE QUITE A BIT OF QG FORCING ACROSS THE
CAROLINAS WITH DEEP CYCLONIC FLOW...HOWEVER A DISTINCT LACK OF
MOISTURE IS NOTED ACROSS OUR FORECAST AREA WITH SURFACE TEMP-DEW
POINT SPREADS OF 20F-30F PROGGED THROUGHOUT THE DAY. WE MAINTAINED
SLIGHT CHANCES OF SHOWERS ACROSS NORTHERN ZONES AND PERHAPS ISOLATED
LIGHT SHOWERS ELSEWHERE NORTH OF I-16 DURING THE AFTERNOON. THERE
COULD BE A FEW LOW-TOPPED TSTMS ACROSS NE SOUTH CAROLINA AND SMALL
HAIL MAY FALL GIVEN FREEZING LEVELS NEAR 6KT. WE INCLUDED A MENTION
OF TSTMS BORDERING THE SANTEE COOPER LAKES AND PEE DEE REGIONS.
SKIES WILL CLEAR FRIDAY NIGHT WITH COOL TEMPS FALLING TO THE LOWER
TO MID 50S BY DAYBREAK ON SATURDAY.

AS UPPER HEIGHTS BUILD ON SATURDAY AND SUNDAY WITH BOUNDARY LAYER
FLOW REMAINING OFFSHORE...A WARMING TREND IS IN STORE WITH AFTERNOON
TEMPS WARMING JUST ABOVE 80 DEGREES IN MANY AREAS ON SATURDAY WITH
PLENTY OF SUNSHINE. EVEN WARMER WEATHER IS ON TAP ON SUNDAY WITH
HIGHS AROUND 90 AND THE SEA BREEZE PINNED CLOSE TO THE BEACHES AND
BARRIER ISLANDS MAKING FOR A WARM AFTERNOON THERE AS WELL.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
MID LEVEL RIDGING EARLY NEXT WEEK WILL GRADUALLY BREAK DOWN THROUGH
MID WEEK. SURFACE HIGH PRES OVER THE ATLANTIC WILL BE THE DOMINANT
SYNOPTIC FEATURE FOR OUR REGION. TEMPS WILL REMAIN ABOVE CLIMO FOR
MUCH THE PERIOD. IT LOOKS LIKE WE WILL RETAIN A DECENT MID LEVEL CAP
ON MONDAY AND PROBABLY AGAIN ON TUESDAY. WE MAINTAINED SLIGHT CHANCES
FOR MAINLY DIURNAL SHOWERS AND TSTMS IN THE MID WEEK TIME FRAME.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
06Z TAFS...VFR THROUGH 06Z FRIDAY. BREEZY/GUSTY W/NW WINDS WILL
PREVAIL AFTER DAYBREAK AT BOTH TERMINALS WITH GUSTS IN THE MID 20
KT RANGE.

EXTENDED AVIATION OUTLOOK...VFR WILL PREVAIL.

&&

.MARINE...
TODAY...LOW END SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED TO
PERSIST THROUGH THE DAY AND INTO THE EVENING FOR AMZ352-354-374.
MODELS INDICATE THAT WINDS COULD BRIEFLY GUST TO LOW END SMALL
CRAFT LEVELS FOR AMZ350 AND THE CHARLESTON HARBOR. BUT CONFIDENCE
WAS NOT HIGH ENOUGH TO PUT THESE TWO ZONES UNDER ADVISORIES.
CONDITIONS WILL GRADUALLY IMPROVE TONIGHT AS THE GRADIENT
DECREASES...ALLOWING WINDS/SEAS TO TREND DOWNWARD.

WINDS AND SEAS WILL DIMINISH ON FRIDAY IN THE WAKE OF THE POTENT
OVERNIGHT SURGE. THERE WILL BE ANOTHER SURGE FRIDAY NIGHT AS THE
UPPER TROUGH MOVES OFF THE COAST BUT THIS SURGE WILL NOT BE AS
SIGNIFICANT WITH A PERIOD OF 15 KT WITH 20 KT GUSTS OVER OUTER
WATERS OVERNIGHT.

OVER THE WEEKEND...SURFACE HIGH PRES WILL BUILD SW TO SE OF THE
WATERS AND THIS WILL RESULT IN THE FLOW BACKING TO SW. THERE COULD
BE BREEZY CONDITIONS IN THE INTRA-COASTAL WATERS EACH AFTERNOON AS
THERMAL GRADIENTS STRENGTHEN THANKS TO WARMER LAND TEMPS EACH DAY
AND ROBUST DEEP MIXING PROFILES DURING MAX HEATING. OTHERWISE SEAS
WILL AVERAGE 2 TO 3 FT.

MONDAY AND TUESDAY...ATLC HIGH PRES WILL MAINTAIN A SOUTHERLY FLOW
MAINLY AT OR BELOW 15 KT WITH SEAS 2 TO 4 FT...HIGHEST OFFSHORE.

&&

.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER AT METTER GEORGIA OPERATING ON
A FREQUENCY OF 162.425 MHZ WILL BE OFF THE AIR UNTIL FURTHER
NOTICE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR AMZ352-354-374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 050446
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1246 AM EDT THU MAY 5 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA THIS MORNING. HIGH
PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST LATE WEEK
AND PREVAIL THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
NO MAJOR CHANGES WITH THE LATEST UPDATE.

A LARGE MID LEVEL TROUGH OF LOW PRESSURE WILL DIG SOUTH OVER THE
EASTERN CONUS OVERNIGHT WITH A LEADING SHORTWAVE MOVING THROUGH
NORTHERN FLORIDA AHEAD OF IT. THIS WILL HELP DEVELOP AN AREA OF
LOW PRESSURE OFF THE NC OUTER BANKS WITH A TRAILING COLD FRONT
PUSHING TOWARD THE SC/GA COAST NEAR DAYBREAK. DESPITE STRONG UPPER
FORCING FOR ASCENT LIMITED MOISTURE WILL PREVENT ANY RAINFALL. COLD
AIR ADVECTION AND A DECENT PRESSURE GRADIENT WILL KEEP A
WEST/NORTHWEST WIND AT LEAST 5-10 MPH FOR MOST AREAS ESPECIALLY AFTER
MIDNIGHT...WITH TEMPERATURES DROPPING INTO THE MID TO UPPER 50S /WARMEST
ALONG THE COAST/.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
A RATHER ANOMALOUS PATTERN WILL PERSIST THROUGH MUCH OF THE PERIOD
AS A DEEP UPPER LOW OVER THE CAROLINAS ON THURSDAY...GRADUALLY MOVES
NORTH INTO THE MID ATLANTIC STATES BY LATER FRIDAY AND SATURDAY.
THIS PATTERN WILL RESULT IN COOLER THAN NORMAL TEMPERATURES THURSDAY
AND FRIDAY AND THEN MODERATING BACK TOWARD NORMAL BY SATURDAY.
EXPECT HIGHS ONLY IN THE LOWER 70S THURSDAY...MID 70S FRIDAY THAN
AROUND 80 TO THE LOWER 80S SATURDAY. LOWS WILL BE CHILLY IN THE
UPPER 40S TO LOWER 50S BY FRIDAY MORNING...THEN MID 50S SATURDAY
MORNING.

NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE PERIOD.
HOWEVER...GIVEN THE NORTHERN PART OF THE AREA WILL BE CLOSEST TO THE
SOUTHERN PERIPHERY OF THE UPPER LOW...THERE WILL BE OCCASIONAL WEAK
VORT LOBES THAT ROTATE ACROSS MAINLY THE NORTHERN 1/3 TO 1/2 OF THE
AREA...MAINLY THURSDAY AND FRIDAY AFTERNOONS. DEEP LAYER MOISTURE
WILL BE VERY MARGINAL. THUS...HAVE KEPT ONLY SLIGHT CHANCE POPS FOR
MAINLY SHOWERS. BY SATURDAY...THE UPPER LOW MOVES FURTHER NORTH AND
KEEPS THE THREAT FOR ANY MEASURABLE PRECIPITATION NORTH OF THE AREA.

EXPECT BREEZY WEST-NORTHWEST WINDS FOR THURSDAY WITH 15 TO 20 MPH
SUSTAINED WINDS WITH GUST 25 TO 30 MPH POSSIBLE. THE PRESSURE
GRADIENT BEGINS TO GRADUALLY WEAKEN FRIDAY AND SATURDAY...WITH
LIGHTER WINDS EXPECTED.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED AT BOTH CHS AND SAV TERMINALS THROUGH
00Z FRI. BREEZY/GUSTY W/NW WINDS WILL PREVAIL AFTER DAYBREAK AT
BOTH TERMS WITH GUSTS IN THE MID 20 KT RANGE.

EXTENDED AVIATION OUTLOOK...VFR WILL PREVAIL.

&&

.MARINE...
TONIGHT...CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THROUGH MIDNIGHT WITH A WEST WIND AT OR BELOW 10-15 KT AND
SEAS BETWEEN 2-4 FT. A STRONG MID/UPPER LVL TROUGH OF LOW PRESSURE
WILL THEN DIG SOUTH OVER THE EASTERN CONUS...FORCING A SFC COLD
FRONT OVER THE COASTAL WATERS LATE. AS THIS OCCURS...THE PRESSURE
GRADIENT WILL ENHANCE AND COLD AIR ADVECTION WILL HELP PROMOTE
MIXING LOW LVL WINDS OVER THE WATERS. EXPECT WINDS/SEAS TO
INCREASE/BUILD AFTER MIDNIGHT...PROMPTING THE ISSUANCE OF A SMALL
CRAFT ADVISORY IN OFFSHORE GEORGIA WATERS LATE. IN GENERAL...WEST
WINDS WILL BECOME NORTHWEST 15-20 KTS OUTSIDE CHS HARBOR. GUSTS
WILL BE AROUND 25 KTS NEAR 20 NM OFFSHORE. SEAS WILL BUILD FROM
2-4 FT TO 3-5 FT...HIGHEST EAST PORTIONS NEAR THE GULF STREAM.

THURSDAY...LOW END SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED TO
PERSIST THROUGH THE DAY AND POSSIBLY INTO THE EVENING FOR THE
OFFSHORE GA WATERS. MODELS INDICATING THAT WINDS COULD REACH LOW END
SMALL CRAFT LEVELS FOR THE REST OF THE WATER DURING THE AFTERNOON
AND INTO THE EVENING...BUT CONDITIONS ARE TOO MARGINAL TO RAISE THE
ADVISORY ON THIS PACKAGE.

THURSDAY NIGHT THROUGH MONDAY...WINDS AND SEAS ARE EXPECTED TO
GRADUALLY DECREASE THROUGH THE WEEKEND AS THE DEEP LOW CENTER OVER
THE CAROLINAS AND THE MID ATLANTIC MOVES SLOWLY NORTHWARD AWAY FROM
THE WATERS. COULD SEE MARGINAL SMALL CRAFT CONDITIONS HANG ON OVER
THE OFFSHORE/BEYOND 20 NM WATERS THROUGH THURSDAY NIGHT...BUT FEEL
NO HIGHLIGHTS WILL BE NEEDED BY FRIDAY AND BEYOND.

&&

.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER AT METTER GEORGIA OPERATING ON
A FREQUENCY OF 162.425 MHZ WILL BE OFF THE AIR UNTIL FURTHER
NOTICE.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EDT FRIDAY FOR AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 050233
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1033 PM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND THURSDAY
MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE
WEST LATE WEEK AND PREVAIL THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
NO MAJOR CHANGES WITH THE LATEST UPDATE.

A LARGE MID LEVEL TROUGH OF LOW PRESSURE WILL DIG SOUTH OVER THE
EASTERN CONUS OVERNIGHT WITH A LEADING SHORTWAVE MOVING THROUGH
NORTHERN FLORIDA AHEAD OF IT. THIS WILL HELP DEVELOP AN AREA OF
LOW PRESSURE OFF THE NC OUTER BANKS WITH A TRAILING COLD FRONT
PUSHING TOWARD THE SC/GA COAST NEAR DAYBREAK. DESPITE STRONG UPPER
FORCING FOR ASCENT LIMITED MOISTURE WILL PREVENT ANY RAINFALL. COLD
AIR ADVECTION AND A DECENT PRESSURE GRADIENT WILL KEEP A
WEST/NORTHWEST WIND AT LEAST 5-10 MPH FOR MOST AREAS ESPECIALLY AFTER
MIDNIGHT...WITH TEMPERATURES DROPPING INTO THE MID TO UPPER 50S /WARMEST
ALONG THE COAST/.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A RATHER ANOMALOUS PATTERN WILL PERSIST THROUGH MUCH OF THE PERIOD
AS A DEEP UPPER LOW OVER THE CAROLINAS ON THURSDAY...GRADUALLY MOVES
NORTH INTO THE MID ATLANTIC STATES BY LATER FRIDAY AND SATURDAY.
THIS PATTERN WILL RESULT IN COOLER THAN NORMAL TEMPERATURES THURSDAY
AND FRIDAY AND THEN MODERATING BACK TOWARD NORMAL BY SATURDAY.
EXPECT HIGHS ONLY IN THE LOWER 70S THURSDAY...MID 70S FRIDAY THAN
AROUND 80 TO THE LOWER 80S SATURDAY. LOWS WILL BE CHILLY IN THE
UPPER 40S TO LOWER 50S BY FRIDAY MORNING...THEN MID 50S SATURDAY
MORNING.

NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE PERIOD.
HOWEVER...GIVEN THE NORTHERN PART OF THE AREA WILL BE CLOSEST TO THE
SOUTHERN PERIPHERY OF THE UPPER LOW...THERE WILL BE OCCASIONAL WEAK
VORT LOBES THAT ROTATE ACROSS MAINLY THE NORTHERN 1/3 TO 1/2 OF THE
AREA...MAINLY THURSDAY AND FRIDAY AFTERNOONS. DEEP LAYER MOISTURE
WILL BE VERY MARGINAL. THUS...HAVE KEPT ONLY SLIGHT CHANCE POPS FOR
MAINLY SHOWERS. BY SATURDAY...THE UPPER LOW MOVES FURTHER NORTH AND
KEEPS THE THREAT FOR ANY MEASURABLE PRECIPITATION NORTH OF THE AREA.

EXPECT BREEZY WEST-NORTHWEST WINDS FOR THURSDAY WITH 15 TO 20 MPH
SUSTAINED WINDS WITH GUST 25 TO 30 MPH POSSIBLE. THE PRESSURE
GRADIENT BEGINS TO GRADUALLY WEAKEN FRIDAY AND SATURDAY...WITH
LIGHTER WINDS EXPECTED.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED AT BOTH CHS AND SAV TERMINALS THROUGH
00Z FRI. BREEZY/GUSTY W/NW WINDS WILL PREVAIL AFTER DAYBREAK AT
BOTH TERMS WITH GUSTS IN THE MID 20 KT RANGE.

EXTENDED AVIATION OUTLOOK...VFR WILL PREVAIL.

&&

.MARINE...
TONIGHT...CONDITIONS WILL REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THROUGH MIDNIGHT WITH A WEST WIND AT OR BELOW 10-15 KT AND
SEAS BETWEEN 2-4 FT. A STRONG MID/UPPER LVL TROUGH OF LOW PRESSURE
WILL THEN DIG SOUTH OVER THE EASTERN CONUS...FORCING A SFC COLD
FRONT OVER THE COASTAL WATERS LATE. AS THIS OCCURS...THE PRESSURE
GRADIENT WILL ENHANCE AND COLD AIR ADVECTION WILL HELP PROMOTE
MIXING LOW LVL WINDS OVER THE WATERS. EXPECT WINDS/SEAS TO
INCREASE/BUILD AFTER MIDNIGHT...PROMPTING THE ISSUANCE OF A SMALL
CRAFT ADVISORY IN OFFSHORE GEORGIA WATERS LATE. IN GENERAL...WEST
WINDS WILL BECOME NORTHWEST 15-20 KTS OUTSIDE CHS HARBOR. GUSTS
WILL BE AROUND 25 KTS NEAR 20 NM OFFSHORE. SEAS WILL BUILD FROM
2-4 FT TO 3-5 FT...HIGHEST EAST PORTIONS NEAR THE GULF STREAM.

THURSDAY...LOW END SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED TO
PERSIST THROUGH THE DAY AND POSSIBLY INTO THE EVENING FOR THE
OFFSHORE GA WATERS. MODELS INDICATING THAT WINDS COULD REACH LOW END
SMALL CRAFT LEVELS FOR THE REST OF THE WATER DURING THE AFTERNOON
AND INTO THE EVENING...BUT CONDITIONS ARE TOO MARGINAL TO RAISE THE
ADVISORY ON THIS PACKAGE.

THURSDAY NIGHT THROUGH MONDAY...WINDS AND SEAS ARE EXPECTED TO
GRADUALLY DECREASE THROUGH THE WEEKEND AS THE DEEP LOW CENTER OVER
THE CAROLINAS AND THE MID ATLANTIC MOVES SLOWLY NORTHWARD AWAY FROM
THE WATERS. COULD SEE MARGINAL SMALL CRAFT CONDITIONS HANG ON OVER
THE OFFSHORE/BEYOND 20 NM WATERS THROUGH THURSDAY NIGHT...BUT FEEL
NO HIGHLIGHTS WILL BE NEEDED BY FRIDAY AND BEYOND.

&&

.EQUIPMENT...
THE NOAA WEATHER RADIO TRANSMITTER AT METTER GEORGIA OPERATING ON
A FREQUENCY OF 162.425 MHZ WILL BE OFF THE AIR UNTIL FURTHER
NOTICE.

THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM THURSDAY TO 2 AM EDT FRIDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...RFM
LONG TERM...RFM
AVIATION...RFM/RJB
MARINE...DPB/RFM
EQUIPMENT...





000
FXUS62 KCHS 042352
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
752 PM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND THURSDAY
MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE
WEST LATE WEEK AND PREVAIL THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A LARGE MID LEVEL TROUGH OF LOW PRESSURE WILL DIG SOUTH OVER THE
EASTERN CONUS OVERNIGHT WITH A LEADING SHORTWAVE MOVING THROUGH
NORTHERN FLORIDA AHEAD OF IT. THIS WILL HELP DEVELOP AN AREA OF
LOW PRESSURE OFF THE NC OUTER BANKS WITH A TRAILING COLD FRONT
PUSHING TOWARD THE SC/GA COAST NEAR DAYBREAK. DESPITE STRONG UPPER
FORCING FOR ASCENT LIMITED MOISTURE WILL PREVENT ANY RAINFALL. COLD
AIR ADVECTION AND A DECENT PRESSURE GRADIENT WILL KEEP A
WEST/NORTHWEST WIND AT LEAST 5-10 MPH FOR MOST AREAS...WITH
TEMPERATURES DROPPING INTO THE MID TO UPPER 50S MOST LOCALES /WARMEST
ALONG THE COAST/.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A RATHER ANOMALOUS PATTERN WILL PERSIST THROUGH MUCH OF THE PERIOD
AS A DEEP UPPER LOW OVER THE CAROLINAS ON THURSDAY...GRADUALLY MOVES
NORTH INTO THE MID ATLANTIC STATES BY LATER FRIDAY AND SATURDAY.
THIS PATTERN WILL RESULT IN COOLER THAN NORMAL TEMPERATURES THURSDAY
AND FRIDAY AND THEN MODERATING BACK TOWARD NORMAL BY SATURDAY.
EXPECT HIGHS ONLY IN THE LOWER 70S THURSDAY...MID 70S FRIDAY THAN
AROUND 80 TO THE LOWER 80S SATURDAY. LOWS WILL BE CHILLY IN THE
UPPER 40S TO LOWER 50S BY FRIDAY MORNING...THEN MID 50S SATURDAY
MORNING.

NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE PERIOD.
HOWEVER...GIVEN THE NORTHERN PART OF THE AREA WILL BE CLOSEST TO THE
SOUTHERN PERIPHERY OF THE UPPER LOW...THERE WILL BE OCCASIONAL WEAK
VORT LOBES THAT ROTATE ACROSS MAINLY THE NORTHERN 1/3 TO 1/2 OF THE
AREA...MAINLY THURSDAY AND FRIDAY AFTERNOONS. DEEP LAYER MOISTURE
WILL BE VERY MARGINAL. THUS...HAVE KEPT ONLY SLIGHT CHANCE POPS FOR
MAINLY SHOWERS. BY SATURDAY...THE UPPER LOW MOVES FURTHER NORTH AND
KEEPS THE THREAT FOR ANY MEASURABLE PRECIPITATION NORTH OF THE AREA.

EXPECT BREEZY WEST-NORTHWEST WINDS FOR THURSDAY WITH 15 TO 20 MPH
SUSTAINED WINDS WITH GUST 25 TO 30 MPH POSSIBLE. THE PRESSURE
GRADIENT BEGINS TO GRADUALLY WEAKEN FRIDAY AND SATURDAY...WITH
LIGHTER WINDS EXPECTED.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED AT BOTH CHS AND SAV TERMINALS THROUGH
00Z FRI. BREEZY/GUSTY W/NW WINDS WILL PREVAIL AFTER DAYBREAK AT
BOTH TERMS WITH GUSTS IN THE MID 20 KT RANGE.

EXTENDED AVIATION OUTLOOK...VFR WILL PREVAIL.

&&

.MARINE...
THIS EVENING AND TONIGHT...CONDITIONS WILL REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH MIDNIGHT WITH A WEST WIND AT OR BELOW 10-15
KT AND SEAS BETWEEN 2-4 FT. A STRONG MID/UPPER LVL TROUGH OF LOW
PRESSURE WILL THEN DIG SOUTH OVER THE EASTERN CONUS...FORCING A SFC
COLD FRONT OVER THE COASTAL WATERS LATE. AS THIS OCCURS...THE
PRESSURE GRADIENT WILL ENHANCE AND COLD AIR ADVECTION WILL HELP
PROMOTE MIXING LOW LVL WINDS OVER THE WATERS. EXPECT WINDS/SEAS TO
INCREASE/BUILD AFTER MIDNIGHT...PROMPTING THE ISSUANCE OF A SMALL
CRAFT ADVISORY IN OFFSHORE GEORGIA WATERS LATE. IN GENERAL...WEST
WINDS WILL BECOME NORTHWEST AROUND 20 KTS OUTSIDE THE CHS HARBOR.
GUSTS WILL BE AROUND 25 KTS IN OFFSHORE GEORGIA WATERS LATE. SEAS
WILL BUILD FROM 2-4 FT TO 3-5 FT...HIGHEST IN OFFSHORE GEORGIA
WATERS LATE.

THURSDAY...LOW END SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED TO
PERSIST THROUGH THE DAY AND POSSIBLY INTO THE EVENING FOR THE
OFFSHORE GA WATERS. MODELS INDICATING THAT WINDS COULD REACH LOW END
SMALL CRAFT LEVELS FOR THE REST OF THE WATER DURING THE AFTERNOON
AND INTO THE EVENING...BUT CONDITIONS ARE TOO MARGINAL TO RAISE THE
ADVISORY ON THIS PACKAGE.

THURSDAY NIGHT THROUGH MONDAY...WINDS AND SEAS ARE EXPECTED TO
GRADUALLY DECREASE THROUGH THE WEEKEND AS THE DEEP LOW CENTER OVER
THE CAROLINAS AND THE MID ATLANTIC MOVES SLOWLY NORTHWARD AWAY FROM
THE WATERS. COULD SEE MARGINAL SMALL CRAFT CONDITIONS HANG ON OVER
THE OFFSHORE/BEYOND 20 NM WATERS THROUGH THURSDAY NIGHT...BUT FEEL
NO HIGHLIGHTS WILL BE NEEDED BY FRIDAY AND BEYOND.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM THURSDAY TO 2 AM EDT FRIDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...RFM
LONG TERM...RFM
AVIATION...RFM/RJB
MARINE...DPB/RFM
EQUIPMENT...





000
FXUS62 KCHS 042352
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
752 PM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT AND THURSDAY
MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE
WEST LATE WEEK AND PREVAIL THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
A LARGE MID LEVEL TROUGH OF LOW PRESSURE WILL DIG SOUTH OVER THE
EASTERN CONUS OVERNIGHT WITH A LEADING SHORTWAVE MOVING THROUGH
NORTHERN FLORIDA AHEAD OF IT. THIS WILL HELP DEVELOP AN AREA OF
LOW PRESSURE OFF THE NC OUTER BANKS WITH A TRAILING COLD FRONT
PUSHING TOWARD THE SC/GA COAST NEAR DAYBREAK. DESPITE STRONG UPPER
FORCING FOR ASCENT LIMITED MOISTURE WILL PREVENT ANY RAINFALL. COLD
AIR ADVECTION AND A DECENT PRESSURE GRADIENT WILL KEEP A
WEST/NORTHWEST WIND AT LEAST 5-10 MPH FOR MOST AREAS...WITH
TEMPERATURES DROPPING INTO THE MID TO UPPER 50S MOST LOCALES /WARMEST
ALONG THE COAST/.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A RATHER ANOMALOUS PATTERN WILL PERSIST THROUGH MUCH OF THE PERIOD
AS A DEEP UPPER LOW OVER THE CAROLINAS ON THURSDAY...GRADUALLY MOVES
NORTH INTO THE MID ATLANTIC STATES BY LATER FRIDAY AND SATURDAY.
THIS PATTERN WILL RESULT IN COOLER THAN NORMAL TEMPERATURES THURSDAY
AND FRIDAY AND THEN MODERATING BACK TOWARD NORMAL BY SATURDAY.
EXPECT HIGHS ONLY IN THE LOWER 70S THURSDAY...MID 70S FRIDAY THAN
AROUND 80 TO THE LOWER 80S SATURDAY. LOWS WILL BE CHILLY IN THE
UPPER 40S TO LOWER 50S BY FRIDAY MORNING...THEN MID 50S SATURDAY
MORNING.

NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE PERIOD.
HOWEVER...GIVEN THE NORTHERN PART OF THE AREA WILL BE CLOSEST TO THE
SOUTHERN PERIPHERY OF THE UPPER LOW...THERE WILL BE OCCASIONAL WEAK
VORT LOBES THAT ROTATE ACROSS MAINLY THE NORTHERN 1/3 TO 1/2 OF THE
AREA...MAINLY THURSDAY AND FRIDAY AFTERNOONS. DEEP LAYER MOISTURE
WILL BE VERY MARGINAL. THUS...HAVE KEPT ONLY SLIGHT CHANCE POPS FOR
MAINLY SHOWERS. BY SATURDAY...THE UPPER LOW MOVES FURTHER NORTH AND
KEEPS THE THREAT FOR ANY MEASURABLE PRECIPITATION NORTH OF THE AREA.

EXPECT BREEZY WEST-NORTHWEST WINDS FOR THURSDAY WITH 15 TO 20 MPH
SUSTAINED WINDS WITH GUST 25 TO 30 MPH POSSIBLE. THE PRESSURE
GRADIENT BEGINS TO GRADUALLY WEAKEN FRIDAY AND SATURDAY...WITH
LIGHTER WINDS EXPECTED.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED AT BOTH CHS AND SAV TERMINALS THROUGH
00Z FRI. BREEZY/GUSTY W/NW WINDS WILL PREVAIL AFTER DAYBREAK AT
BOTH TERMS WITH GUSTS IN THE MID 20 KT RANGE.

EXTENDED AVIATION OUTLOOK...VFR WILL PREVAIL.

&&

.MARINE...
THIS EVENING AND TONIGHT...CONDITIONS WILL REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH MIDNIGHT WITH A WEST WIND AT OR BELOW 10-15
KT AND SEAS BETWEEN 2-4 FT. A STRONG MID/UPPER LVL TROUGH OF LOW
PRESSURE WILL THEN DIG SOUTH OVER THE EASTERN CONUS...FORCING A SFC
COLD FRONT OVER THE COASTAL WATERS LATE. AS THIS OCCURS...THE
PRESSURE GRADIENT WILL ENHANCE AND COLD AIR ADVECTION WILL HELP
PROMOTE MIXING LOW LVL WINDS OVER THE WATERS. EXPECT WINDS/SEAS TO
INCREASE/BUILD AFTER MIDNIGHT...PROMPTING THE ISSUANCE OF A SMALL
CRAFT ADVISORY IN OFFSHORE GEORGIA WATERS LATE. IN GENERAL...WEST
WINDS WILL BECOME NORTHWEST AROUND 20 KTS OUTSIDE THE CHS HARBOR.
GUSTS WILL BE AROUND 25 KTS IN OFFSHORE GEORGIA WATERS LATE. SEAS
WILL BUILD FROM 2-4 FT TO 3-5 FT...HIGHEST IN OFFSHORE GEORGIA
WATERS LATE.

THURSDAY...LOW END SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED TO
PERSIST THROUGH THE DAY AND POSSIBLY INTO THE EVENING FOR THE
OFFSHORE GA WATERS. MODELS INDICATING THAT WINDS COULD REACH LOW END
SMALL CRAFT LEVELS FOR THE REST OF THE WATER DURING THE AFTERNOON
AND INTO THE EVENING...BUT CONDITIONS ARE TOO MARGINAL TO RAISE THE
ADVISORY ON THIS PACKAGE.

THURSDAY NIGHT THROUGH MONDAY...WINDS AND SEAS ARE EXPECTED TO
GRADUALLY DECREASE THROUGH THE WEEKEND AS THE DEEP LOW CENTER OVER
THE CAROLINAS AND THE MID ATLANTIC MOVES SLOWLY NORTHWARD AWAY FROM
THE WATERS. COULD SEE MARGINAL SMALL CRAFT CONDITIONS HANG ON OVER
THE OFFSHORE/BEYOND 20 NM WATERS THROUGH THURSDAY NIGHT...BUT FEEL
NO HIGHLIGHTS WILL BE NEEDED BY FRIDAY AND BEYOND.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM THURSDAY TO 2 AM EDT FRIDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...RFM
LONG TERM...RFM
AVIATION...RFM/RJB
MARINE...DPB/RFM
EQUIPMENT...





000
FXUS62 KCHS 042008
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
408 PM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT. HIGH PRESSURE
WILL THEN EXPAND INTO THE REGION FROM THE WEST LATE WEEK AND PREVAIL
THROUGH EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
THIS EVENING AND TONIGHT...A STRONG MID LVL TROUGH OF LOW PRESSURE
WILL DIG SOUTH OVER THE EASTERN CONUS...HELPING FORCE A SFC COLD
FRONT THROUGH THE AREA LATE TONIGHT INTO EARLY THURSDAY MORNING.
OTHER THAN A FEW CLOUDS ASSOCIATED WITH THE PASSING FRONT...THE
ATMOSPHERE WILL REMAIN QUITE DRY. THUS...A RAIN-FREE FORECAST WILL
BE IN PLACE THROUGH THE OVERNIGHT PERIOD. COLD AIR ADVECTION TO THE
REGION WILL HELP MAINTAIN A WEST/NORTHWEST WIND BETWEEN 5-10
MPH...KEEPING OVERNIGHT LOWS IN THE MID TO UPPER 50S...WARMEST
ALONG THE COAST.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
A RATHER ANOMALOUS PATTERN WILL PERSIST THROUGH MUCH OF THE PERIOD
AS A DEEP UPPER LOW OVER THE CAROLINAS ON THURSDAY...GRADUALLY MOVES
NORTH INTO THE MID ATLANTIC STATES BY LATER FRIDAY AND SATURDAY.
THIS PATTERN WILL RESULT IN COOLER THAN NORMAL TEMPERATURES THURSDAY
AND FRIDAY AND THEN MODERATING BACK TOWARD NORMAL BY SATURDAY.
EXPECT HIGHS ONLY IN THE LOWER 70S THURSDAY...MID 70S FRIDAY THAN
AROUND 80 TO THE LOWER 80S SATURDAY. LOWS WILL BE CHILLY IN THE
UPPER 40S TO LOWER 50S BY FRIDAY MORNING...THEN MID 50S SATURDAY
MORNING.

NO SIGNIFICANT PRECIPITATION IS EXPECTED THROUGH THE PERIOD.
HOWEVER...GIVEN THE NORTHERN PART OF THE AREA WILL BE CLOSEST TO THE
SOUTHERN PERIPHERY OF THE UPPER LOW...THERE WILL BE OCCASIONAL WEAK
VORT LOBES THAT ROTATE ACROSS MAINLY THE NORTHERN 1/3 TO 1/2 OF THE
AREA...MAINLY THURSDAY AND FRIDAY AFTERNOONS. DEEP LAYER MOISTURE
WILL BE VERY MARGINAL. THUS...HAVE KEPT ONLY SLIGHT CHANCE POPS FOR
MAINLY SHOWERS. BY SATURDAY...THE UPPER LOW MOVES FURTHER NORTH AND
KEEPS THE THREAT FOR ANY MEASURABLE PRECIPITATION NORTH OF THE AREA.

EXPECT BREEZY WEST-NORTHWEST WINDS FOR THURSDAY WITH 15 TO 20 MPH
SUSTAINED WINDS WITH GUST 25 TO 30 MPH POSSIBLE. THE PRESSURE
GRADIENT BEGINS TO GRADUALLY WEAKEN FRIDAY AND SATURDAY...WITH
LIGHTER WINDS EXPECTED.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED AT BOTH CHS AND SAV TERMINALS THROUGH
18Z THURSDAY.

EXTENDED AVIATION OUTLOOK...VFR WILL PREVAIL. GUSTY WEST-NORTHWEST
WINDS EXPECTED FOR THURSDAY AFTERNOON WITH 15-20 KNOTS SUSTAINED
ALONG WITH GUSTS 25-30 KNOTS POSSIBLE.

&&

.MARINE...
THIS EVENING AND TONIGHT...CONDITIONS WILL REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH MIDNIGHT WITH A WEST WIND AT OR BELOW 10-15
KT AND SEAS BETWEEN 2-4 FT. A STRONG MID/UPPER LVL TROUGH OF LOW
PRESSURE WILL THEN DIG SOUTH OVER THE EASTERN CONUS...FORCING A SFC
COLD FRONT OVER THE COASTAL WATERS LATE. AS THIS OCCURS...THE
PRESSURE GRADIENT WILL ENHANCE AND COLD AIR ADVECTION WILL HELP
PROMOTE MIXING LOW LVL WINDS OVER THE WATERS. EXPECT WINDS/SEAS TO
INCREASE/BUILD AFTER MIDNIGHT...PROMPTING THE ISSUANCE OF A SMALL
CRAFT ADVISORY IN OFFSHORE GEORGIA WATERS LATE. IN GENERAL...WEST
WINDS WILL BECOME NORTHWEST AROUND 20 KTS OUTSIDE THE CHS HARBOR.
GUSTS WILL BE AROUND 25 KTS IN OFFSHORE GEORGIA WATERS LATE. SEAS
WILL BUILD FROM 2-4 FT TO 3-5 FT...HIGHEST IN OFFSHORE GEORGIA
WATERS LATE.

THURSDAY...LOW END SMALL CRAFT ADVISORY CONDITIONS ARE EXPECTED TO
PERSIST THROUGH THE DAY AND POSSIBLY INTO THE EVENING FOR THE
OFFSHORE GA WATERS. MODELS INDICATING THAT WINDS COULD REACH LOW END
SMALL CRAFT LEVELS FOR THE REST OF THE WATER DURING THE AFTERNOON
AND INTO THE EVENING...BUT CONDITIONS ARE TOO MARGINAL TO RAISE THE
ADVISORY ON THIS PACKAGE.

THURSDAY NIGHT THROUGH MONDAY...WINDS AND SEAS ARE EXPECTED TO
GRADUALLY DECREASE THROUGH THE WEEKEND AS THE DEEP LOW CENTER OVER
THE CAROLINAS AND THE MID ATLANTIC MOVES SLOWLY NORTHWARD AWAY FROM
THE WATERS. COULD SEE MARGINAL SMALL CRAFT CONDITIONS HANG ON OVER
THE OFFSHORE/BEYOND 20 NM WATERS THROUGH THURSDAY NIGHT...BUT FEEL
NO HIGHLIGHTS WILL BE NEEDED BY FRIDAY AND BEYOND.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM THURSDAY TO 2 AM EDT FRIDAY FOR
     AMZ374.

&&

$$
SYNOPSIS...
NEAR TERM...DPB
SHORT TERM...RFM
LONG TERM...RFM
AVIATION...DPB/RFM
MARINE...DPB/RFM
EQUIPMENT...





000
FXUS62 KCHS 041714
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
114 PM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SHIFT OVER THE WESTERN ATLANTIC
THIS AFTERNOON. A SECONDARY COLD FRONT WILL MOVE THROUGH THE AREA
LATE TONIGHT. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM
THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT SHOULD DROP INTO THE CAROLINAS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...QUIET WEATHER CONDITIONS ARE EXPECTED ALONG THE
SOUTHERN PERIPHERY OF A LARGE MID LVL TROUGH OF LOW PRESSURE DIGGING
OVER THE EASTERN CONUS. COLD AIR IN THE MID LVLS WILL HELP PRODUCE A
FEW CLOUDS OVER THE AREA...BUT COVERAGE WILL BE LIMITED DUE TO THE
DRY WESTERLY WIND IN PLACE. IN GENERAL...HIGHS WILL RANGE IN THE
UPPER 70S TO AROUND 80 DEGREES.

TONIGHT...ANOTHER COLD FRONT WILL BE APPROACHING FROM THE NORTHWEST.
IT SHOULD PASS THROUGH OUR AREA LATE. THIS FRONT WILL BE DRY...BRINGING
JUST SOME CLOUDS...BUT NO PRECIPITATION. TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT NIGHTS...ALTHOUGH STILL CLOSE TO
NORMAL...THE MID TO UPPER 50S...AND NEAR 60 DEGREES AT THE
BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY...A DEEP AND DIGGING UPPER LOW WILL REACH THE CAROLINAS
THURSDAY AFTERNOON. THE MAIN VORT LOBE ASSOCIATED WITH THE LOW
CENTER WILL SHIFT SE ACROSS THE FORECAST AREA THROUGH THE AFTERNOON
AS CYCLOGENESIS TAKES OVER EASTERN NORTH CAROLINA. GIVEN THE FORCING
IN PLACE...WE HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO AN IMPRESSIVE -25C 500 MB COLD POOL
REACHING THE CSRA AND MIDLANDS BY LATE DAY. FORECAST SOUNDINGS
INDICATE VERY SMALL REGIONS OF CAPE BETWEEN 6 KFT AND 10 KFT AND
POTENTIAL FOR ANY MIXED GRAUPEL/HAIL PCPN NW ZONES APPEARS QUITE
SLIM AS MOISTURE IS JUST NOT THERE. HIGH TEMPS WILL RUN MUCH COOLER
IN THE LOWER 70S...FALLING THROUGH THE 60S AFTER MID AFTERNOON. THE
PRESSURE GRADIENT WILL TIGHTEN AND WNW WINDS WILL BECOME GUSTY IN
THE AFTERNOON...ROUGHLY 25 TO 30 MPH UNDER PARTLY CLOUDY SKIES.
CONDITIONS SHOULD BE DRY THURSDAY NIGHT BUT QUITE CHILLY WITH LOWS
IN THE UPPER 40S TO LOWER 50S.

FRIDAY THE PATTERN DOES NOT CHANGE VERY MUCH WITH THE DEEP UPPER
TROUGH AND MID LEVEL CUT-OFF LOW REMAINING ALONG THE EAST COAST.
STEEP LOW AND MID LEVEL LAPSE RATES WILL PERSIST WITH CYCLONIC FLOW
ALOFT. WE HAVE ADDED SOME SLIGHT CHANCE POPS FOR SHALLOW DIURNALLY
ENHANCED CONVECTION ACROSS PARTS OF THE CENTRAL SOUTH CAROLINA
COASTAL REGION...OTHERWISE WE MAINTAINED A MAINLY DRY FORECAST AS
LARGE LOW LEVEL TEMP AND DEW POINT SPREADS REMAIN THE NORM.
ANOTHER COOLER THAN CLIMO DAY IN STORE WITH HIGHS IN THE MID 70S
MOST AREAS.

SATURDAY...THE DEEP UPPER LOW ALONG THE EASTERN SEABOARD WILL
FINALLY MOVE AWAY FROM THE REGION AS UPPER HEIGHTS BUILD ACROSS
GEORGIA AND SOUTH CAROLINA. THIS SHOULD RESULT IN SUNSHINE AND
WARMER TEMPERATURES NEARING 80 DEGREES ALONG COASTAL SOUTH
CAROLINA AND REACHING THE LOWER 80S ACROSS INLAND GEORGIA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED AT BOTH CHS AND SAV TERMINALS THROUGH
18Z THURSDAY.

EXTENDED AVIATION OUTLOOK...VFR. GUSTY SURFACE WINDS ARE EXPECTED
ON THURSDAY IN THE WAKE OF A SECONDARY COLD FRONT DURING THE
AFTERNOON.

&&

.MARINE...
THIS AFTERNOON...CONDITIONS WILL REMAIN WELL BELOW SMALL CRAFT
ADVISORY LEVELS BEHIND A COLD FRONT SHIFTING OVER THE WESTERN
ATLANTIC. IN GENERAL...WEST WINDS WILL REMAIN AT OR BELOW 10-15 KT.
SEAS WILL RANGE BETWEEN 2-4 FT...BUT WILL SLOWLY SUBSIDE THROUGH THE
EVENING.

TONIGHT...A SECOND COLD FRONT WILL APPROACH THE REGION FROM THE
NORTHWEST...PASSING THROUGH AROUND DAYBREAK. IN ADVANCE OF THIS
FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT...INCREASING
TO AROUND 15-20 KT AFTER MIDNIGHT. A SMALL CRAFT ADVISORY MIGHT
BE NEEDED FOR THE OUTER GEORGIA WATERS LATE AT NIGHT DUE TO WIND
GUSTS. SEAS WILL BUILD TO ABOUT 3-5 FT BY DAYBREAK.

EXTENDED...THE ARRIVAL OF THE DEEP UPPER LOW AND STRONG VORTICITY
MAXIMA LATE THURSDAY AND THURSDAY NIGHT WILL INCITE STRONG LOW
LEVEL COLD AIR ADVECTION WHICH WILL RESULT IN SUBSTANTIAL SURGES
ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT NEAR SHORE AND 4-7 FT WELL OFFSHORE.
CANNOT RULE OUT A BRIEF SURGE OF GALE FORCE GUSTS FROM GRAYS REEF
SEAWARD THURSDAY EVENING AS THE VORT PASSES OVERHEAD.

CONDITIONS WILL BEGIN TO IMPROVE BY FRIDAY. HIGH PRESSURE WILL
RETURN FRIDAY AFTERNOON AND PERSIST OVER THE WEEKEND WITH WINDS
GENERALLY 15 KT OR LESS. SEAS ON AVERAGE LATE FRIDAY INTO THE
WEEKEND WILL AVERAGE 2-3 FEET. EARLY NEXT WEEK...A S TO SW SYNOPTIC
FLOW WILL PREVAIL ON THE PERIPHERY OF ATLC HIGH PRES OFFSHORE.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...DPB
SHORT TERM...
LONG TERM...
AVIATION...DPB
MARINE...DPB
EQUIPMENT...





000
FXUS62 KCHS 041714
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
114 PM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO SHIFT OVER THE WESTERN ATLANTIC
THIS AFTERNOON. A SECONDARY COLD FRONT WILL MOVE THROUGH THE AREA
LATE TONIGHT. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM
THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT SHOULD DROP INTO THE CAROLINAS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
THIS AFTERNOON...QUIET WEATHER CONDITIONS ARE EXPECTED ALONG THE
SOUTHERN PERIPHERY OF A LARGE MID LVL TROUGH OF LOW PRESSURE DIGGING
OVER THE EASTERN CONUS. COLD AIR IN THE MID LVLS WILL HELP PRODUCE A
FEW CLOUDS OVER THE AREA...BUT COVERAGE WILL BE LIMITED DUE TO THE
DRY WESTERLY WIND IN PLACE. IN GENERAL...HIGHS WILL RANGE IN THE
UPPER 70S TO AROUND 80 DEGREES.

TONIGHT...ANOTHER COLD FRONT WILL BE APPROACHING FROM THE NORTHWEST.
IT SHOULD PASS THROUGH OUR AREA LATE. THIS FRONT WILL BE DRY...BRINGING
JUST SOME CLOUDS...BUT NO PRECIPITATION. TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT NIGHTS...ALTHOUGH STILL CLOSE TO
NORMAL...THE MID TO UPPER 50S...AND NEAR 60 DEGREES AT THE
BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY...A DEEP AND DIGGING UPPER LOW WILL REACH THE CAROLINAS
THURSDAY AFTERNOON. THE MAIN VORT LOBE ASSOCIATED WITH THE LOW
CENTER WILL SHIFT SE ACROSS THE FORECAST AREA THROUGH THE AFTERNOON
AS CYCLOGENESIS TAKES OVER EASTERN NORTH CAROLINA. GIVEN THE FORCING
IN PLACE...WE HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO AN IMPRESSIVE -25C 500 MB COLD POOL
REACHING THE CSRA AND MIDLANDS BY LATE DAY. FORECAST SOUNDINGS
INDICATE VERY SMALL REGIONS OF CAPE BETWEEN 6 KFT AND 10 KFT AND
POTENTIAL FOR ANY MIXED GRAUPEL/HAIL PCPN NW ZONES APPEARS QUITE
SLIM AS MOISTURE IS JUST NOT THERE. HIGH TEMPS WILL RUN MUCH COOLER
IN THE LOWER 70S...FALLING THROUGH THE 60S AFTER MID AFTERNOON. THE
PRESSURE GRADIENT WILL TIGHTEN AND WNW WINDS WILL BECOME GUSTY IN
THE AFTERNOON...ROUGHLY 25 TO 30 MPH UNDER PARTLY CLOUDY SKIES.
CONDITIONS SHOULD BE DRY THURSDAY NIGHT BUT QUITE CHILLY WITH LOWS
IN THE UPPER 40S TO LOWER 50S.

