FXUS62 KMHX 241411
AFDMHX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
911 AM EST THU DEC 24 2009
.SYNOPSIS...
HIGH PRESSURE EXTENDING DOWN THE EAST COAST TODAY WILL MOVE EAST
TONIGHT. A WARM FRONT WILL APPROACH FROM THE SOUTH TONIGHT AND
PASS THROUGH EASTERN NORTH CAROLINA CHRISTMAS DAY. A COLD FRONT
WILL FOLLOW QUICKLY FROM THE WEST LATE CHRISTMAS NIGHT. HIGH
PRESSURE WILL BUILD INTO THE REGION FROM THE WEST BEHIND THE
FRONT INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 240 AM THU...HIGH PRESSURE WILL CONTINUE TO RIDGE DOWN THE
EAST COAST FROM CANADA TODAY. MOISTURE IS LIMITED TO HIGH LEVEL
BKN CIRRUS SHIELD AND THE BOUNDARY LAYER FOR SCT AFTERNOON CU.
BASED ON YESTERDAYS HIGH TEMPS AND SIMILAR CONDITIONS 00Z MAV
HIGHS FOR TODAYLOOK A TAD TOO LOW SO LEANED TOWARD WARMER 00Z NAM
HIGHS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
AS OF 240 AM THU...WINDS WILL STEADILY VEER FROM EAST TO SOUTHEAST
OVERNIGHT AS THE WARM FRONT APPROACHES FROM THE SOUTHWEST.
TEMPERATURE TRACE IN THE MODELS INDICATE AN EVENING LOW WITH
TEMPERATURES RISING OVERNIGHT SO ZONES WILL BE WORDED ACCORDINGLY.
AS FOR THE SPEED/TIMING OF THE SYSTEM HPC SAYS THE NAM IS ON THE
SLOWER SIDE OF THE MODEL SOLUTIONS WHILE THE GFS IS ON THE FASTER
SIDE...WITH THE UKMET IN THE MIDDLE. THEREFORE SPLIT THE
DIFFERENCE ON EVENING LOWS. CHRISTMAS DAY LOOKS TO BE VERY WET
ACROSS THE ENTIRE FORECAST AREA. STRONG ISENTROPIC LIFT AND
PLENTY OF MOISTURE AVAILABLE FOR PRECIP GENERATION AS WARM FRONT
LIFTS THROUGH. WENT CATEGORICAL THROUGHOUT. THE COLD FRONT WILL
MOVE THROUGH FROM THE WEST LATE CHRISTMAS NIGHT AND OFF THE COAST
SATURDAY MORNING. DEEPER MOISTURE SHIFTS EAST CHRISTMAS NIGHT SO
STAYED CLOSE TO PREVIOUS FORECAST WITH CHANCE POPS WEST TO
CATEGORICAL EAST. INSTABILITY FOR THUNDER IS MARGINAL AND CONFINED
TO THE FAR SOUTHERN ZONES EARLY CHRISTMAS EVENING SO WILL NOT PUT
IN A MENTION AT THIS TIME. THE FRONT WILL MOVE OFF THE COAST EARLY
SATURDAY MORNING SO KEPT IN A 20-30 POP ALONG THE COAST AND OUTER
BANKS THROUGH 16Z.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 2 PM WED...STRONG COOL HIGH PRESSURE WILL BUILD OVER THE
EASTERN UNITED STATES FOR THE SUNDAY THROUGH TUESDAY PERIOD. TEMPS
WILL REMAIN BLO NORMAL WITH MAXES IN THE UPPER 40S AND LOWER 50S
AND MINS MAINLY IN THE 30S. THE ECMWF AND GFS ARE HINTING AT WEAK
LOW PRESSURE POSSIBLY PRODUCING PRECIP ON WEDS BUT WITH LITTLE
RUN-TO-RUN CONTINUITY...WILL KEEP THE FORECAST DRY FOR NOW.
