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064
FXUS62 KILM 191150
AFDILM

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WILMINGTON NC
750 AM EDT SAT APR 19 2014

.SYNOPSIS...
WET WEATHER ASSOCIATED WITH AN OFFSHORE STORM SYSTEM WILL LAST
THROUGH TONIGHT AND EVEN THROUGH SUNDAY ALONG THE COAST. THE NEXT
CHANCE FOR RAIN WILL COME TUESDAY WITH A WEAK COLD FRONT. WARMING
TEMPERATURES ARE EXPECTED FOR THE LATTER PART OF NEXT WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM SATURDAY...THE STEADIEST RAIN WILL CONTINUE TO PIVOT N
AND E AND AWAY FROM THE AREA THIS MORNING. A DRY SLOT HAS WORKED ITS
WAY UP THROUGH SOUTH CAROLINA AND THE I-95 CORRIDOR IN NORTH
CAROLINA AT SUNRISE. A SIGNIFICANT LULL IN THE PRECIPITATION IS
EXPECTED AND THIS IS CONSISTENT WITH SOME OF THE MORE RESPECTED
HIGHER RESOLUTION MODELS. THESE SAME MODELS ARE SHOWING
PRECIPITATION REDEVELOPING THIS AFTERNOON...BUT THE COVERAGE SHOULD
BE MORE SCATTERED. ALTHOUGH THE BULK OF THE MEASURABLE RAIN HAS
ALREADY OCCURRED...THE POTENTIAL FOR ADDITIONAL RAINFALL AMOUNTS OF
ONE-HALF TO ONE-INCH DOES EXIST INTO SUN.

PRECIPITABLE WATER VALUES WILL BE NEAR 1.5 INCHES FOR MOST OF THE
PERIOD...DROPPING SLIGHTLY FROM W TO E LATE TONIGHT AND SUN MORNING.
INTO THIS AFTERNOON...A SHALLOW E AND SE FLOW WILL BE TOPPED BY A
MOIST AND DEEP S TO SW FLOW WITH SPEEDS INCREASING WITH HEIGHT AND
THIS WILL ALLOW STRONG ISENTROPIC LIFT TO PERSIST. LATER IN THE DAY
AND TONIGHT...THE DEPTH OF EASTERLY WINDS INCREASES SUBSTANTIALLY.

LOW PRESSURE AT THE SURFACE IS TRAPPED BY AN UPPER LEVEL LOW. AS IS
TYPICAL IN THESE SITUATIONS...ANY MOVEMENT OF THE SYSTEM WILL BE
SLOW. LOW PRESSURE ACROSS N FLORIDA TODAY WILL MOVE ENE AND OFF THE
EAST COAST OF FLORIDA AND GEORGIA TONIGHT. A VERY PRONOUNCED COASTAL
TROUGH WILL EXTEND FROM THE LOW CENTER AND ACROSS THE OFFSHORE
WATERS OF THE CAROLINAS. SATELLITE AND RADAR TRENDS SHOW THE MOIST
CONVEYOR BELT TRENDING UP THE SOUTHEAST COAST AT THIS TIME. ALTHOUGH
THE RAIN MAY FALL HEAVILY AT TIMES...IT WILL BE THE PERSISTENT
NATURE OF THE PRECIPITATION THAT WILL RESULT IN TOTAL RAINFALL
AMOUNTS NEAR 2 INCHES WITH SOME LOCATIONS RECEIVING MORE THAN 3
INCHES. THIS MAY BE ENOUGH RAINFALL TO CAUSE SOME LOCALIZED PONDING
OF WATER IN LOW-LYING AND POOR DRAINAGE AREAS. WE WILL ALSO HAVE TO
WATCH FOR THE DRY SLOT WHICH WILL ROTATE INTO THE FORECAST AREA
BEFORE STALLING AND REORIENTING. THUS...IT WILL LIKELY NOT RAIN ALL
DAY IN MOST AREAS. WHERE RAIN DOES END FOR A TIME...IT WILL LIKELY
RETURN. WILL FORECAST 100 POPS THIS MORNING WITH POPS TRENDING LOWER
LATER THIS MORNING AND THIS AFTERNOON...BUT STILL A LIKELIHOOD OF
RAINFALL. WILL CONTINUE THE DOWNWARD TREND TONIGHT...DROPPING TO
CHANCE...ESPECIALLY LATE AND DURING SUN MORNING. WILL KEEP
THUNDERSTORMS OFF THE COAST...ON THE S AND E SIDE OF THE COASTAL
TROUGH.