FRIDAY THE PATTERN DOES NOT CHANGE VERY MUCH WITH THE DEEP UPPER
TROUGH AND MID LEVEL CUT-OFF LOW REMAINING ALONG THE EAST COAST.
STEEP LOW AND MID LEVEL LAPSE RATES WILL PERSIST WITH CYCLONIC FLOW
ALOFT. WE HAVE ADDED SOME SLIGHT CHANCE POPS FOR SHALLOW DIURNALLY
ENHANCED CONVECTION ACROSS PARTS OF THE CENTRAL SOUTH CAROLINA
COASTAL REGION...OTHERWISE WE MAINTAINED A MAINLY DRY FORECAST AS
LARGE LOW LEVEL TEMP AND DEW POINT SPREADS REMAIN THE NORM.
ANOTHER COOLER THAN CLIMO DAY IN STORE WITH HIGHS IN THE MID 70S
MOST AREAS.

SATURDAY...THE DEEP UPPER LOW ALONG THE EASTERN SEABOARD WILL
FINALLY MOVE AWAY FROM THE REGION AS UPPER HEIGHTS BUILD ACROSS
GEORGIA AND SOUTH CAROLINA. THIS SHOULD RESULT IN SUNSHINE AND
WARMER TEMPERATURES NEARING 80 DEGREES ALONG COASTAL SOUTH
CAROLINA AND REACHING THE LOWER 80S ACROSS INLAND GEORGIA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS ARE EXPECTED AT BOTH CHS AND SAV TERMINALS THROUGH
18Z THURSDAY.

EXTENDED AVIATION OUTLOOK...VFR. GUSTY SURFACE WINDS ARE EXPECTED
ON THURSDAY IN THE WAKE OF A SECONDARY COLD FRONT DURING THE
AFTERNOON.

&&

.MARINE...
THIS AFTERNOON...CONDITIONS WILL REMAIN WELL BELOW SMALL CRAFT
ADVISORY LEVELS BEHIND A COLD FRONT SHIFTING OVER THE WESTERN
ATLANTIC. IN GENERAL...WEST WINDS WILL REMAIN AT OR BELOW 10-15 KT.
SEAS WILL RANGE BETWEEN 2-4 FT...BUT WILL SLOWLY SUBSIDE THROUGH THE
EVENING.

TONIGHT...A SECOND COLD FRONT WILL APPROACH THE REGION FROM THE
NORTHWEST...PASSING THROUGH AROUND DAYBREAK. IN ADVANCE OF THIS
FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT...INCREASING
TO AROUND 15-20 KT AFTER MIDNIGHT. A SMALL CRAFT ADVISORY MIGHT
BE NEEDED FOR THE OUTER GEORGIA WATERS LATE AT NIGHT DUE TO WIND
GUSTS. SEAS WILL BUILD TO ABOUT 3-5 FT BY DAYBREAK.

EXTENDED...THE ARRIVAL OF THE DEEP UPPER LOW AND STRONG VORTICITY
MAXIMA LATE THURSDAY AND THURSDAY NIGHT WILL INCITE STRONG LOW
LEVEL COLD AIR ADVECTION WHICH WILL RESULT IN SUBSTANTIAL SURGES
ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT NEAR SHORE AND 4-7 FT WELL OFFSHORE.
CANNOT RULE OUT A BRIEF SURGE OF GALE FORCE GUSTS FROM GRAYS REEF
SEAWARD THURSDAY EVENING AS THE VORT PASSES OVERHEAD.

CONDITIONS WILL BEGIN TO IMPROVE BY FRIDAY. HIGH PRESSURE WILL
RETURN FRIDAY AFTERNOON AND PERSIST OVER THE WEEKEND WITH WINDS
GENERALLY 15 KT OR LESS. SEAS ON AVERAGE LATE FRIDAY INTO THE
WEEKEND WILL AVERAGE 2-3 FEET. EARLY NEXT WEEK...A S TO SW SYNOPTIC
FLOW WILL PREVAIL ON THE PERIPHERY OF ATLC HIGH PRES OFFSHORE.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...DPB
SHORT TERM...
LONG TERM...
AVIATION...DPB
MARINE...DPB
EQUIPMENT...





000
FXUS62 KCHS 041356
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
956 AM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE OVER THE WESTERN ATLANTIC THIS MORNING. A
SECONDARY COLD FRONT WILL MOVE THROUGH THE AREA EARLY THURSDAY.
HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST LATE
WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR COLD FRONT SHOULD
DROP INTO THE CAROLINAS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A FEW SHOWERS COULD LINGER ALONG COASTAL AREAS LATE THIS
MORNING AS A LARGE MID LVL TROUGH OF LOW PRESSURE DIGS OVER THE
EASTERN CONUS BEHIND A SFC COLD FRONT SHIFTING OVER THE WESTERN
ATLANTIC. RAIN-FREE CONDITIONS ARE THEN EXPECTED BY THE AFTERNOON AS
A DRY WESTERLY FLOW DEVELOPS ACROSS THE REGION. DRY AIR WILL ALSO
HELP ERODE CLOUDS AS THEY SHIFT OFFSHORE INTO EARLY AFTERNOON.
THE SETUP WILL FAVOR A FULL SUN OVER MOST AREAS DURING PEAK
HEATING HOURS. IN GENERAL...HIGHS WILL RANGE IN THE UPPER 70S TO
AROUND 80 DEGREES.

TONIGHT...ANOTHER COLD FRONT WILL BE APPROACHING FROM THE NORTHWEST.
IT SHOULD PASS THROUGH OUR AREA LATE. THIS FRONT WILL BE DRY...BRINGING
JUST SOME CLOUDS...BUT NO PRECIPITATION. TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT NIGHTS...ALTHOUGH STILL CLOSE TO
NORMAL...THE MID TO UPPER 50S...AND NEAR 60 DEGREES AT THE
BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY...A DEEP AND DIGGING UPPER LOW WILL REACH THE CAROLINAS
THURSDAY AFTERNOON. THE MAIN VORT LOBE ASSOCIATED WITH THE LOW
CENTER WILL SHIFT SE ACROSS THE FORECAST AREA THROUGH THE AFTERNOON
AS CYCLOGENESIS TAKES OVER EASTERN NORTH CAROLINA. GIVEN THE FORCING
IN PLACE...WE HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO AN IMPRESSIVE -25C 500 MB COLD POOL
REACHING THE CSRA AND MIDLANDS BY LATE DAY. FORECAST SOUNDINGS
INDICATE VERY SMALL REGIONS OF CAPE BETWEEN 6 KFT AND 10 KFT AND
POTENTIAL FOR ANY MIXED GRAUPEL/HAIL PCPN NW ZONES APPEARS QUITE
SLIM AS MOISTURE IS JUST NOT THERE. HIGH TEMPS WILL RUN MUCH COOLER
IN THE LOWER 70S...FALLING THROUGH THE 60S AFTER MID AFTERNOON. THE
PRESSURE GRADIENT WILL TIGHTEN AND WNW WINDS WILL BECOME GUSTY IN
THE AFTERNOON...ROUGHLY 25 TO 30 MPH UNDER PARTLY CLOUDY SKIES.
CONDITIONS SHOULD BE DRY THURSDAY NIGHT BUT QUITE CHILLY WITH LOWS
IN THE UPPER 40S TO LOWER 50S.

FRIDAY THE PATTERN DOES NOT CHANGE VERY MUCH WITH THE DEEP UPPER
TROUGH AND MID LEVEL CUT-OFF LOW REMAINING ALONG THE EAST COAST.
STEEP LOW AND MID LEVEL LAPSE RATES WILL PERSIST WITH CYCLONIC FLOW
ALOFT. WE HAVE ADDED SOME SLIGHT CHANCE POPS FOR SHALLOW DIURNALLY
ENHANCED CONVECTION ACROSS PARTS OF THE CENTRAL SOUTH CAROLINA
COASTAL REGION...OTHERWISE WE MAINTAINED A MAINLY DRY FORECAST AS
LARGE LOW LEVEL TEMP AND DEW POINT SPREADS REMAIN THE NORM.
ANOTHER COOLER THAN CLIMO DAY IN STORE WITH HIGHS IN THE MID 70S
MOST AREAS.

SATURDAY...THE DEEP UPPER LOW ALONG THE EASTERN SEABOARD WILL
FINALLY MOVE AWAY FROM THE REGION AS UPPER HEIGHTS BUILD ACROSS
GEORGIA AND SOUTH CAROLINA. THIS SHOULD RESULT IN SUNSHINE AND
WARMER TEMPERATURES NEARING 80 DEGREES ALONG COASTAL SOUTH
CAROLINA AND REACHING THE LOWER 80S ACROSS INLAND GEORGIA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED THROUGH 12Z THURSDAY. ISOLATED SHOWERS ARE
POSSIBLE FDR THE NEXT HOUR OR TWO THIS MORNING.

EXTENDED AVIATION OUTLOOK...VFR. GUSTY SURFACE WINDS ARE EXPECTED
ON THURSDAY IN THE WAKE OF A SECONDARY COLD FRONT DURING THE
AFTERNOON.

&&

.MARINE...
TODAY...CONDITIONS WILL REMAIN WELL BELOW SMALL CRAFT ADVISORY
LEVELS BEHIND A COLD FRONT SHIFTING OVER THE WESTERN ATLANTIC. IN
GENERAL...WEST SOUTHWEST WINDS WILL SLIGHTLY VEER TO WEST THIS
AFTERNOON AND REMAIN AT OR BELOW 10-15 KT. SEAS WILL RANGE BETWEEN
2-4 FT...BUT WILL SLOWLY SUBSIDE THROUGH THE EVENING.

TONIGHT...A SECOND COLD FRONT WILL APPROACH THE REGION FROM THE
NORTHWEST...PASSING THROUGH AROUND DAYBREAK. IN ADVANCE OF THIS
FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT...INCREASING
TO AROUND 15-20 KT AFTER MIDNIGHT. A SMALL CRAFT ADVISORY MIGHT
BE NEEDED FOR THE OUTER GEORGIA WATERS LATE AT NIGHT DUE TO WIND
GUSTS. SEAS WILL BUILD TO ABOUT 3-5 FT BY DAYBREAK.

EXTENDED...THE ARRIVAL OF THE DEEP UPPER LOW AND STRONG VORTICITY
MAXIMA LATE THURSDAY AND THURSDAY NIGHT WILL INCITE STRONG LOW
LEVEL COLD AIR ADVECTION WHICH WILL RESULT IN SUBSTANTIAL SURGES
ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT NEAR SHORE AND 4-7 FT WELL OFFSHORE.
CANNOT RULE OUT A BRIEF SURGE OF GALE FORCE GUSTS FROM GRAYS REEF
SEAWARD THURSDAY EVENING AS THE VORT PASSES OVERHEAD.

CONDITIONS WILL BEGIN TO IMPROVE BY FRIDAY. HIGH PRESSURE WILL
RETURN FRIDAY AFTERNOON AND PERSIST OVER THE WEEKEND WITH WINDS
GENERALLY 15 KT OR LESS. SEAS ON AVERAGE LATE FRIDAY INTO THE
WEEKEND WILL AVERAGE 2-3 FEET. EARLY NEXT WEEK...A S TO SW SYNOPTIC
FLOW WILL PREVAIL ON THE PERIPHERY OF ATLC HIGH PRES OFFSHORE.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...DPB
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...DPB
EQUIPMENT...





000
FXUS62 KCHS 041100
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
700 AM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS MORNING. A
SECONDARY COLD FRONT WILL MOVE THROUGH THE AREA EARLY THURSDAY.
HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST LATE
WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR COLD FRONT SHOULD
DROP INTO THE CAROLINAS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
TODAY...A TROUGH WILL BE AMPLIFYING OVER THE EASTERN HALF OF THE
COUNTRY. MEANWHILE AN UPPER LEVEL LOW INITIALLY CENTERED OVER THE
GREAT LAKES WILL SHIFT OVER THE OHIO VALLEY THROUGH THE DAY. AT
THE SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN SMALL POPS DECREASING FROM WEST TO EAST
THIS MORNING. REMNANT SHOWERS SHOULD BE LIMITED TO THE COASTAL
WATERS DURING THE DAY BUT A STRAY LIGHT SHOWER IS NOT OUT OF THE
QUESTION ALONG THE COAST BEFORE NOON. DEEP WESTERLY FLOW WILL DRY
OUT THE ATMOSPHERE WITH SKIES BECOMING MOSTLY SUNNY BY THE
AFTERNOON. HIGH TEMPERATURES ARE EXPECTED TO REACH INTO THE UPPER
70S TO AROUND 80 DEGREES.

TONIGHT...ANOTHER COLD FRONT WILL BE APPROACHING FROM THE
NORTHWEST. IT SHOULD PASS THROUGH OUR AREA LATE. THIS FRONT WILL
BE DRY...BRINGING JUST SOME CLOUDS...BUT NO PRECIPITATION.
TEMPERATURES ARE EXPECTED TO BE MUCH COOLER THAN RECENT
NIGHTS...ALTHOUGH STILL CLOSE TO NORMAL...THE MID TO UPPER
50S...AND NEAR 60 DEGREES AT THE BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...
THURSDAY...A DEEP AND DIGGING UPPER LOW WILL REACH THE CAROLINAS
THURSDAY AFTERNOON. THE MAIN VORT LOBE ASSOCIATED WITH THE LOW
CENTER WILL SHIFT SE ACROSS THE FORECAST AREA THROUGH THE AFTERNOON
AS CYCLOGENESIS TAKES OVER EASTERN NORTH CAROLINA. GIVEN THE FORCING
IN PLACE...WE HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO AN IMPRESSIVE -25C 500 MB COLD POOL
REACHING THE CSRA AND MIDLANDS BY LATE DAY. FORECAST SOUNDINGS
INDICATE VERY SMALL REGIONS OF CAPE BETWEEN 6 KFT AND 10 KFT AND
POTENTIAL FOR ANY MIXED GRAUPEL/HAIL PCPN NW ZONES APPEARS QUITE
SLIM AS MOISTURE IS JUST NOT THERE. HIGH TEMPS WILL RUN MUCH COOLER
IN THE LOWER 70S...FALLING THROUGH THE 60S AFTER MID AFTERNOON. THE
PRESSURE GRADIENT WILL TIGHTEN AND WNW WINDS WILL BECOME GUSTY IN
THE AFTERNOON...ROUGHLY 25 TO 30 MPH UNDER PARTLY CLOUDY SKIES.
CONDITIONS SHOULD BE DRY THURSDAY NIGHT BUT QUITE CHILLY WITH LOWS
IN THE UPPER 40S TO LOWER 50S.

FRIDAY THE PATTERN DOES NOT CHANGE VERY MUCH WITH THE DEEP UPPER
TROUGH AND MID LEVEL CUT-OFF LOW REMAINING ALONG THE EAST COAST.
STEEP LOW AND MID LEVEL LAPSE RATES WILL PERSIST WITH CYCLONIC FLOW
ALOFT. WE HAVE ADDED SOME SLIGHT CHANCE POPS FOR SHALLOW DIURNALLY
ENHANCED CONVECTION ACROSS PARTS OF THE CENTRAL SOUTH CAROLINA
COASTAL REGION...OTHERWISE WE MAINTAINED A MAINLY DRY FORECAST AS
LARGE LOW LEVEL TEMP AND DEW POINT SPREADS REMAIN THE NORM.
ANOTHER COOLER THAN CLIMO DAY IN STORE WITH HIGHS IN THE MID 70S
MOST AREAS.

SATURDAY...THE DEEP UPPER LOW ALONG THE EASTERN SEABOARD WILL
FINALLY MOVE AWAY FROM THE REGION AS UPPER HEIGHTS BUILD ACROSS
GEORGIA AND SOUTH CAROLINA. THIS SHOULD RESULT IN SUNSHINE AND
WARMER TEMPERATURES NEARING 80 DEGREES ALONG COASTAL SOUTH
CAROLINA AND REACHING THE LOWER 80S ACROSS INLAND GEORGIA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS EXPECTED THROUGH 12Z THURSDAY. ISOLATED SHOWERS ARE
POSSIBLE IN THE COASTAL CORRIDOR THROUGH LATE MORNING TODAY.

EXTENDED AVIATION OUTLOOK...VFR. GUSTY SURFACE WINDS ARE EXPECTED
ON THURSDAY IN THE WAKE OF A SECONDARY COLD FRONT DURING THE
AFTERNOON.

&&

.MARINE...
TODAY...A COLD FRONT WILL PASS THROUGH THE REGION THIS MORNING.
BEHIND THE FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT.
SEAS WILL AVERAGE 2-4 FT.

TONIGHT...A SECOND COLD FRONT WILL APPROACH THE REGION FROM THE
NORTHWEST...PASSING THROUGH AROUND DAYBREAK. IN ADVANCE OF THIS
FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT...INCREASING
TO AROUND 15-20 KT AFTER MIDNIGHT. A SMALL CRAFT ADVISORY MIGHT
BE NEEDED FOR THE OUTER GEORGIA WATERS LATE AT NIGHT DUE TO WIND
GUSTS. SEAS WILL BUILD TO ABOUT 3-5 FT BY DAYBREAK.

EXTENDED...THE ARRIVAL OF THE DEEP UPPER LOW AND STRONG VORTICITY
MAXIMA LATE THURSDAY AND THURSDAY NIGHT WILL INCITE STRONG LOW
LEVEL COLD AIR ADVECTION WHICH WILL RESULT IN SUBSTANTIAL SURGES
ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT NEAR SHORE AND 4-7 FT WELL OFFSHORE.
CANNOT RULE OUT A BRIEF SURGE OF GALE FORCE GUSTS FROM GRAYS REEF
SEAWARD THURSDAY EVENING AS THE VORT PASSES OVERHEAD.

CONDITIONS WILL BEGIN TO IMPROVE BY FRIDAY. HIGH PRESSURE WILL
RETURN FRIDAY AFTERNOON AND PERSIST OVER THE WEEKEND WITH WINDS
GENERALLY 15 KT OR LESS. SEAS ON AVERAGE LATE FRIDAY INTO THE
WEEKEND WILL AVERAGE 2-3 FEET. EARLY NEXT WEEK...A S TO SW SYNOPTIC
FLOW WILL PREVAIL ON THE PERIPHERY OF ATLC HIGH PRES OFFSHORE.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040812
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
412 AM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS MORNING. A
SECONDARY COLD FRONT WILL MOVE THROUGH THE AREA EARLY THURSDAY.
HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST LATE
WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR COLD FRONT SHOULD
DROP INTO THE CAROLINAS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...RADAR IS SHOWING SCATTERED CONVECTION ACROSS
PORTIONS OF OUR AREA. THESE ARE ASSOCIATED WITH A LOBE OF ENERGY
ROUNDING THE BASE OF THE TROUGH THAT IS CURRENTLY OVERSPREADING
THE EAST COAST. LIFT FROM AN APPROACHING COLD FRONT AND SOME
REMNANT INSTABILITY LEFT OVER FROM THE PREVIOUS DAY ARE ALSO
HELPING TO SUSTAIN THIS CONVECTION. IT IS EXPECTED TO CONTINUE
FOR THE NEXT FEW HOURS. A COLD FRONT IS FORECASTED TO MOVE THROUGH
OUR AREA AROUND DAYBREAK.

TODAY...A TROUGH WILL BE AMPLIFYING OVER THE EASTERN HALF OF THE
COUNTRY. MEANWHILE AN UPPER LEVEL LOW INITIALLY CENTERED OVER THE
GREAT LAKES WILL SHIFT OVER THE OHIO VALLEY THROUGH THE DAY. AT
THE SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN POPS DECREASING FROM WEST TO EAST DURING
THE DAY. REMNANT SHOWERS SHOULD BE LIMITED TO THE COASTAL WATERS
DURING THE DAY BUT A STRAY LIGHT SHOWER IS NOT OUT OF THE
QUESTION ALONG THE COAST BEFORE NOON. DEEP WESTERLY FLOW WILL DRY
OUT THE ATMOSPHERE WITH SKIES BECOMING MOSTLY SUNNY BY THE
AFTERNOON. HIGH TEMPERATURES ARE EXPECTED TO REACH INTO THE UPPER
70S TO AROUND 80 DEGREES.

TONIGHT...ANOTHER COLD FRONT WILL BE APPROACHING FROM THE
NORTHWEST. IT SHOULD PASS THROUGH OUR AREA LATE. THIS FRONT WILL
BE DRY...BRINGING JUST SOME CLOUDS...BUT NO PRECIPITATION.
TEMPERATURES ARE EXPECTED TO BE MUCH COOLER THAN RECENT
NIGHTS...ALTHOUGH STILL CLOSE TO NORMAL...THE MID TO UPPER
50S...AND NEAR 60 DEGREES AT THE BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...

THURSDAY...A DEEP AND DIGGING UPPER LOW WILL REACH THE CAROLINAS
THURSDAY AFTERNOON. THE MAIN VORT LOBE ASSOCIATED WITH THE LOW
CENTER WILL SHIFT SE ACROSS THE FORECAST AREA THROUGH THE AFTERNOON
AS CYCLOGENESIS TAKES OVER EASTERN NORTH CAROLINA. GIVEN THE FORCING
IN PLACE...WE HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO AN IMPRESSIVE -25C 500 MB COLD POOL
REACHING THE CSRA AND MIDLANDS BY LATE DAY. FORECAST SOUNDINGS
INDICATE VERY SMALL REGIONS OF CAPE BETWEEN 6 KFT AND 10 KFT AND
POTENTIAL FOR ANY MIXED GRAUPEL/HAIL PCPN NW ZONES APPEARS QUITE
SLIM AS MOISTURE IS JUST NOT THERE. HIGH TEMPS WILL RUN MUCH COOLER
IN THE LOWER 70S...FALLING THROUGH THE 60S AFTER MID AFTERNOON. THE
PRESSURE GRADIENT WILL TIGHTEN AND WNW WINDS WILL BECOME GUSTY IN
THE AFTERNOON...ROUGHLY 25 TO 30 MPH UNDER PARTLY CLOUDY SKIES.
CONDITIONS SHOULD BE DRY THURSDAY NIGHT BUT QUITE CHILLY WITH LOWS
IN THE UPPER 40S TO LOWER 50S.

FRIDAY THE PATTERN DOES NOT CHANGE VERY MUCH WITH THE DEEP UPPER
TROUGH AND MID LEVEL CUT-OFF LOW REMAINING ALONG THE EAST COAST.
STEEP LOW AND MID LEVEL LAPSE RATES WILL PERSIST WITH CYCLONIC FLOW
ALOFT. WE HAVE ADDED SOME SLIGHT CHANCE POPS FOR SHALLOW DIURNALLY
ENHANCED CONVECTION ACROSS PARTS OF THE CENTRAL SOUTH CAROLINA
COASTAL REGION OTHERWISE WE MAINTAINED A MAINLY DRY FORECAST AS
LARGE LOW LEVEL TEMP AND DEW POINT SPREADS REMAIN THE NORM. ANOTHER
COOLER THAN CLIMO DAY IN STORE WITH HIGHS IN THE MID 70S MOST AREAS.

SATURDAY...THE DEEP UPPER LOW ALONG THE EASTERN SEABOARD WILL
FINALLY MOVE AWAY FROM THE REGION AS UPPER HEIGHTS BUILD ACROSS
GEORGIA AND SOUTH CAROLINA. THIS SHOULD RESULT IN SUNSHINE AND
WARMER TEMPERATURES NEARING 80 DEGREES ALONG COASTAL SOUTH
CAROLINA AND REACHING THE LOWER 80S ACROSS INLAND GEORGIA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
06Z TAFS...THERE IS THE RISK FOR A BRIEF -SHRA OR -TSRA...MAINLY
BEFORE 09Z. OPTED TO HIGHLIGHT THIS WITH VC WORDING SINCE
CONFIDENCE IS LOW EITHER TERMINAL WILL BE IMPACTED DIRECTLY. THIS
RISK WILL QUICKLY DROP AROUND DAYBREAK AS A COLD FRONT PASSES
THROUGH THE AREA...BRINGING DRIER AIR INTO THE REGION. VFR IS
EXPECTED TO PREVAIL THROUGH 06Z THURSDAY.

EXTENDED AVIATION OUTLOOK...VFR. GUSTY SURFACE WINDS ARE EXPECTED
ON THURSDAY IN THE WAKE OF A SECONDARY COLD FRONT DURING THE
AFTERNOON.

&&

.MARINE...
TODAY...A COLD FRONT WILL PASS THROUGH THE REGION THIS MORNING.
BEHIND THE FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT.
SEAS WILL AVERAGE 2-4 FT.

TONIGHT...A SECOND COLD FRONT WILL APPROACH THE REGION FROM THE
NORTHWEST...PASSING THROUGH AROUND DAYBREAK. IN ADVANCE OF THIS
FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT...INCREASING
TO AROUND 15-20 KT AFTER MIDNIGHT. A SMALL CRAFT ADVISORY MIGHT
BE NEEDED FOR THE OUTER GEORGIA WATERS LATE AT NIGHT DUE TO WIND
GUSTS. SEAS WILL BUILD TO ABOUT 3-5 FT BY DAYBREAK.

EXTENDED...THE ARRIVAL OF THE DEEP UPPER LOW AND STRONG VORTICITY
MAXIMA LATE THURSDAY AND THURSDAY NIGHT WILL INCITE STRONG LOW
LEVEL COLD AIR ADVECTION WHICH WILL RESULT IN SUBSTANTIAL SURGES
ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT NEAR SHORE AND 4-7 FT WELL OFFSHORE.
CANNOT RULE OUT A BRIEF SURGE OF GALE FORCE GUSTS FROM GRAYS REEF
SEAWARD THURSDAY EVENING AS THE VORT PASSES OVERHEAD.

CONDITIONS WILL BEGIN TO IMPROVE BY FRIDAY. HIGH PRESSURE WILL
RETURN FRIDAY AFTERNOON AND PERSIST OVER THE WEEKEND WITH WINDS
GENERALLY 15 KT OR LESS. SEAS ON AVERAGE LATE FRIDAY INTO THE
WEEKEND WILL AVERAGE 2-3 FEET. EARLY NEXT WEEK...A S TO SW SYNOPTIC
FLOW WILL PREVAIL ON THE PERIPHERY OF ATLC HIGH PRES OFFSHORE.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040812
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
412 AM EDT WED MAY 4 2016

.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION THIS MORNING. A
SECONDARY COLD FRONT WILL MOVE THROUGH THE AREA EARLY THURSDAY.
HIGH PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST LATE
WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR COLD FRONT SHOULD
DROP INTO THE CAROLINAS EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
EARLY THIS MORNING...RADAR IS SHOWING SCATTERED CONVECTION ACROSS
PORTIONS OF OUR AREA. THESE ARE ASSOCIATED WITH A LOBE OF ENERGY
ROUNDING THE BASE OF THE TROUGH THAT IS CURRENTLY OVERSPREADING
THE EAST COAST. LIFT FROM AN APPROACHING COLD FRONT AND SOME
REMNANT INSTABILITY LEFT OVER FROM THE PREVIOUS DAY ARE ALSO
HELPING TO SUSTAIN THIS CONVECTION. IT IS EXPECTED TO CONTINUE
FOR THE NEXT FEW HOURS. A COLD FRONT IS FORECASTED TO MOVE THROUGH
OUR AREA AROUND DAYBREAK.

TODAY...A TROUGH WILL BE AMPLIFYING OVER THE EASTERN HALF OF THE
COUNTRY. MEANWHILE AN UPPER LEVEL LOW INITIALLY CENTERED OVER THE
GREAT LAKES WILL SHIFT OVER THE OHIO VALLEY THROUGH THE DAY. AT
THE SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN POPS DECREASING FROM WEST TO EAST DURING
THE DAY. REMNANT SHOWERS SHOULD BE LIMITED TO THE COASTAL WATERS
DURING THE DAY BUT A STRAY LIGHT SHOWER IS NOT OUT OF THE
QUESTION ALONG THE COAST BEFORE NOON. DEEP WESTERLY FLOW WILL DRY
OUT THE ATMOSPHERE WITH SKIES BECOMING MOSTLY SUNNY BY THE
AFTERNOON. HIGH TEMPERATURES ARE EXPECTED TO REACH INTO THE UPPER
70S TO AROUND 80 DEGREES.

TONIGHT...ANOTHER COLD FRONT WILL BE APPROACHING FROM THE
NORTHWEST. IT SHOULD PASS THROUGH OUR AREA LATE. THIS FRONT WILL
BE DRY...BRINGING JUST SOME CLOUDS...BUT NO PRECIPITATION.
TEMPERATURES ARE EXPECTED TO BE MUCH COOLER THAN RECENT
NIGHTS...ALTHOUGH STILL CLOSE TO NORMAL...THE MID TO UPPER
50S...AND NEAR 60 DEGREES AT THE BEACHES.

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY/...

THURSDAY...A DEEP AND DIGGING UPPER LOW WILL REACH THE CAROLINAS
THURSDAY AFTERNOON. THE MAIN VORT LOBE ASSOCIATED WITH THE LOW
CENTER WILL SHIFT SE ACROSS THE FORECAST AREA THROUGH THE AFTERNOON
AS CYCLOGENESIS TAKES OVER EASTERN NORTH CAROLINA. GIVEN THE FORCING
IN PLACE...WE HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO AN IMPRESSIVE -25C 500 MB COLD POOL
REACHING THE CSRA AND MIDLANDS BY LATE DAY. FORECAST SOUNDINGS
INDICATE VERY SMALL REGIONS OF CAPE BETWEEN 6 KFT AND 10 KFT AND
POTENTIAL FOR ANY MIXED GRAUPEL/HAIL PCPN NW ZONES APPEARS QUITE
SLIM AS MOISTURE IS JUST NOT THERE. HIGH TEMPS WILL RUN MUCH COOLER
IN THE LOWER 70S...FALLING THROUGH THE 60S AFTER MID AFTERNOON. THE
PRESSURE GRADIENT WILL TIGHTEN AND WNW WINDS WILL BECOME GUSTY IN
THE AFTERNOON...ROUGHLY 25 TO 30 MPH UNDER PARTLY CLOUDY SKIES.
CONDITIONS SHOULD BE DRY THURSDAY NIGHT BUT QUITE CHILLY WITH LOWS
IN THE UPPER 40S TO LOWER 50S.

FRIDAY THE PATTERN DOES NOT CHANGE VERY MUCH WITH THE DEEP UPPER
TROUGH AND MID LEVEL CUT-OFF LOW REMAINING ALONG THE EAST COAST.
STEEP LOW AND MID LEVEL LAPSE RATES WILL PERSIST WITH CYCLONIC FLOW
ALOFT. WE HAVE ADDED SOME SLIGHT CHANCE POPS FOR SHALLOW DIURNALLY
ENHANCED CONVECTION ACROSS PARTS OF THE CENTRAL SOUTH CAROLINA
COASTAL REGION OTHERWISE WE MAINTAINED A MAINLY DRY FORECAST AS
LARGE LOW LEVEL TEMP AND DEW POINT SPREADS REMAIN THE NORM. ANOTHER
COOLER THAN CLIMO DAY IN STORE WITH HIGHS IN THE MID 70S MOST AREAS.

SATURDAY...THE DEEP UPPER LOW ALONG THE EASTERN SEABOARD WILL
FINALLY MOVE AWAY FROM THE REGION AS UPPER HEIGHTS BUILD ACROSS
GEORGIA AND SOUTH CAROLINA. THIS SHOULD RESULT IN SUNSHINE AND
WARMER TEMPERATURES NEARING 80 DEGREES ALONG COASTAL SOUTH
CAROLINA AND REACHING THE LOWER 80S ACROSS INLAND GEORGIA.

&&

.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
DEEP LAYERED RIDGING SHOULD PERSIST FROM THE LATTER HALF OF THE
WEEKEND INTO EARLY NEXT WEEK. SUNDAY AND MONDAY HAVE THE LOOK OF
MUCH WARMER DAYS AS WEST FLOW IN THE BOUNDARY LAYER AND PLENTY OF
SUNSHINE ARE ON TAP. WE RAISED HIGHS A FEW DEGREES TO SHOW MUCH OF
THE FORECAST AREA REACHING 90 DEGREES. RIDGING SHOULD BEGIN TO BREAK
DOWN HEADED TOWARD MID WEEK WITH ONLY SLIGHT CHANCES OF CONVECTION
AND TEMPS LIKELY REMAINING ABOVE CLIMO.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
06Z TAFS...THERE IS THE RISK FOR A BRIEF -SHRA OR -TSRA...MAINLY
BEFORE 09Z. OPTED TO HIGHLIGHT THIS WITH VC WORDING SINCE
CONFIDENCE IS LOW EITHER TERMINAL WILL BE IMPACTED DIRECTLY. THIS
RISK WILL QUICKLY DROP AROUND DAYBREAK AS A COLD FRONT PASSES
THROUGH THE AREA...BRINGING DRIER AIR INTO THE REGION. VFR IS
EXPECTED TO PREVAIL THROUGH 06Z THURSDAY.

EXTENDED AVIATION OUTLOOK...VFR. GUSTY SURFACE WINDS ARE EXPECTED
ON THURSDAY IN THE WAKE OF A SECONDARY COLD FRONT DURING THE
AFTERNOON.

&&

.MARINE...
TODAY...A COLD FRONT WILL PASS THROUGH THE REGION THIS MORNING.
BEHIND THE FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT.
SEAS WILL AVERAGE 2-4 FT.

TONIGHT...A SECOND COLD FRONT WILL APPROACH THE REGION FROM THE
NORTHWEST...PASSING THROUGH AROUND DAYBREAK. IN ADVANCE OF THIS
FRONT WINDS WILL GENERALLY BE FROM THE W AT 10-15 KT...INCREASING
TO AROUND 15-20 KT AFTER MIDNIGHT. A SMALL CRAFT ADVISORY MIGHT
BE NEEDED FOR THE OUTER GEORGIA WATERS LATE AT NIGHT DUE TO WIND
GUSTS. SEAS WILL BUILD TO ABOUT 3-5 FT BY DAYBREAK.

EXTENDED...THE ARRIVAL OF THE DEEP UPPER LOW AND STRONG VORTICITY
MAXIMA LATE THURSDAY AND THURSDAY NIGHT WILL INCITE STRONG LOW
LEVEL COLD AIR ADVECTION WHICH WILL RESULT IN SUBSTANTIAL SURGES
ACROSS THE COASTAL WATERS. SMALL CRAFT ADVISORIES WILL LIKELY BE
NEEDED BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT NEAR SHORE AND 4-7 FT WELL OFFSHORE.
CANNOT RULE OUT A BRIEF SURGE OF GALE FORCE GUSTS FROM GRAYS REEF
SEAWARD THURSDAY EVENING AS THE VORT PASSES OVERHEAD.

CONDITIONS WILL BEGIN TO IMPROVE BY FRIDAY. HIGH PRESSURE WILL
RETURN FRIDAY AFTERNOON AND PERSIST OVER THE WEEKEND WITH WINDS
GENERALLY 15 KT OR LESS. SEAS ON AVERAGE LATE FRIDAY INTO THE
WEEKEND WILL AVERAGE 2-3 FEET. EARLY NEXT WEEK...A S TO SW SYNOPTIC
FLOW WILL PREVAIL ON THE PERIPHERY OF ATLC HIGH PRES OFFSHORE.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040332
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1132 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE SEVERE/STRONG THUNDERSTORMS HAVE MOSTLY MOVED OUT OF THE AREA.
THE WORST STORMS REMAIN OFFSHORE...AND ARE MOVING FURTHER AWAY
FROM BOTH LAND AND OUR AREA. THE THREAT OF STORMS WILL DECREASE
OVERNIGHT AS THE ATMOSPHERE STABILIZES ATMOSPHERE AND THE COLD
FRONT WITH DRIER AIR APPROACHES OUR AREA. POPS WILL GRADUALLY
TAPER DOWN DURING THE OVERNIGHT HOURS AS REMNANT SHOWERS DECREASE.
WITH PLENTY OF CLOUD COVER AND COLD AIR ADVECTION REACHING OUR
AREA AFTER DAYBREAK...LOWS WILL BE ABOVE NORMAL...THE LOWER 60S
ACROSS THE NW TIER AND MID TO UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
THE WORST SHOWERS AND THUNDERSTORMS HAVE PASSED THROUGH THE
TERMINALS. THERE IS STILL A RISK FOR ANOTHER -SHRA OR -TSRA OVER
THE NEXT FEW HOURS. THIS RISK WILL QUICKLY DROP AROUND DAYBREAK AS
THE COLD FRONT PASSES THROUGH THE AREA. VFR IS EXPECTED TO PREVAIL INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040332
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1132 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE SEVERE/STRONG THUNDERSTORMS HAVE MOSTLY MOVED OUT OF THE AREA.
THE WORST STORMS REMAIN OFFSHORE...AND ARE MOVING FURTHER AWAY
FROM BOTH LAND AND OUR AREA. THE THREAT OF STORMS WILL DECREASE
OVERNIGHT AS THE ATMOSPHERE STABILIZES ATMOSPHERE AND THE COLD
FRONT WITH DRIER AIR APPROACHES OUR AREA. POPS WILL GRADUALLY
TAPER DOWN DURING THE OVERNIGHT HOURS AS REMNANT SHOWERS DECREASE.
WITH PLENTY OF CLOUD COVER AND COLD AIR ADVECTION REACHING OUR
AREA AFTER DAYBREAK...LOWS WILL BE ABOVE NORMAL...THE LOWER 60S
ACROSS THE NW TIER AND MID TO UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /04Z WEDNESDAY THROUGH SUNDAY/...
THE WORST SHOWERS AND THUNDERSTORMS HAVE PASSED THROUGH THE
TERMINALS. THERE IS STILL A RISK FOR ANOTHER -SHRA OR -TSRA OVER
THE NEXT FEW HOURS. THIS RISK WILL QUICKLY DROP AROUND DAYBREAK AS
THE COLD FRONT PASSES THROUGH THE AREA. VFR IS EXPECTED TO PREVAIL INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040224
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1024 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
FOLLOWING COORDINATION WITH SPC...THE SEVERE THUNDERSTORM WATCH
WAS EXTENDED FOR BERKELEY...CHARELESTON AND COLLETON COUNTIES
UNTIL MIDNIGHT. A STRONG LINE OF SEVERE THUNDERSTORMS IS MOVING
THROUGH THESE COUNTIES AND IS EXPECTED TO MOVE TO THE NORTHEAST
AND OUT OF THESE AREAS AROUND MIDNIGHT. THE MAIN WEATHER HAZARDS
FROM THIS LINE ARE DAMAGING WINDS AND MARGINALLY SEVERE HAIL.
DESPITE THE MODELS SHOWING SLIGHT DECREASES IN INSTABILITY...THE
SYSTEM IS MAINTAINING ITSELF AND IS NOT EXPECTED TO WEAKEN TOO
MUCH BEFORE MOVING OUT OF THE AREA. FOLLOWING THIS LINE OF STORMS
THE SEVERE THREAT WILL DECREASE AS THE NIGHT PROGRESSES DUE TO A
STABILIZING ATMOSPHERE AND THE COLD FRONT WITH DRIER AIR
APPROACHING OUR AREA. POPS WILL PERSIST IN THE OVERNIGHT
HOURS...MAINLY FROM REMNANT SHOWERS. THESE WILL DECREASE AROUND
DAYBREAK AS THE FRONT APPROACHES. LOWS WILL BE ABOVE NORMAL...THE
LOWER 60S NW TIER...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
CLUSTERS OF SHRA/TSRA WILL IMPACT THE TERMINALS EARLY TONIGHT IN
ADVANCE OF A COLD FRONT. THE WORST CONDITIONS HAVE ALREADY PASSED
KSAV. WE ARE SHOWING A 2 HOUR TEMPO WINDOW AT KCHS WITH A BOUT
IFR CEILINGS IN +TSRA FROM 02-04Z.

THERE IS STILL A RISK FOR ANOTHER SHRA OR TSRA LATER TONIGHT INTO
EARLY WEDNESDAY UNTIL THE PASSAGE OF A COLD FRONT...BUT FOR THE
MOST PART VFR CONDITIONS WILL PREVAIL OVERNIGHT TONIGHT INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040224
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1024 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
FOLLOWING COORDINATION WITH SPC...THE SEVERE THUNDERSTORM WATCH
WAS EXTENDED FOR BERKELEY...CHARELESTON AND COLLETON COUNTIES
UNTIL MIDNIGHT. A STRONG LINE OF SEVERE THUNDERSTORMS IS MOVING
THROUGH THESE COUNTIES AND IS EXPECTED TO MOVE TO THE NORTHEAST
AND OUT OF THESE AREAS AROUND MIDNIGHT. THE MAIN WEATHER HAZARDS
FROM THIS LINE ARE DAMAGING WINDS AND MARGINALLY SEVERE HAIL.
DESPITE THE MODELS SHOWING SLIGHT DECREASES IN INSTABILITY...THE
SYSTEM IS MAINTAINING ITSELF AND IS NOT EXPECTED TO WEAKEN TOO
MUCH BEFORE MOVING OUT OF THE AREA. FOLLOWING THIS LINE OF STORMS
THE SEVERE THREAT WILL DECREASE AS THE NIGHT PROGRESSES DUE TO A
STABILIZING ATMOSPHERE AND THE COLD FRONT WITH DRIER AIR
APPROACHING OUR AREA. POPS WILL PERSIST IN THE OVERNIGHT
HOURS...MAINLY FROM REMNANT SHOWERS. THESE WILL DECREASE AROUND
DAYBREAK AS THE FRONT APPROACHES. LOWS WILL BE ABOVE NORMAL...THE
LOWER 60S NW TIER...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
CLUSTERS OF SHRA/TSRA WILL IMPACT THE TERMINALS EARLY TONIGHT IN
ADVANCE OF A COLD FRONT. THE WORST CONDITIONS HAVE ALREADY PASSED
KSAV. WE ARE SHOWING A 2 HOUR TEMPO WINDOW AT KCHS WITH A BOUT
IFR CEILINGS IN +TSRA FROM 02-04Z.

THERE IS STILL A RISK FOR ANOTHER SHRA OR TSRA LATER TONIGHT INTO
EARLY WEDNESDAY UNTIL THE PASSAGE OF A COLD FRONT...BUT FOR THE
MOST PART VFR CONDITIONS WILL PREVAIL OVERNIGHT TONIGHT INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040122
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
922 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE SEVERE WEATHER THREAT CONTINUES THROUGH 10 PM. A STRONG LINE
OF SEVERE THUNDERSTORMS IS MOVING THROUGH THE CENTRAL PORTION OF
OUR AREA AT APPROXIMATELY 920 PM...MOVING TO THE NORTHEAST AT A
PRETTY GOOD PACE. THE MAIN WEATHER HAZARDS FROM THIS LINE ARE
DAMAGING WINDS AND MARGINALLY SEVERE HAIL. THE CURRENT RAP IS
STILL INDICATING SBCAPES AROUND 1500 J/KG AHEAD OF THE LINE WITH
DCAPES AROUND 800 J/KG. THIS COULD HELP MAINTAIN THE LINE FOR
POTENTIALLY ANOTHER 1-3 HOURS. THOUGH...THIS DOES NOT MEAN IT WILL
DEFINITELY STAY SEVERE THE ENTIRE TIME. THE SEVERE THREAT WILL
DECREASE AS THE EVENING/NIGHT PROGRESSES DUE TO A STABILIZING
ATMOSPHERE AND THE COLD FRONT WITH DRIER AIR APPROACHING OUR AREA.
THOUGH...STRONG STORMS MAY MAINTAIN UNTIL ABOUT MIDNIGHT,

POPS WILL PERSIST IN THE OVERNIGHT HOURS...MAINLY FROM REMNANT
SHOWERS. THESE WILL DECREASE AROUND DAYBREAK AS THE FRONT
APPROACHES. FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN
FAR ABOVE NORMAL AND THAT SHOULD BE THE CASE AGAIN TONIGHT WITH
THE COOL ADVECTION NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER
WILL BE COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
CLUSTERS OF SHRA/TSRA WILL IMPACT THE TERMINALS EARLY TONIGHT IN
ADVANCE OF A COLD FRONT. THE WORST CONDITIONS HAVE ALREADY PASSED
KSAV. WE ARE SHOWING A 2 HOUR TEMPO WINDOW AT KCHS WITH A BOUT
MVFR CEILINGS IN -TSRA FROM 02-04Z.

