265
FXUS61 KAKQ 232346
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
646 PM EST MON NOV 23 2009
SYNOPSIS
LOW PRESSURE TRACKS NORTHEAST OFF THE EASTERN SEABOARD TONIGHT
THROUGH TUESDAY. WEAK HIGH PRESSURE BUILDS OVER THE REGION TUESDAY
AFTERNOON INTO WEDNESDAY. A WEAK COLD FRONT APPROACHES FROM THE WEST
ON THURSDAY...WHILE ANOTHER LOW PRESSURE SYSTEM FORMS OFF THE MID
ATLANTIC COAST. THE LOW WILL INTENSIFY OVER NEW ENGLAND ON FRIDAY...
AS A SECONDARY COLD FRONT PUSHES OFF THE COAST. HIGH PRESSURE
BUILDS INTO THE REGION FROM THE WEST OVER THE WEEKEND.
NEAR TERM /UNTIL 6 AM TUESDAY MORNING/
LO PRES OFF THE NC CST WILL CONTINUE TO MOVE NE TNGT INTO TUE MORNG.
BULK OF ACCUMULATING RAIN WILL LIFT INTO NE CNTIES (LWR MD) THIS
EVENG/OVRNGT...WITH JUST AREAS OF VRY LGT RAIN OR DRIZZLE IN ITS
WAKE ACRS THE REMAINDER OF THE REGION. AREAS OF FOG ALSO. OTHRWISE
CLDY WITH MIN TEMPS IN THE MID 40S TO LWR 50S.
SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/
STAYING CLSR TO THE PESSIMISTIC NAM FOR CLD COVER TUE THRU
WED...AS BUFR SNDGS SHOW NEARLY SATURATED LAYER FM ARND 800 MB AND
BELOW. KEPT CHC OF LGT RAIN OVR THE LWR MD/VA ERN SHR TUE MORNG
WITH PATCHY DRIZZLE ELSEWHERE...AREAS OF DRIZZLE AND FOG ALL
LOCATIONS TUE NGT INTO ERLY WED MORNG. SLGT CHC OF A SHRA OVR THE
NRN 1/2 OF THE AREA WED AFTN...AS A WEAK BNDRY SWINGS THRU. HIGHS
TUE IN THE MID 50S TO NR 60...AND IN THE MID 50S TO LWR 60S ON WED.
WED NGT AND THU...LO PRES WILL BE MOVNG NE OFF THE SE AND MID ATLC
CST...WHILE A FRNTL BNDRY WILL SWING INTO THE AREA FM THE W. AT
THIS TIME...HAVE ONLY SLGT CHC POPS ALL AREAS DUE TO CWA IN
BETWEEN DEEPER MOIST AND ENERGY OFFSHR AND WELL TO THE NW. SOME
SUNSHINE LIKELY ON THU...WITH HIGHS IN THE UPR 50S TO MID 60S.
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
GFS/ECMWF ARE BECOMING MORE ALIGNED WITH THE 12Z RUNS...WITH
RESPECT TO THE LARGE-SCALE FEATURES LATE THIS WEEK INTO EARLY NEXT
WEEK. SEPERATE LOW PRESSURE SYSTEMS ON THU...BROAD/DEEP TROUGH
OVER UPR MIDWEST-WRN GREAT LAKES REGION AND A BAROCLINIC LOW OFF
THE MID ATLC COAST...PHASE ACROSS NEW ENGLAND ON FRI. THE ONLY
NOTABLE DIFFERENCE IS THE RECENT ECMWF IS A BIT FARTHER E (ALONG
THE NRN NEW ENGLAND COAST) WITH THE EVENTUAL LOW TRACK. FOR OUR
REGION...ONSET OF CYCLOGENESIS AND RAPID DEEPENING OF THIS SYSTEM
WILL RESULT IN STRENGTHENING W TO WNW LLVL FLOW. THIS FLOW PATTERN
WOULD MAXIMIZE DOWNSLOPE EFFECTS INTO OUR REGION...I.E. A)
DECREASING THE LLVL MSTR ACROSS THE REGION (MINIMIZING CHCS FOR
WRAP-AROUND PCPN) AND B) MITIGATING THE LLVL CAA.
THUS UPSHOT..HAVE OPTED TO CONTINUE WITH THE MINIMAL POPS ON FRI
(20-30% TOPS)...KEEPING THESE PROBS CONFINED TO THE NRN 1/3 OF THE
FCST AREA WHERE SLIGHTLY BETTER UPR FORCING (DVPA) WILL EXIST
(CLOSER TO THE MID LVL LOW)...AND WHERE DOWNSLOPE DRYING EFFECTS ARE
NOT AS SIGNIFICANT (ESPECIALLY OVER THE LWR MD ERN SHORE).
