FXUS62 KMHX 050051
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
751 PM EST FRI DEC 4 2009
.SYNOPSIS...
HIGH PRESSURE NORTH AND WEST OF THE AREA WILL WEAKEN TONIGHT. LOW
PRESSURE WILL MOVE NORTHEAST ALONG A STATIONARY FRONT OFF THE
CAROLINA COAST SATURDAY AND MOVE NORTH OF THE AREA EARLY SUNDAY.
HIGH PRESSURE WILL RIDGE INTO THE AREA MONDAY INTO TUESDAY.
ANOTHER STRONG AREA OF LOW PRESSURE WILL APPROACH FROM THE
SOUTHWEST WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 210 PM FRIDAY...CLOUDS CONTINUE TO THICKEN AS MOISTURE IS
TRANSPORTED NE FROM THE GULF REGION IN ADVANCE OF CYCLOGENESIS
OFFSHORE LATER TONIGHT. ALREADY SOME LIGHT RETURNS ON RADAR NEAR
THE NC/SC BORDER. MOST OF THAT PRECIP IS NOT REACHING THE GROUND
BUT AS ATMOSPHERE MOISTENS UP...ANTICIPATE WIDESPREAD PRECIP TO
EXPAND OVER THE AREA...ESPECIALLY AFTER 06Z. WILL HAVE HIGH LIKELY
TO CATEGORICAL POPS. ONLY MINIMAL TEMP DROP FOR TONIGHT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 210 PM FRIDAY...LOW QUICKLY STRENGTHENS OFFSHORE SATURDAY
WITH WIDESPREAD RAINFALL AS STRONG MID-LEVEL SHORTWAVE ENERGY AND
DEEP MOISTURE TRAVERSES THE AREA. POPS WILL REMAIN IN THE HIGH
LIKELY TO CATEGORICAL RANGE. QPF AMOUNTS OF ABOUT ONE TO ONE AND A
HALF INCHES WILL BE POSSIBLE WITH THIS SYSTEM. A RATHER CHILLY
DAY AS TEMPS ONLY CLIMB A FEW DEGREES INTO THE LOWER AND MIDDLE
50S. AS LOW EXITS TO THE NORTH...SOME WRAPAROUND MOISTURE WILL
LINGER TO SHORTLY AFTER MIDNIGHT...BUT COLD AIR WILL LIKELY ARRIVE
TOO LATE TO CREATE ANY PRECIP TYPE ISSUES. HIGH PRESSURE DEVELOPS
SUNDAY WITH CHILLY MAX TEMPS RECOVERING ONLY A FEW DEGREES.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 1205 PM FRIDAY...ACTIVE PATTERN TO CONTINUE IN THE EXTENDED
PERIOD. ECMWF/GFS AND HPC GUIDANCE INDICATE STRONG LOW PRESSURE TO
MOVE FROM THE WESTERN GULF THROUGH THE OHIO VALLEY ON WEDS...DRAGGING
A WARM FRONT NORTH OF THE AREA. ANOTHER HIGH CHANCE OF RAIN
EXPECTED LATE TUESDAY NIGHT INTO WEDNESDAY NIGHT. HIGH PRESSURE
REBUILDS OVER THE AREA FOR THURSDAY INTO FRIDAY. TEMPERATURES
THROUGH MOST OF THE EXTENDED PERIOD WILL BE NEAR OR JUST SLIGHTLY
ABOVE SEASONAL NORMALS.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
AS OF 745 PM FRIDAY...EXPECTING MVFR CONDITIONS TO DEVELOP BEFORE
06Z AND IFR CONDITIONS IN VISIBILITIES AND CEILINGS BY 12Z SATURDAY
AS WIDESPREAD RAIN DEVELOPS OVER THE AREA IN RESPONSE TO A POTENT
MID LEVEL SHORTWAVE WHICH PRODUCE CYCLOGENESIS OFF THE SE COAST
DURING THE NEXT 24 HOURS. THE IFR CONDITIONS IN RAIN WILL PERSIST
FOR MOST OF SATURDAY. SOME IMPROVEMENT TO MVFR IS EXPECTED
SATURDAY EVENING AS THE LOW PULLS AWAY AND DRIER AIR BEGINS TO
FILTER INTO THE AREA.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS WILL RETURN SUNDAY. ANOTHER
STRONG UPPER/SFC LOW SYSTEM WILL BRING GUSTY WINDS AND STORMS TO
THE REGION MID WEEK.
&&
.MARINE...