THERE IS STILL A RISK FOR ANOTHER SHRA OR TSRA LATER TONIGHT INTO
EARLY WEDNESDAY UNTIL THE PASSAGE OF A COLD FRONT...BUT FOR THE
MOST PART VFR CONDITIONS WILL PREVAIL OVERNIGHT TONIGHT INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 040122
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
922 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE SEVERE WEATHER THREAT CONTINUES THROUGH 10 PM. A STRONG LINE
OF SEVERE THUNDERSTORMS IS MOVING THROUGH THE CENTRAL PORTION OF
OUR AREA AT APPROXIMATELY 920 PM...MOVING TO THE NORTHEAST AT A
PRETTY GOOD PACE. THE MAIN WEATHER HAZARDS FROM THIS LINE ARE
DAMAGING WINDS AND MARGINALLY SEVERE HAIL. THE CURRENT RAP IS
STILL INDICATING SBCAPES AROUND 1500 J/KG AHEAD OF THE LINE WITH
DCAPES AROUND 800 J/KG. THIS COULD HELP MAINTAIN THE LINE FOR
POTENTIALLY ANOTHER 1-3 HOURS. THOUGH...THIS DOES NOT MEAN IT WILL
DEFINITELY STAY SEVERE THE ENTIRE TIME. THE SEVERE THREAT WILL
DECREASE AS THE EVENING/NIGHT PROGRESSES DUE TO A STABILIZING
ATMOSPHERE AND THE COLD FRONT WITH DRIER AIR APPROACHING OUR AREA.
THOUGH...STRONG STORMS MAY MAINTAIN UNTIL ABOUT MIDNIGHT,

POPS WILL PERSIST IN THE OVERNIGHT HOURS...MAINLY FROM REMNANT
SHOWERS. THESE WILL DECREASE AROUND DAYBREAK AS THE FRONT
APPROACHES. FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN
FAR ABOVE NORMAL AND THAT SHOULD BE THE CASE AGAIN TONIGHT WITH
THE COOL ADVECTION NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER
WILL BE COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
CLUSTERS OF SHRA/TSRA WILL IMPACT THE TERMINALS EARLY TONIGHT IN
ADVANCE OF A COLD FRONT. THE WORST CONDITIONS HAVE ALREADY PASSED
KSAV. WE ARE SHOWING A 2 HOUR TEMPO WINDOW AT KCHS WITH A BOUT
MVFR CEILINGS IN -TSRA FROM 02-04Z.

THERE IS STILL A RISK FOR ANOTHER SHRA OR TSRA LATER TONIGHT INTO
EARLY WEDNESDAY UNTIL THE PASSAGE OF A COLD FRONT...BUT FOR THE
MOST PART VFR CONDITIONS WILL PREVAIL OVERNIGHT TONIGHT INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 032341
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
741 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THE SEVERE WEATHER THREAT CONTINUES THROUGH 10 PM. THE MAIN
WEATHER HAZARDS ARE DAMAGING WINDS RESULTING FROM DCAPES OVER
1000 J/KG AND ALSO MARGINALLY SEVERE HAIL WITH CAPE VALUES IN THE
HAIL GROWTH REGION OF 500-600 J/KG. IF THE RESULTANT SEA BREEZE IS
ABLE TO BACK WINDS ENOUGH TO THE SOUTH THEN THERE IS ALSO A RISK
FOR AN ISOLATED TORNADO ALONG THE SC COASTAL CORRIDOR THIS
EVENING.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS
1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL THIS WILL SUPPORT THE
RISK FOR AT LEAST LOCALLY HEAVY RAINS. THE ORIENTATION OF STORMS
MAINLY IN A WEST-EAST ALIGNMENT IS IN TANDEM WITH THE STEERING
FLOW AND COULD SUPPORT A RISK FOR AT LEAST MINOR-MODERATE FLOODING
CONCERNS. IF BACK-BUILDING AND/OR TRAINING OCCURS THAN THERE IS A
RISK FOR LOCALIZED FLASH FLOODING.

CONVECTION WILL WANE A FEW HOURS AFTER DARK...BUT WITH THE COLD
FRONT NOT EXPECTED TO MOVE THROUGH UNTIL AFTER MIDNIGHT NW AND NOT
REACHING THE COAST UNTIL CLOSER TO DAYBREAK...WE HAVE HELD ONTO
SLIGHT CHANCE AND CHANCE POPS THROUGH MUCH OF THE NIGHT. A
DIVERGENT PATTERN OF THE SUB-TROPICAL JET TO OUR SOUTH AND THE
POLAR JET TO OUR NORTH/NW WILL CREATE THE NECESSARY DIFLUENCE
ALOFT...AND WE/RE WAITING FOR THE MAIN SHORT WAVE TO ARRIVE CLOSER
TO SUNRISE WEDNESDAY.

FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN FAR ABOVE
NORMAL AND THAT SHOULD BE THE CASE AGAIN TONIGHT WITH THE COOL
ADVECTION NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER WILL BE
COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
CLUSTERS OF SHRA/TSRA WILL IMPACT THE TERMINALS EARLY TONIGHT IN
ADVANCE OF A COLD FRONT. FOR NOW THE STRONGER STORMS APPEAR MORE
IN LINE TO MOVE THROUGH KSAV THAN AT KCHS. WE ARE SHOWING A 3 HOUR
TEMPO WINDOW AT KSAV OF MVFR OR POSSIBLE IFR CONDITIONS WITH A
BOUT OF STRONG WINDS AND MODERATE TO HEAVY RAINS IN +TSRA FROM
00-03Z. AT KCHS WE ARE MORE CONSERVATIVE INDICATING MARGINAL MVFR
CONDITIONS IN -TSRA FROM 02-04Z.

THERE IS STILL A RISK FOR ANOTHER SHRA OR TSRA LATER TONIGHT INTO
EARLY WEDNESDAY UNTIL THE PASSAGE OF A COLD FRONT...BUT FOR THE
MOST PART VFR CONDITIONS WILL PREVAIL OVERNIGHT TONIGHT INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 032334
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
734 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
TIMING OF THE POTENTIAL SEVERE WEATHER CONTINUES THROUGH 10 PM.
MAIN WEATHER HAZARDS WILL BE DAMAGING WINDS WITH DCAPES THAT AREA
NOW OVER 1000 J/KG AND ALSO MARGINALLY SEVERE HAIL WITH CAPE
VALUES IN THE HAIL GROWTH REGION OF 500-600 J/KG. IF THE RESULTANT
SEA BREEZE IS ABLE TO BACK WINDS ENOUGH TO THE SOUTH THEN THERE IS
ALSO A RISK FOR AN ISOLATED TORNADO ALONG THE SC COASTAL CORRIDOR
THIS EVENING.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS
1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR
AT LEAST LOCALLY HEAVY RAINS. THE ORIENTATION OF STORMS MAINLY IN
A WEST-EAST ALIGNMENT IS IN TANDEM WITH THE STEERING FLOW AND
COULD SUPPORT A RISK FOR AT LEAST MINOR-MODERATE FLOODING
CONCERNS. IF BACK-BUILDING AND/OR TRAINING OCCURS THAN THERE IS A
RISK FOR LOCALIZED FLASH FLOODING.

CONVECTION WILL WANE A FEW HOURS AFTER DARK...BUT WITH THE COLD
FRONT NOT EXPECTED TO MOVE THROUGH UNTIL AFTER MIDNIGHT NW AND NOT
REACHI9NG THE COAST UNTIL CLOSER TO DAYBREAK...WE HAVE HELD ONTO
SLIGHT CHANCE AND CHANCE POPS THROUGH MUCH OF THE NIGHT. A
DIVERGENT PATTERN OF THE SUB-TROPICAL JET TO OUR SOUTH AND THE
POLAR JET TO OUR NORTH/NW WILL CREATE THE NECESSARY DIFLUENCE
ALOFT...AND WE/RE WAITING FOR THE MAIN SHORT WAVE TO ARRIVE CLOSER
TO SUNRISE WEDNESDAY.

FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN FAR ABOVE
NORMAL AND THAT/S THE CASE AGAIN TONIGHT WITH THE COOL ADVECTION
NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER WILL BE
COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
CLUSTERS OF SHRA/TSRA WILL IMPACT THE TERMINALS EARLY TONIGHT IN
ADVANCE OF A COLD FRONT. FOR NOW THE STRONGER STORMS APPEAR MORE
IN LINE TO MOVE THROUGH KSAV THAN AT KCHS. WE ARE SHOWING A 3 HOUR
TEMPO WINDOW AT KSAV OF MVFR OR POSSIBLE IFR CONDITIONS WITH A
BOUT OF STRONG WINDS AND MODERATE TO HEAVY RAINS IN +TSRA FROM
00-03Z. AT KCHS WE ARE MORE CONSERVATIVE INDICATING MARGINAL MVFR
CONDITIONS IN -TSRA FROM 02-04Z.

THERE IS STILL A RISK FOR ANOTHER SHRA OR TSRA LATER TONIGHT INTO
EARLY WEDNESDAY UNTIL THE PASSAGE OF A COLD FRONT...BUT FOR THE
MOST PART VFR CONDITIONS WILL PREVAIL OVERNIGHT TONIGHT INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 032334
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
734 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
TIMING OF THE POTENTIAL SEVERE WEATHER CONTINUES THROUGH 10 PM.
MAIN WEATHER HAZARDS WILL BE DAMAGING WINDS WITH DCAPES THAT AREA
NOW OVER 1000 J/KG AND ALSO MARGINALLY SEVERE HAIL WITH CAPE
VALUES IN THE HAIL GROWTH REGION OF 500-600 J/KG. IF THE RESULTANT
SEA BREEZE IS ABLE TO BACK WINDS ENOUGH TO THE SOUTH THEN THERE IS
ALSO A RISK FOR AN ISOLATED TORNADO ALONG THE SC COASTAL CORRIDOR
THIS EVENING.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS
1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR
AT LEAST LOCALLY HEAVY RAINS. THE ORIENTATION OF STORMS MAINLY IN
A WEST-EAST ALIGNMENT IS IN TANDEM WITH THE STEERING FLOW AND
COULD SUPPORT A RISK FOR AT LEAST MINOR-MODERATE FLOODING
CONCERNS. IF BACK-BUILDING AND/OR TRAINING OCCURS THAN THERE IS A
RISK FOR LOCALIZED FLASH FLOODING.

CONVECTION WILL WANE A FEW HOURS AFTER DARK...BUT WITH THE COLD
FRONT NOT EXPECTED TO MOVE THROUGH UNTIL AFTER MIDNIGHT NW AND NOT
REACHI9NG THE COAST UNTIL CLOSER TO DAYBREAK...WE HAVE HELD ONTO
SLIGHT CHANCE AND CHANCE POPS THROUGH MUCH OF THE NIGHT. A
DIVERGENT PATTERN OF THE SUB-TROPICAL JET TO OUR SOUTH AND THE
POLAR JET TO OUR NORTH/NW WILL CREATE THE NECESSARY DIFLUENCE
ALOFT...AND WE/RE WAITING FOR THE MAIN SHORT WAVE TO ARRIVE CLOSER
TO SUNRISE WEDNESDAY.

FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN FAR ABOVE
NORMAL AND THAT/S THE CASE AGAIN TONIGHT WITH THE COOL ADVECTION
NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER WILL BE
COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
CLUSTERS OF SHRA/TSRA WILL IMPACT THE TERMINALS EARLY TONIGHT IN
ADVANCE OF A COLD FRONT. FOR NOW THE STRONGER STORMS APPEAR MORE
IN LINE TO MOVE THROUGH KSAV THAN AT KCHS. WE ARE SHOWING A 3 HOUR
TEMPO WINDOW AT KSAV OF MVFR OR POSSIBLE IFR CONDITIONS WITH A
BOUT OF STRONG WINDS AND MODERATE TO HEAVY RAINS IN +TSRA FROM
00-03Z. AT KCHS WE ARE MORE CONSERVATIVE INDICATING MARGINAL MVFR
CONDITIONS IN -TSRA FROM 02-04Z.

THERE IS STILL A RISK FOR ANOTHER SHRA OR TSRA LATER TONIGHT INTO
EARLY WEDNESDAY UNTIL THE PASSAGE OF A COLD FRONT...BUT FOR THE
MOST PART VFR CONDITIONS WILL PREVAIL OVERNIGHT TONIGHT INTO
WEDNESDAY.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-18 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 032131
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
531 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH THIS EVENING...THE NEAR TERM ENVIRONMENT IS STILL SHOWING
FAVORABLE THERMODYNAMICS AND DECENT LAPSE RATES...BUT NOW WE/RE ALSO
STARTING TO EXPERIENCE SOME SHEAR...MOST ESPECIALLY IN THE 0-6 KM
LAYER WHICH IS OVER 30 KT. BUT THE 0-1 KM SHEAR IS STILL LESS THAN
15 KT AND THAT ALONG WITH THE WESTERLY WINDS HAVING MIXED OUT SOME
OF THE DEW POINTS INTO THE LOWER AND MID 60S AND THE SEA
BREEZE PINNED NEAR THE COAST...THIS HAS ALLOWED FOR ONLY ISOLATED
TO SCATTERED COVERAGE OF NON-SEVERE STORMS SO FAR.

TIMING OF THE POTENTIAL SEVERE WEATHER HAS BEEN DELAYED...BUT IT
STILL LOOKS POSSIBLE THROUGH 9-10 PM. MAIN WEATHER HAZARDS WILL
BE DAMAGING WINDS WITH DCAPES THAT AREA NOW OVER 1000 J/KG AND
ALSO MARGINALLY SEVERE HAIL WITH CAPE VALUES IN THE HAIL GROWTH
REGION OF 500-600 J/KG. IF THE RESULTANT SEA BREEZE IS ABLE TO
BACK WINDS ENOUGH TO THE SOUTH THEN THERE IS ALSO A RISK FOR AN
ISOLATED TORNADO ALONG THE SC COASTAL CORRIDOR THIS EVENING.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS
1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR
AT LEAST LOCALLY HEAVY RAINS. THE ORIENTATION OF STORMS MAINLY IN
A WEST-EAST ALIGNMENT IS IN TANDEM WITH THE STEERING FLOW AND
COULD SUPPORT A RISK FOR AT LEAST MINOR-MODERATE FLOODING
CONCERNS. IF BACK-BUILDING AND/OR TRAINING OCCURS THAN THERE IS A
RISK FOR LOCALIZED FLASH FLOODING.

CONVECTION WILL WANE A FEW HOURS AFTER DARK...BUT WITH THE COLD
FRONT NOT EXPECTED TO MOVE THROUGH UNTIL AFTER MIDNIGHT NW AND NOT
REACHI9NG THE COAST UNTIL CLOSER TO DAYBREAK...WE HAVE HELD ONTO
SLIGHT CHANCE AND CHANCE POPS THROUGH MUCH OF THE NIGHT. A
DIVERGENT PATTERN OF THE SUB-TROPICAL JET TO OUR SOUTH AND THE
POLAR JET TO OUR NORTH/NW WILL CREATE THE NECESSARY DIFLUENCE
ALOFT...AND WE/RE WAITING FOR THE MAIN SHORT WAVE TO ARRIVE CLOSER
TO SUNRISE WEDNESDAY.

FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN FAR ABOVE
NORMAL AND THAT/S THE CASE AGAIN TONIGHT WITH THE COOL ADVECTION
NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER WILL BE
COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
ISOLATED TO SCATTERED CONVECTION WILL OCCUR AT OR NEAR THE
TERMINALS THIS EVENING. AMENDMENTS ARE EXPECTED AS TRENDS BECOME
BETTER DEFINED. ALTHOUGH WE ARE NOT CURRENTLY SHOWING THIS IN THE
18Z TAFS...ANY TSRA INTO THIS EVENING CAN PRODUCE HIGH WINDS AND
HEAVY RAINS AND THUS THE RISK FOR MVFR OR EVEN IFR.

THERE REMAINS A POTENTIAL FOR ADDITIONAL SHRA OR MAYBE A TSRA AT
BOTH AIRFIELDS UNTIL A COLD FRONT PASSES EARLY WEDNESDAY MORNING.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-17 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 032131
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
531 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH THIS EVENING...THE NEAR TERM ENVIRONMENT IS STILL SHOWING
FAVORABLE THERMODYNAMICS AND DECENT LAPSE RATES...BUT NOW WE/RE ALSO
STARTING TO EXPERIENCE SOME SHEAR...MOST ESPECIALLY IN THE 0-6 KM
LAYER WHICH IS OVER 30 KT. BUT THE 0-1 KM SHEAR IS STILL LESS THAN
15 KT AND THAT ALONG WITH THE WESTERLY WINDS HAVING MIXED OUT SOME
OF THE DEW POINTS INTO THE LOWER AND MID 60S AND THE SEA
BREEZE PINNED NEAR THE COAST...THIS HAS ALLOWED FOR ONLY ISOLATED
TO SCATTERED COVERAGE OF NON-SEVERE STORMS SO FAR.

TIMING OF THE POTENTIAL SEVERE WEATHER HAS BEEN DELAYED...BUT IT
STILL LOOKS POSSIBLE THROUGH 9-10 PM. MAIN WEATHER HAZARDS WILL
BE DAMAGING WINDS WITH DCAPES THAT AREA NOW OVER 1000 J/KG AND
ALSO MARGINALLY SEVERE HAIL WITH CAPE VALUES IN THE HAIL GROWTH
REGION OF 500-600 J/KG. IF THE RESULTANT SEA BREEZE IS ABLE TO
BACK WINDS ENOUGH TO THE SOUTH THEN THERE IS ALSO A RISK FOR AN
ISOLATED TORNADO ALONG THE SC COASTAL CORRIDOR THIS EVENING.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS
1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR
AT LEAST LOCALLY HEAVY RAINS. THE ORIENTATION OF STORMS MAINLY IN
A WEST-EAST ALIGNMENT IS IN TANDEM WITH THE STEERING FLOW AND
COULD SUPPORT A RISK FOR AT LEAST MINOR-MODERATE FLOODING
CONCERNS. IF BACK-BUILDING AND/OR TRAINING OCCURS THAN THERE IS A
RISK FOR LOCALIZED FLASH FLOODING.

CONVECTION WILL WANE A FEW HOURS AFTER DARK...BUT WITH THE COLD
FRONT NOT EXPECTED TO MOVE THROUGH UNTIL AFTER MIDNIGHT NW AND NOT
REACHI9NG THE COAST UNTIL CLOSER TO DAYBREAK...WE HAVE HELD ONTO
SLIGHT CHANCE AND CHANCE POPS THROUGH MUCH OF THE NIGHT. A
DIVERGENT PATTERN OF THE SUB-TROPICAL JET TO OUR SOUTH AND THE
POLAR JET TO OUR NORTH/NW WILL CREATE THE NECESSARY DIFLUENCE
ALOFT...AND WE/RE WAITING FOR THE MAIN SHORT WAVE TO ARRIVE CLOSER
TO SUNRISE WEDNESDAY.

FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN FAR ABOVE
NORMAL AND THAT/S THE CASE AGAIN TONIGHT WITH THE COOL ADVECTION
NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER WILL BE
COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
ISOLATED TO SCATTERED CONVECTION WILL OCCUR AT OR NEAR THE
TERMINALS THIS EVENING. AMENDMENTS ARE EXPECTED AS TRENDS BECOME
BETTER DEFINED. ALTHOUGH WE ARE NOT CURRENTLY SHOWING THIS IN THE
18Z TAFS...ANY TSRA INTO THIS EVENING CAN PRODUCE HIGH WINDS AND
HEAVY RAINS AND THUS THE RISK FOR MVFR OR EVEN IFR.

THERE REMAINS A POTENTIAL FOR ADDITIONAL SHRA OR MAYBE A TSRA AT
BOTH AIRFIELDS UNTIL A COLD FRONT PASSES EARLY WEDNESDAY MORNING.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-17 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 032005
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
405 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION TONIGHT AND PASS OFFSHORE
WEDNESDAY MORNING. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA EARLY THURSDAY. HIGH PRESSURE WILL THEN EXPAND INTO THE REGION
FROM THE WEST LATE WEEK AND PREVAIL THROUGH THE WEEKEND. A BACKDOOR
COLD FRONT MAY IMPACT THE AREA EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
THROUGH THIS EVENING...THE NEAR TERM ENVIRONMENT IS STILL SHOWING
FAVORABLE THERMODYNAMICS AND DECENT LAPSE RATES...BUT NOW WE/RE ALSO
STARTING TO EXPERIENCE SOME SHEAR...MOST ESPECIALLY IN THE 0-6 KM
LAYER WHICH IS OVER 30 KT. BUT THE 0-1 KM SHEAR IS STILL LESS THAN
15 KT AND THAT ALONG WITH THE WESTERLY WINDS HAVING MIXED OUT SOME
OF THE DEW POINTS INTO THE LOWER AND MID 60S AND THE SEA
BREEZE...THIS HAS ALLOWED FOR ONLY ISOLATED TO SCATTERED COVERAGE OF
NON-SEVERE STORMS SO FAR.

CONVECTION FROM UPSTREAM TO THE WEST WILL START TO ORGANIZE A
LITTLE MORE INTO A POSSIBLE SQUALL LINE/QLCS OR MULTI-CELLULAR
CLUSTERS AS THE MID-LEVEL FLOW INCREASES OVER THE AREA IN ADVANCE
OF THE AMPLIFYING LARGE SCALE TROUGH OVER THE OH/MS VALLEYS. THIS
ACTIVITY WILL MOVE IN LATE THIS AFTERNOON ALONG OUT NW TIER.
ADDITIONALLY CONVECTION FORMING TO THE SOUTH FROM HEATING AND THE
SEA BREEZE FROM THE GULF WILL ALSO APPROACH...PUTTING OUR SOUTHERN
ZONES AT RISK FROM ABOUT 5-8 PM. THIS INCLUDES SAVANNAH AND
BEAUFORT...WHILE THE CHARLESTON METRO WILL HAVE ITS GREATEST
THREAT FROM 6-9 PM.

TIMING OF THE POTENTIAL SEVERE WEATHER HAS BEEN DELAYED...BUT IT
STILL LOOKS POSSIBLE THROUGH 9-10 PM. MAIN WEATHER HAZARDS WILL
BE DAMAGING WINDS WITH DCAPES THAT AREA NOW OVER 1000 J/KG AND
ALSO MARGINALLY SEVERE HAIL WITH CAPE VALUES IN THE HAIL GROWTH
REGION OF 500-600 J/KG. IF THE RESULTANT SEA BREEZE IS ABLE TO
BACK WINDS ENOUGH TO THE SOUTH THEN THERE IS ALSO A RISK FOR AN
ISOLATED TORNADO ALONG THE SC COASTAL CORRIDOR THIS EVENING.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS
1 TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR
AT LEAST LOCALLY HEAVY RAINS. THE ORIENTATION OF STORMS MAINLY IN
A WEST-EAST ALIGNMENT IS IN TANDEM WITH THE STEERING FLOW AND
COULD SUPPORT A RISK FOR AT LEAST MINOR-MODERATE FLOODING
CONCERNS. IF BACK-BUILDING AND/OR TRAINING OCCURS THAN THERE IS A
RISK FOR LOCALIZED FLASH FLOODING.

CONVECTION WILL WANE A FEW HOURS AFTER DARK...BUT WITH THE COLD
FRONT NOT EXPECTED TO MOVE THROUGH UNTIL AFTER MIDNIGHT NW AND NOT
REACHI9NG THE COAST UNTIL CLOSER TO DAYBREAK...WE HAVE HELD ONTO
SLIGHT CHANCE AND CHANCE POPS THROUGH MUCH OF THE NIGHT. A
DIVERGENT PATTERN OF THE SUB-TROPICAL JET TO OUR SOUTH AND THE
POLAR JET TO OUR NORTH/NW WILL CREATE THE NECESSARY DIFLUENCE
ALOFT...AND WE/RE WAITING FOR THE MAIN SHORT WAVE TO ARRIVE CLOSER
TO SUNRISE WEDNESDAY.

FOR ABOUT THE PAST WEEK OUR NIGHT TIME LOWS HAVE BEEN FAR ABOVE
NORMAL AND THAT/S THE CASE AGAIN TONIGHT WITH THE COOL ADVECTION
NOT MAKING IT IN UNTIL LATE. LOWER 60S NW TIER WILL BE
COMMON...MID AND UPPER 60S MOST ELSEWHERE.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...AN UPPER LOW INITIALLY CENTERED OVER THE NORTHERN GREAT
LAKES WILL SHIFT INTO THE OHIO RIVER VALLEY THROUGH THE DAY. AT THE
SURFACE...A COLD FRONT WILL HAVE SHIFTED OFFSHORE IN THE
MORNING...RESULTING IN PRECIP CHANCES QUICKLY DECREASING AND
BECOMING LIMITED TO THE COASTAL WATERS. DEEP WESTERLY FLOW WILL DRY
OUT THE COLUMN WITH SKIES BECOMING MOSTLY SUNNY BY THE AFTERNOON.
HIGH TEMPERATURES SHOULD STILL BE ABLE TO REACH NEAR NORMAL IN THE
UPPER 70S TO AROUND 80. WEDNESDAY NIGHT...TEMPERATURES ARE EXPECTED
TO BE MUCH COOLER THAN RECENT DAYS...ALTHOUGH STILL AROUND EARLY MAY
NORMALS. LOWS FORECAST TO RANGE FROM LOW 50S INLAND TO UPPER 50S AT
THE BEACHES.

THURSDAY...A DEEP UPPER TROUGH WILL BE ENCOMPASSING THE EASTERN HALF
OF THE COUNTRY. MAIN VORT LOBE ASSOCIATED WITH THE LOW CENTER WILL
SHIFT EAST ACROSS THE MID-ATLANTIC STATES THROUGH THE DAY...HELPING
TO GENERATE A SURFACE LOW OVER THE NC OUTER BANKS. GIVEN THE FORCING
IN PLACE...HAVE MAINTAINED SLIGHT CHANCE POPS ACROSS THE NORTHERN
ZONES IN CLOSER PROXIMITY TO THE AFOREMENTIONED FEATURES. MOISTURE
WILL BE QUITE LIMITED SO NO SUBSTANTIAL ACCUMULATIONS EXPECTED.
PRESSURE GRADIENT WILL TIGHTEN AS THE SURFACE LOW FORMS SO NORTHWEST
WINDS COULD GET A BIT GUSTY IN THE AFTERNOON...ROUGHLY 25 TO 30 MPH.
DESPITE MOSTLY SUNNY SKIES...LINGERING COOL ADVECTION WILL LIMIT
HIGHS TO THE LOW 70S. THURSDAY NIGHT...LOWS FORECAST TO BE SEVERAL
DEGREES BELOW NORMAL...AROUND 50 AWAY FROM THE IMMEDIATE COAST.

FRIDAY...THE UPPER LOW AND SURFACE REFLECTION WILL BE POSITIONED
SOMEWHERE OFF THE VIRGINIA COAST AT DAYBREAK. THESE FEATURE ARE
EXPECTED TO WEAKEN AS THEY LIFT NORTHEAST...ALLOWING HIGH PRESSURE
TO BUILD IN FROM THE WEST THROUGH THE DAY. IT SHOULD BE QUITE A
PLEASANT DAY WITH MOSTLY SUNNY SKIES AND LOW HUMIDITY. HIGHS WILL
STILL BE A BIT COOLER THAN NORMAL...MAINLY IN THE MID 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
CONVECTION WILL CONTINUE TO FORM OVER OR NEAR KCHS THIS AFTERNOON
AND EVENING...BUT OUR CONFIDENCE IS NOT YET HIGH ENOUGH TO CARRY
ANYTHING OTHER THAN VFR CEILINGS WITH VCTS.

AT KSAV THE CHANCES LOOK A LITTLE GREATER FOR DIRECT IMPACTS AT
THE TERMINAL FROM 21Z TO 02Z WEDNESDAY...AND THUS WE ARE SHOWING
MVFR CONDITIONS /POSSIBLY DOWN BRIEFLY TO IFR/ IN TSRA.

ALTHOUGH WE ARE NOT CURRENTLY SHOWING THIS IN THE 18Z TAFS...ANY
TSRA INTO THIS EVENING CAN PRODUCE HIGH WINDS AND HEAVY RAINS
/THUS THE RISK FOR IFR/.

THERE REMAINS A POTENTIAL FOR ADDITIONAL SHRA OR MAYBE A TSRA AT
BOTH AIRFIELDS UNTIL A COLD FRONT PASSES EARLY WEDNESDAY MORNING.

EXTENDED AVIATION OUTLOOK...VFR.

&&

.MARINE...
TONIGHT...A DECENT PACKING OF THE GRADIENT WILL PREVAIL BETWEEN AN
APPROACHING COLD FRONT THAT MOVES INTO OUR COASTAL WATERS AROUND
DAYBREAK WEDNESDAY AND A HIGH PRESSURE RIDGE TO THE SOUTH/SE OF
THE AREA. WARM ADVECTION IN ADVANCE OF THE FRONT WILL BE TAPER THE
AMOUNT OF MIXING AND ONCE CONVECTION MOVES IN THIS WILL ALSO MESS
UP THE SYNOPTIC PATTERN. THUS WE HAVE NOTHING HIGHER THAN ABOUT
15-17 KT. SEAS ON AVERAGE WILL BE 4 FT OR LESS. MARINERS ARE
ADVISED THAT STRONG TO SEVERE STORMS WILL MOVE IN DURING THE FIRST
PART OF THE NIGHT...SOME OF WHICH WILL PRODUCE WIND GUSTS IN
EXCESS OF 40 OR PERHAPS 50 KT...LARGE HAIL..FREQUENT LIGHTNING AND
VERY HEAVY RAINS. STAY IN PORT OR SEEK SAFE HARBOR IF STORMS
APPROACH. MONITOR NOAA WEATHER RADIO ALL HAZARDS.

WEDNESDAY THROUGH SUNDAY...MARINE CONDITIONS WILL DETERIORATE
BEGINNING WEDNESDAY NIGHT/EARLY THURSDAY AS THE PRESSURE GRADIENT
TIGHTENS BETWEEN LOW PRESSURE OVER THE MID ATLANTIC STATES AND HIGH
PRESSURE TO THE WEST. SMALL CRAFT ADVISORIES WILL LIKELY BE NEEDED
BEGINNING EARLY THURSDAY MORNING...STARTING IN THE OUTER GA
WATERS THEN EXPANDING TO ALL WATERS AS WIND GUSTS EXCEED 25 KT.
SEAS WILL BUILD TO 3-5 FT. CONDITIONS WILL BEGIN TO IMPROVE BY
FRIDAY MORNING. HIGH PRESSURE WILL RETURN FRIDAY AND PERSIST OVER
THE WEEKEND WITH WINDS GENERALLY 15 KT OR LESS. SEAS ON AVERAGE
LATE WEEK INTO THE WEEKEND 1-3 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 031727
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
127 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION THROUGH TONIGHT AND PASS
OFFSHORE WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE
REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STORM COVERAGE WILL CONTINUE TO INCREASE THROUGH THE
AFTERNOON...WITH ACTIVITY FORMING ALONG A SUBTLE PRE-FRONTAL
TROUGH IN ADVANCE OF THE ACTUAL COLD FRONT ACROSS OUR NW TIER
THROUGH 2 PM AND THEN STARTING TO FILL IN ELSEWHERE THEREAFTER.
LAPSE RATES HAVE BEEN HELD IN CHECK SO FAR AND MLCAPES ARE
GENERALLY LESS THAN 1500 J/KG. THIS HAS PREVENTED STORMS FROM
GETTING TOO TALL SO FAR. AND SHEAR IS NOT YET THAT SIGNIFICANT
THUS NO ORGANIZED STORMS SO FAR.

BUT THAT IS STILL FORECAST TO CHANGE WITH ANOTHER ACTIVE PATTERN
FROM MID AFTERNOON INTO THIS EVENING AS COVERAGE OF SHOWERS AND
T-STORMS INCREASES...SOME OF WHICH COULD BECOME SEVERE. THE WILD
CARD IS THE SHEAR WHICH WAS LACKING THE PAST TWO DAYS WHICH IS
EVIDENT TODAY. THIS COULD CERTAINLY ALLOW FOR BETTER ORGANIZATION
OF MULTICELLULAR CLUSTERS AND/OR A SQUALL LINE/QLCS/LEWP FEATURE.
BULK SHEAR IN THE 0-6 KM LAYER IS 25-35 KT...ALTHOUGH IN THE
LOWEST 1 KM IS IS ONLY 15 TO PERHAPS 20 KT...WHICH ADDS A LITTLE
UNCERTAINTY TO THE FORECAST PATTERN.

FOR EARLY AFTERNOON THE FORECAST ZONES ARE WITHIN A REGION OF
MAINLY NVA ALOFT IN WAKE OF THE STRONG SHORT WAVE PULLING ACROSS
EASTERN NC. UPSTREAM SHORT IN THE MID MS VALLEY IS PROBABLY NOT
GOING TO ARRIVE UNTIL AFTER DARK AND IS A NON-FACTOR AT THE MOMENT
FOR TODAY/S PATTERN. WE LOOK FOR ISOLATED TO SCATTERED COVERAGE OF
SHOWERS AND T-STORMS TO FORM ON DIFFERENTIAL HEATING BOUNDARIES.
ALL OF THESE STORMS WILL BE SUB-SEVERE WITH ONLY MODEST
THERMODYNAMICS. BUT SINCE DCAPES ARE 600-700 J/KG THERE STILL
COULD BE SOME WIND GUSTS OF 30-40 MPH IN ISOLATED STORMS...SIMILAR
TO WHAT WE SAW AT FT. SUMTER JUST PRIOR TO NOONTIME.

FOR THE MID AND LATE AFTERNOON INTO THIS EVENING IS WHEN THE
SITUATION IS PRIMED TO GET MUCH MORE ACTIVE. EVEN WITH THE LACK OF
SIGNIFICANT FEATURES ALOFT...THERE ARE SUBTLE MID LEVEL
PERTURBATIONS WITHIN THE WEST/SW FLOW ALOFT...AS WELL AS THE
NECESSARY DIFLUENCE UPSTAIRS WITH A DIVERGING PATTERN TO THE POLAR
JET AND SUB TROPICAL JET STREAMS TO OUR NORTH AND
SOUTH...RESPECTIVELY. UPSTREAM COLD FRONT TO THE NW THIS MORNING
WILL STRUGGLE TO MOVES INTO THE UPSTATE AND PEE DEE REGION OF SC
AND THE CENTRAL SAVANNAH RIVER VALLEY OF GA BY NIGHTFALL. STORMS
WILL FORM IN ADVANCE OF THIS FEATURE AND A WEAK PRE-EXISTING
PIEDMONT TROUGH...AS WELL AS TO THE SOUTH/SW OVER NORTHERN FLORIDA
AND SOUTH/SW GEORGIA ALONG SEA BREEZE INTERACTIONS. BOTH OF THESE
REGIONS WILL CONVERGE ON THE CWFA FROM ABOUT 2-8 PM...ASSUMING
MESOSCALE PROCESSES PAN OUT AS WE ARE CURRENTLY FORECASTING. WE
ARE MAINTAINING 50-70 POPS...BUT ADJUSTMENTS WILL LIKELY BE
REQUIRED.

MODIFIED SOUNDINGS SHOW PLENTY OF INSTABILITY DURING PEAK HEATING
WITH LIFTED INDICES OF -6 OR -7C AND SBCAPES OF 2000-3000 J/KG.
PLUS THERE IS THE AFOREMENTIONED SHEAR WHICH IS THE BIGGEST
DIFFERENCE THAT WE SEE FOR TODAY COMPARED TO RECENT DAYS. DCAPES
ARE FORECAST TO EXCEED 800 OR 900 J/KG AND WINDEX VALUES FROM RAOB
ARE 55-65...BOTH SUPPORTIVE OF DAMAGING WINDS. HAIL CAPES OF 800
J/KG OR GREATER AND WET BULB ZERO AROUND 9K FT ARE ALSO CONDUCIVE
FOR LARGE HAIL. IF WINDS ALONG THE COASTAL CORRIDOR ARE ABLE TO
BACK ENOUGH SOUTH WITH A RESULTANT SEA BREEZE THERE WOULD ALSO BE
A VERY LOW END RISK FOR AN ISOLATED TORNADO.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS CLOSE
TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR AT
LEAST LOCALLY HEAVY RAINS. THE MEAN FLOW IS MORE WEST TO EAST
WHILE THE ORIENTATION OF STORMS IS MORE SW TO NE WHICH WILL AID IS
LIMITING BACK-BUILDING AND TRAINING. STILL...ANY DEVIATION OF
THESE TRAJECTORIES MORE IN SYNC WITH EACH OTHER COULD SUPPORT A
HIGHER FLOODING RAIN THREAT.

THERE IS SOME DOWNSLOPE COMPONENT TO THE SYNOPTIC FLOW...AND THAT
ALONG WITH COMPRESSIONAL HEATING IN ADVANCE OF THE COLD FRONT WILL
BOOST MAX TEMPS INTO THE MID AND UPPER 80S BEFORE CONVECTIVE
DEVELOPMENT INCREASES. THIS SAME WESTERLY FLOW WILL ALSO TEND TO
HELP MIX OUT DEW POINTS...AND DEPENDING UPON HOW MUCH OF THIS
OCCURS WILL BE FACTOR IN INSTABILITY. FOR NOW WE DON/T ANTICIPATE
THEM DROPPING ANY LOWER THAN THE MID 60S. WE HAVE ALSO ALTERED
THE DIURNAL TEMP CURVE TO ACCOUNT FOR RAIN-COOLED CONVECTION ONCE
CONVECTION INCREASE IN AREAL COVERAGE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...NUMEROUS SHOWER/TSTMS WILL LIKELY BE ONGOING ACROSS THE
AREA AT SUNSET...MOST OF WHICH WILL TRANSLATE THE COAST DURING THE
EARLY EVENING HOURS. A RISK FOR SEVERE WEATHER WILL PERSIST UNTIL
THIS MAIN AREA OF CONVECTION MOVES OFFSHORE. THE MAIN SHORTWAVE
WILL APPROACH THE AREA AROUND DAYBREAK WEDNESDAY, SO ALTHOUGH THE
GREATER RISK FOR SHOWERS/TSTMS WILL OCCUR EARLY IN THE EVENING,
THERE WILL BE A CONTINUED RISK FOR AT LEAST ISOLATED SHOWERS/TSTMS
FOR MUCH OF THE NIGHT AHEAD OF A SLOW MOVING COLD FRONT. LOWS WILL
RANGE FROM THE LOWER-MID 60S WELL INLAND TO THE UPPER 60S/NEAR 70
AT THE COAST.

WEDNESDAY...A TROUGH WILL BE OVER THE EASTERN HALF OF THE
COUNTRY...WITH AN UPPER LEVEL LOW OVER THE GREAT LAKES. THE COLD
FRONT SHOULD CROSS THROUGH OUR AREA AROUND DAYBREAK. REMNANT SHOWERS
AND THUNDERSTORMS...MAINLY LIMITED TO THE COASTAL COUNTIES...WILL
QUICKLY BE PUSHED OFFSHORE WITH THE FRONT. WESTERLY WINDS WILL BRING
DRIER CONDITIONS AND COOLER TEMPERATURES INTO OUR AREA. DESPITE
PLENTY OF SUNSHINE HIGHS WILL RISE INTO THE UPPER 70S TO NEAR 80
DEGREES...ABOUT AVERAGE FOR THIS TIME OF YEAR. SOME DISTURBANCES
WILL ROUND THE BASE OF THE TROUGH...MOVING ACROSS OUR AREA. THIS
WILL BRING BRIEF INCREASES IN CLOUDS...BUT NO PRECIPITATION. A
REINFORCING COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY
NIGHT. THIS FRONT WILL BE DRY...SO AT MOST WE CAN EXPECT SOME
CLOUDS...BUT NO SHOWERS OR THUNDERSTORMS. WEST-NORTHWEST WILL ALLOW
LOWS TO DROP INTO THE MID 50S INLAND TO AROUND 60 DEGREES ALONG THE
COAST.

THURSDAY...THE TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL
INTENSIFY WHILE THE UPPER LEVEL LOW SHIFTS OVER THE MID-ATLANTIC
REGION. THE MODELS ARE HINTING AT A WEAK SURFACE LOW FORMING AROUND
NORTH CAROLINA. THIS WOULD ALLOW SOME MOISTURE TO ADVECT FURTHER
SOUTH THAN ORIGINALLY EXPECTED. GIVEN THE GENERAL MODEL
CONSENSUS...ADDED SLIGHT CHANCE POPS TO THE FORECAST...MAINLY
LIMITED TO OUR SOUTH CAROLINA COUNTIES IN THE AFTERNOON. QPF SHOULD
BE MINIMAL...IF ANYTHING. WEST TO NORTHWEST FLOW AND WEAK COLD
ADVECTION BEHIND THE COLD FRONT...THAT IS SHIFTING OFFSHORE...WILL
USHER IN COOLER TEMPERATURES AND LOWER DEW POINTS. HIGHS SHOULD RISE
INTO THE MID 70S...SEVERAL DEGREES BELOW NORMAL WHILE THE DEW POINTS
FALL INTO THE 40S. BY THURSDAY NIGHT THE WEAK SURFACE LOW SHIFTS TO
THE NORTHEAST AND ANY SHOWER ACTIVITY WILL FOLLOW IT. CONTINUED
NORTHWEST FLOW AND SOME COLD ADVECTION WILL ALLOW LOWS TO FALL INTO
THE LOWER 50S INLAND...POSSIBLY THE UPPER 40S IN A FEW SPOT...AND
THE MID 50S ALONG THE BEACHES.

FRIDAY...MODELS KEEP THE TROUGH OVER THE EASTERN THIRD OF THE
COUNTRY...BUT THEY SHIFT THE UPPER LEVEL LOW A LITTLE BIT TO THE
NORTH. THIS SHOULD KEEP OUR AREA DRY. THE COMBINATION OF INCREASING
HEIGHTS...NO THREAT OF RAIN AND PLENTY OF SUNSHINE SHOULD ALLOW
TEMPERATURES TO RISE SEVERAL DEGREES. THOUGH THEY WILL REMAIN
SEVERAL DEGREES BELOW NORMAL...THE MID TO UPPER 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /18Z TUESDAY THROUGH SATURDAY/...
CONVECTION WILL CONTINUE TO FORM OVER OR NEAR KCHS THIS AFTERNOON
AND EVENING...BUT OUR CONFIDENCE IS NOT YET HIGH ENOUGH TO CARRY
ANYTHING OTHER THAN VFR CEILINGS WITH VCTS.

AT KSAV THE CHANCES LOOK A LITTLE GREATER FOR DIRECT IMPACTS AT
THE TERMINAL FROM 21Z TO 02Z WEDNESDAY...AND THUS WE ARE SHOWING
MVFR CONDITIONS /POSSIBLY DOWN BRIEFLY TO IFR/ IN TSRA.

ALTHOUGH WE ARE NOT CURRENTLY SHOWING THIS IN THE 18Z TAFS...ANY
TSRA INTO THIS EVENING CAN PRODUCE HIGH WINDS AND HEAVY RAINS
/THUS THE RISK FOR IFR/.

THERE REMAINS A POTENTIAL FOR ADDITIONAL SHRA OR MAYBE A TSRA AT
BOTH AIRFIELDS UNTIL A COLD FRONT PASSES EARLY WEDNESDAY MORNING.

EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT PROBABILITY OF OCCURRENCE.

&&

.MARINE...
THIS AFTERNOON...SOUTHWEST WINDS WILL INCREASE A BIT AS THE
GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING COLD
FRONT TIGHTENS. SHOULD SEE WINDS AS HIGH AS 15 TO PERHAPS 20 KT
CHARLESTON COUNTY AND GEORGIA OFFSHORE WATERS WITH 15 KT REMAINING
LEGS. SEAS WILL AVERAGE 2-4 FT NEARSHORE WATERS AND 3-5 FT
OFFSHORE WATERS. STRONG TSTMS COULD IMPACT THE COASTAL WATERS FROM
TIME TO TIME AND SPECIAL MARINE WARNINGS AND/OR MARINE WEATHER
STATEMENTS COULD BE NEEDED.

TONIGHT...SOUTHWEST WINDS WILL PERSIST AS A COLD FRONT DRAWS
CLOSER. LOW-LEVEL JETTING WILL REMAIN DISPLACED WELL OFFSHORE, SO
NO DIRECT IMPACTS ARE EXPECTED ON THE LOCAL WIND FIELD. SPEEDS
WILL AVERAGE 10-15 KT WITH SEAS 2-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS. THE RISK FOR STRONG TSTMS WILL LINGER FOR MUCH OF
THE NIGHT.

WEDNESDAY...SOUTHWEST TO WEST WINDS 10-15 KT BEHIND THE FRONT. SEAS
2-3 FT WITHIN 20 NM AND 3-4 FT ACROSS THE OUTER GEORGIA WATERS.