OTHERWISE...TEMPS FRI FROM THE LWR 50S N-NW TO UPER 50S SE...AGAIN
AIDED SOMEWHAT BY THE DOWNSLOPING FLOW.
OTHERWISE...A NICE WEEKEND SHAPING UP FOR THE MID ATLC REGION.
ON SAT...HIGH PRESSURE CONTINUES TO BUILD INTO THE AREA FROM THE
WEST WHILE LOW PRESSURE TRACKS INTO FAR ERN QUEBEC. THIS WILL
MAINTAIN THE DOWNSLOPING WRLY FLOW AND THUS DRY/SEASONABLE COOL
CONDITIONS ACROSS THE REGION (HIGHS MID/UPR 50S). ON SUN...HIGH
BECOMES CENTERED ALONG THE MID ATLC COAST...WITH ENSUING SRLY FLOW
ON THE BACKSIDE DEVELOPING LATE. THIS WILL MAKE FOR CONTINUED DRY WX
WITH TEMPS NUDGING CLOSER TO 60F.
INCREASING WAA CLOUDINESS ON MON AHEAD OF THE NEXT SYSTEM (AS IT
DEEPENS ACROSS THE LWR MS VLY). AT THIS POINT...GIVEN THE GFS/ECMWF
TRENDS...APPEARS THE BEST CHCS OF RAIN WILL HOLD OFF UNTIL MON
NIGHT-TUE.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
ONLY MINOR CHANGES WERE MADE TO REFLECT CURRENT TRENDS. AREAS OF
RAIN WL CONT TO MV NWD ACRS THE AREA THROUGH THE EVNG AS A LOW OFF
THE CAROLINA CST MVS NE AND OUT TO SEA. RAIN SHOULD END BY LATE
EVNG BUT LGT DZ WL CONTINUE INTO EARLY TUE WITH THE AID OF MOIST
ONSHORE FLOW. WIDESPREAD IFR CONDS WL CONTINUE TO PREVAIL ACROSS
THE TAF SITES THROUGH TUE MRNG WITH PERIODS OF LIFR BEGINNING
AFTER MIDNIGHT.
WHILE VIS WL SHOULD IMPROVE TO UPR MVFR LVLS BY MIDDAY TUE...IFR
CIGS WL CONTINUE THROUGH TUE NIGHT. NOT MUCH IMPROVEMENT EXPECTED
FOR WED AS SE WNDS DVLP AHEAD OF THE NEXT WX SYSTEM OVER THE GREAT
LAKES.
CONDS WL BE SLOW TO IMPROVE THROUGH THU. NW WNDS BEHIND THE NEXT
WX SYSTEM SHOULD RESULT IN MOSTLY VFR CONDITIONS FRI AND SAT. A
FEW SHWRS AND MVFR CIGS WL BE PSBL DURING THE DAY FRI...ESPECIALLY
AT RIC AND SBY.
MARINE
SCA'S CONTINUE OVER ALL AREAS TONIGHT...MAINLY FOR SEAS OVER THE
CSTL WATERS (6-10FT)...AND FOR ~20KT WINDS OVER CHES BAY AND
CURRITUCK SOUND. GRADIENT FLOW RELAXES SOMEWHAT ON TUE AND ESP TUE
NIGHT AND WED AS WEAK HIGH PRESSURE (CAD WEDGE) SETTLES INTO MID
ATLC REGION. HAVE CONTINUED WITH THE SCA'S (FOR SEAS) OVER THE CSTL
WATERS...BASED ON LINGERING LONG PERIOD ERLY SWELLS. ANTICIPATE
ANOTHER RAMP-UP TO A NEW SET OF MARINE HEADLINES (GALES POSSIBLE)
BY FRI-SAT...AS THE STORM SYSTEM INTENSIFIES OVER NEW ENGLAND.
EQUIPMENT
NWR TRANSMITTER AT WINDSOR NC HAS RETURNED TO SERVICE.
AKQ WATCHES/WARNINGS/ADVISORIES
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ630>632.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ633.
SMALL CRAFT ADVISORY UNTIL 6 PM EST WEDNESDAY FOR ANZ650-652-
654-656-658.
SYNOPSIS...TMG
NEAR TERM...TMG
SHORT TERM...TMG
LONG TERM...BKH
AVIATION...AM
MARINE...BKH
EQUIPMENT...AKQ
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page