000
FXUS61 KRNK 220557
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
157 AM EDT TUE MAY 22 2012

.SYNOPSIS...
A COLD FRONT SLOWLY PUSHES EAST ACROSS THE AREA TODAY...AND THEN
TO THE COAST BY LATE WEDNESDAY. SCATTERED SHOWERS AND
THUNDERSTORMS...WITH SOME POTENTIALLY BRINGING HEAVY RAIN...WILL
BE POSSIBLE THROUGH THURSDAY. HIGH PRESSURE AND DRIER WEATHER WILL
ARRIVE LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 1250 AM EDT TUESDAY...

EXPECT SHOWER/ISOLATED TSRA ACTIVITY TO CONTINUE ACROSS THE
PIEDMONT AND MOUNTAINS THROUGH THE MORNING...BUT ANTICIPATE LESS
INTENSITY. BEST INSTABILITY/HIGHER THETA-E IS KEEPING THIS
CONVECTION GOING. ADJUSTMENTS TO KEEP HIGHER POPS IN THE EAST
EARLY THEN TAPER TO SLIGHT CHANCE/LOW CHANCE REST OF THE MORNING.

CURRENTLY...COLD FRONT IS LINED P FROM THE OHIO/WV BORDER
SOUTHWEST INTO MID TENNESSEE. SOME FOG WILL BE AROUND THIS
MORNING...HOWEVER WILL BE LESS WIDESPREAD DUE TO CLOUD COVER.

TEMPERATURES SHOULD REBOUND INTO THE MID 70S TO NEAR 80 DEGREES
FOR HIGHS ON TUESDAY. THE COLD FRONT WILL APPROACH THE APPALACHIAN
MOUNTAINS...AND GREATER COVERAGE OF SHOWERS AND THUNDERSTORMS WILL
BE ANTICIPATED. A FEW OF THESE STORMS MAY PRODUCE HEAVY
RAINFALL...SO POPS WERE BUMPED UP TO LIKELY FOR MOST OF THE
AREA...AND CATEGORICAL WITHIN THE NEW RIVER VALLEY. THE FLOW ALOFT
WILL CONTINUE TO BE VERY WEAK...SO HYDRO ISSUES HAVE BEEN ADDED TO
THE HWO FOR LATE IN THE DAY.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
AS OF 305 PM EDT MONDAY...

AN UNSETTLED WEATHER PATTERN IS IN STORE FOR THE SHORT TERM
PERIOD...AS A SHORTWAVE TROF DIGGING INTO MISSOURI THIS AFTERNOON
IS FORECAST TO DEEPEN AND CUT OFF OVER OUR AREA BY
WEDNESDAY...BEFORE LIFTING NORTHEAST THURSDAY.

PRECIPITATION COVERAGE INCREASES WEDNESDAY AS THE UPPER LOW/COOL
POOL MOVES OVER OUR AREA. WHILE CLOUD COVER SHOULD KEEP THE
POTENTIAL FOR SEVERE WEATHER LOW...CONCERNED ABOUT LOCALIZED
FLOODING WEDNESDAY CONSIDERING FORECAST CORFIDI VECTORS WILL BE LESS
THAN 10 KTS...AND PWATS WILL BE AROUND 1.5 INCHES...WHICH IS JUST
SHY OF 2 STANDARD DEVIATIONS ABV NORMAL. THEREFORE...WILL INTRODUCE
A MENTION OF LOCALIZED FLOODING IN HWO.

MODEL GUIDANCE SHOWS A BIG DISCREPANCY FOR HIGHS WEDNESDAY...WITH
THE GFS MOS GUIDANCE 5-10 DEGREES WARMER THAN THE NAM MOS GUIDANCE.
CONSIDERING FAIRLY STEEP LAPSE RATES...CLOUDS SHOULD BE
WIDESPREAD...AND LEANED TOWARD THE COOLER NAM MOS FOR HIGHS
WEDNESDAY.

THE UPPER LOW/COOL POOL LIFTS NORTHEAST...BUT A VERY MOIST AIR MASS
REMAINS IN PLACE...AND WEAK UPSLOPE FLOW WILL GENERATE MORE SHOWERS
AND STORMS...WITH GREATEST COVERAGE IN THE ALLEGHANY HIGHLANDS
CLOSER TO THE UPPER LOW. SHOWERS AND A FEW STORMS WILL AGAIN BE SLOW
MOVING WITH CORFIDI VECTORS AGAIN LESS THAN 10 KTS.  ONCE AGAIN
LEANED TOWARD THE COOLER GUIDANCE VALUES WITH EXTENSIVE CLOUD COVER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 305 PM EDT MONDAY...

THE MEDIUM RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT
BUILDING A STRONG UPPER RIDGE...FIRST OVER THE OHIO VALLEY...THEN
ELONGATING INTO THE MID-ATLANTIC REGION SUNDAY INTO MONDAY. THIS
WILL RESULT IN TEMPERATURES WELL ABOVE NORMAL AND LESS COVERAGE IN
PRECIPITATION.

ON FRIDAY...THE LINGERING UPPER LEVEL TROF FINALLY GETS PUSHED
NORTHEAST BY A SHORTWAVE MOVING THROUGH THE GREAT LAKES. WITH A
MOIST (GREATER THAN 1.5 PWATS) AND UNSTABLE AIR MASS IN PLACE AND
WEAK LOW LEVEL CONVERGENCE AND THE SFC...WIDELY SCATTERED
THUNDERSTORMS WILL AGAIN BE POSSIBLE.

THE COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH THROUGH THE
HOLIDAY WEEKEND AS THE UPPER RIDGE BUILDS. HOWEVER...WEAK...BUT
FAIRLY DEEP EAST/SOUTHEAST UPSLOPE LOW LEVEL FLOW MAY BE ABOVE TO
OVERCOME WARMING MID LEVEL TEMPS/RISING HEIGHTS TO INITIATE ISOLATED
TO WIDELY SCT STORMS ALONG THE BLUE RIDGE.

LEARNED TOWARD THE WARMER MEX GUIDANCE FOR TEMPS THROUGH THE LONG
TERM PERIOD...WITH FORECAST HIGHS NEARING RECORDS FOR BLF.

&&

.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 125 AM EDT TUESDAY...

EXPECTING A VARYING IN CIGS/VSBYS THIS MORNING DUE TO INORDINATE
AMOUNT OF SFC MOISTURE WITH RAINFALL FROM THE PAST EVENING. WILL
STILL SEE SHOWERS CLOSER TO LYH/DAN AND BLF/LWB THIS MORNING.
CONFIDENCE IS HIGHER THAN NORMAL THAT ALL TAF SITES WILL SEE SOME
PERIOD OF SUB VFR CIG AND/OR VSBY THIS MORNING. THE POTENTIAL
EXISTS FOR FOG TO BECOME LOCALLY DENSE AND/OR STRATUS TO DEVELOP
BELOW 1KFT AND THIS IS ESPECIALLY LIKELY IN ALL BUT ROA/DAN.

FRONTAL BOUNDARY WILL MOVE INTO THE MOUNTAINS BY MIDDAY TODAY WITH
SHOWER AND STORM COVERAGE INCREASING. WILL SEE IMPROVING
CIGS/VSBYS AFTER 14Z WITH MOST LOCATIONS HAVING VFR.

WILL SEE COVERAGE OF SHRA AND STORMS AT ALL SITES THIS AFTERNOON
BUT WILL LEAVE PREDOMINANT THUNDER OUT OF THE WEATHER AND GO WITH
VCTS. AS WITH ANY STORMS...CIGS/VSBYS WILL DROP TO SUB VFR AT TIMES.

THE UPPER TROUGH HANGING AROUND INTO WEDNESDAY WILL KEEP THE
THREAT OF CONVECTION AROUND AT LEAST UNTIL THURSDAY. CIGS/VSBYS
COULD NOSE DIVE AGAIN TUE NIGHT AND WED NIGHT WITH STRATUS OR FOG
BARRING EXTENSIVE CLOUD COVER OR SHOWERS.

BY FRIDAY INTO SATURDAY...MOST AREAS WILL SEE VFR WEATHER WILL
CHANCE OF CONVECTION MAINLY CONFINED TO ISOLATED COVERAGE. FOG
WILL STILL BE AN ISSUE AT TIMES LATE AT NIGHT ESPECIALLY IN THE VALLEYS.