WEDNESDAY NIGHT INTO THURSDAY...A REINFORCING COLD FRONT WILL MOVE
THROUGH AND BEHIND THE FRONT WILL BE A INCREASING PRESSURE GRADIENT.
THIS WILL CAUSE WESTERLY WINDS TO INCREASE. EXPECT WINDS TO BE 15-20
KTS WITHING 20 NM AND 20-25 KT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL BUILD TO 4 FT BEYOND 15 NM AND 4-5 FT ACROSS THE OUTER GEORGIA
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR WIND GUSTS FOR THE
OUTER GEORGIA WATERS.

FRIDAY AND SATURDAY..THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE MOVES IN FROM THE WEST. EXPECT WINDS OF 15 KTS OR
LESS AND SEAS SUBSIDING BELOW 3 FT.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 031647
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION THROUGH TONIGHT AND PASS
OFFSHORE WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE
REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STORM COVERAGE WILL CONTINUE TO INCREASE THROUGH THE
AFTERNOON...WITH ACTIVITY FORMING ALONG A SUBTLE PRE-FRONTAL
TROUGH IN ADVANCE OF THE ACTUAL COLD FRONT ACROSS OUR NW TIER
THROUGH 2 PM AND THEN STARTING TO FILL IN ELSEWHERE THEREAFTER.
LAPSE RATES HAVE BEEN HELD IN CHECK SO FAR AND MLCAPES ARE
GENERALLY LESS THAN 1500 J/KG. THIS HAS PREVENTED STORMS FROM
GETTING TOO TALL SO FAR. AND SHEAR IS NOT YET THAT SIGNIFICANT
THUS NO ORGANIZED STORMS SO FAR.

BUT THAT IS STILL FORECAST TO CHANGE WITH ANOTHER ACTIVE PATTERN
FROM MID AFTERNOON INTO THIS EVENING AS COVERAGE OF SHOWERS AND
T-STORMS INCREASES...SOME OF WHICH COULD BECOME SEVERE. THE WILD
CARD IS THE SHEAR WHICH WAS LACKING THE PAST TWO DAYS WHICH IS
EVIDENT TODAY. THIS COULD CERTAINLY ALLOW FOR BETTER ORGANIZATION
OF MULTICELLULAR CLUSTERS AND/OR A SQUALL LINE/QLCS/LEWP FEATURE.
BULK SHEAR IN THE 0-6 KM LAYER IS 25-35 KT...ALTHOUGH IN THE
LOWEST 1 KM IS IS ONLY 15 TO PERHAPS 20 KT...WHICH ADDS A LITTLE
UNCERTAINTY TO THE FORECAST PATTERN.

FOR EARLY AFTERNOON THE FORECAST ZONES ARE WITHIN A REGION OF
MAINLY NVA ALOFT IN WAKE OF THE STRONG SHORT WAVE PULLING ACROSS
EASTERN NC. UPSTREAM SHORT IN THE MID MS VALLEY IS PROBABLY NOT
GOING TO ARRIVE UNTIL AFTER DARK AND IS A NON-FACTOR AT THE MOMENT
FOR TODAY/S PATTERN. WE LOOK FOR ISOLATED TO SCATTERED COVERAGE OF
SHOWERS AND T-STORMS TO FORM ON DIFFERENTIAL HEATING BOUNDARIES.
ALL OF THESE STORMS WILL BE SUB-SEVERE WITH ONLY MODEST
THERMODYNAMICS. BUT SINCE DCAPES ARE 600-700 J/KG THERE STILL
COULD BE SOME WIND GUSTS OF 30-40 MPH IN ISOLATED STORMS...SIMILAR
TO WHAT WE SAW AT FT. SUMTER JUST PRIOR TO NOONTIME.

FOR THE MID AND LATE AFTERNOON INTO THIS EVENING IS WHEN THE
SITUATION IS PRIMED TO GET MUCH MORE ACTIVE. EVEN WITH THE LACK OF
SIGNIFICANT FEATURES ALOFT...THERE ARE SUBTLE MID LEVEL
PERTURBATIONS WITHIN THE WEST/SW FLOW ALOFT...AS WELL AS THE
NECESSARY DIFLUENCE UPSTAIRS WITH A DIVERGING PATTERN TO THE POLAR
JET AND SUB TROPICAL JET STREAMS TO OUR NORTH AND
SOUTH...RESPECTIVELY. UPSTREAM COLD FRONT TO THE NW THIS MORNING
WILL STRUGGLE TO MOVES INTO THE UPSTATE AND PEE DEE REGION OF SC
AND THE CENTRAL SAVANNAH RIVER VALLEY OF GA BY NIGHTFALL. STORMS
WILL FORM IN ADVANCE OF THIS FEATURE AND A WEAK PRE-EXISTING
PIEDMONT TROUGH...AS WELL AS TO THE SOUTH/SW OVER NORTHERN FLORIDA
AND SOUTH/SW GEORGIA ALONG SEA BREEZE INTERACTIONS. BOTH OF THESE
REGIONS WILL CONVERGE ON THE CWFA FROM ABOUT 2-8 PM...ASSUMING
MESOSCALE PROCESSES PAN OUT AS WE ARE CURRENTLY FORECASTING. WE
ARE MAINTAINING 50-70 POPS...BUT ADJUSTMENTS WILL LIKELY BE
REQUIRED.

MODIFIED SOUNDINGS SHOW PLENTY OF INSTABILITY DURING PEAK HEATING
WITH LIFTED INDICES OF -6 OR -7C AND SBCAPES OF 2000-3000 J/KG.
PLUS THERE IS THE AFOREMENTIONED SHEAR WHICH IS THE BIGGEST
DIFFERENCE THAT WE SEE FOR TODAY COMPARED TO RECENT DAYS. DCAPES
ARE FORECAST TO EXCEED 800 OR 900 J/KG AND WINDEX VALUES FROM RAOB
ARE 55-65...BOTH SUPPORTIVE OF DAMAGING WINDS. HAIL CAPES OF 800
J/KG OR GREATER AND WET BULB ZERO AROUND 9K FT ARE ALSO CONDUCIVE
FOR LARGE HAIL. IF WINDS ALONG THE COASTAL CORRIDOR ARE ABLE TO
BACK ENOUGH SOUTH WITH A RESULTANT SEA BREEZE THERE WOULD ALSO BE
A VERY LOW END RISK FOR AN ISOLATED TORNADO.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS CLOSE
TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR AT
LEAST LOCALLY HEAVY RAINS. THE MEAN FLOW IS MORE WEST TO EAST
WHILE THE ORIENTATION OF STORMS IS MORE SW TO NE WHICH WILL AID IS
LIMITING BACK-BUILDING AND TRAINING. STILL...ANY DEVIATION OF
THESE TRAJECTORIES MORE IN SYNC WITH EACH OTHER COULD SUPPORT A
HIGHER FLOODING RAIN THREAT.

THERE IS SOME DOWNSLOPE COMPONENT TO THE SYNOPTIC FLOW...AND THAT
ALONG WITH COMPRESSIONAL HEATING IN ADVANCE OF THE COLD FRONT WILL
BOOST MAX TEMPS INTO THE MID AND UPPER 80S BEFORE CONVECTIVE
DEVELOPMENT INCREASES. THIS SAME WESTERLY FLOW WILL ALSO TEND TO
HELP MIX OUT DEW POINTS...AND DEPENDING UPON HOW MUCH OF THIS
OCCURS WILL BE FACTOR IN INSTABILITY. FOR NOW WE DON/T ANTICIPATE
THEM DROPPING ANY LOWER THAN THE MID 60S. WE HAVE ALSO ALTERED
THE DIURNAL TEMP CURVE TO ACCOUNT FOR RAIN-COOLED CONVECTION ONCE
CONVECTION INCREASE IN AREAL COVERAGE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...NUMEROUS SHOWER/TSTMS WILL LIKELY BE ONGOING ACROSS THE
AREA AT SUNSET...MOST OF WHICH WILL TRANSLATE THE COAST DURING THE
EARLY EVENING HOURS. A RISK FOR SEVERE WEATHER WILL PERSIST UNTIL
THIS MAIN AREA OF CONVECTION MOVES OFFSHORE. THE MAIN SHORTWAVE
WILL APPROACH THE AREA AROUND DAYBREAK WEDNESDAY, SO ALTHOUGH THE
GREATER RISK FOR SHOWERS/TSTMS WILL OCCUR EARLY IN THE EVENING,
THERE WILL BE A CONTINUED RISK FOR AT LEAST ISOLATED SHOWERS/TSTMS
FOR MUCH OF THE NIGHT AHEAD OF A SLOW MOVING COLD FRONT. LOWS WILL
RANGE FROM THE LOWER-MID 60S WELL INLAND TO THE UPPER 60S/NEAR 70
AT THE COAST.

WEDNESDAY...A TROUGH WILL BE OVER THE EASTERN HALF OF THE
COUNTRY...WITH AN UPPER LEVEL LOW OVER THE GREAT LAKES. THE COLD
FRONT SHOULD CROSS THROUGH OUR AREA AROUND DAYBREAK. REMNANT SHOWERS
AND THUNDERSTORMS...MAINLY LIMITED TO THE COASTAL COUNTIES...WILL
QUICKLY BE PUSHED OFFSHORE WITH THE FRONT. WESTERLY WINDS WILL BRING
DRIER CONDITIONS AND COOLER TEMPERATURES INTO OUR AREA. DESPITE
PLENTY OF SUNSHINE HIGHS WILL RISE INTO THE UPPER 70S TO NEAR 80
DEGREES...ABOUT AVERAGE FOR THIS TIME OF YEAR. SOME DISTURBANCES
WILL ROUND THE BASE OF THE TROUGH...MOVING ACROSS OUR AREA. THIS
WILL BRING BRIEF INCREASES IN CLOUDS...BUT NO PRECIPITATION. A
REINFORCING COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY
NIGHT. THIS FRONT WILL BE DRY...SO AT MOST WE CAN EXPECT SOME
CLOUDS...BUT NO SHOWERS OR THUNDERSTORMS. WEST-NORTHWEST WILL ALLOW
LOWS TO DROP INTO THE MID 50S INLAND TO AROUND 60 DEGREES ALONG THE
COAST.

THURSDAY...THE TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL
INTENSIFY WHILE THE UPPER LEVEL LOW SHIFTS OVER THE MID-ATLANTIC
REGION. THE MODELS ARE HINTING AT A WEAK SURFACE LOW FORMING AROUND
NORTH CAROLINA. THIS WOULD ALLOW SOME MOISTURE TO ADVECT FURTHER
SOUTH THAN ORIGINALLY EXPECTED. GIVEN THE GENERAL MODEL
CONSENSUS...ADDED SLIGHT CHANCE POPS TO THE FORECAST...MAINLY
LIMITED TO OUR SOUTH CAROLINA COUNTIES IN THE AFTERNOON. QPF SHOULD
BE MINIMAL...IF ANYTHING. WEST TO NORTHWEST FLOW AND WEAK COLD
ADVECTION BEHIND THE COLD FRONT...THAT IS SHIFTING OFFSHORE...WILL
USHER IN COOLER TEMPERATURES AND LOWER DEW POINTS. HIGHS SHOULD RISE
INTO THE MID 70S...SEVERAL DEGREES BELOW NORMAL WHILE THE DEW POINTS
FALL INTO THE 40S. BY THURSDAY NIGHT THE WEAK SURFACE LOW SHIFTS TO
THE NORTHEAST AND ANY SHOWER ACTIVITY WILL FOLLOW IT. CONTINUED
NORTHWEST FLOW AND SOME COLD ADVECTION WILL ALLOW LOWS TO FALL INTO
THE LOWER 50S INLAND...POSSIBLY THE UPPER 40S IN A FEW SPOT...AND
THE MID 50S ALONG THE BEACHES.

FRIDAY...MODELS KEEP THE TROUGH OVER THE EASTERN THIRD OF THE
COUNTRY...BUT THEY SHIFT THE UPPER LEVEL LOW A LITTLE BIT TO THE
NORTH. THIS SHOULD KEEP OUR AREA DRY. THE COMBINATION OF INCREASING
HEIGHTS...NO THREAT OF RAIN AND PLENTY OF SUNSHINE SHOULD ALLOW
TEMPERATURES TO RISE SEVERAL DEGREES. THOUGH THEY WILL REMAIN
SEVERAL DEGREES BELOW NORMAL...THE MID TO UPPER 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /17Z TUESDAY THROUGH SUNDAY/...
CONFIDENCE IS HIGH THAT TSTMS WILL IMPACT KSAV LATE THIS
AFTERNOON AND EVENING. HIGH RESOLUTION DATA SUPPORT A LINE OF
SHOWERS/TSTMS MOVING ACROSS SOUTHEAST GEORGIA PRIOR TO SUNSET.
PROBABILITIES FOR DIRECT IMPACTS ARE HIGHEST ROUGHLY 21-00Z...SO A
TEMPO GROUP FOR MID-RANGE MVFR VSBYS WILL BE INCLUDED IN A TEMPO
GROUP TO COVER. LOWER CONDITIONS...POSSIBLY AS LOW AS IFR...ARE
CERTAINLY POSSIBLE IF HEAVIER TSTMS MOVE ACROSS THE TERMINAL. AT
KCHS...PROBABILITIES ARE LOWER AND CONFIDENCE IS NOT AS GREAT.
WILL CONTINUE TO KEEP TSRA OUT OF THE TAF UNTIL CONFIDENCE
INCREASES.

EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT PROBABILITY OF OCCURRENCE.

&&

.MARINE...
THIS AFTERNOON...SOUTHWEST WINDS WILL INCREASE A BIT AS THE
GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING COLD
FRONT TIGHTENS. SHOULD SEE WINDS AS HIGH AS 15 TO PERHAPS 20 KT
CHARLESTON COUNTY AND GEORGIA OFFSHORE WATERS WITH 15 KT REMAINING
LEGS. SEAS WILL AVERAGE 2-4 FT NEARSHORE WATERS AND 3-5 FT
OFFSHORE WATERS. STRONG TSTMS COULD IMPACT THE COASTAL WATERS FROM
TIME TO TIME AND SPECIAL MARINE WARNINGS AND/OR MARINE WEATHER
STATEMENTS COULD BE NEEDED.

TONIGHT...SOUTHWEST WINDS WILL PERSIST AS A COLD FRONT DRAWS
CLOSER. LOW-LEVEL JETTING WILL REMAIN DISPLACED WELL OFFSHORE, SO
NO DIRECT IMPACTS ARE EXPECTED ON THE LOCAL WIND FIELD. SPEEDS
WILL AVERAGE 10-15 KT WITH SEAS 2-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS. THE RISK FOR STRONG TSTMS WILL LINGER FOR MUCH OF
THE NIGHT.

WEDNESDAY...SOUTHWEST TO WEST WINDS 10-15 KT BEHIND THE FRONT. SEAS
2-3 FT WITHIN 20 NM AND 3-4 FT ACROSS THE OUTER GEORGIA WATERS.

WEDNESDAY NIGHT INTO THURSDAY...A REINFORCING COLD FRONT WILL MOVE
THROUGH AND BEHIND THE FRONT WILL BE A INCREASING PRESSURE GRADIENT.
THIS WILL CAUSE WESTERLY WINDS TO INCREASE. EXPECT WINDS TO BE 15-20
KTS WITHING 20 NM AND 20-25 KT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL BUILD TO 4 FT BEYOND 15 NM AND 4-5 FT ACROSS THE OUTER GEORGIA
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR WIND GUSTS FOR THE
OUTER GEORGIA WATERS.

FRIDAY AND SATURDAY..THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE MOVES IN FROM THE WEST. EXPECT WINDS OF 15 KTS OR
LESS AND SEAS SUBSIDING BELOW 3 FT.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 031647
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1247 PM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION THROUGH TONIGHT AND PASS
OFFSHORE WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE
REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
STORM COVERAGE WILL CONTINUE TO INCREASE THROUGH THE
AFTERNOON...WITH ACTIVITY FORMING ALONG A SUBTLE PRE-FRONTAL
TROUGH IN ADVANCE OF THE ACTUAL COLD FRONT ACROSS OUR NW TIER
THROUGH 2 PM AND THEN STARTING TO FILL IN ELSEWHERE THEREAFTER.
LAPSE RATES HAVE BEEN HELD IN CHECK SO FAR AND MLCAPES ARE
GENERALLY LESS THAN 1500 J/KG. THIS HAS PREVENTED STORMS FROM
GETTING TOO TALL SO FAR. AND SHEAR IS NOT YET THAT SIGNIFICANT
THUS NO ORGANIZED STORMS SO FAR.

BUT THAT IS STILL FORECAST TO CHANGE WITH ANOTHER ACTIVE PATTERN
FROM MID AFTERNOON INTO THIS EVENING AS COVERAGE OF SHOWERS AND
T-STORMS INCREASES...SOME OF WHICH COULD BECOME SEVERE. THE WILD
CARD IS THE SHEAR WHICH WAS LACKING THE PAST TWO DAYS WHICH IS
EVIDENT TODAY. THIS COULD CERTAINLY ALLOW FOR BETTER ORGANIZATION
OF MULTICELLULAR CLUSTERS AND/OR A SQUALL LINE/QLCS/LEWP FEATURE.
BULK SHEAR IN THE 0-6 KM LAYER IS 25-35 KT...ALTHOUGH IN THE
LOWEST 1 KM IS IS ONLY 15 TO PERHAPS 20 KT...WHICH ADDS A LITTLE
UNCERTAINTY TO THE FORECAST PATTERN.

FOR EARLY AFTERNOON THE FORECAST ZONES ARE WITHIN A REGION OF
MAINLY NVA ALOFT IN WAKE OF THE STRONG SHORT WAVE PULLING ACROSS
EASTERN NC. UPSTREAM SHORT IN THE MID MS VALLEY IS PROBABLY NOT
GOING TO ARRIVE UNTIL AFTER DARK AND IS A NON-FACTOR AT THE MOMENT
FOR TODAY/S PATTERN. WE LOOK FOR ISOLATED TO SCATTERED COVERAGE OF
SHOWERS AND T-STORMS TO FORM ON DIFFERENTIAL HEATING BOUNDARIES.
ALL OF THESE STORMS WILL BE SUB-SEVERE WITH ONLY MODEST
THERMODYNAMICS. BUT SINCE DCAPES ARE 600-700 J/KG THERE STILL
COULD BE SOME WIND GUSTS OF 30-40 MPH IN ISOLATED STORMS...SIMILAR
TO WHAT WE SAW AT FT. SUMTER JUST PRIOR TO NOONTIME.

FOR THE MID AND LATE AFTERNOON INTO THIS EVENING IS WHEN THE
SITUATION IS PRIMED TO GET MUCH MORE ACTIVE. EVEN WITH THE LACK OF
SIGNIFICANT FEATURES ALOFT...THERE ARE SUBTLE MID LEVEL
PERTURBATIONS WITHIN THE WEST/SW FLOW ALOFT...AS WELL AS THE
NECESSARY DIFLUENCE UPSTAIRS WITH A DIVERGING PATTERN TO THE POLAR
JET AND SUB TROPICAL JET STREAMS TO OUR NORTH AND
SOUTH...RESPECTIVELY. UPSTREAM COLD FRONT TO THE NW THIS MORNING
WILL STRUGGLE TO MOVES INTO THE UPSTATE AND PEE DEE REGION OF SC
AND THE CENTRAL SAVANNAH RIVER VALLEY OF GA BY NIGHTFALL. STORMS
WILL FORM IN ADVANCE OF THIS FEATURE AND A WEAK PRE-EXISTING
PIEDMONT TROUGH...AS WELL AS TO THE SOUTH/SW OVER NORTHERN FLORIDA
AND SOUTH/SW GEORGIA ALONG SEA BREEZE INTERACTIONS. BOTH OF THESE
REGIONS WILL CONVERGE ON THE CWFA FROM ABOUT 2-8 PM...ASSUMING
MESOSCALE PROCESSES PAN OUT AS WE ARE CURRENTLY FORECASTING. WE
ARE MAINTAINING 50-70 POPS...BUT ADJUSTMENTS WILL LIKELY BE
REQUIRED.

MODIFIED SOUNDINGS SHOW PLENTY OF INSTABILITY DURING PEAK HEATING
WITH LIFTED INDICES OF -6 OR -7C AND SBCAPES OF 2000-3000 J/KG.
PLUS THERE IS THE AFOREMENTIONED SHEAR WHICH IS THE BIGGEST
DIFFERENCE THAT WE SEE FOR TODAY COMPARED TO RECENT DAYS. DCAPES
ARE FORECAST TO EXCEED 800 OR 900 J/KG AND WINDEX VALUES FROM RAOB
ARE 55-65...BOTH SUPPORTIVE OF DAMAGING WINDS. HAIL CAPES OF 800
J/KG OR GREATER AND WET BULB ZERO AROUND 9K FT ARE ALSO CONDUCIVE
FOR LARGE HAIL. IF WINDS ALONG THE COASTAL CORRIDOR ARE ABLE TO
BACK ENOUGH SOUTH WITH A RESULTANT SEA BREEZE THERE WOULD ALSO BE
A VERY LOW END RISK FOR AN ISOLATED TORNADO.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS CLOSE
TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR AT
LEAST LOCALLY HEAVY RAINS. THE MEAN FLOW IS MORE WEST TO EAST
WHILE THE ORIENTATION OF STORMS IS MORE SW TO NE WHICH WILL AID IS
LIMITING BACK-BUILDING AND TRAINING. STILL...ANY DEVIATION OF
THESE TRAJECTORIES MORE IN SYNC WITH EACH OTHER COULD SUPPORT A
HIGHER FLOODING RAIN THREAT.

THERE IS SOME DOWNSLOPE COMPONENT TO THE SYNOPTIC FLOW...AND THAT
ALONG WITH COMPRESSIONAL HEATING IN ADVANCE OF THE COLD FRONT WILL
BOOST MAX TEMPS INTO THE MID AND UPPER 80S BEFORE CONVECTIVE
DEVELOPMENT INCREASES. THIS SAME WESTERLY FLOW WILL ALSO TEND TO
HELP MIX OUT DEW POINTS...AND DEPENDING UPON HOW MUCH OF THIS
OCCURS WILL BE FACTOR IN INSTABILITY. FOR NOW WE DON/T ANTICIPATE
THEM DROPPING ANY LOWER THAN THE MID 60S. WE HAVE ALSO ALTERED
THE DIURNAL TEMP CURVE TO ACCOUNT FOR RAIN-COOLED CONVECTION ONCE
CONVECTION INCREASE IN AREAL COVERAGE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...NUMEROUS SHOWER/TSTMS WILL LIKELY BE ONGOING ACROSS THE
AREA AT SUNSET...MOST OF WHICH WILL TRANSLATE THE COAST DURING THE
EARLY EVENING HOURS. A RISK FOR SEVERE WEATHER WILL PERSIST UNTIL
THIS MAIN AREA OF CONVECTION MOVES OFFSHORE. THE MAIN SHORTWAVE
WILL APPROACH THE AREA AROUND DAYBREAK WEDNESDAY, SO ALTHOUGH THE
GREATER RISK FOR SHOWERS/TSTMS WILL OCCUR EARLY IN THE EVENING,
THERE WILL BE A CONTINUED RISK FOR AT LEAST ISOLATED SHOWERS/TSTMS
FOR MUCH OF THE NIGHT AHEAD OF A SLOW MOVING COLD FRONT. LOWS WILL
RANGE FROM THE LOWER-MID 60S WELL INLAND TO THE UPPER 60S/NEAR 70
AT THE COAST.

WEDNESDAY...A TROUGH WILL BE OVER THE EASTERN HALF OF THE
COUNTRY...WITH AN UPPER LEVEL LOW OVER THE GREAT LAKES. THE COLD
FRONT SHOULD CROSS THROUGH OUR AREA AROUND DAYBREAK. REMNANT SHOWERS
AND THUNDERSTORMS...MAINLY LIMITED TO THE COASTAL COUNTIES...WILL
QUICKLY BE PUSHED OFFSHORE WITH THE FRONT. WESTERLY WINDS WILL BRING
DRIER CONDITIONS AND COOLER TEMPERATURES INTO OUR AREA. DESPITE
PLENTY OF SUNSHINE HIGHS WILL RISE INTO THE UPPER 70S TO NEAR 80
DEGREES...ABOUT AVERAGE FOR THIS TIME OF YEAR. SOME DISTURBANCES
WILL ROUND THE BASE OF THE TROUGH...MOVING ACROSS OUR AREA. THIS
WILL BRING BRIEF INCREASES IN CLOUDS...BUT NO PRECIPITATION. A
REINFORCING COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY
NIGHT. THIS FRONT WILL BE DRY...SO AT MOST WE CAN EXPECT SOME
CLOUDS...BUT NO SHOWERS OR THUNDERSTORMS. WEST-NORTHWEST WILL ALLOW
LOWS TO DROP INTO THE MID 50S INLAND TO AROUND 60 DEGREES ALONG THE
COAST.

THURSDAY...THE TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL
INTENSIFY WHILE THE UPPER LEVEL LOW SHIFTS OVER THE MID-ATLANTIC
REGION. THE MODELS ARE HINTING AT A WEAK SURFACE LOW FORMING AROUND
NORTH CAROLINA. THIS WOULD ALLOW SOME MOISTURE TO ADVECT FURTHER
SOUTH THAN ORIGINALLY EXPECTED. GIVEN THE GENERAL MODEL
CONSENSUS...ADDED SLIGHT CHANCE POPS TO THE FORECAST...MAINLY
LIMITED TO OUR SOUTH CAROLINA COUNTIES IN THE AFTERNOON. QPF SHOULD
BE MINIMAL...IF ANYTHING. WEST TO NORTHWEST FLOW AND WEAK COLD
ADVECTION BEHIND THE COLD FRONT...THAT IS SHIFTING OFFSHORE...WILL
USHER IN COOLER TEMPERATURES AND LOWER DEW POINTS. HIGHS SHOULD RISE
INTO THE MID 70S...SEVERAL DEGREES BELOW NORMAL WHILE THE DEW POINTS
FALL INTO THE 40S. BY THURSDAY NIGHT THE WEAK SURFACE LOW SHIFTS TO
THE NORTHEAST AND ANY SHOWER ACTIVITY WILL FOLLOW IT. CONTINUED
NORTHWEST FLOW AND SOME COLD ADVECTION WILL ALLOW LOWS TO FALL INTO
THE LOWER 50S INLAND...POSSIBLY THE UPPER 40S IN A FEW SPOT...AND
THE MID 50S ALONG THE BEACHES.

FRIDAY...MODELS KEEP THE TROUGH OVER THE EASTERN THIRD OF THE
COUNTRY...BUT THEY SHIFT THE UPPER LEVEL LOW A LITTLE BIT TO THE
NORTH. THIS SHOULD KEEP OUR AREA DRY. THE COMBINATION OF INCREASING
HEIGHTS...NO THREAT OF RAIN AND PLENTY OF SUNSHINE SHOULD ALLOW
TEMPERATURES TO RISE SEVERAL DEGREES. THOUGH THEY WILL REMAIN
SEVERAL DEGREES BELOW NORMAL...THE MID TO UPPER 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /17Z TUESDAY THROUGH SUNDAY/...
CONFIDENCE IS HIGH THAT TSTMS WILL IMPACT KSAV LATE THIS
AFTERNOON AND EVENING. HIGH RESOLUTION DATA SUPPORT A LINE OF
SHOWERS/TSTMS MOVING ACROSS SOUTHEAST GEORGIA PRIOR TO SUNSET.
PROBABILITIES FOR DIRECT IMPACTS ARE HIGHEST ROUGHLY 21-00Z...SO A
TEMPO GROUP FOR MID-RANGE MVFR VSBYS WILL BE INCLUDED IN A TEMPO
GROUP TO COVER. LOWER CONDITIONS...POSSIBLY AS LOW AS IFR...ARE
CERTAINLY POSSIBLE IF HEAVIER TSTMS MOVE ACROSS THE TERMINAL. AT
KCHS...PROBABILITIES ARE LOWER AND CONFIDENCE IS NOT AS GREAT.
WILL CONTINUE TO KEEP TSRA OUT OF THE TAF UNTIL CONFIDENCE
INCREASES.

EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT PROBABILITY OF OCCURRENCE.

&&

.MARINE...
THIS AFTERNOON...SOUTHWEST WINDS WILL INCREASE A BIT AS THE
GRADIENT BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING COLD
FRONT TIGHTENS. SHOULD SEE WINDS AS HIGH AS 15 TO PERHAPS 20 KT
CHARLESTON COUNTY AND GEORGIA OFFSHORE WATERS WITH 15 KT REMAINING
LEGS. SEAS WILL AVERAGE 2-4 FT NEARSHORE WATERS AND 3-5 FT
OFFSHORE WATERS. STRONG TSTMS COULD IMPACT THE COASTAL WATERS FROM
TIME TO TIME AND SPECIAL MARINE WARNINGS AND/OR MARINE WEATHER
STATEMENTS COULD BE NEEDED.

TONIGHT...SOUTHWEST WINDS WILL PERSIST AS A COLD FRONT DRAWS
CLOSER. LOW-LEVEL JETTING WILL REMAIN DISPLACED WELL OFFSHORE, SO
NO DIRECT IMPACTS ARE EXPECTED ON THE LOCAL WIND FIELD. SPEEDS
WILL AVERAGE 10-15 KT WITH SEAS 2-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS. THE RISK FOR STRONG TSTMS WILL LINGER FOR MUCH OF
THE NIGHT.

WEDNESDAY...SOUTHWEST TO WEST WINDS 10-15 KT BEHIND THE FRONT. SEAS
2-3 FT WITHIN 20 NM AND 3-4 FT ACROSS THE OUTER GEORGIA WATERS.

WEDNESDAY NIGHT INTO THURSDAY...A REINFORCING COLD FRONT WILL MOVE
THROUGH AND BEHIND THE FRONT WILL BE A INCREASING PRESSURE GRADIENT.
THIS WILL CAUSE WESTERLY WINDS TO INCREASE. EXPECT WINDS TO BE 15-20
KTS WITHING 20 NM AND 20-25 KT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL BUILD TO 4 FT BEYOND 15 NM AND 4-5 FT ACROSS THE OUTER GEORGIA
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR WIND GUSTS FOR THE
OUTER GEORGIA WATERS.

FRIDAY AND SATURDAY..THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE MOVES IN FROM THE WEST. EXPECT WINDS OF 15 KTS OR
LESS AND SEAS SUBSIDING BELOW 3 FT.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 031425
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1025 AM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION THROUGH TONIGHT AND PASS
OFFSHORE WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE
REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
ANOTHER ACTIVE AFTERNOON/EVENING OF SHOWERS AND T-STORMS IS
EXPECTED...SOME OF WHICH COULD BECOME SEVERE. THE WILD CARD IS THE
SHEAR WHICH WAS LACKING THE PAST TWO DAYS WHICH IS EVIDENT TODAY.
THIS COULD CERTAINLY ALLOW FOR BETTER ORGANIZATION OF
MULTICELLULAR CLUSTERS AND/OR A SQUALL LINE/QLCS/LEWP FEATURE.
BULK SHEAR IN THE 0-6 KM LAYER IS 25-35 KT...ALTHOUGH IN THE
LOWEST 1 KM IS IS ONLY 15 TO PERHAPS 20 KT...WHICH ADDS A LITTLE
UNCERTAINTY TO THE FORECAST PATTERN.

FOR THIS MORNING AND EARLY AFTERNOON THE FORECAST ZONES ARE WITHIN
A REGION OF MAINLY NVA ALOFT IN WAKE OF THE STRONG SHORT WAVE
PULLING ACROSS EASTERN NC. UPSTREAM SHORT IN THE MID MS VALLEY IS
PROBABLY NOT GOING TO ARRIVE UNTIL AFTER DARK AND IS A NON-FACTOR
AT THE MOMENT FOR TODAY/S PATTERN. WE LOOK FOR ISOLATED TO
SCATTERED COVERAGE OF SHOWERS AND T-STORMS TO FORM ON DIFFERENTIAL
HEATING BOUNDARIES WITH CONVECTIVE TEMPS IN THE LOWER 80S THAT ARE
EASILY REACHED. ANY OF THESE STORMS WILL BE SUB-SEVERE WITH ONLY
MODEST THERMODYNAMICS. SINCE DCAPES ARE 600-800 J/KG THERE STILL
COULD BE SOME WIND GUSTS OF 30-40 MPH IN ISOLATED STORMS.

FOR THE MID AND LATE AFTERNOON INTO THIS EVENING IS WHEN THE
SITUATION IS PRIMED TO GET MUCH MORE ACTIVE. EVEN WITH THE LACK OF
SIGNIFICANT FEATURES ALOFT...THERE ARE SUBTLE MID LEVEL
PERTURBATIONS WITHIN THE WEST/SW FLOW ALOFT...AS WELL AS THE
NECESSARY DIFLUENCE UPSTAIRS WITH A DIVERGING PATTERN TO THE POLAR
JET AND SUB TROPICAL JET STREAMS TO OUR NORTH AND
SOUTH...RESPECTIVELY. UPSTREAM COLD FRONT TO THE NW THIS MORNING
WILL STRUGGLE TO MOVES INTO THE UPSTATE AND PEE DEE REGION OF SC
AND THE CENTRAL SAVANNAH RIVER VALLEY OF GA BY NIGHTFALL. STORMS
WILL FORM IN ADVANCE OF THIS FEATURE AND A WEAK PRE-EXISTING
PIEDMONT TROUGH...AS WELL AS TO THE SOUTH/SW OVER NORTHERN FLORIDA
AND SOUTH/SW GEORGIA ALONG SEA BREEZE INTERACTIONS. BOTH OF THESE
REGIONS WILL CONVERGE ON THE CWFA...LIKELY REACHING INTO SE
GEORGIA AND FAR SOUTHERN SC BY 3-4 PM...AND INTO THE CHARLESTON
QUAD-COUNTY REGION BY 5-8 PM...ASSUMING MESOSCALE PROCESSES PAN
OUT AS WE ARE CURRENTLY FORECASTING. WE HAVE DONE LITTLE TO THE
HIGHEST CONVECTIVE CHANCES IN THE 50-70 PERCENTILE...HIGHEST SOUTH
AND EASTERN COUNTIES.

MODIFIED SOUNDINGS SHOW PLENTY OF INSTABILITY DURING PEAK HEATING
WITH LIFTED INDICES OF -6 OR -7C AND SBCAPES OF 2000-3000 J/KG.
PLUS THERE IS THE AFOREMENTIONED SHEAR WHICH IS THE BIGGEST
DIFFERENCE THAT WE SEE FOR TODAY COMPARED TO RECENT DAYS. DCAPES
ARE FORECAST TO EXCEED 800 OR 900 J/KG AND WINDEX VALUES FROM RAOB
ARE 55-65...BOTH SUPPORTIVE OF DAMAGING WINDS. HAIL CAPES OF 800
J/KG OR GREATER AND WET BULB ZERO AROUND 9K FT ARE ALSO CONDUCIVE
FOR LARGE HAIL. IF WINDS ALONG THE COASTAL CORRIDOR ARE ABLE TO
BACK ENOUGH SOUTH WITH A RESULTANT SEA BREEZE THERE WOULD ALSO BE
A VERY LOW END RISK FOR AN ISOLATED TORNADO.

THERE IS MORE STORM MOTION THAN RECENT DAYS...BUT WITH PWATS CLOSE
TO 2 STANDARD DEVIATIONS ABOVE NORMAL WILL SUPPORT THE RISK FOR AT
LEAST LOCALLY HEAVY RAINS. THE MEAN FLOW IS MORE WEST TO EAST
WHILE THE ORIENTATION OF STORMS IS MORE SW TO NE WHICH WILL AID IS
LIMITING BACK-BUILDING AND TRAINING. STILL...ANY DEVIATION OF
THESE TRAJECTORIES MORE IN SYNC WITH EACH OTHER COULD SUPPORT A
HIGHER FLOODING RAIN THREAT.

THERE IS SOME DOWNSLOPE COMPONENT TO THE SYNOPTIC FLOW...AND THAT
ALONG WITH COMPRESSIONAL HEATING IN ADVANCE OF THE COLD FRONT WILL
BOOST MAX TEMPS INTO THE MID AND UPPER 80S BEFORE CONVECTIVE
DEVELOPMENT INCREASES. THIS SAME WESTERLY FLOW WILL ALSO TEND TO
HELP MIX OUT DEW POINTS...AND DEPENDING UPON HOW MUCH OF THIS
OCCURS WILL BE FACTOR IN INSTABILITY. FOR NOW WE DON/T ANTICIPATE
THEM DROPPING ANY LOWER THAN THE MID 60S. WE HAVE ALSO ALTERED
THE DIURNAL TEMP CURVE TO ACCOUNT FOR RAIN-COOLED CONVECTION ONCE
CONVECTION INCREASE IN AREAL COVERAGE.





&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...NUMEROUS SHOWER/TSTMS WILL LIKELY BE ONGOING ACROSS THE
AREA AT SUNSET...MOST OF WHICH WILL TRANSLATE THE COAST DURING THE
EARLY EVENING HOURS. A RISK FOR SEVERE WEATHER WILL PERSIST UNTIL
THIS MAIN AREA OF CONVECTION MOVES OFFSHORE. THE MAIN SHORTWAVE
WILL APPROACH THE AREA AROUND DAYBREAK WEDNESDAY, SO ALTHOUGH THE
GREATER RISK FOR SHOWERS/TSTMS WILL OCCUR EARLY IN THE EVENING,
THERE WILL BE A CONTINUED RISK FOR AT LEAST ISOLATED SHOWERS/TSTMS
FOR MUCH OF THE NIGHT AHEAD OF A SLOW MOVING COLD FRONT. LOWS WILL
RANGE FROM THE LOWER-MID 60S WELL INLAND TO THE UPPER 60S/NEAR 70
AT THE COAST.

WEDNESDAY...A TROUGH WILL BE OVER THE EASTERN HALF OF THE
COUNTRY...WITH AN UPPER LEVEL LOW OVER THE GREAT LAKES. THE COLD
FRONT SHOULD CROSS THROUGH OUR AREA AROUND DAYBREAK. REMNANT SHOWERS
AND THUNDERSTORMS...MAINLY LIMITED TO THE COASTAL COUNTIES...WILL
QUICKLY BE PUSHED OFFSHORE WITH THE FRONT. WESTERLY WINDS WILL BRING
DRIER CONDITIONS AND COOLER TEMPERATURES INTO OUR AREA. DESPITE
PLENTY OF SUNSHINE HIGHS WILL RISE INTO THE UPPER 70S TO NEAR 80
DEGREES...ABOUT AVERAGE FOR THIS TIME OF YEAR. SOME DISTURBANCES
WILL ROUND THE BASE OF THE TROUGH...MOVING ACROSS OUR AREA. THIS
WILL BRING BRIEF INCREASES IN CLOUDS...BUT NO PRECIPITATION. A
REINFORCING COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY
NIGHT. THIS FRONT WILL BE DRY...SO AT MOST WE CAN EXPECT SOME
CLOUDS...BUT NO SHOWERS OR THUNDERSTORMS. WEST-NORTHWEST WILL ALLOW
LOWS TO DROP INTO THE MID 50S INLAND TO AROUND 60 DEGREES ALONG THE
COAST.

THURSDAY...THE TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL
INTENSIFY WHILE THE UPPER LEVEL LOW SHIFTS OVER THE MID-ATLANTIC
REGION. THE MODELS ARE HINTING AT A WEAK SURFACE LOW FORMING AROUND
NORTH CAROLINA. THIS WOULD ALLOW SOME MOISTURE TO ADVECT FURTHER
SOUTH THAN ORIGINALLY EXPECTED. GIVEN THE GENERAL MODEL
CONSENSUS...ADDED SLIGHT CHANCE POPS TO THE FORECAST...MAINLY
LIMITED TO OUR SOUTH CAROLINA COUNTIES IN THE AFTERNOON. QPF SHOULD
BE MINIMAL...IF ANYTHING. WEST TO NORTHWEST FLOW AND WEAK COLD
ADVECTION BEHIND THE COLD FRONT...THAT IS SHIFTING OFFSHORE...WILL
USHER IN COOLER TEMPERATURES AND LOWER DEW POINTS. HIGHS SHOULD RISE
INTO THE MID 70S...SEVERAL DEGREES BELOW NORMAL WHILE THE DEW POINTS
FALL INTO THE 40S. BY THURSDAY NIGHT THE WEAK SURFACE LOW SHIFTS TO
THE NORTHEAST AND ANY SHOWER ACTIVITY WILL FOLLOW IT. CONTINUED
NORTHWEST FLOW AND SOME COLD ADVECTION WILL ALLOW LOWS TO FALL INTO
THE LOWER 50S INLAND...POSSIBLY THE UPPER 40S IN A FEW SPOT...AND
THE MID 50S ALONG THE BEACHES.

FRIDAY...MODELS KEEP THE TROUGH OVER THE EASTERN THIRD OF THE
COUNTRY...BUT THEY SHIFT THE UPPER LEVEL LOW A LITTLE BIT TO THE
NORTH. THIS SHOULD KEEP OUR AREA DRY. THE COMBINATION OF INCREASING
HEIGHTS...NO THREAT OF RAIN AND PLENTY OF SUNSHINE SHOULD ALLOW
TEMPERATURES TO RISE SEVERAL DEGREES. THOUGH THEY WILL REMAIN
SEVERAL DEGREES BELOW NORMAL...THE MID TO UPPER 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
CONFIDENCE IS HIGH THAT TSTMS WILL IMPACT KSAV LATE THIS AFTERNOON
AND EVENING. HIGH RESOLUTION DATA SUPPORT A LINE OF SHOWERS/TSTMS
MOVING ACROSS SOUTHEAST GEORGIA PRIOR TO SUNSET. PROBABILITIES FOR
DIRECT IMPACTS ARE HIGHEST ROUGHLY 21-00Z...SO A TEMPO GROUP FOR
MID-RANGE MVFR VSBYS WILL BE INCLUDED IN A TEMPO GROUP TO COVER.
LOWER CONDITIONS...POSSIBLY AS LOW AS IFR...ARE CERTAINLY POSSIBLE
IF HEAVIER TSTMS MOVE ACROSS THE TERMINAL. AT KCHS...PROBABILITIES
ARE LOWER AND CONFIDENCE IS NOT AS GREAT. WILL CONTINUE TO KEEP
TSRA OUT OF THE TAF UNTIL CONFIDENCE INCREASES.

EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT PROBABILITY OF OCCURRENCE.

&&

.MARINE...
TODAY...SOUTHWEST WINDS WILL INCREASE A BIT AS THE GRADIENT
BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING COLD FRONT
TIGHTENS. SHOULD SEE WINDS AS HIGH AS 15 TO PERHAPS 20 KT
CHARLESTON COUNTY AND GEORGIA OFFSHORE WATERS WITH 15 KT REMAINING
LEGS. SEAS WILL AVERAGE 2-4 FT NEARSHORE WATERS AND 3-5 FT
OFFSHORE WATERS. STRONG TSTMS COULD IMPACT THE COASTAL WATERS LATE
THIS AFTERNOON. SPECIAL MARINE WARNINGS MAY BE NEEDED.

TONIGHT...SOUTHWEST WINDS WILL PERSIST AS A COLD FRONT DRAWS
CLOSER. LOW-LEVEL JETTING WILL REMAIN DISPLACED WELL OFFSHORE, SO
NO DIRECT IMPACTS ARE EXPECTED ON THE LOCAL WIND FIELD. SPEEDS
WILL AVERAGE 10-15 KT WITH SEAS 2-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS. THE RISK FOR STRONG TSTMS WILL LINGER FOR MUCH OF
THE NIGHT.

WEDNESDAY...SOUTHWEST TO WEST WINDS 10-15 KT BEHIND THE FRONT. SEAS
2-3 FT WITHIN 20 NM AND 3-4 FT ACROSS THE OUTER GEORGIA WATERS.

WEDNESDAY NIGHT INTO THURSDAY...A REINFORCING COLD FRONT WILL MOVE
THROUGH AND BEHIND THE FRONT WILL BE A INCREASING PRESSURE GRADIENT.
THIS WILL CAUSE WESTERLY WINDS TO INCREASE. EXPECT WINDS TO BE 15-20
KTS WITHING 20 NM AND 20-25 KT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL BUILD TO 4 FT BEYOND 15 NM AND 4-5 FT ACROSS THE OUTER GEORGIA
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR WIND GUSTS FOR THE
OUTER GEORGIA WATERS.

FRIDAY AND SATURDAY..THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE MOVES IN FROM THE WEST. EXPECT WINDS OF 15 KTS OR
LESS AND SEAS SUBSIDING BELOW 3 FT.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE...AND IT IS POSSIBLE THAT A
SITE VISIT WILL BE PERFORMED BY LATE IN THE WEEK.

