FXUS61 KAKQ 060937
AFDAKQ
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
437 AM EST SUN DEC 6 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE MID ATLANTIC REGION TODAY AND
TONIGHT...THEN MOVE OFFSHORE MONDAY MORNING. A WEAKENING COLD
FRONT WILL SWEEP QUICKLY THROUGH THE AREA MONDAY EVENING...AS HIGH
PRESSURE RETURNS MONDAY NIGHT AND TUESDAY. LOW PRESSURE WILL
DEEPEN OVER THE MIDWEST TUESDAY NIGHT...WHILE ANOTHER WEAKER LOW
FORMS ALONG THE SOUTHEAST COAST. THE LOW ALONG THE COAST WILL LIFT
NORTHEAST ALONG THE ATLANTIC SEABOARD ON WEDNESDAY...AS THE OTHER
LOW TRACKS ACROSS THE GREAT LAKES. HIGH PRESSURE WILL REBUILD
ACROSS THE AREA THURSDAY AND FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HI PRES BUILDS OVR THE FA TDA...BRINGING DRY BUT RELATIVELY COLD
CNDTNS. RUC/GFS/NAM FCST SOUNDINGS SHOW VERY SHALLOW VERTICAL
MIXING TODAY (THOUGH 900 MB TOPS)...AS THE LLVL RIDGE AXIS MOVES
OVER THE MID ATLC REGION. NRLY BNDRY LAYER WINDS WILL ALSO INHIBIT
ANY ADDITIONAL WARMING DUE TO DOWNSLOPE. LCL 1000-850 MB THICKNESS
SCHEME SUPPORTS HIGHS IN THE LOW-MID 40S N AND MID-UPR 40S S...OR
CLOSE TO A MAV/MET MOS GUIDANCE BLEND.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
WAA UPR LVL CLDS AHEAD OF NEXT (FLATTENING) SHORTWAVE BEGIN TO
INCREASE ACROSS THE AREA SUN NIGHT...THOUGH AT THIS POINT FEEL THE
CLOUDS WILL BE SUFFICIENTLY HIGH/TRANSPARENT TO ALLOW FOR AT LEAST
MODEST RADIATIONAL COOLING. HAVE AGAIN FOLLOWED A MAV-MET BLEND...
WHICH IS CLOSE TO THE PREVIOUS FCST. LOWS MID 20 TO MID
30S...COOLEST OVER N/NW LOCALES (A FEW LWR 20S PSBL) AND WARMEST
NEAR THE COAST IN SERN VA/NERN NC.
NAM/SREF/GFS TO SOME DEGREE CONTINUE TO A BRIEF WINDOW OF
RELATIVELY DEEPER OVERRUNNING MSTR WITH THE QUICK MOVING...
DAMPENING UPR SHORTWAVE AND DECAYING SFC COLD FRONT. FLATTENING
VORT LOBE TO REMAIN N OF THE AREA...MEANING THAT ANY OPPORTUNITY
FOR SUFFICIENTLY DEEP MSTR (FOR POPS) WILL BE SHORT-LIVED. WILL
MAINTAIN MINIMAL POPS (20-30% TOPS) OVER SERN VA/NERN NC WHERE SE
BNDRY LAYER FLOW AHEAD OF THE TROUGH (ORIGINATING OVER THE GULF
STREAM) WOULD LEAD TO MORE FVRBL 850-700 MB MOIST ISENTROPIC
ASCENT.
DESPITE THE INCREASE IN CLOUDS/LOW CHCS OF RAIN...LLVL WAA WILL BE
SUFFICIENT TO BOOST TEMPS 5+F ABV SUNDAY'S HIGHS OVER MOST AREAS.
(HIGHS MID 40S NW TO LOW-MID 50S SE).
HIGH PRESSURE BUILDS BACK OVER THE REGION FOR TUESDAY. HIGHS
UPR 40S/NEAR50 N/NW TIER...LWR 50S S/SE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MODELS CONTINUE THEIR TREND OF GOOD CONSISTENCY IN THE EXTENDED
RANGE AS THE STRONG SOUTHERN STREAM CONTINUES WITH SOME INTRUSIONS
FROM THE NORTHERN STREAM EXPECTED AS A STRONG CLOSED LOW DROPS
OVER THE NORTH POLE DROPS SOUTHWARD INTO CENTRAL CANADA LATE IN
THE PERIOD.