&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PW/WP
NEAR TERM...PW/WP
SHORT TERM...PH
LONG TERM...PH
AVIATION...WP

000
FXUS61 KAKQ 220350
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1150 PM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THROUGH MID WEEK. HIGH PRESSURE BUILDS INTO THE AREA LATE THIS WEEK
AND INTO THE HOLIDAY WEEKEND.

&&

.NEAR TERM /THROUGH TUESDAY/...
UPDATE TO ADD 30 PERCENT CHC SHOWERS/ISOLATED THUNDER MOST AREAS
WEST OF THE CHESAPEAKE. HRRR AND OTHER HIGH RES MODELS INDICATE
CONVECTION OVERNIGHT IN AN AREA THAT HAS SLIGHTLY NEGATIVE LI/S.
AS OF 03Z...SHOWERS WERE OVER BRUNSWICK COUNTY AND APPROACHING
LUNENBURG AND MECKLENBURG COUNTY FROM THE WEST. LEFT SLGT CHC
SHOWERS ERN PORTIONS WHERE THE ATMPOSPHERE IS RELATIVELY STABLE.

PREVIOUS DISCUSSION...
MOST PCPN HAS WEAKENED / DISSIPATED SINCE SUNSET WITH ONLY A FEW
SHOWERS OVER I95 CORRIDOR NORTH OF RICHMOND. NOW WATCHING BAND OF
SHOWERS / TSTRMS FROM LYH-DAN. TUFF CALL ON JUST HOW FAR EAST THEY
GET NEXT FEW HOURS AS SHORT RANGE MODELS DIFFER A BIT ON HOW LONG
THEY SURVIVE. THUS...HAVE ADDED ISLTD THUNDER TO EXTREME WESTERN
COUNTIES NEXT FEW HOURS FOR ANY CELL THAT DOES MOVE EAST. OTW...ENUF
MOISTURE IN PLACE FOR AT LESAT ISOLATED SHOWERS FOR THE REST OF THE
NIGHT...ESPECIALLY ACROSS WESTERN HALF OF FA DUE TO LINGERING TROF.
ADDED PATCHY FOG ALONG THE EASTERN SHORE. LATER UPDATES MAY HAVE TO
EXPAND THE FOG THREAT TOWARD SUNRISE. WARM AND HUMID. LOWS 60-65.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
UNSETTLED CONDS...NOT DUE TO TS ALBERTO...WILL CONTINUE THRU THE
SHORT TERM PERIOD WITH THE AFOREMENTIONED UPR-LVL TROF STILL IN
PLACE ALONG THE EASTERN SEABOARD. THIS WILL LEAD TO PERIODIC
CHANCES FOR SHOWERS AND STORMS AS MOIST S/SW FLOW CONTINUES. FOR
TUE...SFC TROF WILL BE SITUATED OVR WESTERN PORTIONS OF THE FA
WHERE HIGHEST POPS (50%) WERE PLACED...30-40% ELSEWHERE. TEMPS
CLIMB INTO THE UPR 70S TO LWR 80S UNDER A MSTLY CLDY SKY. RAIN MAY
LINGER INTO TUE NGT...WITH THE BEST CHC AGAIN OVR WESTERN AREAS.
UPR-LVL TROF CUTS OFF FROM THE MEAN FLOW TUE NGT INTO WED AS A
POTENT S/W DIVES DOWN THE TROF BASE. THE CENTER OF THE RESULTING
UPR-LVL LOW WILL CENTER ITSELF NEAR THE MID ATLANTIC WED INTO
THU...WITH CHANCES FOR RAIN EACH DAY. BEST CHANCE FOR RAIN DURING
THE PERIOD WILL BE WED (LIKELY POPS FOR NW QUADRANT OF FA) WITH A
SFC TROF OVR THE MID ATLANTIC...DECENT FORCING ALOFT...AND A VERY
MOIST ATM. SEASONABLE TEMPS CONTINUE WED AND THU...HIGHS STILL IN
THE UPR 70S TO LWR 80S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE LATEST NUMERICAL GUIDANCE IS SUGGESTING THAT THE PERSISTENT
UPPER LOW MAY LINGER INTO FRIDAY. HOWEVER...AT THIS POINT NOTHING
MORE THAT A SLIGHT CHANCE POP IS NECESSARY. AN UPPER HIGH THEN
BUILDS OVER THE OHIO VALLEY FOR THE MEMORIAL DAY WEEKEND. GIVEN
WHERE THE HIGH SETS UP IT IS POSSIBLE SOME CONVECTION COULD ROUND
THE TOP OF THE RIDGE AND APPROACH THE LOCAL AREA IN MID-LEVEL NNW
FLOW. THE LARGE MAJORITY OF THE TIME IS EXPECTED TO BE DRY AND THERE
IS BASICALLY NO SKILL IN FORECASTING MCS ACTIVITY IN THE MEDIUM
RANGE. TEMPERATURES SHOULD BE ABOVE SEASONAL AVERAGES WITH HIGHS IN
THE MID 80S TO NEAR 90 (SLIGHTLY COOLER ALONG THE COASTS WITH LIGHT
ONSHORE FLOW). LOW TEMPERATURES SHOULD GENERALLY BE IN THE 60S.

&&

.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
WEAK LOW PRESSURE OVER THE REGION WITH MOSTLY LIGHT WINDS FROM THE
E-SE. SOME PERSISTENT SCATTERED SHOWERS CONTINUE MOSTLY OVER THE
NORTHERN PORTIONS OF THE CWA...BUT AN AREA OF SHOWERS AND TSTMS IS
ALSO MOVG THRU THE ROANOKE VALLEY. SOME OF THIS CONVECTION COULD
PSBLY AFFECT WESTERN COUNTIES LATER TONIGHT. BIGGEST CONCERN TONIGHT
IS THE CHANCE OF IFR CONDITIONS DUE TO PLENTY OF LOW LEVEL MOISTURE
WITH IFR CEILINGS DEVELOPING GENERALLY AFTER MIDNIGHT. SOME PATCHY
DENSE FOG WILL LIKELY OCCUR OVER THE EASTERN SHORE BUT FOG WILL
PROBABLY RANGE FROM 1 TO 3 MILES OVER THE REGION DURING THE NIGHT.

VFR CONDITIONS WILL EXPECTED BY MID TO LATE MORNING AS WINDS SHIFT
TO THE S-SW DURING THE OVERNIGHT. MORE SHOWERS AND TSTMS POSSIBLE
FOR TUE AFTN/EVENING AS WEAK INSTABILITY CONTINUES OVER THE REGION.

&&

.MARINE...
THE LATEST SURFACE ANALYSIS SHOWS A RATHER NEBULOUS SURFACE PATTERN
ACROSS THE LOCAL MARNIE AREA AND HENCE WEAK FLOW. THIS GENERAL FLOW
PATTERN SHOULD CONTINUE THROUGH MUCH OF THE WEEK WITH S OR SE FLOW
AOB 10KT. AN AREA OF LOW PRESSURE (NOT TS ALBERTO) PRESENTLY WELL
EAST OF THE NC COAST WILL MOVE NNE ON A TRAJECTORY TOWARD NS THROUGH
TUESDAY. WNA WAVE SHOWS SWELL ASSOCIATED WITH THIS LOW AFFECTING THE
MARINE AREA TUESDAY INTO TUESDAY NIGHT WITH SEAS AOA 5FT GENERALLY
OUT PAST 5-10NM. AN SCA FOR HAZARDOUS SEAS WILL BE RAISED FROM 6AM
TUESDAY TO 6AM WEDNESDAY. OTHERWISE...SEAS SHOULD DROP BELOW SCA FOR
THE REMAINDER OF THE WEEK. UNSETTLED CONDITIONS SHOULD PERSIST MUCH
OF THE WEEK WITH A CHANCE FOR MAINLY AFTERNOON AND EVENING
THUNDERSTORMS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 AM TUESDAY TO 6
     AM EDT WEDNESDAY FOR ANZ650-652-654-656-658.

&&

$$
SYNOPSIS...MAS
NEAR TERM...MPR/LSA
SHORT TERM...MAS
LONG TERM...AJZ
AVIATION...DAP
MARINE...AJZ

000
FXUS61 KAKQ 220209
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1009 PM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THROUGH MID WEEK. HIGH PRESSURE BUILDS INTO THE AREA LATE THIS WEEK
AND INTO THE HOLIDAY WEEKEND.