THE GRAYS REEF BUOY 41008 ALSO REMAINS OUT OF SERVICE...AND A SITE
VISIT BY NDBC IS EXPECTED DURING THE LATTER PART OF MAY TO EITHER
REPAIR THE SITE OR EXCHANGE FOR A NEW BUOY SYSTEM.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 031101
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
701 AM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION THROUGH TONIGHT AND PASS
OFFSHORE WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE
REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST CAMS ARE BEGINNING TO CONVERGE ON A MORE CONSOLIDATED
CONVECTIVE SOLUTION FOR THIS AFTERNOON AND EVENING. THERE ARE
SIGNALS THAT CONVECTION THAT FORMS ACROSS THE FLORDIA PANHANDLE
AND SOUTHWEST GEORGIA EARLY THIS AFTERNOON COULD ORGANIZE INTO AN
LOOSELY ORGANIZED CLUSTER...POSSIBLY IN THE FORM A SQUALL
LINE/QLCS...AS IT MOVES EAST AND ENCOUNTERS MORE FAVORABLE
CONVECTIVE PARAMETERS. THE LINE WOULD TENTATIVELY REACH INTERIOR
SOUTHEAST GEORGIA BY 3-4 PM AND REACH THE GEORGIA AND FAR SOUTHERN
SOUTH CAROLINA COAST BY 6-9 PM ASSUMING MESOSCALE PROCESSES REMAIN
IN CHECK. 0-6KM BULK SHEAR IS CERTAINLY A BIT WEAKER ALONG THE
I-16 CORRIDOR...BUT VALUES AROUND 30 KT IN THAT AREA ARE MORE THAN
SUFFICIENT TO MAINTAIN A QLCS IF IT GETS ORGANIZED. IT IS UNCLEAR
HOW FAR NORTH THE CONVECTIVE LINE WOULD BUILD...BUT IT APPEARS THE
BETTER SEVERE PROBABILITIES COULD POTENTIALLY SETUP ACROSS
SOUTHEAST GEORGIA. PLAN TO REALIGN POPS SLIGHTLY WITH THE SUNRISE
UPDATE...INCREASING POPS TO 70 PERCENT ACROSS MUCH OF SOUTHEAST
GEORGIA AND LOWER THEM TO 50 PERCENT IN ALLENDALE- WALTERBORO-
MONCKS CORNER CORRIDOR.

TODAY...ANOTHER CONVECTIVELY ACTIVE DAY IS ANTICIPATED ACROSS
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA WITH SEVERE
THUNDERSTORMS POSSIBLE. EARLY MORNING CONVECTION SHOULD BE EXITING
THE AREA AROUND SUNRISE AS SHORTWAVE ENERGY OVER GEORGIA
TRANSLATES NORTHEAST. SUBSIDENCE/DAVA SPREADING IN IN THE WAKE OF
THE DEPARTING SHORTWAVE SHOULD RESULT IN A MAINLY DRY MORNING
WITH BREAKS IN THE CLOUD COVER HELPING TO WARM TEMPERATURES
QUICKLY AFTER SUNRISE. CONVECTION IS POISED TO DEVELOP LATER THIS
AFTERNOON AS SUBSIDENCE IS REPLACED WITH INCREASING VERTICAL
VELOCITIES IN RESPONSE TO POTENT SHORTWAVE PIVOTING OUT OF THE
OHIO AND MIDDLE MISSISSIPPI VALLEYS. UPPER FORCING AHEAD OF THIS
FEATURE INTERACTING WITH A MODERATELY UNSTABLE ATMOSPHERE ACROSS
THE SOUTHEAST U.S. WILL SUPPORT THE DEVELOPMENT OF NUMEROUS
SHOWERS AND TSTMS AHEAD OF AN APPROACHING COLD FRONT.

CONVECTION IS EXPECTED TO DEVELOP/PROPAGATE OVER/INTO INLAND
AREAS, THEN GRADUALLY SPREAD EAST TO THE COAST BY LATE AFTERNOON/
EARLY EVENING AS A COLD FRONT DRAWS CLOSER. CONVECTION WILL BE
FURTHER ENHANCED BY MESOSCALE BOUNDARY COLLISIONS AS WELL AS A
CORRIDOR OF UPPER DIFLUENCE THAT WILL BE DIRECTLY OVER SOUTH
CAROLINA AND GEORGIA BETWEEN DIVERGING BRANCHES OF THE POLAR AND
SUBTROPICAL JET STREAMS. THERE REMAINS SOME TIMING ISSUES FOR WHEN
THE CORRIDOR OF GREATEST SHOWER/TSTM COVERAGE WILL AFFECT THE
AREA, SO POPS WILL BE MAXED OUT IN THE LIKELY CATEGORY FOR NOW
UNTIL CONFIDENCE INCREASES. GENERALLY FAVORED THE SSEO CONSENSUS
TO CONSTRUCT THE PLACEMENT AND TIMING OF THE HIGHEST GRIDDED POPS
THROUGH SUNSET.

MODIFIED SOUNDINGS SHOW QUITE A BIT OF INSTABILITY DEVELOPING
DURING MAX HEATING AS AS TEMPERATURES WARM INTO THE MID TO
POSSIBLY UPPER 80S AWAY FROM THE COAST JUXTAPOSED WITH A RIBBON OF
SURFACE DEWPOINTS IN THE UPPER 60S/NEAR 70. 0-6KM BULK SHEAR WILL
BE STRONGER THAN THE PAST SEVERAL DAYS--ON THE ORDER OF 30-40
KT--OWING TO INFLUENCES FROM THE APPROACHING SHORTWAVE, BUT THE
DEGREE OF CONVECTIVE ORGANIZATION IS STILL UNCERTAIN GIVEN THE
VARIOUS TIMING/CONVECTIVE PLACEMENT UNKNOWNS WITHIN THE CORRIDOR
OF STRONGEST UPPER FORCING. THERE IS CERTAINLY A POTENTIAL FOR A
MORE ORGANIZED SEVERE THUNDERSTORM EVENT THIS AFTERNOON WITH LARGE
HAIL AND DAMAGING WINDS BEING THE PRIMARY HAZARDS SO WILL
CONTINUE TO MENTION A POTENTIAL FOR SEVERE THUNDERSTORMS IN THE
HAZARDOUS WEATHER OUTLOOK.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...NUMEROUS SHOWER/TSTMS WILL LIKELY BE ONGOING ACROSS THE
AREA AT SUNSET...MOST OF WHICH WILL TRANSLATE THE COAST DURING THE
EARLY EVENING HOURS. A RISK FOR SEVERE WEATHER WILL PERSIST UNTIL
THIS MAIN AREA OF CONVECTION MOVES OFFSHORE. THE MAIN SHORTWAVE
WILL APPROACH THE AREA AROUND DAYBREAK WEDNESDAY, SO ALTHOUGH THE
GREATER RISK FOR SHOWERS/TSTMS WILL OCCUR EARLY IN THE EVENING,
THERE WILL BE A CONTINUED RISK FOR AT LEAST ISOLATED SHOWERS/TSTMS
FOR MUCH OF THE NIGHT AHEAD OF A SLOW MOVING COLD FRONT. LOWS WILL
RANGE FROM THE LOWER-MID 60S WELL INLAND TO THE UPPER 60S/NEAR 70
AT THE COAST.

WEDNESDAY...A TROUGH WILL BE OVER THE EASTERN HALF OF THE
COUNTRY...WITH AN UPPER LEVEL LOW OVER THE GREAT LAKES. THE COLD
FRONT SHOULD CROSS THROUGH OUR AREA AROUND DAYBREAK. REMNANT SHOWERS
AND THUNDERSTORMS...MAINLY LIMITED TO THE COASTAL COUNTIES...WILL
QUICKLY BE PUSHED OFFSHORE WITH THE FRONT. WESTERLY WINDS WILL BRING
DRIER CONDITIONS AND COOLER TEMPERATURES INTO OUR AREA. DESPITE
PLENTY OF SUNSHINE HIGHS WILL RISE INTO THE UPPER 70S TO NEAR 80
DEGREES...ABOUT AVERAGE FOR THIS TIME OF YEAR. SOME DISTURBANCES
WILL ROUND THE BASE OF THE TROUGH...MOVING ACROSS OUR AREA. THIS
WILL BRING BRIEF INCREASES IN CLOUDS...BUT NO PRECIPITATION. A
REINFORCING COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY
NIGHT. THIS FRONT WILL BE DRY...SO AT MOST WE CAN EXPECT SOME
CLOUDS...BUT NO SHOWERS OR THUNDERSTORMS. WEST-NORTHWEST WILL ALLOW
LOWS TO DROP INTO THE MID 50S INLAND TO AROUND 60 DEGREES ALONG THE
COAST.

THURSDAY...THE TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL
INTENSIFY WHILE THE UPPER LEVEL LOW SHIFTS OVER THE MID-ATLANTIC
REGION. THE MODELS ARE HINTING AT A WEAK SURFACE LOW FORMING AROUND
NORTH CAROLINA. THIS WOULD ALLOW SOME MOISTURE TO ADVECT FURTHER
SOUTH THAN ORIGINALLY EXPECTED. GIVEN THE GENERAL MODEL
CONSENSUS...ADDED SLIGHT CHANCE POPS TO THE FORECAST...MAINLY
LIMITED TO OUR SOUTH CAROLINA COUNTIES IN THE AFTERNOON. QPF SHOULD
BE MINIMAL...IF ANYTHING. WEST TO NORTHWEST FLOW AND WEAK COLD
ADVECTION BEHIND THE COLD FRONT...THAT IS SHIFTING OFFSHORE...WILL
USHER IN COOLER TEMPERATURES AND LOWER DEW POINTS. HIGHS SHOULD RISE
INTO THE MID 70S...SEVERAL DEGREES BELOW NORMAL WHILE THE DEW POINTS
FALL INTO THE 40S. BY THURSDAY NIGHT THE WEAK SURFACE LOW SHIFTS TO
THE NORTHEAST AND ANY SHOWER ACTIVITY WILL FOLLOW IT. CONTINUED
NORTHWEST FLOW AND SOME COLD ADVECTION WILL ALLOW LOWS TO FALL INTO
THE LOWER 50S INLAND...POSSIBLY THE UPPER 40S IN A FEW SPOT...AND
THE MID 50S ALONG THE BEACHES.

FRIDAY...MODELS KEEP THE TROUGH OVER THE EASTERN THIRD OF THE
COUNTRY...BUT THEY SHIFT THE UPPER LEVEL LOW A LITTLE BIT TO THE
NORTH. THIS SHOULD KEEP OUR AREA DRY. THE COMBINATION OF INCREASING
HEIGHTS...NO THREAT OF RAIN AND PLENTY OF SUNSHINE SHOULD ALLOW
TEMPERATURES TO RISE SEVERAL DEGREES. THOUGH THEY WILL REMAIN
SEVERAL DEGREES BELOW NORMAL...THE MID TO UPPER 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
CONFIDENCE IS INCREASING THAT TSTMS WILL IMPACT KSAV LATE THIS
AFTERNOON AND EVENING. HIGH RESOLUTION DATA SUPPORT A LINE
OF SHOWERS/TSTMS MOVING ACROSS SOUTHEAST GEORGIA PRIOR TO SUNSET.
PROBABILITIES FOR DIRECT IMPACTS ARE HIGHEST ROUGHLY 21-00Z...SO A
TEMPO GROUP FOR MID-RANGE MVFR VSBYS WILL BE INCLUDED IN A TEMPO
GROUP TO COVER. LOWER CONDITIONS...POSSIBLY AS LOW AS IFR...ARE
CERTAINLY POSSIBLE IF HEAVIER TSTMS MOVE ACROSS THE TERMINAL. AT
KCHS...PROBABILITIES ARE LOWER AND CONFIDENCE IS NOT AS GREAT.
WILL CONTINUE TO KEEP TSRA OUT OF THE TAF UNTIL CONFIDENCE
INCREASES.

EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT PROBABILITY OF OCCURRENCE.

&&

.MARINE...
TODAY...SOUTHWEST WINDS WILL INCREASE A BIT AS THE GRADIENT
BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING COLD FRONT
TIGHTENS. SHOULD SEE WINDS AS HIGH AS 15-20 KT CHARLESTON COUNTY
AND GEORGIA OFFSHORE WATERS WITH 15 KT REMAINING LEGS. SEAS WILL
AVERAGE 2-4 FT NEARSHORE WATERS AND 3-5 FT OFFSHORE WATERS.
STRONG TSTMS COULD IMPACT THE COASTAL WATERS LATE THIS AFTERNOON.
SPECIAL MARINE WARNINGS MAY BE NEEDED.

TONIGHT...SOUTHWEST WINDS WILL PERSIST AS A COLD FRONT DRAWS
CLOSER. LOW-LEVEL JETTING WILL REMAIN DISPLACED WELL OFFSHORE, SO
NO DIRECT IMPACTS ARE EXPECTED ON THE LOCAL WIND FIELD. SPEEDS
WILL AVERAGE 10-15 KT WITH SEAS 2-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS. THE RISK FOR STRONG TSTMS WILL LINGER FOR MUCH OF
THE NIGHT.

WEDNESDAY...SOUTHWEST TO WEST WINDS 10-15 KT BEHIND THE FRONT. SEAS
2-3 FT WITHIN 20 NM AND 3-4 FT ACROSS THE OUTER GEORGIA WATERS.

WEDNESDAY NIGHT INTO THURSDAY...A REINFORCING COLD FRONT WILL MOVE
THROUGH AND BEHIND THE FRONT WILL BE A INCREASING PRESSURE GRADIENT.
THIS WILL CAUSE WESTERLY WINDS TO INCREASE. EXPECT WINDS TO BE 15-20
KTS WITHING 20 NM AND 20-25 KT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL BUILD TO 4 FT BEYOND 15 NM AND 4-5 FT ACROSS THE OUTER GEORGIA
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR WIND GUSTS FOR THE
OUTER GEORGIA WATERS.

FRIDAY AND SATURDAY..THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE MOVES IN FROM THE WEST. EXPECT WINDS OF 15 KTS OR
LESS AND SEAS SUBSIDING BELOW 3 FT.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$

ST





000
FXUS62 KCHS 031101
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
701 AM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION THROUGH TONIGHT AND PASS
OFFSHORE WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE
REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE LATEST CAMS ARE BEGINNING TO CONVERGE ON A MORE CONSOLIDATED
CONVECTIVE SOLUTION FOR THIS AFTERNOON AND EVENING. THERE ARE
SIGNALS THAT CONVECTION THAT FORMS ACROSS THE FLORDIA PANHANDLE
AND SOUTHWEST GEORGIA EARLY THIS AFTERNOON COULD ORGANIZE INTO AN
LOOSELY ORGANIZED CLUSTER...POSSIBLY IN THE FORM A SQUALL
LINE/QLCS...AS IT MOVES EAST AND ENCOUNTERS MORE FAVORABLE
CONVECTIVE PARAMETERS. THE LINE WOULD TENTATIVELY REACH INTERIOR
SOUTHEAST GEORGIA BY 3-4 PM AND REACH THE GEORGIA AND FAR SOUTHERN
SOUTH CAROLINA COAST BY 6-9 PM ASSUMING MESOSCALE PROCESSES REMAIN
IN CHECK. 0-6KM BULK SHEAR IS CERTAINLY A BIT WEAKER ALONG THE
I-16 CORRIDOR...BUT VALUES AROUND 30 KT IN THAT AREA ARE MORE THAN
SUFFICIENT TO MAINTAIN A QLCS IF IT GETS ORGANIZED. IT IS UNCLEAR
HOW FAR NORTH THE CONVECTIVE LINE WOULD BUILD...BUT IT APPEARS THE
BETTER SEVERE PROBABILITIES COULD POTENTIALLY SETUP ACROSS
SOUTHEAST GEORGIA. PLAN TO REALIGN POPS SLIGHTLY WITH THE SUNRISE
UPDATE...INCREASING POPS TO 70 PERCENT ACROSS MUCH OF SOUTHEAST
GEORGIA AND LOWER THEM TO 50 PERCENT IN ALLENDALE- WALTERBORO-
MONCKS CORNER CORRIDOR.

TODAY...ANOTHER CONVECTIVELY ACTIVE DAY IS ANTICIPATED ACROSS
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA WITH SEVERE
THUNDERSTORMS POSSIBLE. EARLY MORNING CONVECTION SHOULD BE EXITING
THE AREA AROUND SUNRISE AS SHORTWAVE ENERGY OVER GEORGIA
TRANSLATES NORTHEAST. SUBSIDENCE/DAVA SPREADING IN IN THE WAKE OF
THE DEPARTING SHORTWAVE SHOULD RESULT IN A MAINLY DRY MORNING
WITH BREAKS IN THE CLOUD COVER HELPING TO WARM TEMPERATURES
QUICKLY AFTER SUNRISE. CONVECTION IS POISED TO DEVELOP LATER THIS
AFTERNOON AS SUBSIDENCE IS REPLACED WITH INCREASING VERTICAL
VELOCITIES IN RESPONSE TO POTENT SHORTWAVE PIVOTING OUT OF THE
OHIO AND MIDDLE MISSISSIPPI VALLEYS. UPPER FORCING AHEAD OF THIS
FEATURE INTERACTING WITH A MODERATELY UNSTABLE ATMOSPHERE ACROSS
THE SOUTHEAST U.S. WILL SUPPORT THE DEVELOPMENT OF NUMEROUS
SHOWERS AND TSTMS AHEAD OF AN APPROACHING COLD FRONT.

CONVECTION IS EXPECTED TO DEVELOP/PROPAGATE OVER/INTO INLAND
AREAS, THEN GRADUALLY SPREAD EAST TO THE COAST BY LATE AFTERNOON/
EARLY EVENING AS A COLD FRONT DRAWS CLOSER. CONVECTION WILL BE
FURTHER ENHANCED BY MESOSCALE BOUNDARY COLLISIONS AS WELL AS A
CORRIDOR OF UPPER DIFLUENCE THAT WILL BE DIRECTLY OVER SOUTH
CAROLINA AND GEORGIA BETWEEN DIVERGING BRANCHES OF THE POLAR AND
SUBTROPICAL JET STREAMS. THERE REMAINS SOME TIMING ISSUES FOR WHEN
THE CORRIDOR OF GREATEST SHOWER/TSTM COVERAGE WILL AFFECT THE
AREA, SO POPS WILL BE MAXED OUT IN THE LIKELY CATEGORY FOR NOW
UNTIL CONFIDENCE INCREASES. GENERALLY FAVORED THE SSEO CONSENSUS
TO CONSTRUCT THE PLACEMENT AND TIMING OF THE HIGHEST GRIDDED POPS
THROUGH SUNSET.

MODIFIED SOUNDINGS SHOW QUITE A BIT OF INSTABILITY DEVELOPING
DURING MAX HEATING AS AS TEMPERATURES WARM INTO THE MID TO
POSSIBLY UPPER 80S AWAY FROM THE COAST JUXTAPOSED WITH A RIBBON OF
SURFACE DEWPOINTS IN THE UPPER 60S/NEAR 70. 0-6KM BULK SHEAR WILL
BE STRONGER THAN THE PAST SEVERAL DAYS--ON THE ORDER OF 30-40
KT--OWING TO INFLUENCES FROM THE APPROACHING SHORTWAVE, BUT THE
DEGREE OF CONVECTIVE ORGANIZATION IS STILL UNCERTAIN GIVEN THE
VARIOUS TIMING/CONVECTIVE PLACEMENT UNKNOWNS WITHIN THE CORRIDOR
OF STRONGEST UPPER FORCING. THERE IS CERTAINLY A POTENTIAL FOR A
MORE ORGANIZED SEVERE THUNDERSTORM EVENT THIS AFTERNOON WITH LARGE
HAIL AND DAMAGING WINDS BEING THE PRIMARY HAZARDS SO WILL
CONTINUE TO MENTION A POTENTIAL FOR SEVERE THUNDERSTORMS IN THE
HAZARDOUS WEATHER OUTLOOK.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
TONIGHT...NUMEROUS SHOWER/TSTMS WILL LIKELY BE ONGOING ACROSS THE
AREA AT SUNSET...MOST OF WHICH WILL TRANSLATE THE COAST DURING THE
EARLY EVENING HOURS. A RISK FOR SEVERE WEATHER WILL PERSIST UNTIL
THIS MAIN AREA OF CONVECTION MOVES OFFSHORE. THE MAIN SHORTWAVE
WILL APPROACH THE AREA AROUND DAYBREAK WEDNESDAY, SO ALTHOUGH THE
GREATER RISK FOR SHOWERS/TSTMS WILL OCCUR EARLY IN THE EVENING,
THERE WILL BE A CONTINUED RISK FOR AT LEAST ISOLATED SHOWERS/TSTMS
FOR MUCH OF THE NIGHT AHEAD OF A SLOW MOVING COLD FRONT. LOWS WILL
RANGE FROM THE LOWER-MID 60S WELL INLAND TO THE UPPER 60S/NEAR 70
AT THE COAST.

WEDNESDAY...A TROUGH WILL BE OVER THE EASTERN HALF OF THE
COUNTRY...WITH AN UPPER LEVEL LOW OVER THE GREAT LAKES. THE COLD
FRONT SHOULD CROSS THROUGH OUR AREA AROUND DAYBREAK. REMNANT SHOWERS
AND THUNDERSTORMS...MAINLY LIMITED TO THE COASTAL COUNTIES...WILL
QUICKLY BE PUSHED OFFSHORE WITH THE FRONT. WESTERLY WINDS WILL BRING
DRIER CONDITIONS AND COOLER TEMPERATURES INTO OUR AREA. DESPITE
PLENTY OF SUNSHINE HIGHS WILL RISE INTO THE UPPER 70S TO NEAR 80
DEGREES...ABOUT AVERAGE FOR THIS TIME OF YEAR. SOME DISTURBANCES
WILL ROUND THE BASE OF THE TROUGH...MOVING ACROSS OUR AREA. THIS
WILL BRING BRIEF INCREASES IN CLOUDS...BUT NO PRECIPITATION. A
REINFORCING COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY
NIGHT. THIS FRONT WILL BE DRY...SO AT MOST WE CAN EXPECT SOME
CLOUDS...BUT NO SHOWERS OR THUNDERSTORMS. WEST-NORTHWEST WILL ALLOW
LOWS TO DROP INTO THE MID 50S INLAND TO AROUND 60 DEGREES ALONG THE
COAST.

THURSDAY...THE TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL
INTENSIFY WHILE THE UPPER LEVEL LOW SHIFTS OVER THE MID-ATLANTIC
REGION. THE MODELS ARE HINTING AT A WEAK SURFACE LOW FORMING AROUND
NORTH CAROLINA. THIS WOULD ALLOW SOME MOISTURE TO ADVECT FURTHER
SOUTH THAN ORIGINALLY EXPECTED. GIVEN THE GENERAL MODEL
CONSENSUS...ADDED SLIGHT CHANCE POPS TO THE FORECAST...MAINLY
LIMITED TO OUR SOUTH CAROLINA COUNTIES IN THE AFTERNOON. QPF SHOULD
BE MINIMAL...IF ANYTHING. WEST TO NORTHWEST FLOW AND WEAK COLD
ADVECTION BEHIND THE COLD FRONT...THAT IS SHIFTING OFFSHORE...WILL
USHER IN COOLER TEMPERATURES AND LOWER DEW POINTS. HIGHS SHOULD RISE
INTO THE MID 70S...SEVERAL DEGREES BELOW NORMAL WHILE THE DEW POINTS
FALL INTO THE 40S. BY THURSDAY NIGHT THE WEAK SURFACE LOW SHIFTS TO
THE NORTHEAST AND ANY SHOWER ACTIVITY WILL FOLLOW IT. CONTINUED
NORTHWEST FLOW AND SOME COLD ADVECTION WILL ALLOW LOWS TO FALL INTO
THE LOWER 50S INLAND...POSSIBLY THE UPPER 40S IN A FEW SPOT...AND
THE MID 50S ALONG THE BEACHES.

FRIDAY...MODELS KEEP THE TROUGH OVER THE EASTERN THIRD OF THE
COUNTRY...BUT THEY SHIFT THE UPPER LEVEL LOW A LITTLE BIT TO THE
NORTH. THIS SHOULD KEEP OUR AREA DRY. THE COMBINATION OF INCREASING
HEIGHTS...NO THREAT OF RAIN AND PLENTY OF SUNSHINE SHOULD ALLOW
TEMPERATURES TO RISE SEVERAL DEGREES. THOUGH THEY WILL REMAIN
SEVERAL DEGREES BELOW NORMAL...THE MID TO UPPER 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
CONFIDENCE IS INCREASING THAT TSTMS WILL IMPACT KSAV LATE THIS
AFTERNOON AND EVENING. HIGH RESOLUTION DATA SUPPORT A LINE
OF SHOWERS/TSTMS MOVING ACROSS SOUTHEAST GEORGIA PRIOR TO SUNSET.
PROBABILITIES FOR DIRECT IMPACTS ARE HIGHEST ROUGHLY 21-00Z...SO A
TEMPO GROUP FOR MID-RANGE MVFR VSBYS WILL BE INCLUDED IN A TEMPO
GROUP TO COVER. LOWER CONDITIONS...POSSIBLY AS LOW AS IFR...ARE
CERTAINLY POSSIBLE IF HEAVIER TSTMS MOVE ACROSS THE TERMINAL. AT
KCHS...PROBABILITIES ARE LOWER AND CONFIDENCE IS NOT AS GREAT.
WILL CONTINUE TO KEEP TSRA OUT OF THE TAF UNTIL CONFIDENCE
INCREASES.

EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT PROBABILITY OF OCCURRENCE.

&&

.MARINE...
TODAY...SOUTHWEST WINDS WILL INCREASE A BIT AS THE GRADIENT
BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING COLD FRONT
TIGHTENS. SHOULD SEE WINDS AS HIGH AS 15-20 KT CHARLESTON COUNTY
AND GEORGIA OFFSHORE WATERS WITH 15 KT REMAINING LEGS. SEAS WILL
AVERAGE 2-4 FT NEARSHORE WATERS AND 3-5 FT OFFSHORE WATERS.
STRONG TSTMS COULD IMPACT THE COASTAL WATERS LATE THIS AFTERNOON.
SPECIAL MARINE WARNINGS MAY BE NEEDED.

TONIGHT...SOUTHWEST WINDS WILL PERSIST AS A COLD FRONT DRAWS
CLOSER. LOW-LEVEL JETTING WILL REMAIN DISPLACED WELL OFFSHORE, SO
NO DIRECT IMPACTS ARE EXPECTED ON THE LOCAL WIND FIELD. SPEEDS
WILL AVERAGE 10-15 KT WITH SEAS 2-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS. THE RISK FOR STRONG TSTMS WILL LINGER FOR MUCH OF
THE NIGHT.

WEDNESDAY...SOUTHWEST TO WEST WINDS 10-15 KT BEHIND THE FRONT. SEAS
2-3 FT WITHIN 20 NM AND 3-4 FT ACROSS THE OUTER GEORGIA WATERS.

WEDNESDAY NIGHT INTO THURSDAY...A REINFORCING COLD FRONT WILL MOVE
THROUGH AND BEHIND THE FRONT WILL BE A INCREASING PRESSURE GRADIENT.
THIS WILL CAUSE WESTERLY WINDS TO INCREASE. EXPECT WINDS TO BE 15-20
KTS WITHING 20 NM AND 20-25 KT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL BUILD TO 4 FT BEYOND 15 NM AND 4-5 FT ACROSS THE OUTER GEORGIA
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR WIND GUSTS FOR THE
OUTER GEORGIA WATERS.

FRIDAY AND SATURDAY..THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE MOVES IN FROM THE WEST. EXPECT WINDS OF 15 KTS OR
LESS AND SEAS SUBSIDING BELOW 3 FT.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$

ST





000
FXUS62 KCHS 030752
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
352 AM EDT TUE MAY 3 2016

.SYNOPSIS...
A COLD FRONT WILL APPROACH THE REGION THROUGH TONIGHT AND PASS
OFFSHORE WEDNESDAY. A REINFORCING COLD FRONT WILL MOVE THROUGH THE
AREA THURSDAY MORNING. HIGH PRESSURE WILL THEN EXPAND INTO THE
REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
THROUGH SUNRISE...NEGATIVELY TILTED SHORTWAVE ENERGY IS MOVING
QUICKLY NORTHEAST ACROSS GEORGIA THIS MORNING. QUASI-GEOSTROPHIC
FORCING WITH THIS FEATURE IS SUPPORTING QUITE A BIT OF
SHOWER/TSTM ACTIVITY ACROSS THE SOUTH CAROLINA UPSTATE AND
MIDLANDS WITH A SECONDARY AREA OF CONVECTION NOTED OFF THE
CHARLESTON COUNTY COAST. ADDITIONAL CONVECTION COULD FIRE
ACROSS THE SOUTHERN MIDLANDS...CSRA AND FAR INLAND ZONES OVER THE
NEXT FEW HOURS...POSSIBLY IMPACTING THE CHARLESTON METRO AREA
BEFORE SUBSIDENCE/DAVA ADVECTS IN WITH THE PASSAGE OF THE
SHORTWAVE. AN ISOLATED STRONG TSTM CAN NOT BE RULED OUT WITH GUSTY
WINDS AND SMALL HAIL, BUT THE RISK FOR A SEVERE TSTM IS LOW. WILL
CARRY 20-30 PERCENT POPS ACROSS THE FAR INTERIOR THROUGH 12Z WITH
THE HIGHEST GRIDDED POPS TRANSLATING NORTHEAST WITH TIME. THE
SAVANNAH METRO AREA SHOULD REMAIN DRY FOR THE MORNING COMMUTE.

TODAY...ANOTHER CONVECTIVELY ACTIVE DAY IS ANTICIPATED ACROSS
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA WITH SEVERE
THUNDERSTORMS POSSIBLE. EARLY MORNING CONVECTION SHOULD BE EXITING
THE AREA AROUND SUNRISE AS SHORTWAVE ENERGY OVER GEORGIA
TRANSLATES NORTHEAST. SUBSIDENCE/DAVA SPREADING IN IN THE WAKE OF
THE DEPARTING SHORTWAVE SHOULD RESULT IN A MAINLY DRY MORNING
WITH BREAKS IN THE CLOUD COVER HELPING TO WARM TEMPERATURES
QUICKLY AFTER SUNRISE. CONVECTION IS POISED TO DEVELOP LATER THIS
AFTERNOON AS SUBSIDENCE IS REPLACED WITH INCREASING VERTICAL
VELOCITIES IN RESPONSE TO POTENT SHORTWAVE PIVOTING OUT OF THE
OHIO AND MIDDLE MISSISSIPPI VALLEYS. UPPER FORCING AHEAD OF THIS
FEATURE INTERACTING WITH A MODERATELY UNSTABLE ATMOSPHERE ACROSS
THE SOUTHEAST U.S. WILL SUPPORT THE DEVELOPMENT OF NUMEROUS
SHOWERS AND TSTMS AHEAD OF AN APPROACHING COLD FRONT.

CONVECTION IS EXPECTED TO DEVELOP/PROPAGATE OVER/INTO INLAND
AREAS, THEN GRADUALLY SPREAD EAST TO THE COAST BY LATE AFTERNOON/
EARLY EVENING AS A COLD FRONT DRAWS CLOSER. CONVECTION WILL BE
FURTHER ENHANCED BY MESOSCALE BOUNDARY COLLISIONS AS WELL AS A
CORRIDOR OF UPPER DIFLUENCE THAT WILL DIRECTLY OVER SOUTH CAROLINA
AND GEORGIA BETWEEN DIVERGING BRANCHES OF THE POLAR AND
SUBTROPICAL JET STREAMS. THERE REMAINS SOME TIMING ISSUES FOR WHEN
THE CORRIDOR OF GREATEST SHOWER/TSTM COVERAGE WILL AFFECT THE
AREA, SO POPS WILL BE MAXED OUT IN THE LOW-END LIKELY CATEGORY FOR
NOW UNTIL CONFIDENCE INCREASES. GENERALLY FAVORED THE SSEO
CONSENSUS TO CONSTRUCT THE PLACEMENT AND TIMING OF THE HIGHEST
GRIDDED POPS THROUGH SUNSET.

MODIFIED SOUNDINGS SHOW QUITE A BIT OF INSTABILITY DEVELOPING
DURING MAX HEATING AS AS TEMPERATURES WARM INTO THE MID TO
POSSIBLY UPPER 80S AWAY FROM THE COAST JUXTAPOSED WITH A RIBBON OF
SURFACE DEWPOINTS IN THE UPPER 60S/NEAR 70. 0-6KM BULK SHEAR WILL
BE STRONGER THAN THE PAST SEVERAL DAYS--ON THE ORDER OF 30-40
KT--OWING TO INFLUENCES FROM THE APPROACHING SHORTWAVE, BUT THE
DEGREE OF CONVECTIVE ORGANIZATION IS STILL UNCERTAIN GIVEN THE
VARIOUS TIMING/CONVECTIVE PLACEMENT UNKNOWNS WITHIN THE CORRIDOR
OF STRONGEST UPPER FORCING. THERE IS CERTAINLY A POTENTIAL FOR A
MORE ORGANIZED SEVERE THUNDERSTORM EVENT THIS AFTERNOON WITH LARGE
HAIL AND DAMAGING WINDS BEING THE PRIMARY HAZARDS SO WILL
CONTINUE TO MENTION A POTENTIAL FOR SEVERE THUNDERSTORMS IN THE
HAZARDOUS WEATHER OUTLOOK.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...
TONIGHT...NUMEROUS SHOWER/TSTMS WILL LIKELY BE ONGOING ACROSS THE
AREA AT SUNSET...MOST OF WHICH WILL TRANSLATE THE COAST DURING THE
EARLY EVENING HOURS. A RISK FOR SEVERE WEATHER WILL PERSIST UNTIL
THIS MAIN AREA OF CONVECTION MOVES OFFSHORE. THE MAIN SHORTWAVE
WILL APPROACH THE AREA AROUND DAYBREAK WEDNESDAY, SO ALTHOUGH THE
GREATER RISK FOR SHOWERS/TSTMS WILL OCCUR EARLY IN THE EVENING,
THERE WILL BE A CONTINUED RISK FOR AT LEAST ISOLATED SHOWERS/TSTMS
FOR MUCH OF THE NIGHT AHEAD OF A SLOW MOVING COLD FRONT. LOWS WILL
RANGE FROM THE LOWER-MID 60S WELL INLAND TO THE UPPER 60S/NEAR 70
AT THE COAST.

WEDNESDAY...A TROUGH WILL BE OVER THE EASTERN HALF OF THE
COUNTRY...WITH AN UPPER LEVEL LOW OVER THE GREAT LAKES. THE COLD
FRONT SHOULD CROSS THROUGH OUR AREA AROUND DAYBREAK. REMNANT SHOWERS
AND THUNDERSTORMS...MAINLY LIMITED TO THE COASTAL COUNTIES...WILL
QUICKLY BE PUSHED OFFSHORE WITH THE FRONT. WESTERLY WINDS WILL BRING
DRIER CONDITIONS AND COOLER TEMPERATURES INTO OUR AREA. DESPITE
PLENTY OF SUNSHINE HIGHS WILL RISE INTO THE UPPER 70S TO NEAR 80
DEGREES...ABOUT AVERAGE FOR THIS TIME OF YEAR. SOME DISTURBANCES
WILL ROUND THE BASE OF THE TROUGH...MOVING ACROSS OUR AREA. THIS
WILL BRING BRIEF INCREASES IN CLOUDS...BUT NO PRECIPITATION. A
REINFORCING COLD FRONT WILL PASS THROUGH THE AREA LATE WEDNESDAY
NIGHT. THIS FRONT WILL BE DRY...SO AT MOST WE CAN EXPECT SOME
CLOUDS...BUT NO SHOWERS OR THUNDERSTORMS. WEST-NORTHWEST WILL ALLOW
LOWS TO DROP INTO THE MID 50S INLAND TO AROUND 60 DEGREES ALONG THE
COAST.

THURSDAY...THE TROUGH OVER THE EASTERN HALF OF THE COUNTRY WILL
INTENSIFY WHILE THE UPPER LEVEL LOW SHIFTS OVER THE MID-ATLANTIC
REGION. THE MODELS ARE HINTING AT A WEAK SURFACE LOW FORMING AROUND
NORTH CAROLINA. THIS WOULD ALLOW SOME MOISTURE TO ADVECT FURTHER
SOUTH THAN ORIGINALLY EXPECTED. GIVEN THE GENERAL MODEL
CONSENSUS...ADDED SLIGHT CHANCE POPS TO THE FORECAST...MAINLY
LIMITED TO OUR SOUTH CAROLINA COUNTIES IN THE AFTERNOON. QPF SHOULD
BE MINIMAL...IF ANYTHING. WEST TO NORTHWEST FLOW AND WEAK COLD
ADVECTION BEHIND THE COLD FRONT...THAT IS SHIFTING OFFSHORE...WILL
USHER IN COOLER TEMPERATURES AND LOWER DEW POINTS. HIGHS SHOULD RISE
INTO THE MID 70S...SEVERAL DEGREES BELOW NORMAL WHILE THE DEW POINTS
FALL INTO THE 40S. BY THURSDAY NIGHT THE WEAK SURFACE LOW SHIFTS TO
THE NORTHEAST AND ANY SHOWER ACTIVITY WILL FOLLOW IT. CONTINUED
NORTHWEST FLOW AND SOME COLD ADVECTION WILL ALLOW LOWS TO FALL INTO
THE LOWER 50S INLAND...POSSIBLY THE UPPER 40S IN A FEW SPOT...AND
THE MID 50S ALONG THE BEACHES.

FRIDAY...MODELS KEEP THE TROUGH OVER THE EASTERN THIRD OF THE
COUNTRY...BUT THEY SHIFT THE UPPER LEVEL LOW A LITTLE BIT TO THE
NORTH. THIS SHOULD KEEP OUR AREA DRY. THE COMBINATION OF INCREASING
HEIGHTS...NO THREAT OF RAIN AND PLENTY OF SUNSHINE SHOULD ALLOW
TEMPERATURES TO RISE SEVERAL DEGREES. THOUGH THEY WILL REMAIN
SEVERAL DEGREES BELOW NORMAL...THE MID TO UPPER 70S.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM JUST OFF
THE EAST COAST FRIDAY NIGHT TO FAR OFFSHORE BY SUNDAY. ZONAL FLOW
OVERSPREADS OUR AREA ON SUNDAY FOLLOWED BY A WEAK RIDGE BUILDING
FROM THE CENTRAL U.S. ON MONDAY. OVERALL WE EXPECT DRY CONDITIONS
THROUGH THIS PERIOD WITH TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
TSTMS WILL PASS SOUTH OF THE KCHS THROUGH 07Z. WATCHING FOR
POSSIBLE REDEVELOPMENT WELL INLAND AFTER 09Z...WHICH COULD IMPACT
KCHS PRIOR TO SUNRISE. WILL CARRY VCTS TO ACCOUNT FOR THIS...BUT
NOT INCLUDE PREVAILING OR TEMPO GROUPS FOR TSRA JUST YET. KSAV
LOOKS TO REMAIN DRY...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A
LITTLE SHALLOW GROUND FOG DEVELOP THERE PRIOR TO DAYBREAK. NO
IMPACTS ARE ANTICIPATED. ATTN SHIFTS TO THIS AFTERNOON WHEN
ANOTHER ROUND OF SHRA/TSRA WILL IMPACT THE REGION. TIMING/COVERAGE
IS STILL QUITE UNCERTAIN THIS FAR OUT...BUT MOST GUIDANCE SUGGESTS
ANY IMPACTS TO THE TERMINALS WILL BE AFTER 20-21Z. WILL THEREFORE
NOT INCLUDE ANY MENTION OF TSRA THIS FAR OUT FOR THE 06Z TAF
CYCLE. THIS WILL BE REEVALUATED FOR THE 12Z TAF CYCLE ONCE THE 06Z
MODEL DATA ARE RECEIVED.

EXTENDED AVIATION OUTLOOK...THERE ARE NO CONCERNS WITH A GREATER
THAN 30 PERCENT PROBABILITY OF OCCURRENCE.

&&

.MARINE...
TODAY...SOUTHWEST WINDS WILL INCREASE A BIT AS THE GRADIENT
BETWEEN HIGH PRESSURE OFFSHORE AND AN APPROACHING COLD FRONT
TIGHTENS. SHOULD SEE WINDS AS HIGH AS 15-20 KT CHARLESTON COUNTY
AND GEORGIA OFFSHORE WATERS WITH 15 KT REMAINING LEGS. SEAS WILL
AVERAGE 2-4 FT NEARSHORE WATERS AND 3-5 FT OFFSHORE WATERS.
STRONG TSTMS COULD IMPACT THE COASTAL WATERS LATE THIS AFTERNOON.
SPECIAL MARINE WARNINGS MAY BE NEEDED.

TONIGHT...SOUTHWEST WINDS WILL PERSIST AS A COLD FRONT DRAWS
CLOSER. LOW-LEVEL JETTING WILL REMAIN DISPLACED WELL OFFSHORE, SO
NO DIRECT IMPACTS ARE EXPECTED ON THE LOCAL WIND FIELD. SPEEDS
WILL AVERAGE 10-15 KT WITH SEAS 2-3 FT NEARSHORE WATERS...3-4 FT
OFFSHORE WATERS. THE RISK FOR STRONG TSTMS WILL LINGER FOR MUCH OF
THE NIGHT.

WEDNESDAY...SOUTHWEST TO WEST WINDS 10-15 KT BEHIND THE FRONT. SEAS
2-3 FT WITHIN 20 NM AND 3-4 FT ACROSS THE OUTER GEORGIA WATERS.

WEDNESDAY NIGHT INTO THURSDAY...A REINFORCING COLD FRONT WILL MOVE
THROUGH AND BEHIND THE FRONT WILL BE A INCREASING PRESSURE GRADIENT.
THIS WILL CAUSE WESTERLY WINDS TO INCREASE. EXPECT WINDS TO BE 15-20
KTS WITHING 20 NM AND 20-25 KT ACROSS THE OUTER GEORGIA WATERS. SEAS
WILL BUILD TO 4 FT BEYOND 15 NM AND 4-5 FT ACROSS THE OUTER GEORGIA
WATERS. SMALL CRAFT ADVISORIES MAY BE NEEDED FOR WIND GUSTS FOR THE
OUTER GEORGIA WATERS.