IN ADDITION TO THE RAINFALL...WE WILL HAVE TO CONTEND WITH STIFF AND
PERSISTENT NE WINDS. THESE WINDS SHOULD ONLY INCREASE TONIGHT AND
SUN AS THE PRESSURE GRADIENT REALLY TIGHTENS UP BETWEEN OFFSHORE LOW
PRESSURE AND STRONG HIGH PRESSURE TO THE N. EXPECT WIND GUSTS AS
HIGH AS 35 TO 40 MPH AT THE COAST AND 30 TO 35 MPH FOR INLAND
LOCATIONS. THE STRONGEST WINDS WILL OCCUR AT THE BEACHES. THE STRONG
AND PERSISTENT WINDS MAY RESULT IN SOME BEACH EROSION...MAINLY IN
AREAS EXPOSED TO NE WINDS. THE RISK WILL BE HIGHEST DURING EACH HIGH
TIDE CYCLE. HIGH TIDE IS AT 11 AM AND NEAR MIDNIGHT.

MOISTURE PROFILES AND MODEL SOUNDINGS INDICATE WE WILL NOT BE ABLE
TO SHRUG OFF THE THICK CLOUDS...EVEN IF THE RAIN SHOULD CUT-OFF IN
ANY GIVEN LOCATION FOR A PERIOD OF TIME. THE COOL NE WINDS AND
CLOUDS SHOULD ONLY ALLOW TEMPS TO RISE TO THE UPPER 50S AND LOWER
60S FOR MOST OF US. TEMPS MAY NOT RISE ABOVE THE MID 50S WEST OF
INTERSTATE 95. PORTIONS OF THE THE SOUTHERN GRAND STRAND AND SOUTH
SANTEE RIVER AREA MAY EEK OUT MID 60S. NOT A SIGNIFICANT TEMP CHANGE
TONIGHT. TEMPS WILL BE COOLEST WELL INLAND...UPPER 40S. NEARER TO
THE COAST...LOWER TO MID 50S WILL BE MORE COMMON.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...MOISTURE FROM THE NEAR TERM STORM SYSTEM TO
LINGER INTO SUNDAY.  THE MAIN FORECAST ISSUE THEN IS HOW FAR INLAND
RAIN MANAGES TO SPREAD AND WHAT THE AMOUNTS END UP LOOKING LIKE.
THIS SYSTEM WILL ALSO BRING VERY BREEZY CONDITIONS TO THE COAST THAT
MAY APPROACH WIND ADVISORY LEVELS ESPECIALLY IF SSTS DO NOT INHIBIT
VERTICAL MIXING IN THE STRONG ONSHORE JETTING. BL FLOW BACKS SUNDAY
NIGHT ALLOWING FOR LESS OF AN INLAND PUSH OF MOISTURE. SOME LOW RAIN
CHANCES MAY PERSIST ALONG THE IMMEDIATE COAST BUT THATS ABOUT IT. MONDAY
BRINGS MID LEVEL RIDGING/DRYING. THE LOW LEVEL MOISTURE MAY BE SLOW
TO ERODE FROM THE EASTERN ZONES HOWEVER ESPECIALLY IF THE INVERSION
SHOWN IN GFS MODEL SOUNDINGS DEVELOPS TO HELP TRAP IT. THIS FEATURE
DOES NOT APPEAR IN WRF MODEL SOUNDINGS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...COLD FRONT APPROACHES ON TUESDAY BRINGING
SOME LOW RAIN CHANCES ON ACCOUNT OF LIMITED PREFRONTAL MOISTURE
FLUX. HEIGHT RISES ARE QUICK TO FOLLOW THE BOUNDARY OFFSETTING ANY
LOW LEVEL COOL ADVECTION...WHICH THERE DOESNT SEEM TO BE MUCH OF
ANYWAY. LATE WEEK TEMPS TO STAY ON THE WARM SIDE OF CLIMO AS MID
LEVEL RIDGE BUILDS AND SURFACE HIGH ONLY VERY SLOWLY MIGRATES
EASTWARD.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...THE HEAVIEST RAINS ARE NOW OVER KILM AND SHIFTING TO
THE N-NE. IN THE WAKE OF THIS AREA FLIGHT CONDITIONS IMPROVED
TEMPORARILY TO VFR. BUT GENERALLY FLIGHT CONDITIONS WILL BE IFR.
VFR/MVFR VSBYS WITH TEMPO IFR VSBYS IN -RA DZ/BR WILL BE POSSIBLE
THROUGH MID-LATE MORNING.