&&

.NEAR TERM /THROUGH TUESDAY/...
MOST PCPN HAS WEAKENED / DISSIPATED SINCE SUNSET WITH ONLY A FEW
SHOWERS OVER I95 CORRIDOR NORTH OF RICHMOND. NOW WATCHING BAND OF
SHOWERS / TSTRMS FROM LYH-DAN. TUFF CALL ON JUST HOW FAR EAST THEY
GET NEXT FEW HOURS AS SHORT RANGE MODELS DIFFER A BIT ON HOW LONG
THEY SURVIVE. THUS...HAVE ADDED ISLTD THUNDER TO EXTREME WESTERN
COUNTIES NEXT FEW HOURS FOR ANY CELL THAT DOES MOVE EAST. OTW...ENUF
MOISTURE IN PLACE FOR AT LESAT ISOLATED SHOWERS FOR THE REST OF THE
NIGHT...ESPECIALLY ACROSS WESTERN HALF OF FA DUE TO LINGERING TROF.
ADDED PATCHY FOG ALONG THE EASTERN SHORE. LATER UPDATES MAY HAVE TO
EXPAND THE FOG THREAT TOWARD SUNRISE. WARM AND HUMID. LOWS 60-65.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
UNSETTLED CONDS...NOT DUE TO TS ALBERTO...WILL CONTINUE THRU THE
SHORT TERM PERIOD WITH THE AFOREMENTIONED UPR-LVL TROF STILL IN
PLACE ALONG THE EASTERN SEABOARD. THIS WILL LEAD TO PERIODIC
CHANCES FOR SHOWERS AND STORMS AS MOIST S/SW FLOW CONTINUES. FOR
TUE...SFC TROF WILL BE SITUATED OVR WESTERN PORTIONS OF THE FA
WHERE HIGHEST POPS (50%) WERE PLACED...30-40% ELSEWHERE. TEMPS
CLIMB INTO THE UPR 70S TO LWR 80S UNDER A MSTLY CLDY SKY. RAIN MAY
LINGER INTO TUE NGT...WITH THE BEST CHC AGAIN OVR WESTERN AREAS.
UPR-LVL TROF CUTS OFF FROM THE MEAN FLOW TUE NGT INTO WED AS A
POTENT S/W DIVES DOWN THE TROF BASE. THE CENTER OF THE RESULTING
UPR-LVL LOW WILL CENTER ITSELF NEAR THE MID ATLANTIC WED INTO
THU...WITH CHANCES FOR RAIN EACH DAY. BEST CHANCE FOR RAIN DURING
THE PERIOD WILL BE WED (LIKELY POPS FOR NW QUADRANT OF FA) WITH A
SFC TROF OVR THE MID ATLANTIC...DECENT FORCING ALOFT...AND A VERY
MOIST ATM. SEASONABLE TEMPS CONTINUE WED AND THU...HIGHS STILL IN
THE UPR 70S TO LWR 80S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE LATEST NUMERICAL GUIDANCE IS SUGGESTING THAT THE PERSISTENT
UPPER LOW MAY LINGER INTO FRIDAY. HOWEVER...AT THIS POINT NOTHING
MORE THAT A SLIGHT CHANCE POP IS NECESSARY. AN UPPER HIGH THEN
BUILDS OVER THE OHIO VALLEY FOR THE MEMORIAL DAY WEEKEND. GIVEN
WHERE THE HIGH SETS UP IT IS POSSIBLE SOME CONVECTION COULD ROUND
THE TOP OF THE RIDGE AND APPROACH THE LOCAL AREA IN MID-LEVEL NNW
FLOW. THE LARGE MAJORITY OF THE TIME IS EXPECTED TO BE DRY AND THERE
IS BASICALLY NO SKILL IN FORECASTING MCS ACTIVITY IN THE MEDIUM
RANGE. TEMPERATURES SHOULD BE ABOVE SEASONAL AVERAGES WITH HIGHS IN
THE MID 80S TO NEAR 90 (SLIGHTLY COOLER ALONG THE COASTS WITH LIGHT
ONSHORE FLOW). LOW TEMPERATURES SHOULD GENERALLY BE IN THE 60S.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
WEAK LOW PRESSURE OVER THE REGION WITH MOSTLY LIGHT WINDS FROM THE
E-SE. SOME PERSISTENT SCATTERED SHOWERS CONTINUE MOSTLY OVER THE
NORTHERN PORTIONS OF THE CWA...BUT AN AREA OF SHOWERS AND TSTMS IS
ALSO MOVG THRU THE ROANOKE VALLEY. SOME OF THIS CONVECTION COULD
PSBLY AFFECT WESTERN COUNTIES LATER TONIGHT. BIGGEST CONCERN TONIGHT
IS THE CHANCE OF IFR CONDITIONS DUE TO PLENTY OF LOW LEVEL MOISTURE
WITH IFR CEILINGS DEVELOPING GENERALLY AFTER MIDNIGHT. SOME PATCHY
DENSE FOG WILL LIKELY OCCUR OVER THE EASTERN SHORE BUT FOG WILL
PROBABLY RANGE FROM 1 TO 3 MILES OVER THE REGION DURING THE NIGHT.

VFR CONDITIONS WILL EXPECTED BY MID TO LATE MORNING AS WINDS SHIFT
TO THE S-SW DURING THE OVERNIGHT. MORE SHOWERS AND TSTMS POSSIBLE
FOR TUE AFTN/EVENING AS WEAK INSTABILITY CONTINUES OVER THE REGION.

&&

.MARINE...
THE LATEST SURFACE ANALYSIS SHOWS A RATHER NEBULOUS SURFACE PATTERN
ACROSS THE LOCAL MARNIE AREA AND HENCE WEAK FLOW. THIS GENERAL FLOW
PATTERN SHOULD CONTINUE THROUGH MUCH OF THE WEEK WITH S OR SE FLOW
AOB 10KT. AN AREA OF LOW PRESSURE (NOT TS ALBERTO) PRESENTLY WELL
EAST OF THE NC COAST WILL MOVE NNE ON A TRAJECTORY TOWARD NS THROUGH
TUESDAY. WNA WAVE SHOWS SWELL ASSOCIATED WITH THIS LOW AFFECTING THE
MARINE AREA TUESDAY INTO TUESDAY NIGHT WITH SEAS AOA 5FT GENERALLY
OUT PAST 5-10NM. AN SCA FOR HAZARDOUS SEAS WILL BE RAISED FROM 6AM
TUESDAY TO 6AM WEDNESDAY. OTHERWISE...SEAS SHOULD DROP BELOW SCA FOR
THE REMAINDER OF THE WEEK. UNSETTLED CONDITIONS SHOULD PERSIST MUCH
OF THE WEEK WITH A CHANCE FOR MAINLY AFTERNOON AND EVENING
THUNDERSTORMS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 AM TUESDAY TO 6
     AM EDT WEDNESDAY FOR ANZ650-652-654-656-658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...MAS
LONG TERM...AJZ
AVIATION...JEF
MARINE...AJZ

000
FXUS61 KLWX 220148
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
948 PM EDT MON MAY 21 2012

.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL STALL OVER THE AREA THROUGH TUESDAY.
AN UPPER LOW MOVES THROUGH WEDNESDAY AND THURSDAY. HIGH PRESSURE
WILL RETURN TO THE AREA FOR THE MEMORIAL DAY WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATEST WV LOOP AND MODEL ANALYSIS SHOWS A BROAD LARGE-SCALE TROUGH
OVER THE ERN-THIRD CONUS..WITH SEVERAL SHORTWAVE TROUGHS ROTATING
AROUND THE TROUGH. ONE OF THESE SHORTWAVE TROUGH IS NEGATIVELY
TILTED AND HAS STALLED NEAR THE BLUE RIDGE. A SELY LLVL JET AHEAD
OF THE TROUGH HAS PRODUCED NUMEROUS TO WIDESPREAD SHOWERS OVER THE
NRN PIEDMONT...NRN VA...THE ERN WV PANHANDLE AND NORTH-CENTRAL MD
FOR MOST OF THE DAY. WITH LITTLE PROGRESSION OF THE LLVL TROUGH...
EXPECT SHOWERS TO CONTINUE OVER THE SAME LOCATIONS THRU THE
REMAINDER OF THE EVE. A STABILIZING ATMOSPHERE LATE TNGT WILL
CAUSE SHOWER ACTIVITY TO DIMINISH LATE TNGT AND ERY TUE MRNG.
ASIDE FROM SCT SHOWERS/TSTMS ACROSS THE FAR SWRN CWA THIS
EVE...THE REMAINDER OF THE CWA SHOULD NOT EXPECT MUCH MORE
THAN AN ISO SHOWER TNGT.

