FXUS61 KMHX 240921
AFDMHX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEWPORT/MOREHEAD CITY NC
420 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 /THROUGH TODAY/...
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 /TONIGHT 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 /07Z THURSDAY THROUGH MONDAY/...
PESKY STEAM FOG FROM NEARBY RIVERS WILL AFFECT KEWN AND KPGV AGAIN 
EARLY THIS MORNING WITH PERIODS OF IFR TO LIFR...MAINLY VSBYS. 
PERIOD OF MVFR VSBY LIKELY KOAJ AND KISO. CONDITIONS BECOMING VFR BY 
14Z WITH INCREASING NE WIND. 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...
NNE WINDS GRADUALLY INCREASING OVER AREA EARLY THIS MORNING WITH 
REINFORCING SFC HIGH BUILDING IN FROM N. LATEST WW3 AND LOCAL SWAN 
SUPPORT SEAS BUILDING TO 6 FT NRN HALF OF WATERS THIS MORNING AND 
SRN WATERS THIS AFTN...THUS NO CHANGE TO SCA HEADLINES. 

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 FROM 8 AM THIS MORNING TO 3 PM EST SUNDAY 
     FOR AMZ150-152-154.
     SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM EST 
     SUNDAY FOR AMZ156-158.

&&

$$

SYNOPSIS...HSA
NEAR TERM...HSA
SHORT TERM...HSA
LONG TERM...CTC
AVIATION...JBM
MARINE...JBM