BECAUSE OF SATURATION OF THE LOW LEVELS AND FORECAST SOUNDINGS
INDICATING AN INVERSION AROUND 1K...THERE APPEARS TO BE GOOD
CHANCE THAT IFR WILL PERSIST THROUGH THIS AFTERNOON AND INTO THE
EVENING. CIGS COULD EVEN REACH MVFR BRIEFLY AT KLBT LATE THIS
AFTERNOON. AS ANOTHER LOW PASSES OFFSHORE THIS EVENING EXPECT
ANOTHER ROUND OF RAIN. KLBT/KFLO SHOULD HAVE THE LIGHTEST RAIN
WITH THE HEAVIEST AT THE COASTAL TERMINALS...PARTICULARITY KMYR
WHICH WILL BE NEAREST THE LOW. AFTER THE LOW PASSES RAIN SHOULD
END AND CIGS IMPROVE TO MVFR 08-10Z. VFR COULD DEVELOP BY 12Z BUT
DID NOT INDICATE THIS IN TAFS ATTM.

EXTENDED OUTLOOK...TEMPO MVFR CIGS SUNDAY...OTHERWISE VFR. VFR ON
MONDAY. CHANCE OF SHOWERS/TEMPO MVFR ON TUESDAY WITH A COLD FRONT.
VFR WEDNESDAY.

&&

.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM SATURDAY...A GALE WARNING IS IN EFFECT INTO SUN. LOW
PRESSURE ACROSS NORTH FLORIDA...SURFACE AND ALOFT...WILL EVER SO
SLOWLY MOVE UP THE SOUTHEAST COAST...WITH A TRACK MORE EAST THAN
NORTH...ESPECIALLY AS IT GAINS LATITUDE THROUGH THE WEEKEND. A VERY
PRONOUNCED COASTAL TROUGH EXTENDS FROM THE AREA OF LOW PRESSURE UP
THROUGH THE OFFSHORE WATERS OF THE CAROLINAS. THE PATTERN WILL
EVOLVE VERY SLOWLY WITH THE CENTER OF LOW PRESSURE STILL SOUTH OF
THE WATERS SUN MORNING. THIS WILL KEEP STRONG NE WINDS IN PLACE. IN
FACT...A VERY TIGHT PRESSURE GRADIENT IS EXPECTED TO DEVELOP BETWEEN
OFFSHORE LOW PRESSURE AND STRONG HIGH PRESSURE ACROSS THE CAROLINAS.
THE TIGHTEST OF THE GRADIENT SHOULD BE REALIZED LATE TONIGHT AND ON
SUN. FREQUENT GUSTS TO GALE FORCE ARE EXPECTED AND A PERIOD OF
SUSTAINED GALES IS POSSIBLE. THESE STRONG AND PERSISTENT NE WINDS
WILL DRIVE SEAS UP TO 8 TO 12 FT WITH 14 FT POSSIBLE AROUND FRYING
PAN SHOALS. LOCATIONS BLOCKED BY NE FLOW...SUCH AS LONG BAY WILL
HAVE SIGNIFICANTLY LOWER WAVE HEIGHTS.

SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...VERY UNSETTLED WITH FLAGS IN PLACE FOR THE
ENTIRE PERIOD. THOSE FLAGS LIKELY IN THE FORM OF GALE WARNING EARLY
IN THE PERIOD AND THERE IS JUST ENOUGH MODEL DIFFERENCES TO ERODE
CONFIDENCE AS TO WHEN THAT WILL LOWER TO SMALL CRAFT
ADVISORY...COULD BE DURING THE DAY SUNDAY OR NOT UNTIL SUNDAY NIGHT.
MEANWHILE WAVES REMAIN VERY STEEP AND LARGE. ABATING TREND ON MONDAY
SHOULD DROP WINDS BELOW ADVISORY THRESHOLDS ALTHOUGH THE LAGGING
SEAS COULD MAKE IT UNTIL LATE DAY WHEN FLAGS ARE LOWERED.


LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 300 AM SATURDAY...BACKING WIND ON TUESDAY ASSOC WITH THE
APPROACH OF A COLD FRONT FROM THE NW. A SHARP VEER TO OFFSHORE ON
TUESDAY NIGHT WITH FROPA MAY ALSO BE ACCOMPANIED BY A BRIEF SURGE
THAT COULD NECESSITATE A BRIEF ADVISORY BUT THINGS LOOK TO SETTLE
PRETTY QUICKLY HEADING INTO WEDNESDAY. THE COOL AIR HAS TROUBLE
MAKING IT THIS FAR SOUTH AND THUS THERE IS NO BIG PUSH OF HIGH
PRESSURE...THE CENTER OF WHICH REMAINS OVER THE GREAT LAKES. IT WILL
HOWEVER DROP SOUTH AND EAST BY THURSDAY AND BE FOUND CENTERED UP AND
DOWN MUCH OF THE EAST COAST.

&&

.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING UNTIL 6 PM EDT SUNDAY FOR AMZ250-252-254-256.

&&

$$

NEAR TERM...RJD
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...MRR









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