LOW CLOUDS AND FOG WILL DEVELOP LATE THIS EVE AND OVNGT. STRATUS
SHOULD LIMIT COVERAGE AND DENSITY OF FOG. HAVE KEPT PATCHY FOG
WORDING IN THE GRIDS...EXCEPT FOR AREAS OF FOG ALONG THE RIDGE TOPS.
WITH CLOUD COVER AND A MOIST ATMOSPHERE...MIN TEMPS WILL ONLY FALL A
FEW DEGREES FROM CURRENT READINGS...RANGING FROM THE 50S IN THE
POTOMAC HIGHLANDS TO THE MID 60S EAST OF THE BLUE RIDGE.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AN UPPER-LEVEL TROUGH WILL APPROACH THE REGION FROM THE WEST WHILE A
SURFACE TROUGH OF LOW PRESSURE REMAINS OVER THE REGION. LOW CLOUDS
AND PATCHY FOG WILL SLOWLY MIX OUT DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS. SOME AFTERNOON SUNSHINE IS EXPECTED AND THAT WILL
POTENTIALL LEAD TO MODERATE AMOUNTS OF INSTABILITY.

MODERATE INSTABILITY WILL COMBINE WITH FORCING FROM THE SURFACE
TROUGH TO TRIGGER SOME SHOWERS AND THUNDERSTORMS...MAINLY DURING
THE AFTERNOON HOURS. THUNDERSTORMS WILL BE SLOW MOVING AND
CONTAINING MAY CONTAIN LOCALLY HEAVY DOWNPOURS. WILL HOLD OFF ON
ISSUANCE OF A FLASH FLOOD WATCH ATTM AS FFG IS HIGH AND COVERAGE
OF STORMS ARE UNCERTAIN.

MAX TEMPS WILL BE WARMER TUESDAY COMPARED TO MONDAY DUE TO MORE
AFTERNOON SUNSHINE. MAX TEMPS WILL RANGE FROM THE UPPER 60S ALONG
THE RIDGE TOPS TO THE UPPER 70S AND LOWER 80S ACROSS MOST OTHER
LOCATIONS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
UPPER LEVEL TROUGH OF LOW PRES XPCTD TO MOVE OUT OF THE TN VLLY
TUE NGT AND BECOME A CLOSED LOW OVR THE MID ATLC WED. NOT A
PARTICULARLY DEEP CLOSED LOW...BUT STILL ENOUGH OF ONE THAT HV
PUSHED POPS ACROSS THE ENTIRE CWA TO LKLY FOR WED AFTN. THERE
CERTAINLY COULD BE THUNDER...BUT AT THIS TIME SVR THREAT LOOKS
MINIMAL. THIS LOOKS TO SLOWLY NE AWAY FM THE AREA...AND HV POPS
SLOWLY DIMINISHING AS WELL.

WED AND THU XPCT HIGH TEMPS A80 MUCH OF THE AREA. LOWS IN THE LM60S.

AFTR THE UPR LOW EXITS A PATTERN SHIFT OCCURS. UPR LVL TROF PUSHES
DOWN THE PACIFIC CST..AND IN RESPONSE HGTS START TO RISE IN THE
ERN 1/3 OF THE COUNTRY. AFTR A MUCH-ABV-NRML MAR TEMPS IN APR AND
MAY HV BEEN MORE TEMPERATE. 1000-500 HGTS MAY EXCEED 590 DM...AND
TEMPS COULD TOP 90 DEG...ESPECIALLY SUN AND MON. GIVEN THIS IS
"THE UNOFFICIAL START OF SUMMER" PLUS MEMORIAL DAY WKND WE`RE A
BIT CONCERNED OF HOW PEOPLE WL REACT TO THE CHG. WE`RE A LONG WAY
FM ISSUING ANY HEAT SPECIFIC PRODUCTS BUT WE`VE ADDED MENTION OF
THE WARMER TEMPS/HOLIDAY WKND TO THE HWO. ONLY PTNL FOR TSTMS THIS
WKND LOOKS TO BE DIURNALLY DRIVEN OVR THE MTNS. OTHERWISE SKIES
SHOULD BE M SUN DURG THE DAY.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
A LLVL TROUGH REMAINS STATIONARY NEAR THE BLUE RIDGE THIS EVE.
NUMEROUS SHRA WILL CONTINUE TO IMPACT MRB/IAD THIS EVE...WHICH
WILL ALLOW FLIGHT CAT TO DEGRADE TO IFR LVLS /MAINLY DUE TO CIGS/.
ELSEHWERE...CIGS WILL LOWER TO IFR AROUND OR SHORTLY AFTER
MIDNIGHT. VIFR CIGS LIKELY FOR MOST TERMINALS LATE TNGT AND ERY
TUE MRNG. LOW STRATUS SHOULD LIMIT SFC VSBY IMPACT FROM FOG.

CIGS WILL BE SLOW TO IMPROVE TUE MRNG...AND MAY NOT IMPROVE TO
MVFR UNTIL MIDDAY/ERY AFTN. THE TROUGH WILL REMAIN OVER THE AREA
TUE WHILE BREAKS IN THE CLOUDS TUE AFTN WILL FUEL THE DEVELOPMENT
OF SHRA LATER IN THE DAY. HAVE NOT MENTIONED TS IN THE 00Z
TAFS...BUT IT MAY NEED TO BE ADDED IN LATER TAF CYCLES AS
CONFIDENCE INCREASES.

LOW CIGS/VSBYS XPCTD TUE NGT THRU WED NGT W/ PDS OF RAIN/ISOLD TSTMS.
CONDS SHOULD BE IMPRVG DURG THE 2ND HALF OF THE WK INTO THE WKND
AS A LARGE AREA OF HIGH PRES SETS UP OVR THE ERN U.S.

&&

.MARINE...
LOW PRESSURE WILL REMAIN WEST OF THE WATERS TNGT. AN EAST-SOUTHEAST
FLOW IS EXPECTED DURING THIS TIME. SLY TO SELY WINDS UNDER 15 KT
EXPECTED TNGT.

THE SURFACE TROUGH WILL REMAIN WEST OF THE WATERS TUESDAY. WIND
SPEEDS WILL REMAIN BELOW SCA CRITERIA. SHOWERS AND T-STORMS ARE
POSSIBLE...MAINLY IN THE AFTERNOON.

WINDS XPCTD TO RMN BLO SCA TUE NGT THRU THE END OF THE WORK WK.
RW/TSTMS LKLY ON WED.

&&

.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES REMAIN AROUND THREE-QUARTERS TO ONE FOOT ABOVE
NORMAL THIS EVE. POSITIVE TIDAL ANOMALIES SHOULD REMAIN THE SAME
OR INCREASE GRADUALLY DUE TO THE SELY FLOW. ANOMALIES OF THIS
MAGNITUDE WILL LEAD TO MINOR COASTAL FLOODING ALONG THE UPPER
TIDAL POTOMAC RVR AND WRN SHORE OF THE MD CHSPK BAY FROM
ANNAPOLIS-NWD DURING THE TUE MRNG HIGH TIDE. HAVE ISSUED A COASTAL
FLOOD ADVISORY FOR THESE LOCATIONS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY FROM 6 AM TO NOON EDT TUESDAY FOR
     DCZ001.
MD...COASTAL FLOOD ADVISORY FROM 6 AM TO NOON EDT TUESDAY FOR
     MDZ007-011-014.
VA...COASTAL FLOOD ADVISORY FROM 6 AM TO NOON EDT TUESDAY FOR
     VAZ054.
WV...NONE.
MARINE...NONE.

&&

$$
UPDATE...KLEIN
PREV DISC...BJL/WOODY!

000
FXUS61 KRNK 220103
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
903 PM EDT MON MAY 21 2012

.SYNOPSIS...
A COLD FRONT WILL ARRIVE ON TUESDAY...AND THEN SLOWLY PUSH
EASTWARD TO THE COAST BY LATE WEDNESDAY. SCATTERED SHOWERS AND
THUNDERSTORMS...WITH SOME POTENTIALLY BRINGING HEAVY RAIN...WILL
BE POSSIBLE THROUGH THURSDAY. HIGH PRESSURE AND DRIER WEATHER WILL
ARRIVE LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 850 PM EDT MONDAY...
THIS EVENING 00Z/8PM RNK SOUNDING WAS QUITE MOIST WITH PWAT AT
1.10 INCHES AND A SE-S LOW LEVEL FLOW UP TO 5 KFT. THE UPPER LOW
MEANDERING ABOUT THE SOUTHEAST COMBINED WITH UPPER TROUGH MOVING
IN FROM THE OHIO VALLEY WILL CONTINUE THE SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS OUR REGION. KFCX 88D SHOWED THUNDERSTORMS
HAVE SPREAD INTO THE FOOTHILLS AND PIEDMONT THIS EVENING. LEANED
POPS TOWARDS WRFARW- RNK THIS EVENING INTO TONIGHT. INCREASED POPS
AND EASTWARD COVERAGE OF THUNDERSTORMS TONIGHT UNTIL MIDNIGHT...THEN
TRIMMED BACK POPS WITH LOSS OF SOLAR HEATING AND FOG OVERNIGHT.
RAISED LOW TEMPERATURES UP A FEW DEGREES TONIGHT WITH READINGS
FROM THE MID 50S IN THE WEST TO THE LOWER 60S IN THE SOUTHEAST.