WITH THE CONTINUED NORTH ATLANTIC OSCILLATION (NAO) AND STRONG
RIDGING OVER THE WESTERN UNITED STATES...SUPPORTED BY THE MJO
PULSE IN PHASES 8, 1 AND 2 OVER THE NEXT COUPLE OF WEEKS...ANTICIPATE
A COLD AND SOMEWHAT STORMY PATTERN CONTINUING OVER THE EASTERN
UNITED STATES IN MID JANUARY.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
AS OF 9AM THU...STEAM FOG HAS ENDED AND EXPECTING VFR THROUGH THE
DAY WITH HIGH PRES TO OUR NORTH. SOME SCU PSBL THIS AFTN BUT VFR
EXPECTED TO PREVAIL INTO EVENING. INCREASING ONSHORE FLOW AND LOW
LVL MSTR EXPECTED TO LEAD TO MVFR CIGS LATE TONIGHT.
FURTHER DETERIORATING CONDITIONS EXPECTED THROUGH THE DAY ON FRI AS
FRONTAL SYSTEM APPROACHES FROM THE W. PREDOMINANT MVFR APPEARS
LIKELY WITH OCCN IFR AS PRECIP MOVES IN BY FRI AFTN AND CONTINUES
INTO THE EVENING HOURS. STRONG AND GUSTY SE WINDS ALSO EXPECTED TO
BE AN ISSUE ON FRI. CONDITIONS IMPROVE TO VFR BY SAT MORNING AS
FRONT PUSHES OFFSHORE. MAINLY VFR TO PERSIST INTO EARLY NEXT WEEK
WITH BUILDING HIGH PRES AND PERSISTENT WLY WINDS.
&&
.MARINE...
AS OF 9AM THU...
ONLY CHANGE WAS TO BEEF UP WINDS IN SRN WATERS A BIT AND START
ADVISORY A FEW HOURS EARLIER. WHILE WE DONT HAVE ANY OBS IN THAT
ZONE ANYMORE SINCE 41035 IS OUT AND 36 IS ADRIFT...THE 7AM OB
FROM THE 38 BUOY JUST SE OF WRIGHTSVILLE SUGGESTS WINDS BETWEEN CAPE FEAR AND
LOOKOUT MAY BE A LITTLE STRONGER WHERE PRES GRADIENT IS PINCHED
MORE BTWN HIGH PRES N OF AREA AND WEAK COASTAL TROF OFFSHORE.
OVERALL THOUGH STILL LOOKS LIKE A MARGINAL SMALL CRAFT ADVISORY
TODAY WITH SEAS UP TO 6FT ACROSS OUTER PORTION OF WATERS...AND
N/NE WINDS 12-21 KTS ACROSS THE REGION. WE WILL BE ADDING THE
SOUNDS TO THE ADVISORY WITH THE AFTERNOON PACKAGE FOR THE
CHRISTMAS DAY EVENT.
PREVIOUS DISCUSSION...WINDS EXPECTED TO INCREASE TO SOLID SCA ALL
WATERS FRI AFTN AHEAD OF ADVANCING COLD FRONT AND CONTINUE INTO
FRI NIGHT. MAIN FCST MODEL DIFFERENCE IS TIMING OF FRONTAL
PASSAGE...WITH NAM MUCH SLOWER THAN GFS AND ECMWF WHICH HAVE IT
OFF COAST BY 12Z SAT. LEANED TO PREVIOUS FCST WHICH IS COMPROMISE
SOLUTION AND KEEPS STRONGER SRLY WINDS OVER WATERS THROUGH SAT
MORNING. DID DECREASE WINDS LATE SAT NIGHT AND SUN WITH ALL MODELS
SUPPORTING WEAKER PRES GRAD AND LIGHTER WINDS. CAA SURGE EXPECTED
TO KICK IN SUN NIGHT AND CONT MON WITH WINDS TO AROUND 20 KTS AND
SCA SEAS LIKELY INTO TUE.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM EST
SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...HSA
NEAR TERM...HSA
SHORT TERM...HSA
LONG TERM...CTC
AVIATION...JBM/MW
MARINE...JBM/MW