FRIDAY AND SATURDAY..THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE MOVES IN FROM THE WEST. EXPECT WINDS OF 15 KTS OR
LESS AND SEAS SUBSIDING BELOW 3 FT.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$

ST/MS





000
FXUS62 KCHS 030525
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
125 AM EDT TUE MAY 3 2016

.SYNOPSIS...
MULTIPLE AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION OVERNIGHT THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY A REINFORCING COLD FRONT ON THURSDAY. HIGH
PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST THROUGH
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
ONE CONCENTRATED AREA OF SHOWER/TSTMS WILL PASS ALONG THE
CHARLESTON COUNTY COAST THROUGH 3 AM. EXPECT DRY CONDITIONS MOST
AREAS FOR THE NEXT SEVERAL HOURS. EXPECT ISOLATED TO SCATTERED
SHOWERS/TSTMS TO DEVELOPING INLAND AND POSSIBLY MOVING INTO THE
CHARLESTON TRI-COUNTY AREA 3AM-SUNRISE. MAINTAINED ELEVATED POPS
AROUND 30 PERCENT IN THIS AREA TO COVER. NUDGED OVERNIGHT LOWS UP
A DEGREE OR SO PER GOING TRENDS. REST OF THE FORECAST IS FINE.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING
OUR REGION DURING THE AFTERNOON. THE COMPLICATING FACTOR FOR
FIGURING OUT THE THUNDERSTORM AND SEVERE POTENTIAL IS THE AMOUNT
OF CONVECTION THAT MIGHT BE PRESENT IN THE MORNING. ALL MODELS
INDICATE THAT AT LEAST SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN RAPIDLY
MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE WILL
DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING
LATER IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A
SIMILAR AMOUNT OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE
BASED CAPES OF 1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT
LOBES WILL MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW THROUGH
THE DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY ONE
IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A
LOW/MARGINAL RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON.
THE MAIN THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES
IN THE 500- 700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL FOR
TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY RAINFALL.
HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW
OVER THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-
NORTHWEST LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE
UPPER 70S AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT
LOBES WILL MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING
TROUGH. HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO
MEASURABLE PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-
REINFORCING COLD FRONT WILL MOVE THROUGH...BUT IS EXPECTED TO COME
THROUGH DRY. WINDS WILL STAY UP ALL NIGHT FROM THE WEST-
NORTHWEST...WITH LOWS DROPPING TO THE MID 50S INLAND TO AROUND 60
COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
TSTMS WILL PASS SOUTH OF THE KCHS THROUGH 07Z. WATCHING FOR
POSSIBLE REDEVELOPMENT WELL INLAND AFTER 09Z...WHICH COULD IMPACT
KCHS PRIOR TO SUNRISE. WILL CARRY VCTS TO ACCOUNT FOR THIS...BUT
NOT INCLUDE PREVAILING OR TEMPO GROUPS FOR TSRA JUST YET. KSAV
LOOKS TO REMAIN DRY...ALTHOUGH WOULD NOT BE SURPRISED TO SEE A
LITTLE SHALLOW GROUND FOG DEVELOP THERE PRIOR TO DAYBREAK. NO
IMPACTS ARE ANTICIPATED. ATTN SHIFTS TO THIS AFTERNOON WHEN
ANOTHER ROUND OF SHRA/TSRA WILL IMPACT THE REGION. TIMING/COVERAGE
IS STILL QUITE UNCERTAIN THIS FAR OUT...BUT MOST GUIDANCE SUGGESTS
ANY IMPACTS TO THE TERMINALS WILL BE AFTER 20-21Z. WILL THEREFORE
NOT INCLUDE ANY MENTION OF TSRA THIS FAR OUT FOR THE 06Z TAF
CYCLE. THIS WILL BE REEVALUATED FOR THE 12Z TAF CYCLE ONCE THE 06Z
MODEL DATA ARE RECEIVED.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
TUESDAY NIGHT...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
OVERNIGHT...A WEAK GRADIENT SUPPORTING S WINDS MAINLY 10 KT OR
LESS WILL TRANSITION TO A TIGHTENING PRESSURE GRADIENT/INCREASING
LOW-LEVEL WINDS. AS A RESULT...S/SW WINDS SHOULD INCREASE TO 15-20
KT...AND SEAS SHOULD BUILD FROM 2-3 FT TO 3-5 FT MOST
AREAS...HIGHEST BEYOND 20 NM. SCA CONDITIONS ARE NOT ANTICIPATED.
ALSO OF NOTE...THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE
ACROSS COASTAL WATERS OVERNIGHT...AND LOCALIZED HAZARDOUS/SPECIAL
MARINE WARNING CONDITIONS ARE POSSIBLE.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$

ST





000
FXUS62 KCHS 030209
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1009 PM EDT MON MAY 2 2016

.SYNOPSIS...
MULTIPLE AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION OVERNIGHT THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY A REINFORCING COLD FRONT ON THURSDAY. HIGH
PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST THROUGH
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATE MONDAY EVENING...ADJUSTED POPS TO ACCOUNT FOR
ONGOING/EXPECTED RADAR TRENDS ESPECIALLY FOR THE NEXT SEVERAL
HOURS. SPECIFICALLY...SCATTERED SHOWERS/THUNDERSTORMS MOVING
THROUGH THE LOWER SAVANNAH RIVER REGION WILL LIFT NORTHEAST INTO
SOUTH CAROLINA COUNTIES ALONG/EAST OF I-95...INCLUDING COASTAL
LOCATIONS AND ADJECENT NEAR SHORE COASTAL WATERS. THESE
SHOWERS/THUNDERSTORMS COULD WEAKEN OR DISSIPATE BEFORE REACHING
THE CHARLESTON TRI-COUNTY REGION AND ADJACENT MARINE ZONES...BUT
AT LEAST LOW CHANCE POPS ARE JUSTIFIED IN THIS AREA OVER THE NEXT
FEW HOURS. ALTHOUGH MOST OTHER SHOWERS/THUNDERSTORMS REMAIN
NORTH/WEST OF THE FORECAST AREA LATE MONDAY EVENMING...ISOLATED/
SCATTERED SHOWERS/THUNDERSTORMS COULD DEVELOP AT ANY TIME ALONG
VARIOUS MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION. THUS...SLIGHT CHANCE/CHANCE POPS REMAIN IN ORDER
THROUGH THE NEXT SEVERAL HOURS.

LATER TONIGHT...ADDITIONAL SHORTWAVE TROUGHS WILL EJECT ENE
INTO THE REGION AS A POSTIVELY TILTED LONGWAVE UPPER TROUGH DIGS
TOWARD THE S/SE. AS A RESULT...COVERAGE OF SHOWERS/THUNDERSTORMS
COULD INCREASE LATER TONIGHT...ESPECIALLY ACROSS INLAND/NORTHERN
COUNTIES...AND THIS TREND IS REFLECTED WITHIN THE LATEST POP
FORECAST.

THE POTENTIAL FOR SEVERE WEATHER WILL REMAIN VERY LOW FOR THE
REMAINDER OF TONIGHT. FOR THE NEXT SEVERAL HOURS...THE POTENTIAL
FOR LOCALLY HEAVY RAINFALL WILL REMAIN LOW...BUT THIS POTENTIAL
COULD INCREASE AS COVERAGE OF SHOWERS/THUNDERSTORMS INCREASES LATE
TONIGHT.

OTHERWISE...AREAS OF STRATUS/PATCHY FOG COULD DEVELOP OVERNIGHT.
THE COVERAGE/IMPACT OF FOG SHOULD REMAIN LIMITED BY INCREASING
LOW-LEVEL WINDS...SO FOG IS NOT YET MENTIONED WITHIN PUBLIC
FORECASTS. WILL CONTINUE TO ASSESS.

TEMPERATURES WILL ONLY BOTTOM OUT IN THE UPPER 60S/LOWER 70S MOST
LOCATIONS.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING
OUR REGION DURING THE AFTERNOON. THE COMPLICATING FACTOR FOR
FIGURING OUT THE THUNDERSTORM AND SEVERE POTENTIAL IS THE AMOUNT
OF CONVECTION THAT MIGHT BE PRESENT IN THE MORNING. ALL MODELS
INDICATE THAT AT LEAST SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN RAPIDLY
MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE WILL
DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING
LATER IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A
SIMILAR AMOUNT OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE
BASED CAPES OF 1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT
LOBES WILL MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW THROUGH
THE DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY ONE
IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A
LOW/MARGINAL RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON.
THE MAIN THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES
IN THE 500- 700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL FOR
TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY RAINFALL.
HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW
OVER THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-
NORTHWEST LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE
UPPER 70S AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT
LOBES WILL MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING
TROUGH. HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO
MEASURABLE PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-
REINFORCING COLD FRONT WILL MOVE THROUGH...BUT IS EXPECTED TO COME
THROUGH DRY. WINDS WILL STAY UP ALL NIGHT FROM THE WEST-
NORTHWEST...WITH LOWS DROPPING TO THE MID 50S INLAND TO AROUND 60
COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
BRIEF THUNDERSTORMS WILL IMPACT KSAV THIS EVENING...AND SHOWERS
COULD ADVANCE INTO KCHS A BIT LATER. OTHERWISE...CONDITIONS WILL
REMAIN FAVORABLE FOR OCCASIONAL MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY...AND IFR/LIFR CEILINGTS CANNOT BE RULED OUT. ALSO...FLIGHT
RESTRICTIONS ARE POSSIBLE IN SHOWERS/TSTMS TUESDAY...ALTHOUGH
PRECISE TIMING OF CONVECTION REMAINS TOO UNCERTAIN TO INCLUDE
WITHIN 00Z TAFS. FOR NOW...ONLY -SHRA AND VCTS/CBS ARE JUSTIFIED
MUCH OF TUESDAY.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
TUESDAY NIGHT...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
OVERNIGHT...A WEAK GRADIENT SUPPORTING S WINDS MAINLY 10 KT OR
LESS WILL TRANSITION TO A TIGHTENING PRESSURE GRADIENT/INCREASING
LOW-LEVEL WINDS. AS A RESULT...S/SW WINDS SHOULD INCREASE TO 15-20
KT...AND SEAS SHOULD BUILD FROM 2-3 FT TO 3-5 FT MOST
AREAS...HIGHEST BEYOND 20 NM. SCA CONDITIONS ARE NOT ANTICIPATED.
ALSO OF NOTE...THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE
ACROSS COASTAL WATERS OVERNIGHT...AND LOCALIZED HAZARDOUS/SPECIAL
MARINE WARNING CONDITIONS ARE POSSIBLE.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.CLIMATE...
THUS FAR...THE MAY 2 LOW TEMPERATURE IN DOWNTOWN CHARLESTON IS
73F...AND TEMPERATURES REMAINED IN THE MID 70S LATE MONDAY
EVENING. THE RECORD HIGH MINIMUM TEMPERATURE FOR MAY 2 IS 72F SET
IN 2010.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...
LONG TERM...
AVIATION...SPR
MARINE...SPR
EQUIPMENT...





000
FXUS62 KCHS 030209
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1009 PM EDT MON MAY 2 2016

.SYNOPSIS...
MULTIPLE AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION OVERNIGHT THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY A REINFORCING COLD FRONT ON THURSDAY. HIGH
PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST THROUGH
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATE MONDAY EVENING...ADJUSTED POPS TO ACCOUNT FOR
ONGOING/EXPECTED RADAR TRENDS ESPECIALLY FOR THE NEXT SEVERAL
HOURS. SPECIFICALLY...SCATTERED SHOWERS/THUNDERSTORMS MOVING
THROUGH THE LOWER SAVANNAH RIVER REGION WILL LIFT NORTHEAST INTO
SOUTH CAROLINA COUNTIES ALONG/EAST OF I-95...INCLUDING COASTAL
LOCATIONS AND ADJECENT NEAR SHORE COASTAL WATERS. THESE
SHOWERS/THUNDERSTORMS COULD WEAKEN OR DISSIPATE BEFORE REACHING
THE CHARLESTON TRI-COUNTY REGION AND ADJACENT MARINE ZONES...BUT
AT LEAST LOW CHANCE POPS ARE JUSTIFIED IN THIS AREA OVER THE NEXT
FEW HOURS. ALTHOUGH MOST OTHER SHOWERS/THUNDERSTORMS REMAIN
NORTH/WEST OF THE FORECAST AREA LATE MONDAY EVENMING...ISOLATED/
SCATTERED SHOWERS/THUNDERSTORMS COULD DEVELOP AT ANY TIME ALONG
VARIOUS MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION. THUS...SLIGHT CHANCE/CHANCE POPS REMAIN IN ORDER
THROUGH THE NEXT SEVERAL HOURS.

LATER TONIGHT...ADDITIONAL SHORTWAVE TROUGHS WILL EJECT ENE
INTO THE REGION AS A POSTIVELY TILTED LONGWAVE UPPER TROUGH DIGS
TOWARD THE S/SE. AS A RESULT...COVERAGE OF SHOWERS/THUNDERSTORMS
COULD INCREASE LATER TONIGHT...ESPECIALLY ACROSS INLAND/NORTHERN
COUNTIES...AND THIS TREND IS REFLECTED WITHIN THE LATEST POP
FORECAST.

THE POTENTIAL FOR SEVERE WEATHER WILL REMAIN VERY LOW FOR THE
REMAINDER OF TONIGHT. FOR THE NEXT SEVERAL HOURS...THE POTENTIAL
FOR LOCALLY HEAVY RAINFALL WILL REMAIN LOW...BUT THIS POTENTIAL
COULD INCREASE AS COVERAGE OF SHOWERS/THUNDERSTORMS INCREASES LATE
TONIGHT.

OTHERWISE...AREAS OF STRATUS/PATCHY FOG COULD DEVELOP OVERNIGHT.
THE COVERAGE/IMPACT OF FOG SHOULD REMAIN LIMITED BY INCREASING
LOW-LEVEL WINDS...SO FOG IS NOT YET MENTIONED WITHIN PUBLIC
FORECASTS. WILL CONTINUE TO ASSESS.

TEMPERATURES WILL ONLY BOTTOM OUT IN THE UPPER 60S/LOWER 70S MOST
LOCATIONS.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING
OUR REGION DURING THE AFTERNOON. THE COMPLICATING FACTOR FOR
FIGURING OUT THE THUNDERSTORM AND SEVERE POTENTIAL IS THE AMOUNT
OF CONVECTION THAT MIGHT BE PRESENT IN THE MORNING. ALL MODELS
INDICATE THAT AT LEAST SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN RAPIDLY
MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE WILL
DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING
LATER IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A
SIMILAR AMOUNT OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE
BASED CAPES OF 1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT
LOBES WILL MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW THROUGH
THE DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY ONE
IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A
LOW/MARGINAL RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON.
THE MAIN THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES
IN THE 500- 700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL FOR
TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY RAINFALL.
HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW
OVER THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-
NORTHWEST LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE
UPPER 70S AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT
LOBES WILL MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING
TROUGH. HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO
MEASURABLE PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-
REINFORCING COLD FRONT WILL MOVE THROUGH...BUT IS EXPECTED TO COME
THROUGH DRY. WINDS WILL STAY UP ALL NIGHT FROM THE WEST-
NORTHWEST...WITH LOWS DROPPING TO THE MID 50S INLAND TO AROUND 60
COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
BRIEF THUNDERSTORMS WILL IMPACT KSAV THIS EVENING...AND SHOWERS
COULD ADVANCE INTO KCHS A BIT LATER. OTHERWISE...CONDITIONS WILL
REMAIN FAVORABLE FOR OCCASIONAL MVFR CEILINGS OVERNIGHT INTO EARLY
TUESDAY...AND IFR/LIFR CEILINGTS CANNOT BE RULED OUT. ALSO...FLIGHT
RESTRICTIONS ARE POSSIBLE IN SHOWERS/TSTMS TUESDAY...ALTHOUGH
PRECISE TIMING OF CONVECTION REMAINS TOO UNCERTAIN TO INCLUDE
WITHIN 00Z TAFS. FOR NOW...ONLY -SHRA AND VCTS/CBS ARE JUSTIFIED
MUCH OF TUESDAY.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
TUESDAY NIGHT...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
OVERNIGHT...A WEAK GRADIENT SUPPORTING S WINDS MAINLY 10 KT OR
LESS WILL TRANSITION TO A TIGHTENING PRESSURE GRADIENT/INCREASING
LOW-LEVEL WINDS. AS A RESULT...S/SW WINDS SHOULD INCREASE TO 15-20
KT...AND SEAS SHOULD BUILD FROM 2-3 FT TO 3-5 FT MOST
AREAS...HIGHEST BEYOND 20 NM. SCA CONDITIONS ARE NOT ANTICIPATED.
ALSO OF NOTE...THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE
ACROSS COASTAL WATERS OVERNIGHT...AND LOCALIZED HAZARDOUS/SPECIAL
MARINE WARNING CONDITIONS ARE POSSIBLE.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.CLIMATE...
THUS FAR...THE MAY 2 LOW TEMPERATURE IN DOWNTOWN CHARLESTON IS
73F...AND TEMPERATURES REMAINED IN THE MID 70S LATE MONDAY
EVENING. THE RECORD HIGH MINIMUM TEMPERATURE FOR MAY 2 IS 72F SET
IN 2010.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...
LONG TERM...
AVIATION...SPR
MARINE...SPR
EQUIPMENT...





000
FXUS62 KCHS 022347
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
747 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION TONIGHT THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY A REINFORCING COLD FRONT ON THURSDAY. HIGH
PRESSURE WILL THEN EXPAND INTO THE REGION FROM THE WEST THROUGH
THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THIS EVENING...BEST COVERAGE OF SHOWERS/THUNDERSTORMS WILL REMAIN
ALONG/WEST OF I-95...WITH MAINLY SCATTERED SHOWERS EAST. THE
POTENTIAL FOR ISOLATED SEVERE AND FOR LOCALLY HEAVY RAIN WILL
CONTINUE TO DIMINISH WITH TIME.

AFTER DARK...CONVECTION WILL STEADILY FADE WITH THE LOSS OF
HEATING AND TYPICAL NOCTURNAL STABILIZING INFLUENCES.
HOWEVER...THERE IS STILL DECENT FORCING THAT OCCURS WITH A SHORT
WAVE ALONG THE NORTHERN GULF COAST THIS EVENING TO PASS INTO THE
AREA OVERNIGHT AND INTO THE ATLANTIC AROUND DAYBREAK. IN ADDITION
THERE IS DIFLUENCE ALOFT WITH DIVERGING BRANCHES OF THE POLAR JET
TO THE NORTH/NW AND SUB- TROPICAL JET TO THE SOUTH/SW. ALTHOUGH
OUR CONFIDENCE IS MODERATE AT BEST...THIS DOES SUPPORT AT LEAST
SLIGHT CHANCE/CHANCE POPS AFTER DIURNAL CONVECTION DWINDLES FAR
INLAND AFTER 9-10 PM. THIS IS MORE IN LINE WITH THE HIGH-RES
MODELS AND THE SREF...RATHER THAN THE GLOBAL MODELS WHICH HAVE HAD
A DIFFICULT TIME OF LATE WITH NOCTURNAL CONVECTION. INSTEAD THEY
SEEM TO BE FOCUSING MORE ON LOW STRATUS THAT SHOULD OCCUR. THERE
IS LIKELY TOO MUCH MIXING OF THE PLANETARY BOUNDARY LAYER WITH
GEOSTROPHIC WINDS OF 15 KT OR GREATER TO PERSIST...SO OTHER THAN A
LITTLE GROUND FOG WHERE RAINS OCCURRED...THERE ARE NO SIGNIFICANT
FOG CONCERNS.

THE FORMATION OF AT LEAST PATCHY LOW STRATUS...DEBRIS CLOUDS
FROM EARLIER CONVECTION AND THE ELEVATED DEW POINTS WON/T ALLOW
FOR MIN TEMPS ANY LOWER THAN THE UPPER 60S TO NEAR 70. DOWNTOWN
CHARLESTON HAS A CHANCE OF A POSSIBLE RECORD HIGH MINIMUM FOR MAY
2ND /72F SET IN 2010/ IF THEY DON/T RECEIVE TOO MUCH RAIN PRIOR TO
THE END OF THE CALENDAR DAY.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING
OUR REGION DURING THE AFTERNOON. THE COMPLICATING FACTOR FOR
FIGURING OUT THE THUNDERSTORM AND SEVERE POTENTIAL IS THE AMOUNT
OF CONVECTION THAT MIGHT BE PRESENT IN THE MORNING. ALL MODELS
INDICATE THAT AT LEAST SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN RAPIDLY
MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE WILL
DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING
LATER IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A
SIMILAR AMOUNT OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE
BASED CAPES OF 1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT
LOBES WILL MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW
THROUGH THE DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY
ONE IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A
LOW/MARGINAL RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON.
THE MAIN THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES
IN THE 500- 700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL
FOR TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY
RAINFALL. HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW OVER
THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-NORTHWEST
LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE UPPER 70S
AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT LOBES WILL
MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING TROUGH.
HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO MEASURABLE
PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-REINFORCING COLD FRONT
WILL MOVE THROUGH...BUT IS EXPECTED TO COME THROUGH DRY. WINDS WILL
STAY UP ALL NIGHT FROM THE WEST-NORTHWEST...WITH LOWS DROPPING TO
THE MID 50S INLAND TO AROUND 60 COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
OCCASIONAL MVFR CEILINGS AND SPRINKLES/LIGHT RAIN SHOWERS WILL
PERSIST THIS EVENING. THEN...VFR CONDITIONS ARE INDICATED AT KCHS
AND KSAV OVERNIGHT THROUGH TUESDAY. HOWEVER...MVFR OR LOWER CEILINGS
AND MVFR VISIBILITIES ARE POSSIBLE OVERNIGHT INTO EARLY TUESDAY.
ALSO...FLIGHT RESTRICTIONS ARE POSSIBLE IN SHOWERS/TSTMS
TUESDAY...ALTHOUGH PRECISE TIMING REMAINS TOO UNCERTAIN TO
INCLUDE WITHIN 00Z TAFS. FOR NOW...ONLY PERIODS OF SHRA AND
VCTS/CBS ARE JUSTIFIED MUCH OF TUESDAY.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
TUESDAY NIGHT...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
TONIGHT...THE PRESSURE PATTERN WILL TIGHTEN BETWEEN STRONG HIGH
PRESSURE TO THE DISTANT EAST/NE OF BERMUDA AND LOW PRESSURE REACHING
FROM NORTHERN VIRGINIA TO SOUTHERN NEW JERSEY BY MORNING. A TRAILING
COLD FRONT FROM THE LOW WILL CROSS THE APPALACHIANS EARLY TONIGHT
AND INTO THE SC UPSTATE AND CENTRAL SAVANNAH RIVER VALLEY LATE.
ALTHOUGH WARM ADVECTION WILL LIMIT HOW MUCH MIXING OF A 25-35 KT LOW
LEVEL JET WILL OCCUR...SOUTH/SW WINDS OVER THE LOCAL WATERS WILL
STILL REACH AS HIGH AS 15 OR 20 KT. A FEW INFREQUENT GUSTS TO 25 KT
WILL OCCUR...ESPECIALLY OVER AMZ350-374...BUT NOT ENOUGH TO HOIST A
SMALL CRAFT ADVISORY. SEAS COULD BUILD TO AS HIGH AS 3-5
FT...HIGHEST ACROSS THE OUTER GA WATERS BEYOND 40 NM OFF THE
COAST. ALSO...MARINE INTEREST SHOULD REMAIN ALERT DUE TO ISOLATED
TO SCATTERED SHOWERS/T-STORMS.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...SPR
SHORT TERM...
LONG TERM...
AVIATION...SPR
MARINE...SPR
EQUIPMENT...





000
FXUS62 KCHS 022205
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
605 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION THROUGH TUESDAY...PRODUCING UNSETTLED CONDITIONS.
THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY NIGHT...FOLLOWED
BY A REINFORCING COLD FRONT ON THURSDAY. HIGH PRESSURE WILL THEN
EXPAND INTO THE REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THROUGH THIS EVENING...WHILE THERE IS STILL AN ISOLATED SEVERE
RISK IT IS NOW CONFINED TO ONLY ALLENDALE AND HAMPTON COUNTIES IN
SE AND FROM JENKINS AND SCREVEN COUNTIES TO TATTNALL AND EVANS IN
GA. LAPSE RATES ARE BECOMING LESS FAVORABLE AND EVEN INSTABILITY
IS NOT AS IMPRESSIVE AS IT WAS EARLIER IN THE DAY. HOWEVER...WITH
DCAPES STILL 800-900 J/KG THERE IS STILL A RISK FOR ISOLATED
DAMAGING WINDS. PLUS THE CAPE IN THE HAIL GROWTH LAYER OF 400-500
J/KG COULD YET RESULT IN MARGINALLY SEVERE HAIL. THE CHANCES FOR
SEVERE WEATHER WILL COME TO AN END BY 8 PM WITH SUNSET.

IN ADDITION THERE HAS BEEN SLOW MOVEMENT TO STORMS NEAR THE US-301
CORRIDOR AND WITH CELLS ALIGNED IN TANDEM WITH THE MEAN FLOW THERE
REMAINS THE POTENTIAL FOR ADDITIONAL TRAINING/BACK-BUILDING TO
LEAD TO AT LEAST MINOR FLOODING CONCERNS. THERE IS HOWEVER A SMALL RISK
FOR MORE SIGNIFICANT FLOODING AND POSSIBLE FLASH FLOODING
CONCERNS...MAINLY IN ALLENDALE AND BULLOCH COUNTIES.

THE TEMP CURVE HAS SEEN FURTHER REFINEMENTS TO ACCOUNT FOR THE
RAIN COOLED CONDITIONS AND EXTENSIVE CLOUD COVER.

FOR TONIGHT...CONVECTION WILL STEADILY FADE WITH THE LOSS OF HEATING
AND TYPICAL NOCTURNAL STABILIZING INFLUENCES. HOWEVER...THERE IS
STILL DECENT FORCING THAT OCCURS WITH A SHORT WAVE ALONG THE
NORTHERN GULF COAST THIS EVENING TO PASS INTO THE AREA OVERNIGHT AND
INTO THE ATLANTIC AROUND DAYBREAK. IN ADDITION THERE IS DIFLUENCE
ALOFT WITH DIVERGING BRANCHES OF THE POLAR JET TO THE NORTH/NW AND
SUB-TROPICAL JET TO THE SOUTH/SW. ALTHOUGH OUR CONFIDENCE IS
MODERATE AT BEST...THIS DOES SUPPORT AT LEAST SLIGHT CHANCE AND
CHANCE POPS AFTER DIURNAL CONVECTION DWINDLES FAR INLAND AFTER 9-10
PM. THIS IS MORE IN LINE WITH THE HIGH-RES MODELS AND THE
SREF...RATHER THAN THE GLOBAL MODELS WHICH HAVE HAD A DIFFICULT TIME
OF LATE WITH NOCTURNAL CONVECTION. INSTEAD THEY SEEM TO BE FOCUSING
MORE ON LOW STRATUS THAT SHOULD OCCUR. THERE IS LIKELY TOO MUCH
MIXING OF THE PLANETARY BOUNDARY LAYER WITH GEOSTROPHIC WINDS OF 15
KT OR GREATER TO PERSIST...SO OTHER THAN A LITTLE GROUND FOG WHERE
RAINS OCCURRED...THERE ARE NO SIGNIFICANT FOG CONCERNS.

THE FORMATION OF AT LEAST PATCHY LOW STRATUS...DEBRIS CLOUDS FROM
EARLIER CONVECTION AND THE ELEVATED DEW POINTS WON/T ALLOW FOR MIN
TEMPS ANY LOWER THAN THE UPPER 60S TO NEAR 70. DOWNTOWN CHARLESTON
HAS A CHANCE OF A POSSIBLE RECORD HIGH MINIMUM FOR MAY 2ND /72F
SET IN 2010/ IF THEY DON/T RECEIVE TOO MUCH RAIN PRIOR TO THE END
OF THE CALENDAR DAY.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING OUR
REGION. THE COMPLICATING FACTOR FOR FIGURING OUT THE THUNDERSTORM AND
SEVERE POTENTIAL IS THE AMOUNT OF CONVECTION THAT MIGHT BE PRESENT IN
THE MORNING. ALL MODELS INDICATE THAT AT LEAST SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN
RAPIDLY MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE
WILL DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING LATER
IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A SIMILAR AMOUNT
OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE BASED CAPES OF
1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT LOBES WILL
MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW THROUGH THE
DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY ONE
IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A LOW/MARGINAL
RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON. THE MAIN
THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES IN THE 500-
700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL FOR
TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY RAINFALL.
HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW OVER
THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-NORTHWEST
LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE UPPER 70S
AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT LOBES WILL
MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING TROUGH.
HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO MEASURABLE
PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-REINFORCING COLD FRONT
WILL MOVE THROUGH...BUT IS EXPECTED TO COME THROUGH DRY. WINDS WILL
STAY UP ALL NIGHT FROM THE WEST-NORTHWEST...WITH LOWS DROPPING TO
THE MID 50S INLAND TO AROUND 60 COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
MOST OF THE VALID 18Z TAF CYCLE WILL BE VFR.

ALTHOUGH EITHER SITE COULD STILL EXPERIENCE A SHRA THIS
EVENING...NO SIGNIFICANT IMPACTS WILL OCCUR.

CONVECTION WILL LIKELY FADE IN COVERAGE THIS EVENING...BUT WITH
THE APPROACH OF ENERGY ALOFT OVERNIGHT THERE CERTAINLY COULD BE A
RISK OF SHRA/TSRA AT KCHS AGAIN. BUT PROBABILITIES ARE TOO LOW TO
INCLUDE AT THIS TIME.

THERE IS LIKELY TOO MUCH WIND TONIGHT TO CAUSE ANY FOG
CONCERNS...BUT AREAS OF LOW STRATUS MAY OCCUR LATE TONIGHT INTO
THE MIDDLE OF TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
DURING THE AFTERNOON...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
TONIGHT...THE PRESSURE PATTERN WILL TIGHTEN BETWEEN STRONG HIGH
PRESSURE TO THE DISTANT EAST/NE OF BERMUDA AND LOW PRESSURE REACHING
FROM NORTHERN VIRGINIA TO SOUTHERN NEW JERSEY BY MORNING. A TRAILING
COLD FRONT FROM THE LOW WILL CROSS THE APPALACHIANS EARLY TONIGHT
AND INTO THE SC UPSTATE AND CENTRAL SAVANNAH RIVER VALLEY LATE.
ALTHOUGH WARM ADVECTION WILL LIMIT HOW MUCH MIXING OF A 25-35 KT LOW
LEVEL JET WILL OCCUR...SOUTH/SW WINDS OVER THE LOCAL WATERS WILL
STILL REACH AS HIGH AS 15 OR 20 KT. A FEW INFREQUENT GUSTS TO 25 KT
WILL OCCUR...ESPECIALLY OVER AMZ350-374...BUT NOT ENOUGH TO HOIST A
SMALL CRAFT ADVISORY. SEAS ARE ABLE TO BUILD TO AS HIGH AS 3-5
FT...HIGHEST ACROSS THE OUTER GA WATERS BEYOND 40 NM OFF THE
COAST. MARINE INTEREST SHOULD REMAIN ALERT DUE TO ISOLATED TO
SCATTERED SHOWERS/T-STORMS WILL OCCUR.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 022116
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
516 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION THROUGH TUESDAY...PRODUCING UNSETTLED CONDITIONS.
THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY NIGHT...FOLLOWED
BY A REINFORCING COLD FRONT ON THURSDAY. HIGH PRESSURE WILL THEN
EXPAND INTO THE REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE MOST RECENT UPDATE HAS BEEN ISSUED TO ACCOUNT FOR LATEST
RADAR/OBSERVATION/SATELLITE TRENDS. NO MAJOR CHANGES HOWEVER.

THROUGH THIS EVENING...CONVECTION WILL CONTINUE TO DEVELOP IN AN
UNCAPPED ATMOSPHERE WITH FAVORABLE THERMODYNAMICS...PWATS NEAR 2
STANDARD DEVIATIONS ABOVE NORMAL AND SEVERAL MESOSCALE BOUNDARIES
SUCH AS THE SEA BREEZE...PIEDMONT TROUGH AND OUTFLOWS. PER
THE MESO-ANALYSIS FROM SPC WE FIND SBCAPES THAT ARE AS HIGH AS
3000-3500 J/KG...MLCAPES ARE 1500-2500 J/KG...AND LIFTED INDICES
ARE AS LOW AS -6 TO -7C. BOUNDARY INTERACTIONS/MERGERS WILL ALLOW
FOR A CONTINUED INCREASE IN COVERAGE OF SHOWERS/T-STORMS WITH THE
GREATEST PROBABILITIES IN THE LIKELY RANGE NEAR AND WEST OF I-95.
LOWEST RAIN CHANCES WILL BE OVER THE COASTAL CORRIDOR WITH STORMS
FOR THE MOST PART TO STAY INLAND WITH THE SEA BREEZE BOUNDARY.

DCAPE OF 800-1000 J/KG SUPPORTS THE POTENTIAL FOR DAMAGING WIND
GUSTS AND CAPE IN THE HAIL GROWTH LAYER OF 500 J/KG SUPPORTS HAIL
MAYBE AS LARGE AS 1 INCH. GIVEN THE LACK OF ANY SIGNIFICANT
SHEAR...THERE IS ONLY AN ISOLATED RISK OF PULSE SEVERE STORMS. CELLS
ON RADAR ARE STARTING TO ALIGN THEMSELVES WITH THE MEAN STEERING
FLOW...AND THAT ALONG WITH THE HIGH MOISTURE CONTENT SUPPORTS A RISK
OF LOCALIZED FLOODING SHOULD TRAINING/BACK-BUILDING OCCUR. THE TEMP
CURVE HAS BEEN ALTERED AS WE ATTEMPT TO ACCOUNT FOR THE
CONVECTION...THAT CAUSES TEMPS TO DROP INTO THE MID AND UPPER 70S
WHERE THE MORE PERSISTENT RAINS OCCUR.

FOR TONIGHT...CONVECTION WILL STEADILY FADE WITH THE LOSS OF HEATING
AND TYPICAL NOCTURNAL STABILIZING INFLUENCES. HOWEVER...THERE IS
STILL DECENT FORCING THAT OCCURS WITH A SHORT WAVE ALONG THE
NORTHERN GULF COAST THIS EVENING TO PASS INTO THE AREA OVERNIGHT AND
INTO THE ATLANTIC AROUND DAYBREAK. IN ADDITION THERE IS DIFLUENCE
ALOFT WITH DIVERGING BRANCHES OF THE POLAR JET TO THE NORTH/NW AND
SUB-TROPICAL JET TO THE SOUTH/SW. ALTHOUGH OUR CONFIDENCE IS
MODERATE AT BEST...THIS DOES SUPPORT AT LEAST SLIGHT CHANCE AND
CHANCE POPS AFTER DIURNAL CONVECTION DWINDLES FAR INLAND AFTER 9-10
PM. THIS IS MORE IN LINE WITH THE HIGH-RES MODELS AND THE
SREF...RATHER THAN THE GLOBAL MODELS WHICH HAVE HAD A DIFFICULT TIME
OF LATE WITH NOCTURNAL CONVECTION. INSTEAD THEY SEEM TO BE FOCUSING
MORE ON LOW STRATUS THAT SHOULD OCCUR. THERE IS LIKELY TOO MUCH
MIXING OF THE PLANETARY BOUNDARY LAYER WITH GEOSTROPHIC WINDS OF 15
KT OR GREATER TO PERSIST...SO OTHER THAN A LITTLE GROUND FOG WHERE
RAINS OCCURRED...THERE ARE NO SIGNIFICANT FOG CONCERNS.

THE FORMATION OF AT LEAST PATCHY LOW STRATUS...DEBRIS CLOUDS FROM
EARLIER CONVECTION AND THE ELEVATED DEW POINTS WON/T ALLOW FOR MIN
TEMPS ANY LOWER THAN THE UPPER 60S TO NEAR 70. DOWNTOWN CHARLESTON
HAS A CHANCE OF A POSSIBLE RECORD HIGH MINIMUM FOR MAY 2ND /72F
SET IN 2010/ IF THEY DON/T RECEIVE TOO MUCH RAIN PRIOR TO THE END
OF THE CALENDAR DAY.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING OUR
REGION. THE COMPLICATING FACTOR FOR FIGURING OUT THE THUNDERSTORM AND
SEVERE POTENTIAL IS THE AMOUNT OF CONVECTION THAT MIGHT BE PRESENT IN
THE MORNING. ALL MODELS INDICATE THAT AT LEAST SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN
RAPIDLY MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE
WILL DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING LATER
IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A SIMILAR AMOUNT
OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE BASED CAPES OF
1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT LOBES WILL
MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW THROUGH THE
DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY ONE
IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A LOW/MARGINAL
RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON. THE MAIN
THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES IN THE 500-
700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL FOR
TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY RAINFALL.
HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW OVER
THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-NORTHWEST
LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE UPPER 70S
AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT LOBES WILL
MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING TROUGH.
HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO MEASURABLE
PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-REINFORCING COLD FRONT
WILL MOVE THROUGH...BUT IS EXPECTED TO COME THROUGH DRY. WINDS WILL
STAY UP ALL NIGHT FROM THE WEST-NORTHWEST...WITH LOWS DROPPING TO
THE MID 50S INLAND TO AROUND 60 COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
MOST OF THE VALID 18Z TAF CYCLE WILL BE VFR.

ALTHO0UGH EITHER SITE COULD STILL EXPERIENCE A SHRA THIS
EVENING...NO SIGNIFICANT IMPACTS WILL OCCUR.

CONVECTION WILL LIKELY FADE IN COVERAGE THIS EVENING...BUT WITH
THE APPROACH OF ENERGY ALOFT OVERNIGHT THERE CERTAINLY COULD BE A
RISK OF SHRA/TSRA AT KCHS AGAIN. BUT PROBABILITIES ARE TOO LOW TO
INCLUDE AT THIS TIME.

THERE IS LIKELY TOO MUCH WIND TONIGHT TO CAUSE ANY FOG
CONCERNS...BUT AREAS OF LOW STRATUS MAY OCCUR LATE TONIGHT INTO
THE MIDDLE OF TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
DURING THE AFTERNOON...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
TONIGHT...THE PRESSURE PATTERN WILL TIGHTEN BETWEEN STRONG HIGH
PRESSURE TO THE DISTANT EAST/NE OF BERMUDA AND LOW PRESSURE REACHING
FROM NORTHERN VIRGINIA TO SOUTHERN NEW JERSEY BY MORNING. A TRAILING
COLD FRONT FROM THE LOW WILL CROSS THE APPALACHIANS EARLY TONIGHT
AND INTO THE SC UPSTATE AND CENTRAL SAVANNAH RIVER VALLEY LATE.
ALTHOUGH WARM ADVECTION WILL LIMIT HOW MUCH MIXING OF A 25-35 KT LOW
LEVEL JET WILL OCCUR...SOUTH/SW WINDS OVER THE LOCAL WATERS WILL
STILL REACH AS HIGH AS 15 OR 20 KT. A FEW INFREQUENT GUSTS TO 25 KT
WILL OCCUR...ESPECIALLY OVER AMZ350-374...BUT NOT ENOUGH TO HOIST A
SMALL CRAFT ADVISORY. SEAS ARE ABLE TO BUILD TO AS HIGH AS 3-5
FT...HIGHEST ACROSS THE OUTER GA WATERS BEYOND 40 NM OFF THE
COAST. MARINE INTEREST SHOULD REMAIN ALERT DUE TO ISOLATED TO
SCATTERED SHOWERS/T-STORMS WILL OCCUR.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 022116
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
516 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION THROUGH TUESDAY...PRODUCING UNSETTLED CONDITIONS.
THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY NIGHT...FOLLOWED
BY A REINFORCING COLD FRONT ON THURSDAY. HIGH PRESSURE WILL THEN
EXPAND INTO THE REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE MOST RECENT UPDATE HAS BEEN ISSUED TO ACCOUNT FOR LATEST
RADAR/OBSERVATION/SATELLITE TRENDS. NO MAJOR CHANGES HOWEVER.

THROUGH THIS EVENING...CONVECTION WILL CONTINUE TO DEVELOP IN AN
UNCAPPED ATMOSPHERE WITH FAVORABLE THERMODYNAMICS...PWATS NEAR 2
STANDARD DEVIATIONS ABOVE NORMAL AND SEVERAL MESOSCALE BOUNDARIES
SUCH AS THE SEA BREEZE...PIEDMONT TROUGH AND OUTFLOWS. PER
THE MESO-ANALYSIS FROM SPC WE FIND SBCAPES THAT ARE AS HIGH AS
3000-3500 J/KG...MLCAPES ARE 1500-2500 J/KG...AND LIFTED INDICES
ARE AS LOW AS -6 TO -7C. BOUNDARY INTERACTIONS/MERGERS WILL ALLOW
FOR A CONTINUED INCREASE IN COVERAGE OF SHOWERS/T-STORMS WITH THE
GREATEST PROBABILITIES IN THE LIKELY RANGE NEAR AND WEST OF I-95.
LOWEST RAIN CHANCES WILL BE OVER THE COASTAL CORRIDOR WITH STORMS
FOR THE MOST PART TO STAY INLAND WITH THE SEA BREEZE BOUNDARY.

DCAPE OF 800-1000 J/KG SUPPORTS THE POTENTIAL FOR DAMAGING WIND
GUSTS AND CAPE IN THE HAIL GROWTH LAYER OF 500 J/KG SUPPORTS HAIL
MAYBE AS LARGE AS 1 INCH. GIVEN THE LACK OF ANY SIGNIFICANT
SHEAR...THERE IS ONLY AN ISOLATED RISK OF PULSE SEVERE STORMS. CELLS
ON RADAR ARE STARTING TO ALIGN THEMSELVES WITH THE MEAN STEERING
FLOW...AND THAT ALONG WITH THE HIGH MOISTURE CONTENT SUPPORTS A RISK
OF LOCALIZED FLOODING SHOULD TRAINING/BACK-BUILDING OCCUR. THE TEMP
CURVE HAS BEEN ALTERED AS WE ATTEMPT TO ACCOUNT FOR THE
CONVECTION...THAT CAUSES TEMPS TO DROP INTO THE MID AND UPPER 70S
WHERE THE MORE PERSISTENT RAINS OCCUR.

FOR TONIGHT...CONVECTION WILL STEADILY FADE WITH THE LOSS OF HEATING
AND TYPICAL NOCTURNAL STABILIZING INFLUENCES. HOWEVER...THERE IS
STILL DECENT FORCING THAT OCCURS WITH A SHORT WAVE ALONG THE
NORTHERN GULF COAST THIS EVENING TO PASS INTO THE AREA OVERNIGHT AND
INTO THE ATLANTIC AROUND DAYBREAK. IN ADDITION THERE IS DIFLUENCE
ALOFT WITH DIVERGING BRANCHES OF THE POLAR JET TO THE NORTH/NW AND
SUB-TROPICAL JET TO THE SOUTH/SW. ALTHOUGH OUR CONFIDENCE IS
MODERATE AT BEST...THIS DOES SUPPORT AT LEAST SLIGHT CHANCE AND
CHANCE POPS AFTER DIURNAL CONVECTION DWINDLES FAR INLAND AFTER 9-10
PM. THIS IS MORE IN LINE WITH THE HIGH-RES MODELS AND THE
SREF...RATHER THAN THE GLOBAL MODELS WHICH HAVE HAD A DIFFICULT TIME
OF LATE WITH NOCTURNAL CONVECTION. INSTEAD THEY SEEM TO BE FOCUSING
MORE ON LOW STRATUS THAT SHOULD OCCUR. THERE IS LIKELY TOO MUCH
MIXING OF THE PLANETARY BOUNDARY LAYER WITH GEOSTROPHIC WINDS OF 15
KT OR GREATER TO PERSIST...SO OTHER THAN A LITTLE GROUND FOG WHERE
RAINS OCCURRED...THERE ARE NO SIGNIFICANT FOG CONCERNS.

THE FORMATION OF AT LEAST PATCHY LOW STRATUS...DEBRIS CLOUDS FROM
EARLIER CONVECTION AND THE ELEVATED DEW POINTS WON/T ALLOW FOR MIN
TEMPS ANY LOWER THAN THE UPPER 60S TO NEAR 70. DOWNTOWN CHARLESTON
HAS A CHANCE OF A POSSIBLE RECORD HIGH MINIMUM FOR MAY 2ND /72F
SET IN 2010/ IF THEY DON/T RECEIVE TOO MUCH RAIN PRIOR TO THE END
OF THE CALENDAR DAY.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING OUR
REGION. THE COMPLICATING FACTOR FOR FIGURING OUT THE THUNDERSTORM AND
SEVERE POTENTIAL IS THE AMOUNT OF CONVECTION THAT MIGHT BE PRESENT IN
THE MORNING. ALL MODELS INDICATE THAT AT LEAST SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN
RAPIDLY MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE
WILL DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING LATER
IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A SIMILAR AMOUNT
OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE BASED CAPES OF
1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT LOBES WILL
MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW THROUGH THE
DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY ONE
IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A LOW/MARGINAL
RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON. THE MAIN
THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES IN THE 500-
700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL FOR
TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY RAINFALL.
HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW OVER
THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-NORTHWEST
LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE UPPER 70S
AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT LOBES WILL
MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING TROUGH.
HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO MEASURABLE
PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-REINFORCING COLD FRONT
WILL MOVE THROUGH...BUT IS EXPECTED TO COME THROUGH DRY. WINDS WILL
STAY UP ALL NIGHT FROM THE WEST-NORTHWEST...WITH LOWS DROPPING TO
THE MID 50S INLAND TO AROUND 60 COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /21Z MONDAY THROUGH SATURDAY/...
MOST OF THE VALID 18Z TAF CYCLE WILL BE VFR.

ALTHO0UGH EITHER SITE COULD STILL EXPERIENCE A SHRA THIS
EVENING...NO SIGNIFICANT IMPACTS WILL OCCUR.

CONVECTION WILL LIKELY FADE IN COVERAGE THIS EVENING...BUT WITH
THE APPROACH OF ENERGY ALOFT OVERNIGHT THERE CERTAINLY COULD BE A
RISK OF SHRA/TSRA AT KCHS AGAIN. BUT PROBABILITIES ARE TOO LOW TO
INCLUDE AT THIS TIME.