AS OF 525 PM EDT MONDAY...
INCREASED POPS ACROSS THE WESTERN MOUNTAINS TO MATCH UP WITH
LATEST RADAR TRENDS. MADE SOME MINOR CHANGES IN TEMPERATURES AND
CLOUD COVER THIS EVENING.


AS OF 330 PM EDT MONDAY...

CURRENTLY...THE AREA IS PINCHED IN BETWEEN AN APPROACHING COLD
FRONT OVER THE OHIO RIVER VALLEY...AND A SLOW MOVING LOW
PRESSURE SYSTEM OVER THE DELMARVA PENINSULA. THE 12Z SOUNDING
SHOWS SEVERAL CAPS IN PLACE THAT DAYTIME HEATING HAS GRADUALLY
ERODED TO PRODUCE CONVECTION THIS EVENING. WITH 1000-1500 J/KG OF
CAPE AND INCREASING LOW LEVEL MOISTURE...SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP THROUGH MIDNIGHT. WINDS
ALOFT ARE VERY LIGHT...SO ANY STORMS THAT DEVELOP WILL BE SLOW TO
MOVE AND COULD PRESENT SOME HYDRO ISSUES IF TRAINING OCCURS.

THE SHOWERS AND THUNDERSTORMS SHOULD TAPER OFF AFTER MIDNIGHT...AS
DAYTIME HEATING AND INSTABILITY WILL BE LOST. HOWEVER...DUE TO
ABUNDANT SURFACE MOISTURE OVER THE AREA...AREAS OF FOG WILL
LIKELY DEVELOP DURING THE EARLY MORNING OF TUESDAY. SOME SHELTERED
LOCATIONS COULD SEE PATCHY DENSE FOG BY SUNRISE. TEMPERATURES
WERE ADJUSTED SLIGHTLY DOWNWARD FOR THE FOG AND POSSIBLE LOW
CLOUDS...WITH LOW TO MID 50S ALONG AND WEST OF THE BLUE
RIDGE...AND UPPER 50S IN THE PIEDMONT.

ONCE THE FOG RETREATS...TEMPERATURES SHOULD REBOUND INTO THE MID
70S TO NEAR 80 DEGREES FOR HIGHS ON TUESDAY. THE COLD FRONT WILL
APPROACH THE WESTERN APPALACHIAN MOUNTAINS...AND GREATER COVERAGE
OF SHOWERS AND THUNDERSTORMS WILL BE ANTICIPATED. A FEW OF THESE
STORMS MAY PRODUCE HEAVY RAINFALL...SO POPS WERE BUMPED UP TO
LIKELY FOR MOST OF THE AREA...AND CATEGORICAL WITHIN THE NEW RIVER
VALLEY. THE FLOW ALOFT WILL CONTINUE TO BE VERY WEAK...SO HYDRO
ISSUES HAVE BEEN ADDED TO THE HWO FOR LATE IN THE DAY.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 305 PM EDT MONDAY...

AN UNSETTLED WEATHER PATTERN IS IN STORE FOR THE SHORT TERM
PERIOD...AS A SHORTWAVE TROF DIGGING INTO MISSOURI THIS AFTERNOON
IS FORECAST TO DEEPEN AND CUT OFF OVER OUR AREA BY
WEDNESDAY...BEFORE LIFTING NORTHEAST THURSDAY.

PRECIPITATION COVERAGE INCREASES WEDNESDAY AS THE UPPER LOW/COOL
POOL MOVES OVER OUR AREA. WHILE CLOUD COVER SHOULD KEEP THE
POTENTIAL FOR SEVERE WEATHER LOW...CONCERNED ABOUT LOCALIZED
FLOODING WEDNESDAY CONSIDERING FORECAST CORFIDI VECTORS WILL BE LESS
THAN 10 KTS...AND PWATS WILL BE AROUND 1.5 INCHES...WHICH IS JUST
SHY OF 2 STANDARD DEVIATIONS ABV NORMAL. THEREFORE...WILL INTRODUCE
A MENTION OF LOCALIZED FLOODING IN HWO.

MODEL GUIDANCE SHOWS A BIG DISCREPANCY FOR HIGHS WEDNESDAY...WITH
THE GFS MOS GUIDANCE 5-10 DEGREES WARMER THAN THE NAM MOS GUIDANCE.
CONSIDERING FAIRLY STEEP LAPSE RATES...CLOUDS SHOULD BE
WIDESPREAD...AND LEANED TOWARD THE COOLER NAM MOS FOR HIGHS
WEDNESDAY.

THE UPPER LOW/COOL POOL LIFTS NORTHEAST...BUT A VERY MOIST AIR MASS
REMAINS IN PLACE...AND WEAK UPSLOPE FLOW WILL GENERATE MORE SHOWERS
AND STORMS...WITH GREATEST COVERAGE IN THE ALLEGHANY HIGHLANDS
CLOSER TO THE UPPER LOW. SHOWERS AND A FEW STORMS WILL AGAIN BE SLOW
MOVING WITH CORFIDI VECTORS AGAIN LESS THAN 10 KTS.  ONCE AGAIN
LEANED TOWARD THE COOLER GUIDANCE VALUES WITH EXTENSIVE CLOUD COVER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 305 PM EDT MONDAY...

THE MEDIUM RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT
BUILDING A STRONG UPPER RIDGE...FIRST OVER THE OHIO VALLEY...THEN
ELONGATING INTO THE MID-ATLANTIC REGION SUNDAY INTO MONDAY. THIS
WILL RESULT IN TEMPERATURES WELL ABOVE NORMAL AND LESS COVERAGE IN
PRECIPITATION.

ON FRIDAY...THE LINGERING UPPER LEVEL TROF FINALLY GETS PUSHED
NORTHEAST BY A SHORTWAVE MOVING THROUGH THE GREAT LAKES. WITH A
MOIST (GREATER THAN 1.5 PWATS) AND UNSTABLE AIR MASS IN PLACE AND
WEAK LOW LEVEL CONVERGENCE AND THE SFC...WIDELY SCATTERED
THUNDERSTORMS WILL AGAIN BE POSSIBLE.

THE COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH THROUGH THE
HOLIDAY WEEKEND AS THE UPPER RIDGE BUILDS. HOWEVER...WEAK...BUT
FAIRLY DEEP EAST/SOUTHEAST UPSLOPE LOW LEVEL FLOW MAY BE ABOVE TO
OVERCOME WARMING MID LEVEL TEMPS/RISING HEIGHTS TO INITIATE ISOLATED
TO WIDELY SCT STORMS ALONG THE BLUE RIDGE.

LEARNED TOWARD THE WARMER MEX GUIDANCE FOR TEMPS THROUGH THE LONG
TERM PERIOD...WITH FORECAST HIGHS NEARING RECORDS FOR BLF.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
AS OF 845 PM EDT MONDAY...