AS OF 745 PM FRIDAY...MADE A FEW CHANGES TO THE FORECAST FOR
TONIGHT AND SATURDAY. CONSENSUS OF THE GUIDANCE...INCLUDING THE
USUALLY SUPERIOR ECMWF MODEL...INDICATES THAT SOUTHERLY FLOW WILL
DEVELOP OVER THE NC WATERS SOUTH OF OREGON INLET LATE TONIGHT
THROUGH MID SATURDAY AFTERNOON. THE SURFACE PATTERN LOOKS QUITE
COMPLEX WITH THE MAIN BAROCLINIC LOW FORMING WELL OFF THE COAST
SATURDAY. HOWEVER...THE MODELS ARE INDICATING A WEAKER
LOW/BOUNDARY JUST INLAND FROM THE COAST WITH SOUTHERLY FLOW OF 10-20
KT FORECAST OVER THE SOUTHERN 2/3RDS OF THE NC WATERS. THE GFS IS
THE ONLY MODEL WHICH DOES NOT IMPLICITLY FORECAST THIS TO OCCUR
ALTHOUGH IT HINTS AT THIS WITH THE FORECAST VALID 18Z SAT. THE 18Z
NAM HAD THE STRONGEST WINDS BUT APPEARED TO BE CONTAMINATED BY
CONVECTIVE FEEDBACK. USED OUR NEW LOCAL ARW MODEL WHICH KEEPS THE
SOUTHERLY FLOW 20 KT OR LESS. USING THESE WINDS IN THE SWAN MODEL
PRODUCED 6 FT SEAS AS FAR SOUTH AS THE SOUTHERN WATERS BEFORE
SATURDAY AFTERNOON. THEREFORE THE BEGINNING TIMES OF THE SCA FOR
THE WATERS SOUTH OF HATTERAS WAS MOVED UP TO 14Z SATURDAY. THE
STRONGEST WINDS ARE FORECAST MID SATURDAY AFTERNOON AND SATURDAY
EVENING ON THE BACK SIDE OF THE LOW IN NORTHERLY/NORTHWESTERLY
FLOW. THERE COULD BE A BRIEF PERIOD OF GALE FORCE WINDS SATURDAY
EVENING NORTH OF OCRACOKE WHICH WE WILL CONTINUE TO MONITOR.
EXPECT SEAS TO BUILD TO 7-10 FT BY SATURDAY EVENING AND CONTINUE
INTO SATURDAY NIGHT.
PREVIOUS DISCUSSION...CONDITIONS FAIRLY BENIGN WITH DIMINISHING
SWELLS AND WINDS 10KT OR LESS. AN APPROACHING DEEP UPPER LVL TROF
WILL MOVE OUT OF TX AND TOWARDS TN/KY SATURDAY. THIS FEATURE WILL
SUPPORT CYCLOGENESIS OFF THE SOUTHEAST COAST OVERNIGHT...WHICH
WILL DEEPEN SAT AFTERNOON AS IT PULLS OFF TOWARDS THE NORTHEAST.
THE IMPACTS OVERNIGHT WILL BE A SLIGHT INCREASE IN WINDS AS PRES
FALLS OFFSHORE COMBINED WITH THE HIGH TO OUR N TIGHTEN THE PRES
GRAD. THE MODELS ARE FAIRLY CONSISTANT IN THE TRACK/STRENGTH OF
THE FEATURE AS IT SKIRTS OUR S COAST...DEEPENING AS IT PULLS AWAY
FROM HATTERAS. THE WINDS WILL INCREASE TO SCA AHEAD OF THE SYSTEM
MAINLY OVER FAR N WATERS CLOSER TO THE HIGH...BUT THE NW WINDS ON
THE BACKSIDE OF THE SFC LOW WILL INCREASE TO STRONG SCA 25 TO 30
KT. SOME GUSTS TO 35 KT WILL BE POSSIBLE...BUT FOR NOW THINK WE
AREN'T LOOKING AT SUSTAINED GALE FORCE WINDS. WINDS WILL REMAIN
BREEZY INTO SUN AS CAA CONTINUE TO MOVE INTO THE REGION OVER THE
STILL WARM COASTAL WATERS. HIGH PRES WILL SLIDE OVER THE REGION
INTO EARLY NEXT WEEK. ANOTHER STRONG UPPER LVL FEATURE ASSOCIATED
WITH THE S STREAM JET WILL BE RESPONSIBLE FOR A DEEPENING SFC LOW
MOVING UP THE OHIO VALLEY. THE BIGGEST IMPACT LOCALLY WILL BE A
RESULT OF THE STRONG LOW LVL JET AND POTENTIAL CONVECTION. SEAS
ARE EXP TO BUILD TO NEAR DOUBLE DIGITS AND WINDS TO STRONG SMALL
CRAFT IF NOT GALES.
&&
.HYDROLOGY...
AS OF 210 PM TUESDAY...MINOR FLOODING CONTINUES ACROSS PORTIONS OF THE
ROANOKE RIVER FROM HAMILTON TO WILLIAMSTON PRIMARILY AS A RESULT
OF UP STREAM DAM RELEASES. THE RFC FORECAST SHOWS WILLIAMSTON
REMAINING IN FLOOD STAGE FOR THE FORESEEABLE FUTURE. ALL OTHER
RIVERS ARE ABOVE NORMAL FROM RECENT RAIN AND THOUGH AT THIS TIME
FORECASTED RAIN WILL NOT BE SUFFICIENT TO PRODUCE
FLOODING...LOCALLY HIGHER AMOUNTS COULD PUSH RIVERS INTO MINOR
FLOOD STAGE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 3 PM SATURDAY TO 7 AM EST SUNDAY FOR
AMZ130-135.
SMALL CRAFT ADVISORY FROM 9 AM SATURDAY TO 1 AM EST MONDAY FOR
AMZ154.
SMALL CRAFT ADVISORY FROM 9 AM SATURDAY TO 7 PM EST SUNDAY FOR
AMZ156.
SMALL CRAFT ADVISORY FROM 7 AM SATURDAY TO 1 AM EST MONDAY FOR
AMZ150-152.
SMALL CRAFT ADVISORY FROM 9 AM SATURDAY TO 4 PM EST SUNDAY FOR
AMZ158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...CTC
AVIATION...JME/SJ
MARINE...JME/SJ
HYDROLOGY...SJ