ON TUESDAY NIGHT INTO WEDNESDAY...THE MODELS CONTINUE TO BE IN
GOOD AGREEMENT SHOWING A STRONG WAVE EJECTING OUT OT THE
SOUTHWESTERN US AND AMPLIFYING OVER THE CENTRAL PLAINS AND LIFTING
INTO THE GREAT LAKES BY WED AFTERNOON. AHEAD OF THIS WAVE...GOOD
AMOUNT OF GULF MOISTURE WILL HEAD NORTHWARD...PROVIDING ANOTHER
SHOT OF MODERATE RAIN FOR THE EASTERN SEABOARD. AT THIS POINT...IT
SHOULD BE ALL RAIN...BUT WITH A WEDGE IN PLACE...WILL HAVE TO
MONITOR AS INITIAL RAIN COULD BE FALLING INTO A VERY DRY AIR
MASS...WHICH COULD LEAD TO SOME POTENTIAL WINTRY PCPN ALONG THE
BLUE RIDGE AND AREAS WEST. THE DRY SLOT SHOULD PUSH IN BY WED
AFTERNOON...CUTTING OFF ALL THE PCPN...ALLOWING FOR SOME
CLEARING. BUT THE COLD POLAR AIRMASS THAT GETS PULLED SOUTH WITH
THIS WAVE WILL NOT ARRIVE UNTIL THURSDAY WHEN THE SURFACE LOW
PULLS OFF THE COAST.
HIGH PRESSURE WITH THE COOLER AIR MASS HANGS AROUND THROUGH FRIDAY
AS HEIGHTS AGAIN BEGIN TO BUILD. BUT BY SATURDAY...THE ACTIVE
SOUTHERN STREAM ONCE AGAIN KICKS A WAVE EASTWARD FROM THE SOUTHERN
ROCKIES...TAPPING THE GULF AGAIN AND SENDS MORE MOISTURE INTO THE
SOUTHEASTERN AND MID ATLANTIC STATES.
FOR TEMPERATURES HAVE GENERALLY FOLLOWED ALONG WITH THE HPC
GUIDANCE...BUT DID ALLOW FOR MORE COOLING ON WED NIGHT THROUGH
THURSDAY NIGHT AS THE MOS GUIDANCE IS MUCH LOWER...WHICH IS
INDICATIVE OF THE COOLING SHOWN IN THE GFS.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
ISLTD MVFR CIGS NR THE CST ERLY THIS MORNG. OTHRWISE...VFR
CONDITIONS WILL PREVAIL TDY INTO ERLY MON MORNG...AS HI PRES BLDS OVR
THE REGION. MAINLY VFR CONDITIONS SHUD CONTINUE INTO TUE AFTN WITH
HI AND MID LVL CLDS. LWR CIGS AND VSBYS LIKELY TUE NGT INTO WED
AFTN...AS ANOTHER STORM SYSTEM MOVES THRU.
&&
.MARINE...
HAVE DROPPED GALE WRNGS AND NOW HAVE SCA'S UNTIL NOON TDY FOR THE
CHES BAY AND CURRITUCK SND...AND THRU THIS AFTN FOR THE CSTL WTRS.
HI PRES WILL BLD RIGHT OVR THE WTRS BY THIS EVENG/ERLY TNGT...THEN
SLIDE OFFSHR BY LATE MON. A WEAK COLD FRNT WILL SWING THRU MON NGT
WITH HI PRES RETURNING FOR TUE. ANOTHER STORM SYSTEM WILL AFFECT THE
AREA TUE NGT INTO WED AFTN WITH SCA CONDITIONS LIKELY.
&&
.HYDROLOGY...
RIVER FLOOD WARNING FOR SEBRELL REMAINS IN EFFECT...EFFECTIVE MON
MORNING AND WILL LIKELY CONTINUE INTO MIDWEEK.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ630>633.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ650-
652-654-656-658.
&&
$$
SYNOPSIS...BKH
NEAR TERM...BKH
SHORT TERM...BKH/MAM
LONG TERM...ESS
AVIATION...TMG
MARINE...TMG
HYDROLOGY...AKQ