MAIN CONCERNS THROUGH TAF VALID PERIOD ARE EVENING CONVECTION TODAY
AND TOMORROW AND FOG DEVELOPMENT OVERNIGHT. WEAK UPPER LOW
MEANDERING ABOUT THE SOUTHEAST THROUGH TUE WILL COMBINE WITH AN
EQUALLY WEAK UPPER TROUGH DRIFTING IN FROM THE OHIO VALLEY. THE
COMBINATION OF THESE TWO FEATURES WILL RESULT IN UPPER LOW PRESSURE
DOMINATING THE FORECAST AREA THROUGH MID-WEEK...WITH A RESULTANT
UNSETTLED WEATHER PATTERN. THE PRIMARILY CATALYST FOR CONVECTION
WILL BE DIURNAL HEATING...HENCE TSRA SHOULD BE CONFINED MOSTLY TO
THE 18Z-02Z TIME FRAME NEXT TWO DAYS. FOG/CLOUD DEVELOPMENT
OVERNIGHT/EARLY TUE IS A BIGGER QUESTION AND CERTAINLY NOT CLEAR.
RAINFALL TODAY WAS SPOTTY AND CONFINED MAINLY TO THE AREAS ALONG AND
IMMEDIATELY EAST OF THE ALLEGHANYS...BUT DID MANAGE TO AFFECT
ROA/BCB/LWB. THIS COULD PROMOTE EARLY MORNING FOG DEVELOPMENT.
HOWEVER...MODEL SOUNDINGS SHOW NEAR SATURATION IN THE MID-UPPER
LEVELS OF THE ATMOSPHERE IN ASSOCIATION WITH THE CLOSED UPPER LOW
DRIFTING IN/NEAR THE AREA OVERNIGHT/TUE. CURRENT THINKING IS THAT
MID/UPPER-LEVEL CLOUDS WILL BE TOO ABUNDANT TO ALLOW FOR WIDESPREAD
DEVELOPMENT OF DENSE FOG. HAVE SIDED MORE TOWARD DENSE MID CLOUDS
AND MVFR BR...SPOTTY IFR AT THE USUAL SPOTS EARLY TUE. THESE
EXPECTED CLOUDS MAY ALSO DELAY/INHIBIT TSRA DEVELOPMENT TUE
AFTERNOON...BUT ALL INDICATIONS ARE THAT THERE WILL BE ENOUGH BREAKS
IN THE OVC TO ALLOW FOR SUFFICIENT SUNSHINE. GIVEN RELATIVELY COLD
AIR ALOFT...ANY HEATING...ALBEIT LIMITED...SHOULD RESULT IN QUICK
DEVELOPMENT OF AFTERNOON CONVECTION. HAVE CONFINED CONVECTION TO
VCTS UNTIL A BETTER HANDLE ON TIMING CAN BE ACQUIRED.

VERY LIGHT/RATHER UNDEFINABLE WIND FIELD PRESENT ACROSS THE CWA.
OUTSIDE AFTERNOON/EVENING CONVECTION...VRB03KT OR 00000KT GENERALLY
WORKS WELL AT MOST TAF SITES THROUGH TAF VALID PERIOD.


&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PW
NEAR TERM...KK/PW
SHORT TERM...PH
LONG TERM...PH
AVIATION...PW/RAB

000
FXUS61 KAKQ 212257
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
657 PM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THIS WEEK. HIGH PRESSURE BUILDS IN FOR THE UPCOMING WEEKEND.

&&

.NEAR TERM /THROUGH TUESDAY/...
EARLY EVENING SFC MAP SHOWING ELONGATED TROF LOCATED IVOF I95
CORRIDOR. THIS IS WHERE THE MAJORITY OF ANY CONVECTION HAS
DEVELOPED / MOVED PAST FEW HOURS. RUC/WRF/RADAR TRENDS SEEM TO
KEEP THIS TREND GOING THROUGH THE EVENING HOURS...NOTING THE FINE
LINE ON RADAR CURRENTLY MOVG WEST FROM AKQ AND APPROACHING I95.
ADJUSTED WX AND POPS GRIDS A BIT TO TAKE OUT THUNDER BOTH EAST AND
WEST OF I95 AND LOWER POP TO 30%...BUT KEPT 40% POP WITH ISLTD
THUNDER GOING ALONG THE I95 CORRIDOR NEXT FEW HOURS. SKIES PT TO M
CLDY FOR THE REST OF THE EVENING BECOME M CLDY AFTER MIDNIGHT DUE
TO THE ABUNDANT LOW LEVEL MOISTURE. WARM / HUMID. LOWS 60-65.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
UNSETTLED CONDS...NOT DUE TO TS ALBERTO...WILL CONTINUE THRU THE
SHORT TERM PERIOD WITH THE AFOREMENTIONED UPR-LVL TROF STILL IN
PLACE ALONG THE EASTERN SEABOARD. THIS WILL LEAD TO PERIODIC
CHANCES FOR SHOWERS AND STORMS AS MOIST S/SW FLOW CONTINUES. FOR
TUE...SFC TROF WILL BE SITUATED OVR WESTERN PORTIONS OF THE FA
WHERE HIGHEST POPS (50%) WERE PLACED...30-40% ELSEWHERE. TEMPS
CLIMB INTO THE UPR 70S TO LWR 80S UNDER A MSTLY CLDY SKY. RAIN MAY
LINGER INTO TUE NGT...WITH THE BEST CHC AGAIN OVR WESTERN AREAS.
UPR-LVL TROF CUTS OFF FROM THE MEAN FLOW TUE NGT INTO WED AS A
POTENT S/W DIVES DOWN THE TROF BASE. THE CENTER OF THE RESULTING
UPR-LVL LOW WILL CENTER ITSELF NEAR THE MID ATLANTIC WED INTO
THU...WITH CHANCES FOR RAIN EACH DAY. BEST CHANCE FOR RAIN DURING
THE PERIOD WILL BE WED (LIKELY POPS FOR NW QUADRANT OF FA) WITH A
SFC TROF OVR THE MID ATLANTIC...DECENT FORCING ALOFT...AND A VERY
MOIST ATM. SEASONABLE TEMPS CONTINUE WED AND THU...HIGHS STILL IN
THE UPR 70S TO LWR 80S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE LATEST NUMERICAL GUIDANCE IS SUGGESTING THAT THE PERSISTENT
UPPER LOW MAY LINGER INTO FRIDAY. HOWEVER...AT THIS POINT NOTHING
MORE THAT A SLIGHT CHANCE POP IS NECESSARY. AN UPPER HIGH THEN
BUILDS OVER THE OHIO VALLEY FOR THE MEMORIAL DAY WEEKEND. GIVEN
WHERE THE HIGH SETS UP IT IS POSSIBLE SOME CONVECTION COULD ROUND
THE TOP OF THE RIDGE AND APPROACH THE LOCAL AREA IN MID-LEVEL NNW
FLOW. THE LARGE MAJORITY OF THE TIME IS EXPECTED TO BE DRY AND THERE
IS BASICALLY NO SKILL IN FORECASTING MCS ACTIVITY IN THE MEDIUM
RANGE. TEMPERATURES SHOULD BE ABOVE SEASONAL AVERAGES WITH HIGHS IN
THE MID 80S TO NEAR 90 (SLIGHTLY COOLER ALONG THE COASTS WITH LIGHT
ONSHORE FLOW). LOW TEMPERATURES SHOULD GENERALLY BE IN THE 60S.

&&

.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
WEAK AREA OF LOW PRESSURE CENTERED OVER THE AREA AT 19Z. ISOLATED
SHOWERS WILL CONTINUE TO POP UP THROUGH THE EVENING HOURS. LIGHT
ONSHORE FLOW WILL KEEP ATMOSPHERE MOIST AND ALLOW CEILINGS TO
REMAIN SCT/BKN 2K-3K FT. IFR/LIFR CONDITIONS ARE POSSIBLE
OVERNIGHT...RAISING TO VFR AROUND 14Z FOR MOST SITES. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE TUE AFTN AS UPPER TROUGH CROSSES THE
AREA.

UPPER LOW REMAINS OVER THE AREA THROUGH FRIDAY CREATING UNSETTLED
WEATHER WITH FLIGHT RESTRICTIONS POSSIBLE.

&&

.MARINE...
THE LATEST SURFACE ANALYSIS SHOWS A RATHER NEBULOUS SURFACE PATTERN
ACROSS THE LOCAL MARNIE AREA AND HENCE WEAK FLOW. THIS GENERAL FLOW
PATTERN SHOULD CONTINUE THROUGH MUCH OF THE WEEK WITH S OR SE FLOW
AOB 10KT. AN AREA OF LOW PRESSURE (NOT TS ALBERTO) PRESENTLY WELL
EAST OF THE NC COAST WILL MOVE NNE ON A TRAJECTORY TOWARD NS THROUGH
TUESDAY. WNA WAVE SHOWS SWELL ASSOCIATED WITH THIS LOW AFFECTING THE
MARINE AREA TUESDAY INTO TUESDAY NIGHT WITH SEAS AOA 5FT GENERALLY
OUT PAST 5-10NM. AN SCA FOR HAZARDOUS SEAS WILL BE RAISED FROM 6AM
TUESDAY TO 6AM WEDNESDAY. OTHERWISE...SEAS SHOULD DROP BELOW SCA FOR
THE REMAINDER OF THE WEEK. UNSETTLED CONDITIONS SHOULD PERSIST MUCH
OF THE WEEK WITH A CHANCE FOR MAINLY AFTERNOON AND EVENING
THUNDERSTORMS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 AM TUESDAY TO 6
     AM EDT WEDNESDAY FOR ANZ650-652-654-656-658.