THERE IS LIKELY TOO MUCH WIND TONIGHT TO CAUSE ANY FOG
CONCERNS...BUT AREAS OF LOW STRATUS MAY OCCUR LATE TONIGHT INTO
THE MIDDLE OF TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
DURING THE AFTERNOON...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
TONIGHT...THE PRESSURE PATTERN WILL TIGHTEN BETWEEN STRONG HIGH
PRESSURE TO THE DISTANT EAST/NE OF BERMUDA AND LOW PRESSURE REACHING
FROM NORTHERN VIRGINIA TO SOUTHERN NEW JERSEY BY MORNING. A TRAILING
COLD FRONT FROM THE LOW WILL CROSS THE APPALACHIANS EARLY TONIGHT
AND INTO THE SC UPSTATE AND CENTRAL SAVANNAH RIVER VALLEY LATE.
ALTHOUGH WARM ADVECTION WILL LIMIT HOW MUCH MIXING OF A 25-35 KT LOW
LEVEL JET WILL OCCUR...SOUTH/SW WINDS OVER THE LOCAL WATERS WILL
STILL REACH AS HIGH AS 15 OR 20 KT. A FEW INFREQUENT GUSTS TO 25 KT
WILL OCCUR...ESPECIALLY OVER AMZ350-374...BUT NOT ENOUGH TO HOIST A
SMALL CRAFT ADVISORY. SEAS ARE ABLE TO BUILD TO AS HIGH AS 3-5
FT...HIGHEST ACROSS THE OUTER GA WATERS BEYOND 40 NM OFF THE
COAST. MARINE INTEREST SHOULD REMAIN ALERT DUE TO ISOLATED TO
SCATTERED SHOWERS/T-STORMS WILL OCCUR.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 022008
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
408 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION THROUGH TUESDAY...PRODUCING UNSETTLED CONDITIONS.
THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY NIGHT...FOLLOWED
BY A REINFORCING COLD FRONT ON THURSDAY. HIGH PRESSURE WILL THEN
EXPAND INTO THE REGION FROM THE WEST THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THROUGH THIS EVENING...CONVECTION WILL CONTINUE TO DEVELOP IN AN
UNCAPPED ATMOSPHERE WITH FAVORABLE THERMODYNAMICS...PWATS NEAR 2
STANDARD DEVIATIONS ABOVE NORMAL AND SEVERAL MESOSCALE BOUNDARIES
SUCH AS THE SEA BREEZE...PIEDMONT TROUGH AND OUTFLOWS. PER
THE MESO-ANALYSIS FROM SPC WE FIND SBCAPES THAT ARE AS HIGH AS
3000-3500 J/KG...MLCAPES ARE 1500-2500 J/KG...AND LIFTED INDICES
ARE AS LOW AS -6 TO -7C. BOUNDARY INTERACTIONS/MERGERS WILL ALLOW
FOR A CONTINUED INCREASE IN COVERAGE OF SHOWERS/T-STORMS WITH THE
GREATEST PROBABILITIES IN THE LIKELY RANGE NEAR AND WEST OF I-95.
LOWEST RAIN CHANCES WILL BE OVER THE COASTAL CORRIDOR WITH STORMS
FOR THE MOST PART TO STAY INLAND WITH THE SEA BREEZE BOUNDARY.

DCAPE OF 800-1000 J/KG SUPPORTS THE POTENTIAL FOR DAMAGING WIND
GUSTS AND CAPE IN THE HAIL GROWTH LAYER OF 500 J/KG SUPPORTS HAIL
MAYBE AS LARGE AS 1 INCH. GIVEN THE LACK OF ANY SIGNIFICANT
SHEAR...THERE IS ONLY AN ISOLATED RISK OF PULSE SEVERE STORMS. CELLS
ON RADAR ARE STARTING TO ALIGN THEMSELVES WITH THE MEAN STEERING
FLOW...AND THAT ALONG WITH THE HIGH MOISTURE CONTENT SUPPORTS A RISK
OF LOCALIZED FLOODING SHOULD TRAINING/BACK-BUILDING OCCUR. THE TEMP
CURVE HAS BEEN ALTERED AS WE ATTEMPT TO ACCOUNT FOR THE
CONVECTION...THAT CAUSES TEMPS TO DROP INTO THE MID AND UPPER 70S
WHERE THE MORE PERSISTENT RAINS OCCUR.

FOR TONIGHT...CONVECTION WILL STEADILY FADE WITH THE LOSS OF HEATING
AND TYPICAL NOCTURNAL STABILIZING INFLUENCES. HOWEVER...THERE IS
STILL DECENT FORCING THAT OCCURS WITH A SHORT WAVE ALONG THE
NORTHERN GULF COAST THIS EVENING TO PASS INTO THE AREA OVERNIGHT AND
INTO THE ATLANTIC AROUND DAYBREAK. IN ADDITION THERE IS DIFLUENCE
ALOFT WITH DIVERGING BRANCHES OF THE POLAR JET TO THE NORTH/NW AND
SUB-TROPICAL JET TO THE SOUTH/SW. ALTHOUGH OUR CONFIDENCE IS
MODERATE AT BEST...THIS DOES SUPPORT AT LEAST SLIGHT CHANCE AND
CHANCE POPS AFTER DIURNAL CONVECTION DWINDLES FAR INLAND AFTER 9-10
PM. THIS IS MORE IN LINE WITH THE HIGH-RES MODELS AND THE
SREF...RATHER THAN THE GLOBAL MODELS WHICH HAVE HAD A DIFFICULT TIME
OF LATE WITH NOCTURNAL CONVECTION. INSTEAD THEY SEEM TO BE FOCUSING
MORE ON LOW STRATUS THAT SHOULD OCCUR. THERE IS LIKELY TOO MUCH
MIXING OF THE PLANETARY BOUNDARY LAYER WITH GEOSTROPHIC WINDS OF 15
KT OR GREATER TO PERSIST...SO OTHER THAN A LITTLE GROUND FOG WHERE
RAINS OCCURRED...THERE ARE NO SIGNIFICANT FOG CONCERNS.

THE FORMATION OF AT LEAST PATCHY LOW STRATUS...DEBRIS CLOUDS FROM
EARLIER CONVECTION AND THE ELEVATED DEW POINTS WON/T ALLOW FOR MIN
TEMPS ANY LOWER THAN THE UPPER 60S TO NEAR 70. DOWNTOWN CHARLESTON
HAS A CHANCE OF A POSSIBLE RECORD HIGH MINIMUM FOR MAY 2ND /72F
SET IN 2010/ IF THEY DON/T RECEIVE TOO MUCH RAIN PRIOR TO THE END
OF THE CALENDAR DAY.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
TUESDAY...A BROAD...POSITIVELY TILTED UPPER TROUGH WILL BE OVER THE
CENTRAL U.S. WITH A TRAILING COLD FRONT RUNNING FROM THE MID
ATLANTIC...SOUTHWEST ACROSS THE SOUTHEAST U.S....APPROACHING OUR
REGION. THE COMPLICATING FACTOR FOR FIGURING OUT THE THUNDERSTORM AND
SEVERE POTENTIAL IS THE AMOUNT OF CONVECTION THAT MIGHT BE PRESENT IN
THE MORNING. ALL MODELS INDICATE THAT AT LEAST SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS WILL BE AROUND BETWEEN 06Z AND 15Z...THEN
RAPIDLY MOVES EAST. THE NAM THEN INDICATES THAT DEEP LAYER MOISTURE
WILL DROP THROUGH THE DAY...LIMITING CONVECTIVE COVERAGE...WHILE THE
GLOBAL MODELS KEEP SUFFICIENT DEEP LAYER MOISTURE IN PLACE. GOING
WITH THE MAJORITY AND KEEPING SOME CONSISTENCY WITH PREVIOUS
FORECASTS...HAVE KEPT HIGH END CHANCE/LIKELY POPS REDEVELOPING LATER
IN THE MORNING AND THROUGH THE AFTERNOON. WILL HAVE A SIMILAR AMOUNT
OF INSTABILITY AS PREVIOUS DAYS...GENERALLY SURFACE BASED CAPES OF
1000-2000 J/KG IN PLACE. IN ADDITION...WEAK VORT LOBES WILL
MOVE ACROSS THE AREA IN THE SOUTHWEST UPPER FLOW THROUGH THE
DAY. AT THIS POINT...IT IS VERY DIFFICULT TO TIME ANY ONE
IMPULSE. GIVEN THESE CONDITIONS...FEEL THERE IS STILL A LOW/MARGINAL
RISK FOR ISOLATED SEVERE STORMS DURING THE AFTERNOON. THE MAIN
THREAT WILL BE STRONG/DAMAGING WINDS WITH DOWNDRAFT CAPES IN THE 500-
700 J/KG RANGE. SMALL HAIL WILL ALSO BE POSSIBLE. DEEP
SOUTHWEST/UNIDIRECTIONAL FLOW MAY ALSO LEAD TO THE POTENTIAL FOR
TRAINING OF CELLS...WHICH COULD RESULT IN LOCALLY HEAVY RAINFALL.
HIGHS IN THE LOWER 80S.

THE BULK OF THE CONVECTION IS EXPECTED TO END BY MIDNIGHT AS THE
SURFACE FRONT MOVES THROUGH THE AREA AND DEEP LEVEL DRYING MOVES IN.
LOWS IN THE LOWER 60S. KEPT THE TREND OF LOWER POPS FROM WEST TO
EAST THROUGH THE NIGHT...WITH MOST POPS LESS THAN 15% OVER LAND BY
MORNING.

WEDNESDAY...COOLER AND DRIER CONDITIONS ARE EXPECTED AS THE LARGE
SCALE PATTERN TRANSITIONS TO THE BLOCK...WITH A DEEP UPPER LOW OVER
THE OH RIVER VALLEY AND RIDGE OVER THE ROCKIES. A WEST-NORTHWEST
LOW LEVEL FLOW...MOSTLY SUNNY SKIES AND HIGHS IN THE UPPER 70S
AROUND 80. THIS IS CLOSE TO NORMAL. PERIODIC UPPER VORT LOBES WILL
MOVE ACROSS THE AREA ON THE BASE OF THE UPPER/BLOCKING TROUGH.
HOWEVER...OTHER THAN BRIEF INCREASES IN CLOUDS...NO MEASURABLE
PRECIP. IS EXPECTED. BY WEDNESDAY NIGHT...A RE-REINFORCING COLD FRONT
WILL MOVE THROUGH...BUT IS EXPECTED TO COME THROUGH DRY. WINDS WILL
STAY UP ALL NIGHT FROM THE WEST-NORTHWEST...WITH LOWS DROPPING TO
THE MID 50S INLAND TO AROUND 60 COAST...CLOSER TO NORMAL.

THURSDAY...THE AREA WILL REMAIN ON THE SOUTHERN END OF THE BLOCKING
UPPER LOW...WHICH WILL DRIFT INTO THE NORTHEAST AND MID ATLANTIC
REGION. EVEN WITH SUNNY SKIES...NORTHWEST FLOW AND WEAK COLD
ADVECTION WILL KEEP HIGHS IN THE MID 70S...ABOUT 3-5 DEGREES BELOW
NORMAL.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
MOST OF THE VALID 18Z TAF CYCLE WILL BE VFR.

SCATTERED SHRA/TSRA WILL LIKELY STAY JUST OUTSIDE THE KCHS TERMINAL
THIS AFTERNOON. BUT KSAV WILL EXPERIENCE SHRA/TSRA LATE THIS
AFTERNOON/EARLY EVENING GIVEN SEVERAL BOUNDARY INTERACTIONS. SOME OF
THESE WILL CAUSE WIND GUSTS OF 25-30 KT AND AT LEAST PERIODIC FLIGHT
RESTRICTIONS WITH MODERATE TO PERHAPS OCCASIONAL HEAVY RAINS.

CONVECTION WILL LIKELY FADE IN COVERAGE THIS EVENING...BUT WITH
THE APPROACH OF ENERGY ALOFT OVERNIGHT THERE CERTAINLY COULD BE A
RISK OF SHRA/TSRA AT KCHS AGAIN. BUT PROBABILITIES ARE TOO LOW TO
INCLUDE AT THIS TIME.

THERE IS LIKELY TOO MUCH WIND TONIGHT TO CAUSE ANY FOG
CONCERNS...BUT AREAS OF LOW STRATUS MAY OCCUR LATE TONIGHT INTO
THE MIDDLE OF TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

EXTENDED AVIATION OUTLOOK...FOR TUESDAY...PERIODIC FLIGHT
RESTRICTIONS POSSIBLE IN SCATTERED SHOWERS/THUNDERSTORMS...ESPECIALLY
DURING THE AFTERNOON...AT BOTH KCHS AND KSAV. WEDNESDAY THROUGH
SATURDAY...VFR WILL PREVAIL BOTH SITES.

&&

.MARINE...
TONIGHT...THE PRESSURE PATTERN WILL TIGHTEN BETWEEN STRONG HIGH
PRESSURE TO THE DISTANT EAST/NE OF BERMUDA AND LOW PRESSURE REACHING
FROM NORTHERN VIRGINIA TO SOUTHERN NEW JERSEY BY MORNING. A TRAILING
COLD FRONT FROM THE LOW WILL CROSS THE APPALACHIANS EARLY TONIGHT
AND INTO THE SC UPSTATE AND CENTRAL SAVANNAH RIVER VALLEY LATE.
ALTHOUGH WARM ADVECTION WILL LIMIT HOW MUCH MIXING OF A 25-35 KT LOW
LEVEL JET WILL OCCUR...SOUTH/SW WINDS OVER THE LOCAL WATERS WILL
STILL REACH AS HIGH AS 15 OR 20 KT. A FEW INFREQUENT GUSTS TO 25 KT
WILL OCCUR...ESPECIALLY OVER AMZ350-374...BUT NOT ENOUGH TO HOIST A
SMALL CRAFT ADVISORY. SEAS ARE ABLE TO BUILD TO AS HIGH AS 3-5
FT...HIGHEST ACROSS THE OUTER GA WATERS BEYOND 40 NM OFF THE
COAST. MARINE INTEREST SHOULD REMAIN ALERT DUE TO ISOLATED TO
SCATTERED SHOWERS/T-STORMS WILL OCCUR.

TUESDAY AND WEDNESDAY...CONDITIONS ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY LEVELS. A COLD FRONT WILL BE APPROACHING THE
REGION ON TUESDAY...THE MOVE THROUGH THE WATERS ON WEDNESDAY. WINDS
COULD PERIODICALLY GET AS HIGH AS 15-20 KNOTS FROM THE SOUTHWEST
THROUGH WEDNESDAY MORNING AHEAD OF THE FRONT...BUT GENERALLY 15
KNOTS OR LESS EXPECTED TO PREVAIL. WINDS WILL SHIFT TO WEST-
NORTHWEST WEDNESDAY AFTERNOON BEHIND THE FRONT...BUT EXPECTED TO
REMAIN 15-20 KNOTS OR LESS WITH BUILDING SEAS TO 4 FEET
OFFSHORE/BEYOND 20 NM.

WEDNESDAY NIGHT AND THURSDAY...WINDS INCREASING BACK TO 15-20 KNOTS
FROM THE WEST-NORTHWEST AS A REINFORCING COLD FRONT MOVES THROUGH
AND STRONGER HIGH PRESSURE BUILDS FROM THE WEST. SEAS BUILDING TO 4-5
FEET BEYOND 20 NM.

FRIDAY AND SATURDAY...THE PRESSURE GRADIENT GRADUALLY DECREASES AS
HIGH PRESSURE CONTINUES MOVING IN FROM THE WEST. EXPECT WINDS OF 15
KNOTS OR LESS AND SEAS DECREASING TO 3 TO 4 FEET.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 021753
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
153 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION TODAY THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY ANOTHER COLD FRONT ON THURSDAY. HIGH PRESSURE
WILL THEN EXPAND INTO THE REGION OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE MADE A FEW MINOR ADJUSTMENTS TO RAISE MAX TEMPS ABOUT 1-2F IN
A COUPLE OF SPOTS. ALSO...WE/RE STARTING TO SEE A FEW SHOWERS
POPPING ALONG THE RESULTANT SEA BREEZE BOUNDARY NEAR OR JUST
INLAND FROM THE US-17 CORRIDOR IN SC. LOOK FOR ADDITIONAL POP-UPS
EARLY THIS AFTERNOON AS WE CONVECTIVE TEMPS ARE SURPASSED.

THE MEAN POSITION OF A POSITIVELY TILTED LARGE SCALE TROUGH COVERS
MUCH OF THE EASTERN HALF OF THE NATION...WITH AN ANTICYCLONE ALOFT
CENTERED NEAR CENTRAL AMERICA AND THE BAY OF CAMPECHE. SEVERAL
PERTURBATIONS WITHIN THE SW/WEST FLOW OVERHEAD WILL PASS BY WITHIN
AN ANOMALOUS MOIST ENVIRONMENT WHERE PWATS ARE CLOSE TO THE 90TH
PERCENTILE FOR THIS TIME OF YEAR.

THESE CONDITIONS WILL COMBINE WITH MODERATE TO HIGH INSTABILITY TO
PRODUCE ANOTHER ACTIVE CONVECTIVE AFTERNOON. MODIFIED SOUNDING
FROM KCHS IS INDICATING IMPRESSIVE THERMODYNAMICS...SUCH AS LIFTED
INDICES OF MINUS 7C AND SBCAPE OF 2275 J/KG. FAVORABLE LOW AND MID
LEVEL LAPSE RATES SHOULD SUPPORT FAIRLY VIGOROUS UPDRAFTS ONCE WE
ACHIEVE E OUR CONVECTIVE TEMP IN THE MID 80S DURING THE EARLY
AFTERNOON.

THE SEA BREEZE BOUNDARY GETS AN EARLY START WITH THE FLOW ALREADY
SOUTHERLY AND ACTIVITY WILL INITIATE ALONG THIS BOUNDARY FIRST
DURING THE EARLY AFTERNOON...AS WELL AS INLAND IN CLOSER PROXIMITY
TO A PIEDMONT TROUGH BY 2 PM. COVERAGE WILL THEN EXPAND DURING
THE MID AND LATE AFTERNOON HOURS AS MESOSCALE INTERACTIONS TAKE
PLACE. WE HAVE LIMITED COVERAGE TO SCATTERED AND NUMEROUS SHOWERS
AND T-STORMS...BUT THIS WILL LIKELY NEED ADJUSTMENTS ONCE TRENDS
BECOME MORE DEFINED. HIGHEST PROBABILITIES OVERALL LOOK TO BE NEAR
AND WEST OF I-95.

WHILE NO ORGANIZED SEVERE WEATHER WILL OCCUR WITH LITTLE
SHEAR...THE DCAPES GREATER THAN 1000 J/KG AND HAIL CAPES OF 700
J/KG SUPPORT A RISK FOR AT LEAST ISOLATED SEVERE STORMS WITH
DOWNBURSTS OF DAMAGING WIND AND 1 INCH HAIL.

THERE IS ALSO A RISK FOR AT LEAST LOCALLY HEAVY RAINS WITH THE
EXCESSIVE PWATS AND SLOW STORM MOVEMENT...ESPECIALLY IF BACK-
BUILDING AND TRAINING OF CELLS OCCURS. WE/LL KEEP A SHARP WATCH
FOR THE ORIENTATION OF CELLS IN AN ORIENTATION THAT IS SIMILAR TO
THE MEAN WEST/SW TO EAST/NE FLOW WHICH WOULD BE FAVORABLE FOR
FLOODING CONCERNS.

THE DIURNAL TEMP CURVE WILL NEED REFINEMENTS ONCE CONVECTIVE
COVERAGE INCREASES...BUT PRIOR TO THEN WE ANTICIPATE HIGHS MID AND
UPPER 80S MOST PLACES INLAND...MAYBE A FEW SPOTS TOUCHING 90 NEAR
THE ALTAMAHA RIVER. NEARBY OCEAN WATERS HAVE WARMED INTO THE LOWER
AND MIDDLE 70S...BUT STILL LOW ENOUGH TO KEEP MAX TEMPS AT THE
SHORE FROM GETTING ANY HIGHER THAN UPPER 70S AND LOWER 80S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING ACROSS
INLAND AREAS AT SUNSET. THERE REMAINS MUCH UNCERTAINTY HOW THE
CONVECTIVE PATTERN WILL EVOLVE OVERNIGHT WITH THE BULK OF UPPER
FORCING PROGGED TO BE DISPLACED ACROSS THE MIDLANDS AS SHORTWAVE
ENERGY PASSES TO THE NORTH WHILE INSTABILITY WANES. IN FACT..THERE
IS QUITE A BIT OF ANTICYCLONIC VORTICITY ADVECTION /AVA/ AND
SUBSIDENCE PROGGED TO OVERSPREAD MUCH OF THE FORECAST AREA AFTER
MIDNIGHT WITH AN AVA MAXIMUM SETTING UP NEAR AUGUSTA BY SUNRISE
TUESDAY. THIS WOULD SUGGEST LOW CHANCES FOR MEASURABLE RAINFALL
OVERNIGHT. HOWEVER...THE VARIOUS NAM/GFS/ECMWF MOS NUMBERS ALL
SHOW HIGH CHANCE TO LIKELY POPS FOR MUCH OF THE NIGHT WHICH IS
CURIOUS. IT COULD BE THAT THE MODELS ARE HAVING A HARD TIME
RESOLVING POSSIBLE LOW STRATUS DEVELOPMENT IN THE WARM/MOIST FLOW
AHEAD OF THE APPROACHING COLD FRONT...BUT THIS IS UNCLEAR. THE
LATEST SREF MEAN CERTAINLY DOES NOT SUPPORT MOS POP NUMBERS NEARLY
THAT HIGH...WHICH INCREASES THE UNCERTAINTY EVEN MORE. PLAN TO
TAPPER DOWN POPS INTO THE 20-30 PERCENT RANGE FROM LATE EVENING
ON...BUT THERE IS CERTAINLY A BIG BUST POTENTIAL HERE. LOWS WILL
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.

TUESDAY AND TUESDAY NIGHT...A TROUGH WILL BE OVER THE EAST COAST
WHILE SEVERAL SHORTWAVES ROUND THE BASE OF THE TROUGH...CROSSING
THROUGH THE REGION. MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION NEAR OUR AREA WILL COMBINE WITH PLENTY OF DEEP-LAYERED
MOISTURE IN PLACE...PWATS RANGING FROM 1.5-1.75 INCHES...TO GENERATE
SHOWERS AND THUNDERSTORMS. ADDITIONALLY...A COLD FRONT WILL BE
APPROACHING FROM THE WEST WHICH WILL INCREASE FORCING. THIS
FAVORABLE THERMODYNAMIC/KINEMATIC ENVIRONMENT WILL PRODUCE STRONG
THUNDERSTORMS. A FEW OF THESE STORMS COULD BECOME
SEVERE...ESPECIALLY IN THE AFTERNOON AND EVENING. DAMAGING
WINDS...LOCALLY HEAVY RAINFALL...AND HAIL WILL BE THE GREATEST
THREATS. THERE IS STILL SOME UNCERTAINTY WHERE THE BEST COVERAGE
WILL BE AS THIS WILL DEPEND ON THE ANTECEDENT/DEVELOPING MESOSCALE
ENVIRONMENT. ELEVATED POPS REMAIN IN FORECAST WITH THE HIGHEST POPS
INITIALLY ACROSS THE INLAND COUNTIES IN THE MORNING THEN EXPANDING
INTO MUCH OF THE AREA BY THE AFTERNOON. THE HEAVIEST PRECIPITATION
WILL SHIFT OFFSHORE IN THE EVENING. THE FRONT SHOULD CROSS THROUGH
THE AREA LATE TUESDAY NIGHT AND POPS WILL RAPIDLY DIMINISH FOLLOWING
ITS PASSAGE. HIGH TEMPERATURES WILL GENERALLY BE IN THE LOWER 80S.
THOUGH BREAKS IN THE CLOUDS COULD CAUSE THEM TO RISE MUCH HIGHER.
LOWS SHOULD BE IN THE 60S.

WEDNESDAY AND WEDNESDAY NIGHT...THE COLD FRONT SHOULD CROSS THROUGH
OUR AREA AROUND DAYBREAK. REMNANT SHOWERS AND THUNDERSTORMS...MAINLY
LIMITED TO THE COASTAL COUNTIES...WILL QUICKLY BE PUSHED OFFSHORE
WITH THE FRONT. THE REST OF THE MORNING INTO THE AFTERNOON WILL BE
DRY WITH CLEARING SKIES. DEW POINTS WILL FALL INTO THE 50S WHILE
HIGHS WILL BE IN THE UPPER 70S TO NEAR 80 DEGREES. ANOTHER COLD
FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. THIS FRONT IS
LACKING MOISTURE...SO AT MOST WE CAN EXPECT SOME CLOUDS...BUT NO
SHOWERS OR THUNDERSTORMS. LOWS WILL BE IN THE UPPER 50S TO NEAR 60
DEGREES.

THURSDAY...A TROUGH WILL REMAIN OVER THE EAST COAST. AT THE SURFACE
A STORM SYSTEM WILL BE SPREAD ACROSS THE NORTHEASTERN STATES WHILE
BROAD HIGH PRESSURE WILL BE SPREAD ACROSS THE CENTRAL PLAINS. THIS
SYNOPTIC FLOW WILL LEAD TO WEST WINDS AT THE SURFACE AND NORTHWEST
FLOW ALOFT. DESPITE PLENTY OF SUNSHINE...HIGHS WILL BE SEVERAL
DEGREES BELOW NORMAL...IN THE MID 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MOST OF THE VALID 18Z TAF CYCLE WILL BE VFR.

SCATTERED SHRA/TSRA WILL LIKELY STAY JUST OUTSIDE THE KCHS
TERMINAL THIS AFTERNOON...BUT CLOSE ENOUGH WHERE WE HAVE VCSH
UNTIL MID AFTERNOON. A BETTER CHANCE EXISTS AT KSAV DURING THE
MID-LATE AFTERNOON...SHOWING A FEW HOURS OF PERIODIC MVFR
CONDITIONS IN TSRA.

CONVECTION WILL LIKELY FADE IN COVERAGE THIS EVENING...BUT WITH
THE APPROACH OF ENERGY ALOFT OVERNIGHT THERE CERTAINLY COULD BE A
RISK OF SHRA/TSRA AT KCHS AGAIN. BUT PROBABILITIES ARE TOO LOW TO
INCLUDE AT THIS TIME.

THERE IS LIKELY TOO MUCH WIND TONIGHT TO CAUSE ANY FOG
CONCERNS...BUT AREAS OF LOW STRATUS MAY OCCUR LATE TONIGHT INTO
THE MIDDLE OF TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

&&

.MARINE...
THIS AFTERNOON...THE WESTERN PORTION OF ATLANTIC HIGH PRESSURE
STRETCHES ACROSS THE LOCAL WATERS...CREATING A GENERAL SOUTH/SW
FLOW. SEA BREEZE CIRCULATIONS WILL ADD A FEW KNOTS OF WIND TO THE
CHARLESTON HARBOR AND NEAR THE COAST...BUT ON AVERAGE SPEEDS NO
GREATER THAN AROUND 15 KT. LOOK FOR A FEW SMALL SURGES TOWARD 20
KT NEAR THE MOUTH OF CHARLESTON HARBOR. SEAS WILL BE A MIX OF WIND
WAVES AND SWELLS...BUT NO HIGHER THAN 2-3 FT.

TONIGHT...NOCTURNAL SURGING WILL OCCUR AHEAD OF AN APPROACHING
COLD FRONT. WINDS LOOK TO MAX OUT AT 15-20 KT...HIGHEST ACROSS THE
GEORGIA OFFSHORE AND CHARLESTON COUNTY WATERS. FREQUENT GUSTS LOOK
TO REMAIN BELOW 25 KT FOR NOW...SO A SMALL CRAFT ADVISORY IS NOT
NEEDED ATTM. SEAS WILL BUILD 3-5 FT GEORGIA OFFSHORE AND
CHARLESTON COUNTY WATERS WITH 2-4 FT REMAINING COASTAL LEGS.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL PASS THROUGH THE AREA
TUESDAY NIGHT/WEDNESDAY MORNING...FOLLOWED BY ANOTHER COLD FRONT
WEDNESDAY NIGHT/THURSDAY MORNING. OFFSHORE WINDS WILL PREVAIL
THROUGH LATE WEEK. THE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN
LATE WEDNESDAY NIGHT INTO EARLY FRIDAY MORNING. SMALL CRAFT
ADVISORIES MAY BE NEEDED FOR WINDS GUSTS...ESPECIALLY FOR THE
OUTER GEORGIA WATERS. CONDITIONS IMPROVE ON FRIDAY AS THE GRADIENT
WEAKENS.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 021734
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
134 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION TODAY THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY ANOTHER COLD FRONT ON THURSDAY. HIGH PRESSURE
WILL THEN EXPAND INTO THE REGION OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE MADE A FEW MINOR ADJUSTMENTS TO RAISE MAX TEMPS ABOUT 1-2F IN
A COUPLE OF SPOTS. ALSO...WE/RE STARTING TO SEE A FEW SHOWERS
POPPING ALONG THE RESULTANT SEA BREEZE BOUNDARY NEAR OR JUST
INLAND FROM THE US-17 CORRIDOR IN SC. LOOK FOR ADDITIONAL POP-UPS
EARLY THIS AFTERNOON AS WE CONVECTIVE TEMPS ARE SURPASSED.

THE MEAN POSITION OF A POSITIVELY TILTED LARGE SCALE TROUGH COVERS
MUCH OF THE EASTERN HALF OF THE NATION...WITH AN ANTICYCLONE ALOFT
CENTERED NEAR CENTRAL AMERICA AND THE BAY OF CAMPECHE. SEVERAL
PERTURBATIONS WITHIN THE SW/WEST FLOW OVERHEAD WILL PASS BY WITHIN
AN ANOMALOUS MOIST ENVIRONMENT WHERE PWATS ARE CLOSE TO THE 90TH
PERCENTILE FOR THIS TIME OF YEAR.

THESE CONDITIONS WILL COMBINE WITH MODERATE TO HIGH INSTABILITY TO
PRODUCE ANOTHER ACTIVE CONVECTIVE AFTERNOON. MODIFIED SOUNDING
FROM KCHS IS INDICATING IMPRESSIVE THERMODYNAMICS...SUCH AS LIFTED
INDICES OF MINUS 7C AND SBCAPE OF 2275 J/KG. FAVORABLE LOW AND MID
LEVEL LAPSE RATES SHOULD SUPPORT FAIRLY VIGOROUS UPDRAFTS ONCE WE
ACHIEVE E OUR CONVECTIVE TEMP IN THE MID 80S DURING THE EARLY
AFTERNOON.

THE SEA BREEZE BOUNDARY GETS AN EARLY START WITH THE FLOW ALREADY
SOUTHERLY AND ACTIVITY WILL INITIATE ALONG THIS BOUNDARY FIRST
DURING THE EARLY AFTERNOON...AS WELL AS INLAND IN CLOSER PROXIMITY
TO A PIEDMONT TROUGH BY 2 PM. COVERAGE WILL THEN EXPAND DURING
THE MID AND LATE AFTERNOON HOURS AS MESOSCALE INTERACTIONS TAKE
PLACE. WE HAVE LIMITED COVERAGE TO SCATTERED AND NUMEROUS SHOWERS
AND T-STORMS...BUT THIS WILL LIKELY NEED ADJUSTMENTS ONCE TRENDS
BECOME MORE DEFINED. HIGHEST PROBABILITIES OVERALL LOOK TO BE NEAR
AND WEST OF I-95.

WHILE NO ORGANIZED SEVERE WEATHER WILL OCCUR WITH LITTLE
SHEAR...THE DCAPES GREATER THAN 1000 J/KG AND HAIL CAPES OF 700
J/KG SUPPORT A RISK FOR AT LEAST ISOLATED SEVERE STORMS WITH
DOWNBURSTS OF DAMAGING WIND AND 1 INCH HAIL.

THERE IS ALSO A RISK FOR AT LEAST LOCALLY HEAVY RAINS WITH THE
EXCESSIVE PWATS AND SLOW STORM MOVEMENT...ESPECIALLY IF BACK-
BUILDING AND TRAINING OF CELLS OCCURS. WE/LL KEEP A SHARP WATCH
FOR THE ORIENTATION OF CELLS IN AN ORIENTATION THAT IS SIMILAR TO
THE MEAN WEST/SW TO EAST/NE FLOW WHICH WOULD BE FAVORABLE FOR
FLOODING CONCERNS.

THE DIURNAL TEMP CURVE WILL NEED REFINEMENTS ONCE CONVECTIVE
COVERAGE INCREASES...BUT PRIOR TO THEN WE ANTICIPATE HIGHS MID AND
UPPER 80S MOST PLACES INLAND...MAYBE A FEW SPOTS TOUCHING 90 NEAR
THE ALTAMAHA RIVER. NEARBY OCEAN WATERS HAVE WARMED INTO THE LOWER
AND MIDDLE 70S...BUT STILL LOW ENOUGH TO KEEP MAX TEMPS AT THE
SHORE FROM GETTING ANY HIGHER THAN UPPER 70S AND LOWER 80S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING ACROSS
INLAND AREAS AT SUNSET. THERE REMAINS MUCH UNCERTAINTY HOW THE
CONVECTIVE PATTERN WILL EVOLVE OVERNIGHT WITH THE BULK OF UPPER
FORCING PROGGED TO BE DISPLACED ACROSS THE MIDLANDS AS SHORTWAVE
ENERGY PASSES TO THE NORTH WHILE INSTABILITY WANES. IN FACT..THERE
IS QUITE A BIT OF ANTICYCLONIC VORTICITY ADVECTION /AVA/ AND
SUBSIDENCE PROGGED TO OVERSPREAD MUCH OF THE FORECAST AREA AFTER
MIDNIGHT WITH AN AVA MAXIMUM SETTING UP NEAR AUGUSTA BY SUNRISE
TUESDAY. THIS WOULD SUGGEST LOW CHANCES FOR MEASURABLE RAINFALL
OVERNIGHT. HOWEVER...THE VARIOUS NAM/GFS/ECMWF MOS NUMBERS ALL
SHOW HIGH CHANCE TO LIKELY POPS FOR MUCH OF THE NIGHT WHICH IS
CURIOUS. IT COULD BE THAT THE MODELS ARE HAVING A HARD TIME
RESOLVING POSSIBLE LOW STRATUS DEVELOPMENT IN THE WARM/MOIST FLOW
AHEAD OF THE APPROACHING COLD FRONT...BUT THIS IS UNCLEAR. THE
LATEST SREF MEAN CERTAINLY DOES NOT SUPPORT MOS POP NUMBERS NEARLY
THAT HIGH...WHICH INCREASES THE UNCERTAINTY EVEN MORE. PLAN TO
TAPPER DOWN POPS INTO THE 20-30 PERCENT RANGE FROM LATE EVENING
ON...BUT THERE IS CERTAINLY A BIG BUST POTENTIAL HERE. LOWS WILL
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.

TUESDAY AND TUESDAY NIGHT...A TROUGH WILL BE OVER THE EAST COAST
WHILE SEVERAL SHORTWAVES ROUND THE BASE OF THE TROUGH...CROSSING
THROUGH THE REGION. MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION NEAR OUR AREA WILL COMBINE WITH PLENTY OF DEEP-LAYERED
MOISTURE IN PLACE...PWATS RANGING FROM 1.5-1.75 INCHES...TO GENERATE
SHOWERS AND THUNDERSTORMS. ADDITIONALLY...A COLD FRONT WILL BE
APPROACHING FROM THE WEST WHICH WILL INCREASE FORCING. THIS
FAVORABLE THERMODYNAMIC/KINEMATIC ENVIRONMENT WILL PRODUCE STRONG
THUNDERSTORMS. A FEW OF THESE STORMS COULD BECOME
SEVERE...ESPECIALLY IN THE AFTERNOON AND EVENING. DAMAGING
WINDS...LOCALLY HEAVY RAINFALL...AND HAIL WILL BE THE GREATEST
THREATS. THERE IS STILL SOME UNCERTAINTY WHERE THE BEST COVERAGE
WILL BE AS THIS WILL DEPEND ON THE ANTECEDENT/DEVELOPING MESOSCALE
ENVIRONMENT. ELEVATED POPS REMAIN IN FORECAST WITH THE HIGHEST POPS
INITIALLY ACROSS THE INLAND COUNTIES IN THE MORNING THEN EXPANDING
INTO MUCH OF THE AREA BY THE AFTERNOON. THE HEAVIEST PRECIPITATION
WILL SHIFT OFFSHORE IN THE EVENING. THE FRONT SHOULD CROSS THROUGH
THE AREA LATE TUESDAY NIGHT AND POPS WILL RAPIDLY DIMINISH FOLLOWING
ITS PASSAGE. HIGH TEMPERATURES WILL GENERALLY BE IN THE LOWER 80S.
THOUGH BREAKS IN THE CLOUDS COULD CAUSE THEM TO RISE MUCH HIGHER.
LOWS SHOULD BE IN THE 60S.

WEDNESDAY AND WEDNESDAY NIGHT...THE COLD FRONT SHOULD CROSS THROUGH
OUR AREA AROUND DAYBREAK. REMNANT SHOWERS AND THUNDERSTORMS...MAINLY
LIMITED TO THE COASTAL COUNTIES...WILL QUICKLY BE PUSHED OFFSHORE
WITH THE FRONT. THE REST OF THE MORNING INTO THE AFTERNOON WILL BE
DRY WITH CLEARING SKIES. DEW POINTS WILL FALL INTO THE 50S WHILE
HIGHS WILL BE IN THE UPPER 70S TO NEAR 80 DEGREES. ANOTHER COLD
FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. THIS FRONT IS
LACKING MOISTURE...SO AT MOST WE CAN EXPECT SOME CLOUDS...BUT NO
SHOWERS OR THUNDERSTORMS. LOWS WILL BE IN THE UPPER 50S TO NEAR 60
DEGREES.

THURSDAY...A TROUGH WILL REMAIN OVER THE EAST COAST. AT THE SURFACE
A STORM SYSTEM WILL BE SPREAD ACROSS THE NORTHEASTERN STATES WHILE
BROAD HIGH PRESSURE WILL BE SPREAD ACROSS THE CENTRAL PLAINS. THIS
SYNOPTIC FLOW WILL LEAD TO WEST WINDS AT THE SURFACE AND NORTHWEST
FLOW ALOFT. DESPITE PLENTY OF SUNSHINE...HIGHS WILL BE SEVERAL
DEGREES BELOW NORMAL...IN THE MID 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MOST OF THE VALID 18Z TAF CYCLE WILL BE VFR.

SCATTERED SHRA/TSRA WILL LIKELY STAY JUST OUTSIDE THE KCHS
TERMINAL THIS AFTERNOON...BUT CLOSE ENOUGH WHERE WE HAVE ADDED
VCTS UNTIL MID AFTERNOON. A BETTER CHANCE EXISTS AT KSAV DURING
THE MID-LATE AFTERNOON...SHOWING A FEW HOURS OF PERIODIC MVFR
CONDITIONS IN TSRA.

CONVECTION WILL LIKELY FADE IN COVERAGE THIS EVENING...BUT WITH
THE APPROACH OF ENERGY ALOFT OVERNIGHT THERE CERTAINLY COULD BE A
RISK OF SHRA/TSRA AT KCHS AGAIN. BUT PROBABILITIES ARE TOO LOW TO
INCLUDE AT THIS TIME.

THERE IS LIKELY TOO MUCH WIND TONIGHT TO CAUSE ANY FOG
CONCERNS...BUT AREAS OF LOW STRATUS MAY OCCUR LATE TONIGHT INTO
THE MIDDLE OF TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

&&

.MARINE...
THIS AFTERNOON...THE WESTERN PORTION OF ATLANTIC HIGH PRESSURE
STRETCHES ACROSS THE LOCAL WATERS...CREATING A GENERAL SOUTH/SW
FLOW. SEA BREEZE CIRCULATIONS WILL ADD A FEW KNOTS OF WIND TO THE
CHARLESTON HARBOR AND NEAR THE COAST...BUT ON AVERAGE SPEEDS NO
GREATER THAN AROUND 15 KT. LOOK FOR A FEW SMALL SURGES TOWARD 20
KT NEAR THE MOUTH OF CHARLESTON HARBOR. SEAS WILL BE A MIX OF WIND
WAVES AND SWELLS...BUT NO HIGHER THAN 2-3 FT.

TONIGHT...NOCTURNAL SURGING WILL OCCUR AHEAD OF AN APPROACHING
COLD FRONT. WINDS LOOK TO MAX OUT AT 15-20 KT...HIGHEST ACROSS THE
GEORGIA OFFSHORE AND CHARLESTON COUNTY WATERS. FREQUENT GUSTS LOOK
TO REMAIN BELOW 25 KT FOR NOW...SO A SMALL CRAFT ADVISORY IS NOT
NEEDED ATTM. SEAS WILL BUILD 3-5 FT GEORGIA OFFSHORE AND
CHARLESTON COUNTY WATERS WITH 2-4 FT REMAINING COASTAL LEGS.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL PASS THROUGH THE AREA
TUESDAY NIGHT/WEDNESDAY MORNING...FOLLOWED BY ANOTHER COLD FRONT
WEDNESDAY NIGHT/THURSDAY MORNING. OFFSHORE WINDS WILL PREVAIL
THROUGH LATE WEEK. THE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN
LATE WEDNESDAY NIGHT INTO EARLY FRIDAY MORNING. SMALL CRAFT
ADVISORIES MAY BE NEEDED FOR WINDS GUSTS...ESPECIALLY FOR THE
OUTER GEORGIA WATERS. CONDITIONS IMPROVE ON FRIDAY AS THE GRADIENT
WEAKENS.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 021734
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
134 PM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION TODAY THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY ANOTHER COLD FRONT ON THURSDAY. HIGH PRESSURE
WILL THEN EXPAND INTO THE REGION OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE MADE A FEW MINOR ADJUSTMENTS TO RAISE MAX TEMPS ABOUT 1-2F IN
A COUPLE OF SPOTS. ALSO...WE/RE STARTING TO SEE A FEW SHOWERS
POPPING ALONG THE RESULTANT SEA BREEZE BOUNDARY NEAR OR JUST
INLAND FROM THE US-17 CORRIDOR IN SC. LOOK FOR ADDITIONAL POP-UPS
EARLY THIS AFTERNOON AS WE CONVECTIVE TEMPS ARE SURPASSED.

THE MEAN POSITION OF A POSITIVELY TILTED LARGE SCALE TROUGH COVERS
MUCH OF THE EASTERN HALF OF THE NATION...WITH AN ANTICYCLONE ALOFT
CENTERED NEAR CENTRAL AMERICA AND THE BAY OF CAMPECHE. SEVERAL
PERTURBATIONS WITHIN THE SW/WEST FLOW OVERHEAD WILL PASS BY WITHIN
AN ANOMALOUS MOIST ENVIRONMENT WHERE PWATS ARE CLOSE TO THE 90TH
PERCENTILE FOR THIS TIME OF YEAR.

THESE CONDITIONS WILL COMBINE WITH MODERATE TO HIGH INSTABILITY TO
PRODUCE ANOTHER ACTIVE CONVECTIVE AFTERNOON. MODIFIED SOUNDING
FROM KCHS IS INDICATING IMPRESSIVE THERMODYNAMICS...SUCH AS LIFTED
INDICES OF MINUS 7C AND SBCAPE OF 2275 J/KG. FAVORABLE LOW AND MID
LEVEL LAPSE RATES SHOULD SUPPORT FAIRLY VIGOROUS UPDRAFTS ONCE WE
ACHIEVE E OUR CONVECTIVE TEMP IN THE MID 80S DURING THE EARLY
AFTERNOON.

THE SEA BREEZE BOUNDARY GETS AN EARLY START WITH THE FLOW ALREADY
SOUTHERLY AND ACTIVITY WILL INITIATE ALONG THIS BOUNDARY FIRST
DURING THE EARLY AFTERNOON...AS WELL AS INLAND IN CLOSER PROXIMITY
TO A PIEDMONT TROUGH BY 2 PM. COVERAGE WILL THEN EXPAND DURING
THE MID AND LATE AFTERNOON HOURS AS MESOSCALE INTERACTIONS TAKE
PLACE. WE HAVE LIMITED COVERAGE TO SCATTERED AND NUMEROUS SHOWERS
AND T-STORMS...BUT THIS WILL LIKELY NEED ADJUSTMENTS ONCE TRENDS
BECOME MORE DEFINED. HIGHEST PROBABILITIES OVERALL LOOK TO BE NEAR
AND WEST OF I-95.

WHILE NO ORGANIZED SEVERE WEATHER WILL OCCUR WITH LITTLE
SHEAR...THE DCAPES GREATER THAN 1000 J/KG AND HAIL CAPES OF 700
J/KG SUPPORT A RISK FOR AT LEAST ISOLATED SEVERE STORMS WITH
DOWNBURSTS OF DAMAGING WIND AND 1 INCH HAIL.

THERE IS ALSO A RISK FOR AT LEAST LOCALLY HEAVY RAINS WITH THE
EXCESSIVE PWATS AND SLOW STORM MOVEMENT...ESPECIALLY IF BACK-
BUILDING AND TRAINING OF CELLS OCCURS. WE/LL KEEP A SHARP WATCH
FOR THE ORIENTATION OF CELLS IN AN ORIENTATION THAT IS SIMILAR TO
THE MEAN WEST/SW TO EAST/NE FLOW WHICH WOULD BE FAVORABLE FOR
FLOODING CONCERNS.