&&

$$
SYNOPSIS...MAS
NEAR TERM...MAS/MPR
SHORT TERM...MAS
LONG TERM...AJZ
AVIATION...DAP
MARINE...AJZ

000
FXUS61 KRNK 212129
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
529 PM EDT MON MAY 21 2012

.SYNOPSIS...
A COLD FRONT WILL ARRIVE ON TUESDAY...AND THEN SLOWLY PUSH
EASTWARD TO THE COAST BY LATE WEDNESDAY. SCATTERED SHOWERS AND
THUNDERSTORMS...WITH SOME POTENTIALLY BRINGING HEAVY RAIN...WILL
BE POSSIBLE THROUGH THURSDAY. HIGH PRESSURE AND DRIER WEATHER WILL
ARRIVE LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 525 PM EDT MONDAY...
INCREASED POPS ACROSS THE WESTERN MOUNTAINS TO MATCH UP WITH
LATEST RADAR TRENDS. MADE SOME MINOR CHANGES IN TEMPERATURES AND
CLOUD COVER THIS EVENING.


AS OF 330 PM EDT MONDAY...

CURRENTLY...THE AREA IS PINCHED IN BETWEEN AN APPROACHING COLD
FRONT OVER THE OHIO RIVER VALLEY...AND A SLOW MOVING LOW
PRESSURE SYSTEM OVER THE DELMARVA PENINSULA. THE 12Z SOUNDING
SHOWS SEVERAL CAPS IN PLACE THAT DAYTIME HEATING HAS GRADUALLY
ERODED TO PRODUCE CONVECTION THIS EVENING. WITH 1000-1500 J/KG OF
CAPE AND INCREASING LOW LEVEL MOISTURE...SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP THROUGH MIDNIGHT. WINDS
ALOFT ARE VERY LIGHT...SO ANY STORMS THAT DEVELOP WILL BE SLOW TO
MOVE AND COULD PRESENT SOME HYDRO ISSUES IF TRAINING OCCURS.

THE SHOWERS AND THUNDERSTORMS SHOULD TAPER OFF AFTER MIDNIGHT...AS
DAYTIME HEATING AND INSTABILITY WILL BE LOST. HOWEVER...DUE TO
ABUNDANT SURFACE MOISTURE OVER THE AREA...AREAS OF FOG WILL
LIKELY DEVELOP DURING THE EARLY MORNING OF TUESDAY. SOME SHELTERED
LOCATIONS COULD SEE PATCHY DENSE FOG BY SUNRISE. TEMPERATURES
WERE ADJUSTED SLIGHTLY DOWNWARD FOR THE FOG AND POSSIBLE LOW
CLOUDS...WITH LOW TO MID 50S ALONG AND WEST OF THE BLUE
RIDGE...AND UPPER 50S IN THE PIEDMONT.

ONCE THE FOG RETREATS...TEMPERATURES SHOULD REBOUND INTO THE MID
70S TO NEAR 80 DEGREES FOR HIGHS ON TUESDAY. THE COLD FRONT WILL
APPROACH THE WESTERN APPALACHIAN MOUNTAINS...AND GREATER COVERAGE
OF SHOWERS AND THUNDERSTORMS WILL BE ANTICIPATED. A FEW OF THESE
STORMS MAY PRODUCE HEAVY RAINFALL...SO POPS WERE BUMPED UP TO
LIKELY FOR MOST OF THE AREA...AND CATEGORICAL WITHIN THE NEW RIVER
VALLEY. THE FLOW ALOFT WILL CONTINUE TO BE VERY WEAK...SO HYDRO
ISSUES HAVE BEEN ADDED TO THE HWO FOR LATE IN THE DAY.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 305 PM EDT MONDAY...

AN UNSETTLED WEATHER PATTERN IS IN STORE FOR THE SHORT TERM
PERIOD...AS A SHORTWAVE TROF DIGGING INTO MISSOURI THIS AFTERNOON
IS FORECAST TO DEEPEN AND CUT OFF OVER OUR AREA BY
WEDNESDAY...BEFORE LIFTING NORTHEAST THURSDAY.

PRECIPITATION COVERAGE INCREASES WEDNESDAY AS THE UPPER LOW/COOL
POOL MOVES OVER OUR AREA. WHILE CLOUD COVER SHOULD KEEP THE
POTENTIAL FOR SEVERE WEATHER LOW...CONCERNED ABOUT LOCALIZED
FLOODING WEDNESDAY CONSIDERING FORECAST CORFIDI VECTORS WILL BE LESS
THAN 10 KTS...AND PWATS WILL BE AROUND 1.5 INCHES...WHICH IS JUST
SHY OF 2 STANDARD DEVIATIONS ABV NORMAL. THEREFORE...WILL INTRODUCE
A MENTION OF LOCALIZED FLOODING IN HWO.

MODEL GUIDANCE SHOWS A BIG DISCREPANCY FOR HIGHS WEDNESDAY...WITH
THE GFS MOS GUIDANCE 5-10 DEGREES WARMER THAN THE NAM MOS GUIDANCE.
CONSIDERING FAIRLY STEEP LAPSE RATES...CLOUDS SHOULD BE
WIDESPREAD...AND LEANED TOWARD THE COOLER NAM MOS FOR HIGHS
WEDNESDAY.

THE UPPER LOW/COOL POOL LIFTS NORTHEAST...BUT A VERY MOIST AIR MASS
REMAINS IN PLACE...AND WEAK UPSLOPE FLOW WILL GENERATE MORE SHOWERS
AND STORMS...WITH GREATEST COVERAGE IN THE ALLEGHANY HIGHLANDS
CLOSER TO THE UPPER LOW. SHOWERS AND A FEW STORMS WILL AGAIN BE SLOW
MOVING WITH CORFIDI VECTORS AGAIN LESS THAN 10 KTS.  ONCE AGAIN
LEANED TOWARD THE COOLER GUIDANCE VALUES WITH EXTENSIVE CLOUD COVER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 305 PM EDT MONDAY...

THE MEDIUM RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT
BUILDING A STRONG UPPER RIDGE...FIRST OVER THE OHIO VALLEY...THEN
ELONGATING INTO THE MID-ATLANTIC REGION SUNDAY INTO MONDAY. THIS
WILL RESULT IN TEMPERATURES WELL ABOVE NORMAL AND LESS COVERAGE IN
PRECIPITATION.

ON FRIDAY...THE LINGERING UPPER LEVEL TROF FINALLY GETS PUSHED
NORTHEAST BY A SHORTWAVE MOVING THROUGH THE GREAT LAKES. WITH A
MOIST (GREATER THAN 1.5 PWATS) AND UNSTABLE AIR MASS IN PLACE AND
WEAK LOW LEVEL CONVERGENCE AND THE SFC...WIDELY SCATTERED
THUNDERSTORMS WILL AGAIN BE POSSIBLE.

THE COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH THROUGH THE
HOLIDAY WEEKEND AS THE UPPER RIDGE BUILDS. HOWEVER...WEAK...BUT
FAIRLY DEEP EAST/SOUTHEAST UPSLOPE LOW LEVEL FLOW MAY BE ABOVE TO
OVERCOME WARMING MID LEVEL TEMPS/RISING HEIGHTS TO INITIATE ISOLATED
TO WIDELY SCT STORMS ALONG THE BLUE RIDGE.

LEARNED TOWARD THE WARMER MEX GUIDANCE FOR TEMPS THROUGH THE LONG
TERM PERIOD...WITH FORECAST HIGHS NEARING RECORDS FOR BLF.

&&

.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM EDT MONDAY...

VFR CONDITIONS SHOULD PREVAIL THROUGH THE REST OF TODAY. A FEW
SCATTERED SHOWERS AND THUNDERSTORMS WILL POP UP LATER IN THE
AFTERNOON. ADDED THE MENTION OF THUNDERSTORM TO BCB AND KEPT
VCSH AT REST OF SITES FOR THE NEXT COUPLE OF HOURS.