THE DIURNAL TEMP CURVE WILL NEED REFINEMENTS ONCE CONVECTIVE
COVERAGE INCREASES...BUT PRIOR TO THEN WE ANTICIPATE HIGHS MID AND
UPPER 80S MOST PLACES INLAND...MAYBE A FEW SPOTS TOUCHING 90 NEAR
THE ALTAMAHA RIVER. NEARBY OCEAN WATERS HAVE WARMED INTO THE LOWER
AND MIDDLE 70S...BUT STILL LOW ENOUGH TO KEEP MAX TEMPS AT THE
SHORE FROM GETTING ANY HIGHER THAN UPPER 70S AND LOWER 80S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING ACROSS
INLAND AREAS AT SUNSET. THERE REMAINS MUCH UNCERTAINTY HOW THE
CONVECTIVE PATTERN WILL EVOLVE OVERNIGHT WITH THE BULK OF UPPER
FORCING PROGGED TO BE DISPLACED ACROSS THE MIDLANDS AS SHORTWAVE
ENERGY PASSES TO THE NORTH WHILE INSTABILITY WANES. IN FACT..THERE
IS QUITE A BIT OF ANTICYCLONIC VORTICITY ADVECTION /AVA/ AND
SUBSIDENCE PROGGED TO OVERSPREAD MUCH OF THE FORECAST AREA AFTER
MIDNIGHT WITH AN AVA MAXIMUM SETTING UP NEAR AUGUSTA BY SUNRISE
TUESDAY. THIS WOULD SUGGEST LOW CHANCES FOR MEASURABLE RAINFALL
OVERNIGHT. HOWEVER...THE VARIOUS NAM/GFS/ECMWF MOS NUMBERS ALL
SHOW HIGH CHANCE TO LIKELY POPS FOR MUCH OF THE NIGHT WHICH IS
CURIOUS. IT COULD BE THAT THE MODELS ARE HAVING A HARD TIME
RESOLVING POSSIBLE LOW STRATUS DEVELOPMENT IN THE WARM/MOIST FLOW
AHEAD OF THE APPROACHING COLD FRONT...BUT THIS IS UNCLEAR. THE
LATEST SREF MEAN CERTAINLY DOES NOT SUPPORT MOS POP NUMBERS NEARLY
THAT HIGH...WHICH INCREASES THE UNCERTAINTY EVEN MORE. PLAN TO
TAPPER DOWN POPS INTO THE 20-30 PERCENT RANGE FROM LATE EVENING
ON...BUT THERE IS CERTAINLY A BIG BUST POTENTIAL HERE. LOWS WILL
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.

TUESDAY AND TUESDAY NIGHT...A TROUGH WILL BE OVER THE EAST COAST
WHILE SEVERAL SHORTWAVES ROUND THE BASE OF THE TROUGH...CROSSING
THROUGH THE REGION. MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION NEAR OUR AREA WILL COMBINE WITH PLENTY OF DEEP-LAYERED
MOISTURE IN PLACE...PWATS RANGING FROM 1.5-1.75 INCHES...TO GENERATE
SHOWERS AND THUNDERSTORMS. ADDITIONALLY...A COLD FRONT WILL BE
APPROACHING FROM THE WEST WHICH WILL INCREASE FORCING. THIS
FAVORABLE THERMODYNAMIC/KINEMATIC ENVIRONMENT WILL PRODUCE STRONG
THUNDERSTORMS. A FEW OF THESE STORMS COULD BECOME
SEVERE...ESPECIALLY IN THE AFTERNOON AND EVENING. DAMAGING
WINDS...LOCALLY HEAVY RAINFALL...AND HAIL WILL BE THE GREATEST
THREATS. THERE IS STILL SOME UNCERTAINTY WHERE THE BEST COVERAGE
WILL BE AS THIS WILL DEPEND ON THE ANTECEDENT/DEVELOPING MESOSCALE
ENVIRONMENT. ELEVATED POPS REMAIN IN FORECAST WITH THE HIGHEST POPS
INITIALLY ACROSS THE INLAND COUNTIES IN THE MORNING THEN EXPANDING
INTO MUCH OF THE AREA BY THE AFTERNOON. THE HEAVIEST PRECIPITATION
WILL SHIFT OFFSHORE IN THE EVENING. THE FRONT SHOULD CROSS THROUGH
THE AREA LATE TUESDAY NIGHT AND POPS WILL RAPIDLY DIMINISH FOLLOWING
ITS PASSAGE. HIGH TEMPERATURES WILL GENERALLY BE IN THE LOWER 80S.
THOUGH BREAKS IN THE CLOUDS COULD CAUSE THEM TO RISE MUCH HIGHER.
LOWS SHOULD BE IN THE 60S.

WEDNESDAY AND WEDNESDAY NIGHT...THE COLD FRONT SHOULD CROSS THROUGH
OUR AREA AROUND DAYBREAK. REMNANT SHOWERS AND THUNDERSTORMS...MAINLY
LIMITED TO THE COASTAL COUNTIES...WILL QUICKLY BE PUSHED OFFSHORE
WITH THE FRONT. THE REST OF THE MORNING INTO THE AFTERNOON WILL BE
DRY WITH CLEARING SKIES. DEW POINTS WILL FALL INTO THE 50S WHILE
HIGHS WILL BE IN THE UPPER 70S TO NEAR 80 DEGREES. ANOTHER COLD
FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. THIS FRONT IS
LACKING MOISTURE...SO AT MOST WE CAN EXPECT SOME CLOUDS...BUT NO
SHOWERS OR THUNDERSTORMS. LOWS WILL BE IN THE UPPER 50S TO NEAR 60
DEGREES.

THURSDAY...A TROUGH WILL REMAIN OVER THE EAST COAST. AT THE SURFACE
A STORM SYSTEM WILL BE SPREAD ACROSS THE NORTHEASTERN STATES WHILE
BROAD HIGH PRESSURE WILL BE SPREAD ACROSS THE CENTRAL PLAINS. THIS
SYNOPTIC FLOW WILL LEAD TO WEST WINDS AT THE SURFACE AND NORTHWEST
FLOW ALOFT. DESPITE PLENTY OF SUNSHINE...HIGHS WILL BE SEVERAL
DEGREES BELOW NORMAL...IN THE MID 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
MOST OF THE VALID 18Z TAF CYCLE WILL BE VFR.

SCATTERED SHRA/TSRA WILL LIKELY STAY JUST OUTSIDE THE KCHS
TERMINAL THIS AFTERNOON...BUT CLOSE ENOUGH WHERE WE HAVE ADDED
VCTS UNTIL MID AFTERNOON. A BETTER CHANCE EXISTS AT KSAV DURING
THE MID-LATE AFTERNOON...SHOWING A FEW HOURS OF PERIODIC MVFR
CONDITIONS IN TSRA.

CONVECTION WILL LIKELY FADE IN COVERAGE THIS EVENING...BUT WITH
THE APPROACH OF ENERGY ALOFT OVERNIGHT THERE CERTAINLY COULD BE A
RISK OF SHRA/TSRA AT KCHS AGAIN. BUT PROBABILITIES ARE TOO LOW TO
INCLUDE AT THIS TIME.

THERE IS LIKELY TOO MUCH WIND TONIGHT TO CAUSE ANY FOG
CONCERNS...BUT AREAS OF LOW STRATUS MAY OCCUR LATE TONIGHT INTO
THE MIDDLE OF TUESDAY MORNING.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

&&

.MARINE...
THIS AFTERNOON...THE WESTERN PORTION OF ATLANTIC HIGH PRESSURE
STRETCHES ACROSS THE LOCAL WATERS...CREATING A GENERAL SOUTH/SW
FLOW. SEA BREEZE CIRCULATIONS WILL ADD A FEW KNOTS OF WIND TO THE
CHARLESTON HARBOR AND NEAR THE COAST...BUT ON AVERAGE SPEEDS NO
GREATER THAN AROUND 15 KT. LOOK FOR A FEW SMALL SURGES TOWARD 20
KT NEAR THE MOUTH OF CHARLESTON HARBOR. SEAS WILL BE A MIX OF WIND
WAVES AND SWELLS...BUT NO HIGHER THAN 2-3 FT.

TONIGHT...NOCTURNAL SURGING WILL OCCUR AHEAD OF AN APPROACHING
COLD FRONT. WINDS LOOK TO MAX OUT AT 15-20 KT...HIGHEST ACROSS THE
GEORGIA OFFSHORE AND CHARLESTON COUNTY WATERS. FREQUENT GUSTS LOOK
TO REMAIN BELOW 25 KT FOR NOW...SO A SMALL CRAFT ADVISORY IS NOT
NEEDED ATTM. SEAS WILL BUILD 3-5 FT GEORGIA OFFSHORE AND
CHARLESTON COUNTY WATERS WITH 2-4 FT REMAINING COASTAL LEGS.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL PASS THROUGH THE AREA
TUESDAY NIGHT/WEDNESDAY MORNING...FOLLOWED BY ANOTHER COLD FRONT
WEDNESDAY NIGHT/THURSDAY MORNING. OFFSHORE WINDS WILL PREVAIL
THROUGH LATE WEEK. THE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN
LATE WEDNESDAY NIGHT INTO EARLY FRIDAY MORNING. SMALL CRAFT
ADVISORIES MAY BE NEEDED FOR WINDS GUSTS...ESPECIALLY FOR THE
OUTER GEORGIA WATERS. CONDITIONS IMPROVE ON FRIDAY AS THE GRADIENT
WEAKENS.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 021553
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1153 AM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION TODAY THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY ANOTHER COLD FRONT ON THURSDAY. HIGH PRESSURE
WILL THEN EXPAND INTO THE REGION OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WE MADE A FEW MINOR ADJUSTMENTS TO RAISE MAX TEMPS ABOUT 1-2F IN
A COUPLE OF SPOTS. ALSO...WE/RE STARTING TO SEE A FEW SHOWERS
POPPING ALONG THE RESULTANT SEA BREEZE BOUNDARY NEAR OR JUST
INLAND FROM THE US-17 CORRIDOR IN SC. LOOK FOR ADDITIONAL POP-UPS
EARLY THIS AFTERNOON AS WE CONVECTIVE TEMPS ARE SURPASSED.

THE MEAN POSITION OF A POSITIVELY TILTED LARGE SCALE TROUGH COVERS
MUCH OF THE EASTERN HALF OF THE NATION...WITH AN ANTICYCLONE ALOFT
CENTERED NEAR CENTRAL AMERICA AND THE BAY OF CAMPECHE. SEVERAL
PERTURBATIONS WITHIN THE SW/WEST FLOW OVERHEAD WILL PASS BY WITHIN
AN ANOMALOUS MOIST ENVIRONMENT WHERE PWATS ARE CLOSE TO THE 90TH
PERCENTILE FOR THIS TIME OF YEAR.

THESE CONDITIONS WILL COMBINE WITH MODERATE TO HIGH INSTABILITY TO
PRODUCE ANOTHER ACTIVE CONVECTIVE AFTERNOON. MODIFIED SOUNDING
FROM KCHS IS INDICATING IMPRESSIVE THERMODYNAMICS...SUCH AS LIFTED
INDICES OF MINUS 7C AND SBCAPE OF 2275 J/KG. FAVORABLE LOW AND MID
LEVEL LAPSE RATES SHOULD SUPPORT FAIRLY VIGOROUS UPDRAFTS ONCE WE
ACHIEVE E OUR CONVECTIVE TEMP IN THE MID 80S DURING THE EARLY
AFTERNOON.

THE SEA BREEZE BOUNDARY GETS AN EARLY START WITH THE FLOW ALREADY
SOUTHERLY AND ACTIVITY WILL INITIATE ALONG THIS BOUNDARY FIRST
DURING THE EARLY AFTERNOON...AS WELL AS INLAND IN CLOSER PROXIMITY
TO A PIEDMONT TROUGH BY 2 PM. COVERAGE WILL THEN EXPAND DURING
THE MID AND LATE AFTERNOON HOURS AS MESOSCALE INTERACTIONS TAKE
PLACE. WE HAVE LIMITED COVERAGE TO SCATTERED AND NUMEROUS SHOWERS
AND T-STORMS...BUT THIS WILL LIKELY NEED ADJUSTMENTS ONCE TRENDS
BECOME MORE DEFINED. HIGHEST PROBABILITIES OVERALL LOOK TO BE NEAR
AND WEST OF I-95.

WHILE NO ORGANIZED SEVERE WEATHER WILL OCCUR WITH LITTLE
SHEAR...THE DCAPES GREATER THAN 1000 J/KG AND HAIL CAPES OF 700
J/KG SUPPORT A RISK FOR AT LEAST ISOLATED SEVERE STORMS WITH
DOWNBURSTS OF DAMAGING WIND AND 1 INCH HAIL.

THERE IS ALSO A RISK FOR AT LEAST LOCALLY HEAVY RAINS WITH THE
EXCESSIVE PWATS AND SLOW STORM MOVEMENT...ESPECIALLY IF BACK-
BUILDING AND TRAINING OF CELLS OCCURS. WE/LL KEEP A SHARP WATCH
FOR THE ORIENTATION OF CELLS IN AN ORIENTATION THAT IS SIMILAR TO
THE MEAN WEST/SW TO EAST/NE FLOW WHICH WOULD BE FAVORABLE FOR
FLOODING CONCERNS.

THE DIURNAL TEMP CURVE WILL NEED REFINEMENTS ONCE CONVECTIVE
COVERAGE INCREASES...BUT PRIOR TO THEN WE ANTICIPATE HIGHS MID AND
UPPER 80S MOST PLACES INLAND...MAYBE A FEW SPOTS TOUCHING 90 NEAR
THE ALTAMAHA RIVER. NEARBY OCEAN WATERS HAVE WARMED INTO THE LOWER
AND MIDDLE 70S...BUT STILL LOW ENOUGH TO KEEP MAX TEMPS AT THE
SHORE FROM GETTING ANY HIGHER THAN UPPER 70S AND LOWER 80S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING ACROSS
INLAND AREAS AT SUNSET. THERE REMAINS MUCH UNCERTAINTY HOW THE
CONVECTIVE PATTERN WILL EVOLVE OVERNIGHT WITH THE BULK OF UPPER
FORCING PROGGED TO BE DISPLACED ACROSS THE MIDLANDS AS SHORTWAVE
ENERGY PASSES TO THE NORTH WHILE INSTABILITY WANES. IN FACT..THERE
IS QUITE A BIT OF ANTICYCLONIC VORTICITY ADVECTION /AVA/ AND
SUBSIDENCE PROGGED TO OVERSPREAD MUCH OF THE FORECAST AREA AFTER
MIDNIGHT WITH AN AVA MAXIMUM SETTING UP NEAR AUGUSTA BY SUNRISE
TUESDAY. THIS WOULD SUGGEST LOW CHANCES FOR MEASURABLE RAINFALL
OVERNIGHT. HOWEVER...THE VARIOUS NAM/GFS/ECMWF MOS NUMBERS ALL
SHOW HIGH CHANCE TO LIKELY POPS FOR MUCH OF THE NIGHT WHICH IS
CURIOUS. IT COULD BE THAT THE MODELS ARE HAVING A HARD TIME
RESOLVING POSSIBLE LOW STRATUS DEVELOPMENT IN THE WARM/MOIST FLOW
AHEAD OF THE APPROACHING COLD FRONT...BUT THIS IS UNCLEAR. THE
LATEST SREF MEAN CERTAINLY DOES NOT SUPPORT MOS POP NUMBERS NEARLY
THAT HIGH...WHICH INCREASES THE UNCERTAINTY EVEN MORE. PLAN TO
TAPPER DOWN POPS INTO THE 20-30 PERCENT RANGE FROM LATE EVENING
ON...BUT THERE IS CERTAINLY A BIG BUST POTENTIAL HERE. LOWS WILL
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.

TUESDAY AND TUESDAY NIGHT...A TROUGH WILL BE OVER THE EAST COAST
WHILE SEVERAL SHORTWAVES ROUND THE BASE OF THE TROUGH...CROSSING
THROUGH THE REGION. MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION NEAR OUR AREA WILL COMBINE WITH PLENTY OF DEEP-LAYERED
MOISTURE IN PLACE...PWATS RANGING FROM 1.5-1.75 INCHES...TO GENERATE
SHOWERS AND THUNDERSTORMS. ADDITIONALLY...A COLD FRONT WILL BE
APPROACHING FROM THE WEST WHICH WILL INCREASE FORCING. THIS
FAVORABLE THERMODYNAMIC/KINEMATIC ENVIRONMENT WILL PRODUCE STRONG
THUNDERSTORMS. A FEW OF THESE STORMS COULD BECOME
SEVERE...ESPECIALLY IN THE AFTERNOON AND EVENING. DAMAGING
WINDS...LOCALLY HEAVY RAINFALL...AND HAIL WILL BE THE GREATEST
THREATS. THERE IS STILL SOME UNCERTAINTY WHERE THE BEST COVERAGE
WILL BE AS THIS WILL DEPEND ON THE ANTECEDENT/DEVELOPING MESOSCALE
ENVIRONMENT. ELEVATED POPS REMAIN IN FORECAST WITH THE HIGHEST POPS
INITIALLY ACROSS THE INLAND COUNTIES IN THE MORNING THEN EXPANDING
INTO MUCH OF THE AREA BY THE AFTERNOON. THE HEAVIEST PRECIPITATION
WILL SHIFT OFFSHORE IN THE EVENING. THE FRONT SHOULD CROSS THROUGH
THE AREA LATE TUESDAY NIGHT AND POPS WILL RAPIDLY DIMINISH FOLLOWING
ITS PASSAGE. HIGH TEMPERATURES WILL GENERALLY BE IN THE LOWER 80S.
THOUGH BREAKS IN THE CLOUDS COULD CAUSE THEM TO RISE MUCH HIGHER.
LOWS SHOULD BE IN THE 60S.

WEDNESDAY AND WEDNESDAY NIGHT...THE COLD FRONT SHOULD CROSS THROUGH
OUR AREA AROUND DAYBREAK. REMNANT SHOWERS AND THUNDERSTORMS...MAINLY
LIMITED TO THE COASTAL COUNTIES...WILL QUICKLY BE PUSHED OFFSHORE
WITH THE FRONT. THE REST OF THE MORNING INTO THE AFTERNOON WILL BE
DRY WITH CLEARING SKIES. DEW POINTS WILL FALL INTO THE 50S WHILE
HIGHS WILL BE IN THE UPPER 70S TO NEAR 80 DEGREES. ANOTHER COLD
FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. THIS FRONT IS
LACKING MOISTURE...SO AT MOST WE CAN EXPECT SOME CLOUDS...BUT NO
SHOWERS OR THUNDERSTORMS. LOWS WILL BE IN THE UPPER 50S TO NEAR 60
DEGREES.

THURSDAY...A TROUGH WILL REMAIN OVER THE EAST COAST. AT THE SURFACE
A STORM SYSTEM WILL BE SPREAD ACROSS THE NORTHEASTERN STATES WHILE
BROAD HIGH PRESSURE WILL BE SPREAD ACROSS THE CENTRAL PLAINS. THIS
SYNOPTIC FLOW WILL LEAD TO WEST WINDS AT THE SURFACE AND NORTHWEST
FLOW ALOFT. DESPITE PLENTY OF SUNSHINE...HIGHS WILL BE SEVERAL
DEGREES BELOW NORMAL...IN THE MID 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
VFR. TSTM PROBABILITIES APPEAR GOOD AT KSAV SO A TEMPO GROUP FOR
MARGINAL MVFR VSBYS IN TSRA WILL BE INCLUDED FROM 20-23Z. TSTMS
LOOK TO REMAIN WEST OF KCHS TODAY...ALTHOUGH A SHRA OR TWO IS
STILL POSSIBLE EARLY THIS AFTERNOON.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

&&

.MARINE...
THIS AFTERNOON...THE WESTERN PORTION OF ATLANTIC HIGH PRESSURE
STRETCHES ACROSS THE LOCAL WATERS...CREATING A GENERAL SOUTH/SW
FLOW. SEA BREEZE CIRCULATIONS WILL ADD A FEW KNOTS OF WIND TO THE
CHARLESTON HARBOR AND NEAR THE COAST...BUT ON AVERAGE SPEEDS NO
GREATER THAN AROUND 15 KT. LOOK FOR A FEW SMALL SURGES TOWARD 20
KT NEAR THE MOUTH OF CHARLESTON HARBOR. SEAS WILL BE A MIX OF WIND
WAVES AND SWELLS...BUT NO HIGHER THAN 2-3 FT.

TONIGHT...NOCTURNAL SURGING WILL OCCUR AHEAD OF AN APPROACHING
COLD FRONT. WINDS LOOK TO MAX OUT AT 15-20 KT...HIGHEST ACROSS THE
GEORGIA OFFSHORE AND CHARLESTON COUNTY WATERS. FREQUENT GUSTS LOOK
TO REMAIN BELOW 25 KT FOR NOW...SO A SMALL CRAFT ADVISORY IS NOT
NEEDED ATTM. SEAS WILL BUILD 3-5 FT GEORGIA OFFSHORE AND
CHARLESTON COUNTY WATERS WITH 2-4 FT REMAINING COASTAL LEGS.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL PASS THROUGH THE AREA
TUESDAY NIGHT/WEDNESDAY MORNING...FOLLOWED BY ANOTHER COLD FRONT
WEDNESDAY NIGHT/THURSDAY MORNING. OFFSHORE WINDS WILL PREVAIL
THROUGH LATE WEEK. THE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN
LATE WEDNESDAY NIGHT INTO EARLY FRIDAY MORNING. SMALL CRAFT
ADVISORIES MAY BE NEEDED FOR WINDS GUSTS...ESPECIALLY FOR THE
OUTER GEORGIA WATERS. CONDITIONS IMPROVE ON FRIDAY AS THE GRADIENT
WEAKENS.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 021404
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
1004 AM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION TODAY THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY ANOTHER COLD FRONT ON THURSDAY. HIGH PRESSURE
WILL THEN EXPAND INTO THE REGION OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE MEAN POSITION OF A POSITIVELY TILTED LARGE SCALE TROUGH COVERS
MUCH OF THE EASTERN HALF OF THE NATION...WITH AN ANTICYCLONE ALOFT
CENTERED NEAR CENTRAL AMERICA AND THE BAY OF CAMPECHE. SEVERAL
PERTURBATIONS WITHIN THE SW/WEST FLOW OVERHEAD WILL PASS BY WITHIN
AN ANOMALOUS MOIST ENVIRONMENT WHERE PWATS ARE CLOSE TO THE 90TH
PERCENTILE FOR THIS TIME OF YEAR.

THESE CONDITIONS WILL COMBINE WITH MODERATE TO HIGH INSTABILITY TO
PRODUCE ANOTHER ACTIVE CONVECTIVE AFTERNOON. MODIFIED SOUNDING
FROM KCHS IS INDICATING IMPRESSIVE THERMODYNAMICS...SUCH AS LIFTED
INDICES OF MINUS 7C AND SBCAPE OF 2275 J/KG. FAVORABLE LOW AND MID
LEVEL LAPSE RATES SHOULD SUPPORT FAIRLY VIGOROUS UPDRAFTS ONCE WE
ACHIEVE E OUR CONVECTIVE TEMP IN THE MID 80S DURING THE EARLY
AFTERNOON.

THE SEA BREEZE BOUNDARY GETS AN EARLY START WITH THE FLOW ALREADY
SOUTHERLY AND ACTIVITY WILL INITIATE ALONG THIS BOUNDARY FIRST
AROUND 1-2 PM...AS WELL AS INLAND IN CLOSER PROXIMITY TO A
PIEDMONT TROUGH. COVERAGE WILL THEN EXPAND DURING THE MID AND LATE
AFTERNOON HOURS AS MESOSCALE INTERACTIONS TAKE PLACE. WE HAVE
LIMITED COVERAGE TO SCATTERED AND NUMEROUS SHOWERS AND
T-STORMS...BUT THIS WILL LIKELY NEED ADJUSTMENTS ONCE TRENDS
BECOME MORE DEFINED. HIGHEST PROBABILITIES OVERALL LOOK TO BE
NEAR AND WEST OF I-95.

WHILE NO ORGANIZED SEVERE WEATHER WILL OCCUR WITH LITTLE
SHEAR...THE DCAPES GREATER THAN 1000 J/KG AND HAIL CAPES OF 700
J/KG SUPPORT A RISK FOR AT LEAST ISOLATED SEVERE STORMS WITH
DOWNBURSTS OF DAMAGING WIND AND 1 INCH HAIL.

THERE IS ALSO A RISK FOR AT LEAST LOCALLY HEAVY RAINS WITH THE
EXCESSIVE PWATS AND SLOW STORM MOVEMENT...ESPECIALLY IF BACK-
BUILDING AND TRAINING OF CELLS OCCURS. WE/LL KEEP A SHARP WATCH
FOR THE ORIENTATION OF CELLS IN AN ORIENTATION THAT IS SIMILAR TO
THE MEAN WEST/SW TO EAST/NE FLOW WHICH WOULD BE FAVORABLE FOR
FLOODING CONCERNS.

THE DIURNAL TEMP CURVE WILL NEED REFINEMENTS ONCE CONVECTIVE
COVERAGE INCREASES...BUT PRIOR TO THEN WE ANTICIPATE HIGHS MID AND
UPPER 80S MOST PLACES INLAND...MAYBE A FEW SPOTS TOUCHING 90 NEAR
THE ALTAMAHA RIVER. NEARBY OCEAN WATERS HAVE WARMED INTO THE LOWER
AND MIDDLE 70S...BUT STILL LOW ENOUGH TO KEEP MAX TEMPS AT THE
SHORE FROM GETTING ANY HIGHER THAN UPPER 70S AND LOWER 80S.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING ACROSS
INLAND AREAS AT SUNSET. THERE REMAINS MUCH UNCERTAINTY HOW THE
CONVECTIVE PATTERN WILL EVOLVE OVERNIGHT WITH THE BULK OF UPPER
FORCING PROGGED TO BE DISPLACED ACROSS THE MIDLANDS AS SHORTWAVE
ENERGY PASSES TO THE NORTH WHILE INSTABILITY WANES. IN FACT..THERE
IS QUITE A BIT OF ANTICYCLONIC VORTICITY ADVECTION /AVA/ AND
SUBSIDENCE PROGGED TO OVERSPREAD MUCH OF THE FORECAST AREA AFTER
MIDNIGHT WITH AN AVA MAXIMUM SETTING UP NEAR AUGUSTA BY SUNRISE
TUESDAY. THIS WOULD SUGGEST LOW CHANCES FOR MEASURABLE RAINFALL
OVERNIGHT. HOWEVER...THE VARIOUS NAM/GFS/ECMWF MOS NUMBERS ALL
SHOW HIGH CHANCE TO LIKELY POPS FOR MUCH OF THE NIGHT WHICH IS
CURIOUS. IT COULD BE THAT THE MODELS ARE HAVING A HARD TIME
RESOLVING POSSIBLE LOW STRATUS DEVELOPMENT IN THE WARM/MOIST FLOW
AHEAD OF THE APPROACHING COLD FRONT...BUT THIS IS UNCLEAR. THE
LATEST SREF MEAN CERTAINLY DOES NOT SUPPORT MOS POP NUMBERS NEARLY
THAT HIGH...WHICH INCREASES THE UNCERTAINTY EVEN MORE. PLAN TO
TAPPER DOWN POPS INTO THE 20-30 PERCENT RANGE FROM LATE EVENING
ON...BUT THERE IS CERTAINLY A BIG BUST POTENTIAL HERE. LOWS WILL
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.

TUESDAY AND TUESDAY NIGHT...A TROUGH WILL BE OVER THE EAST COAST
WHILE SEVERAL SHORTWAVES ROUND THE BASE OF THE TROUGH...CROSSING
THROUGH THE REGION. MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION NEAR OUR AREA WILL COMBINE WITH PLENTY OF DEEP-LAYERED
MOISTURE IN PLACE...PWATS RANGING FROM 1.5-1.75 INCHES...TO GENERATE
SHOWERS AND THUNDERSTORMS. ADDITIONALLY...A COLD FRONT WILL BE
APPROACHING FROM THE WEST WHICH WILL INCREASE FORCING. THIS
FAVORABLE THERMODYNAMIC/KINEMATIC ENVIRONMENT WILL PRODUCE STRONG
THUNDERSTORMS. A FEW OF THESE STORMS COULD BECOME
SEVERE...ESPECIALLY IN THE AFTERNOON AND EVENING. DAMAGING
WINDS...LOCALLY HEAVY RAINFALL...AND HAIL WILL BE THE GREATEST
THREATS. THERE IS STILL SOME UNCERTAINTY WHERE THE BEST COVERAGE
WILL BE AS THIS WILL DEPEND ON THE ANTECEDENT/DEVELOPING MESOSCALE
ENVIRONMENT. ELEVATED POPS REMAIN IN FORECAST WITH THE HIGHEST POPS
INITIALLY ACROSS THE INLAND COUNTIES IN THE MORNING THEN EXPANDING
INTO MUCH OF THE AREA BY THE AFTERNOON. THE HEAVIEST PRECIPITATION
WILL SHIFT OFFSHORE IN THE EVENING. THE FRONT SHOULD CROSS THROUGH
THE AREA LATE TUESDAY NIGHT AND POPS WILL RAPIDLY DIMINISH FOLLOWING
ITS PASSAGE. HIGH TEMPERATURES WILL GENERALLY BE IN THE LOWER 80S.
THOUGH BREAKS IN THE CLOUDS COULD CAUSE THEM TO RISE MUCH HIGHER.
LOWS SHOULD BE IN THE 60S.

WEDNESDAY AND WEDNESDAY NIGHT...THE COLD FRONT SHOULD CROSS THROUGH
OUR AREA AROUND DAYBREAK. REMNANT SHOWERS AND THUNDERSTORMS...MAINLY
LIMITED TO THE COASTAL COUNTIES...WILL QUICKLY BE PUSHED OFFSHORE
WITH THE FRONT. THE REST OF THE MORNING INTO THE AFTERNOON WILL BE
DRY WITH CLEARING SKIES. DEW POINTS WILL FALL INTO THE 50S WHILE
HIGHS WILL BE IN THE UPPER 70S TO NEAR 80 DEGREES. ANOTHER COLD
FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. THIS FRONT IS
LACKING MOISTURE...SO AT MOST WE CAN EXPECT SOME CLOUDS...BUT NO
SHOWERS OR THUNDERSTORMS. LOWS WILL BE IN THE UPPER 50S TO NEAR 60
DEGREES.

THURSDAY...A TROUGH WILL REMAIN OVER THE EAST COAST. AT THE SURFACE
A STORM SYSTEM WILL BE SPREAD ACROSS THE NORTHEASTERN STATES WHILE
BROAD HIGH PRESSURE WILL BE SPREAD ACROSS THE CENTRAL PLAINS. THIS
SYNOPTIC FLOW WILL LEAD TO WEST WINDS AT THE SURFACE AND NORTHWEST
FLOW ALOFT. DESPITE PLENTY OF SUNSHINE...HIGHS WILL BE SEVERAL
DEGREES BELOW NORMAL...IN THE MID 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR. TSTM PROBABILITIES APPEAR TO BE INCREASING FOR KSAV SO A
TEMPO GROUP FOR MARGINAL MVFR VSBYS IN TSRA WILL BE INCLUDED FROM
20-23Z. TSTMS LOOK TO REMAIN WEST OF KCHS TODAY.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

&&

.MARINE...
TODAY...THE WESTERN PORTION OF ATLANTIC HIGH PRESSURE STRETCHES
ACROSS THE LOCAL WATERS...CREATING A GENERAL SOUTH/SW FLOW. SEA
BREEZE CIRCULATIONS WILL ADD A FEW KNOTS OF WIND TO THE CHARLESTON
HARBOR AND NEAR THE COAST...BUT ON AVERAGE SPEEDS NO GREATER THAN
AROUND 15 KT. MAYBE A FEW SMALL SURGES TOWARD 20 KT NEAR THE MOUTH
OF CHARLESTON HARBOR. SEAS WILL BE A MIX OF WIND WAVES AND
SWELLS...BUT NO HIGHER THAN 2-3 FT.

TONIGHT...NOCTURNAL SURGING WILL OCCUR AHEAD OF AN APPROACHING
COLD FRONT. WINDS LOOK TO MAX OUT AT 15-20 KT...HIGHEST ACROSS THE
GEORGIA OFFSHORE AND CHARLESTON COUNTY WATERS. FREQUENT GUSTS LOOK
TO REMAIN BELOW 25 KT FOR NOW...SO A SMALL CRAFT ADVISORY IS NOT
NEEDED ATTM. SEAS WILL BUILD 3-5 FT GEORGIA OFFSHORE AND
CHARLESTON COUNTY WATERS WITH 2-4 FT REMAINING COASTAL LEGS.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL PASS THROUGH THE AREA
TUESDAY NIGHT/WEDNESDAY MORNING...FOLLOWED BY ANOTHER COLD FRONT
WEDNESDAY NIGHT/THURSDAY MORNING. OFFSHORE WINDS WILL PREVAIL
THROUGH LATE WEEK. THE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN
LATE WEDNESDAY NIGHT INTO EARLY FRIDAY MORNING. SMALL CRAFT
ADVISORIES MAY BE NEEDED FOR WINDS GUSTS...ESPECIALLY FOR THE
OUTER GEORGIA WATERS. CONDITIONS IMPROVE ON FRIDAY AS THE GRADIENT
WEAKENS.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
EQUIPMENT...





000
FXUS62 KCHS 021041
AFDCHS

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHARLESTON SC
641 AM EDT MON MAY 2 2016

.SYNOPSIS...
SEVERAL AREAS OF LOW PRESSURE WILL GRADUALLY PUSH A COLD FRONT
TOWARD THE REGION TODAY THROUGH TUESDAY...PRODUCING UNSETTLED
CONDITIONS. THE COLD FRONT WILL PASS THROUGH THE REGION TUESDAY
NIGHT...FOLLOWED BY ANOTHER COLD FRONT ON THURSDAY. HIGH PRESSURE
WILL THEN EXPAND INTO THE REGION OVER THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LOOKS LIKE A BIT MORE SUN WILL OCCUR THIS MORNING THAN WHAT WAS
EXPECTED EARLIER. HAVE RAISED HIGHS ABOUT 1-2 DEGREES FROM THE
PREVIOUS FORECAST FOR MOST AREAS.

TODAY...ANOTHER CONVECTIVELY ACTIVE AFTERNOON IS EXPECTED ACROSS
MUCH OF SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA AS SOUTHERN
STREAM SHORTWAVE ENERGY APPROACHES FROM THE WEST. MODEST
INSTABILITY...DEEP MOISTURE AND INCREASING FORCING INDUCED BY
DIFFERENTIAL CYCLONIC VORTICITY ADVECTION WILL SUPPORT ANOTHER
ROUND OF SCATTERED TO NUMEROUS SHOWERS AND TSTMS. MOST OF THE HIGH
RESOLUTION MODELS ARE KEYING IN INTERIOR SOUTHEAST GEORGIA FOR THE
GREATEST COVERAGE OF CONVECTION DURING THE MID-LATE AFTERNOON AS
THIS REGION APPEARS TO HAVE THE BEST JUXTAPOSITION OF LOW-LEVEL
CONVERGENCE AND SURFACE BASED INSTABILITY. CONVECTION WILL BE
FURTHER ENHANCED BY INCREASING DIFLUENCE ALOFT INDUCED BY
DIVERGING BRANCHES OF THE POLAR AND SUBTROPICAL JET STREAMS.

ACCURATELY PINNING DOWN THE CONVECTIVE PATTERN THIS FAR OUT IS
EXTREMELY DIFFICULT DUE TO LIKELY MESOSCALE INTERACTIONS...THUS
POPS ACROSS THE INTERIOR WILL BE CAPPED AT 50-60 PERCENT FOR NOW.
HIGHER POPS WILL LIKELY BE NEEDED AT SOME POINT...BUT FURTHER
EVALUATION OF THE MESOSCALE ENVIRONMENT WILL BE NEEDED LATER THIS
MORNING. HIGHS WILL SIMILAR TO SUNDAY...RANGING FROM THE MID 70S
AT THE BEACHES TO THE UPPER 80S ACROSS INTERIOR SOUTHEAST GEORGIA.
ONCE AGAIN...A FEW INSTANCES OF 90 DEGREES CAN NOT BE RULED OUT
ACROSS INTERIOR SOUTHEAST GEORGIA...ESPECIALLY SOUTH OF THE I-16
CORRIDOR.

NO ORGANIZED SEVERE WEATHER IS EXPECTED THIS AFTERNOON IN THE
ABSENCE OF ANY MEANINGFUL SHEAR...HOWEVER DCAPES NEAR 1200 J/KG
COUPLED WITH MODEST HCAPE WITHIN THE -10 TO -30C LAYER WILL
SUPPORT A RISK FOR ISOLATED SEVERE TSTMS...ESPECIALLY WHERE
UPDRAFTS ARE AUGMENTED BY MESOSCALE BOUNDARY COLLISIONS. THE
PRIMARY HAZARDS WILL BE DAMAGING WINDS...MARGINALLY SEVERE HAIL
AND LOCALLY HEAVY RAINFALL.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...NUMEROUS SHOWERS/TSTMS WILL LIKELY BE ONGOING ACROSS
INLAND AREAS AT SUNSET. THERE REMAINS MUCH UNCERTAINTY HOW THE
CONVECTIVE PATTERN WILL EVOLVE OVERNIGHT WITH THE BULK OF UPPER
FORCING PROGGED TO BE DISPLACED ACROSS THE MIDLANDS AS SHORTWAVE
ENERGY PASSES TO THE NORTH WHILE INSTABILITY WANES. IN FACT..THERE
IS QUITE A BIT OF ANTICYCLONIC VORTICITY ADVECTION /AVA/ AND
SUBSIDENCE PROGGED TO OVERSPREAD MUCH OF THE FORECAST AREA AFTER
MIDNIGHT WITH AN AVA MAXIMUM SETTING UP NEAR AUGUSTA BY SUNRISE
TUESDAY. THIS WOULD SUGGEST LOW CHANCES FOR MEASURABLE RAINFALL
OVERNIGHT. HOWEVER...THE VARIOUS NAM/GFS/ECMWF MOS NUMBERS ALL
SHOW HIGH CHANCE TO LIKELY POPS FOR MUCH OF THE NIGHT WHICH IS
CURIOUS. IT COULD BE THAT THE MODELS ARE HAVING A HARD TIME
RESOLVING POSSIBLE LOW STRATUS DEVELOPMENT IN THE WARM/MOIST FLOW
AHEAD OF THE APPROACHING COLD FRONT...BUT THIS IS UNCLEAR. THE
LATEST SREF MEAN CERTAINLY DOES NOT SUPPORT MOS POP NUMBERS NEARLY
THAT HIGH...WHICH INCREASES THE UNCERTAINTY EVEN MORE. PLAN TO
TAPPER DOWN POPS INTO THE 20-30 PERCENT RANGE FROM LATE EVENING
ON...BUT THERE IS CERTAINLY A BIG BUST POTENTIAL HERE. LOWS WILL
RANGE FROM THE UPPER 60S INLAND TO THE LOWER 70S AT THE COAST.

TUESDAY AND TUESDAY NIGHT...A TROUGH WILL BE OVER THE EAST COAST
WHILE SEVERAL SHORTWAVES ROUND THE BASE OF THE TROUGH...CROSSING
THROUGH THE REGION. MESOSCALE BOUNDARIES CREATED BY EARLIER/ONGOING
CONVECTION NEAR OUR AREA WILL COMBINE WITH PLENTY OF DEEP-LAYERED
MOISTURE IN PLACE...PWATS RANGING FROM 1.5-1.75 INCHES...TO GENERATE
SHOWERS AND THUNDERSTORMS. ADDITIONALLY...A COLD FRONT WILL BE
APPROACHING FROM THE WEST WHICH WILL INCREASE FORCING. THIS
FAVORABLE THERMODYNAMIC/KINEMATIC ENVIRONMENT WILL PRODUCE STRONG
THUNDERSTORMS. A FEW OF THESE STORMS COULD BECOME
SEVERE...ESPECIALLY IN THE AFTERNOON AND EVENING. DAMAGING
WINDS...LOCALLY HEAVY RAINFALL...AND HAIL WILL BE THE GREATEST
THREATS. THERE IS STILL SOME UNCERTAINTY WHERE THE BEST COVERAGE
WILL BE AS THIS WILL DEPEND ON THE ANTECEDENT/DEVELOPING MESOSCALE
ENVIRONMENT. ELEVATED POPS REMAIN IN FORECAST WITH THE HIGHEST POPS
INITIALLY ACROSS THE INLAND COUNTIES IN THE MORNING THEN EXPANDING
INTO MUCH OF THE AREA BY THE AFTERNOON. THE HEAVIEST PRECIPITATION
WILL SHIFT OFFSHORE IN THE EVENING. THE FRONT SHOULD CROSS THROUGH
THE AREA LATE TUESDAY NIGHT AND POPS WILL RAPIDLY DIMINISH FOLLOWING
ITS PASSAGE. HIGH TEMPERATURES WILL GENERALLY BE IN THE LOWER 80S.
THOUGH BREAKS IN THE CLOUDS COULD CAUSE THEM TO RISE MUCH HIGHER.
LOWS SHOULD BE IN THE 60S.

WEDNESDAY AND WEDNESDAY NIGHT...THE COLD FRONT SHOULD CROSS THROUGH
OUR AREA AROUND DAYBREAK. REMNANT SHOWERS AND THUNDERSTORMS...MAINLY
LIMITED TO THE COASTAL COUNTIES...WILL QUICKLY BE PUSHED OFFSHORE
WITH THE FRONT. THE REST OF THE MORNING INTO THE AFTERNOON WILL BE
DRY WITH CLEARING SKIES. DEW POINTS WILL FALL INTO THE 50S WHILE
HIGHS WILL BE IN THE UPPER 70S TO NEAR 80 DEGREES. ANOTHER COLD
FRONT WILL PUSH THROUGH THE AREA WEDNESDAY NIGHT. THIS FRONT IS
LACKING MOISTURE...SO AT MOST WE CAN EXPECT SOME CLOUDS...BUT NO
SHOWERS OR THUNDERSTORMS. LOWS WILL BE IN THE UPPER 50S TO NEAR 60
DEGREES.

THURSDAY...A TROUGH WILL REMAIN OVER THE EAST COAST. AT THE SURFACE
A STORM SYSTEM WILL BE SPREAD ACROSS THE NORTHEASTERN STATES WHILE
BROAD HIGH PRESSURE WILL BE SPREAD ACROSS THE CENTRAL PLAINS. THIS
SYNOPTIC FLOW WILL LEAD TO WEST WINDS AT THE SURFACE AND NORTHWEST
FLOW ALOFT. DESPITE PLENTY OF SUNSHINE...HIGHS WILL BE SEVERAL
DEGREES BELOW NORMAL...IN THE MID 70S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MODELS ARE IN GOOD AGREEMENT SHIFTING THE TROUGH AXIS FROM OVER THE
EAST COAST THURSDAY NIGHT TO FAR OFFSHORE BY SUNDAY.
REPLACING THE TROUGH WILL BE A BUILDING RIDGE...ORIGINATING FROM THE
CENTRAL U.S. EXPECT DRY CONDITIONS THROUGH THIS PERIOD WITH
TEMPERATURES TRENDING UPWARD EACH DAY.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR. TSTM PROBABILITIES APPEAR TO BE INCREASING FOR KSAV SO A
TEMPO GROUP FOR MARGINAL MVFR VSBYS IN TSRA WILL BE INCLUDED FROM
20-23Z. TSTMS LOOK TO REMAIN WEST OF KCHS TODAY.

EXTENDED AVIATION OUTLOOK...PERIODIC FLIGHT RESTRICTIONS WITHIN
SCATTERED SHOWERS/THUNDERSTORMS MONDAY NIGHT THROUGH TUESDAY
NIGHT.

&&

.MARINE...
TODAY...A SOUTHERLY WIND REGIME WILL HOLD FIRM WITH WINDS 10-15
KT WITH SEAS 2-4 FT.

TONIGHT...NOCTURNAL SURGING WILL OCCUR AHEAD OF AN APPROACHING
COLD FRONT. WINDS LOOK TO MAX OUT AT 15-20 KT...HIGHEST ACROSS THE
GEORGIA OFFSHORE AND CHARLESTON COUNTY WATERS. FREQUENT GUSTS LOOK
TO REMAIN BELOW 25 KT FOR NOW...SO A SMALL CRAFT ADVISORY IS NOT
NEEDED ATTM. SEAS WILL BUILD 3-5 FT GEORGIA OFFSHORE AND
CHARLESTON COUNTY WATERS WITH 2-4 FT REMAINING COASTAL LEGS.

TUESDAY THROUGH FRIDAY...A COLD FRONT WILL PASS THROUGH THE AREA
TUESDAY NIGHT/WEDNESDAY MORNING...FOLLOWED BY ANOTHER COLD FRONT
WEDNESDAY NIGHT/THURSDAY MORNING. OFFSHORE WINDS WILL PREVAIL
THROUGH LATE WEEK. THE PRESSURE GRADIENT IS EXPECTED TO STRENGTHEN
LATE WEDNESDAY NIGHT INTO EARLY FRIDAY MORNING. SMALL CRAFT
ADVISORIES MAY BE NEEDED FOR WINDS GUSTS...ESPECIALLY FOR THE
OUTER GEORGIA WATERS. CONDITIONS IMPROVE ON FRIDAY AS THE GRADIENT
WEAKENS.

&&

.EQUIPMENT...
THE CHARLESTON HARBOR NOS TIDE GAUGE HAS STOPPED REPORTING ALL
METEOROLOGICAL AND TIDE DATA. THE NATIONAL OCEAN SERVICE IS
INVESTIGATING THE CAUSE OF THE OUTAGE. AN ESTIMATED TIME FOR DATA
RESTORATION IS UNKNOWN AT THIS TIME.

&&

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

&&

$$

ST/MS





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