ALTHOUGH THE THREAT OF SHOWERS WILL DISSIPATE BY MIDNIGHT...ALL
GUIDANCE IS PREDICTING THE DEVELOPMENT OF FOG DUE TO PLENTIFUL
SURFACE MOISTURE. WHETHER DENSE FOG OR LOW STRATUS CLOUDS FORMS
REMAINS THE MOST CHALLENGING ASPECT OF THIS FORECAST. FOR
NOW...FOG WILL BE FORECASTED AT LYH...ROA...BCB...AND LWB DURING
THE EARLY HOURS OF TUESDAY MORNING. IFR CONDITIONS APPEAR LIKELY
FOR BCB AND LWB...SO THE TAFS FOR THESE SITES WILL REFLECT MORE
PESSIMISTIC VISIBILITIES. MEANWHILE...CONDITIONS FOR BLF AND DAN
SEEM TO SUGGEST A LOWER PROBABILITY OF FOG...AND HAVE DECIDED TO
KEEP IT OUT OF THE TAFS. VFR CONDITIONS WILL RETURN FOR ALL SITES
LATER IN THE MORNING.

THE AREA WILL REMAIN INFLUENCED BY AN UPPER LEVEL TROUGH AND WEAK
COLD FRONT UNTIL MIDWEEK...WHICH WILL BE KEEPING A THREAT OF
SHRA/TSRA AND SUB VFR WX AROUND UNTIL THEN. MAINLY VFR WX EXPECTED
FOR THU-FRI UNDER HIGH PRESSURE TO THE NORTHEAST...ALTHOUGH SOME
LATE NIGHT FOG/STRATUS IS NOT OUT OF THE QUESTION.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PW
NEAR TERM...KK/PW
SHORT TERM...PH
LONG TERM...PH
AVIATION...KK/PW

000
FXUS61 KRNK 211938
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
338 PM EDT MON MAY 21 2012

.SYNOPSIS...
A COLD FRONT WILL ARRIVE ON TUESDAY...AND THEN SLOWLY PUSH
EASTWARD TO THE COAST BY LATE WEDNESDAY. SCATTERED SHOWERS AND
THUNDERSTORMS...WITH SOME POTENTIALLY BRINGING HEAVY RAIN...WILL
BE POSSIBLE THROUGH THURSDAY. HIGH PRESSURE AND DRIER WEATHER WILL
ARRIVE LATE IN THE WEEK.

&&

.NEAR TERM /TONIGHT THROUGH TUESDAY/...
AS OF 330 PM EDT MONDAY...

CURRENTLY...THE AREA IS PINCHED IN BETWEEN AN APPROACHING COLD
FRONT OVER THE OHIO RIVER VALLEY...AND A SLOW MOVING LOW
PRESSURE SYSTEM OVER THE DELMARVA PENINSULA. THE 12Z SOUNDING
SHOWS SEVERAL CAPS IN PLACE THAT DAYTIME HEATING HAS GRADUALLY
ERODED TO PRODUCE CONVECTION THIS EVENING. WITH 1000-1500 J/KG OF
CAPE AND INCREASING LOW LEVEL MOISTURE...SCATTERED SHOWERS AND
THUNDERSTORMS WILL CONTINUE TO DEVELOP THROUGH MIDNIGHT. WINDS
ALOFT ARE VERY LIGHT...SO ANY STORMS THAT DEVELOP WILL BE SLOW TO
MOVE AND COULD PRESENT SOME HYDRO ISSUES IF TRAINING OCCURS.

THE SHOWERS AND THUNDERSTORMS SHOULD TAPER OFF AFTER MIDNIGHT...AS
DAYTIME HEATING AND INSTABILITY WILL BE LOST. HOWEVER...DUE TO
ABUNDANT SURFACE MOISTURE OVER THE AREA...AREAS OF FOG WILL
LIKELY DEVELOP DURING THE EARLY MORNING OF TUESDAY. SOME SHELTERED
LOCATIONS COULD SEE PATCHY DENSE FOG BY SUNRISE. TEMPERATURES
WERE ADJUSTED SLIGHTLY DOWNWARD FOR THE FOG AND POSSIBLE LOW
CLOUDS...WITH LOW TO MID 50S ALONG AND WEST OF THE BLUE
RIDGE...AND UPPER 50S IN THE PIEDMONT.

ONCE THE FOG RETREATS...TEMPERATURES SHOULD REBOUND INTO THE MID
70S TO NEAR 80 DEGREES FOR HIGHS ON TUESDAY. THE COLD FRONT WILL
APPROACH THE WESTERN APPALACHIAN MOUNTAINS...AND GREATER COVERAGE
OF SHOWERS AND THUNDERSTORMS WILL BE ANTICIPATED. A FEW OF THESE
STORMS MAY PRODUCE HEAVY RAINFALL...SO POPS WERE BUMPED UP TO
LIKELY FOR MOST OF THE AREA...AND CATEGORICAL WITHIN THE NEW RIVER
VALLEY. THE FLOW ALOFT WILL CONTINUE TO BE VERY WEAK...SO HYDRO
ISSUES HAVE BEEN ADDED TO THE HWO FOR LATE IN THE DAY.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 305 PM EDT MONDAY...

AN UNSETTLED WEATHER PATTERN IS IN STORE FOR THE SHORT TERM
PERIOD...AS A SHORTWAVE TROF DIGGING INTO MISSOURI THIS AFTERNOON
IS FORECAST TO DEEPEN AND CUT OFF OVER OUR AREA BY
WEDNESDAY...BEFORE LIFTING NORTHEAST THURSDAY.

PRECIPITATION COVERAGE INCREASES WEDNESDAY AS THE UPPER LOW/COOL
POOL MOVES OVER OUR AREA. WHILE CLOUD COVER SHOULD KEEP THE
POTENTIAL FOR SEVERE WEATHER LOW...CONCERNED ABOUT LOCALIZED
FLOODING WEDNESDAY CONSIDERING FORECAST CORFIDI VECTORS WILL BE LESS
THAN 10 KTS...AND PWATS WILL BE AROUND 1.5 INCHES...WHICH IS JUST
SHY OF 2 STANDARD DEVIATIONS ABV NORMAL. THEREFORE...WILL INTRODUCE
A MENTION OF LOCALIZED FLOODING IN HWO.

MODEL GUIDANCE SHOWS A BIG DISCREPANCY FOR HIGHS WEDNESDAY...WITH
THE GFS MOS GUIDANCE 5-10 DEGREES WARMER THAN THE NAM MOS GUIDANCE.
CONSIDERING FAIRLY STEEP LAPSE RATES...CLOUDS SHOULD BE
WIDESPREAD...AND LEANED TOWARD THE COOLER NAM MOS FOR HIGHS
WEDNESDAY.

THE UPPER LOW/COOL POOL LIFTS NORTHEAST...BUT A VERY MOIST AIR MASS
REMAINS IN PLACE...AND WEAK UPSLOPE FLOW WILL GENERATE MORE SHOWERS
AND STORMS...WITH GREATEST COVERAGE IN THE ALLEGHANY HIGHLANDS
CLOSER TO THE UPPER LOW. SHOWERS AND A FEW STORMS WILL AGAIN BE SLOW
MOVING WITH CORFIDI VECTORS AGAIN LESS THAN 10 KTS.  ONCE AGAIN
LEANED TOWARD THE COOLER GUIDANCE VALUES WITH EXTENSIVE CLOUD COVER.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 305 PM EDT MONDAY...

THE MEDIUM RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT
BUILDING A STRONG UPPER RIDGE...FIRST OVER THE OHIO VALLEY...THEN
ELONGATING INTO THE MID-ATLANTIC REGION SUNDAY INTO MONDAY. THIS
WILL RESULT IN TEMPERATURES WELL ABOVE NORMAL AND LESS COVERAGE IN
PRECIPITATION.

ON FRIDAY...THE LINGERING UPPER LEVEL TROF FINALLY GETS PUSHED
NORTHEAST BY A SHORTWAVE MOVING THROUGH THE GREAT LAKES. WITH A
MOIST (GREATER THAN 1.5 PWATS) AND UNSTABLE AIR MASS IN PLACE AND
WEAK LOW LEVEL CONVERGENCE AND THE SFC...WIDELY SCATTERED
THUNDERSTORMS WILL AGAIN BE POSSIBLE.

THE COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH THROUGH THE
HOLIDAY WEEKEND AS THE UPPER RIDGE BUILDS. HOWEVER...WEAK...BUT
FAIRLY DEEP EAST/SOUTHEAST UPSLOPE LOW LEVEL FLOW MAY BE ABOVE TO
OVERCOME WARMING MID LEVEL TEMPS/RISING HEIGHTS TO INITIATE ISOLATED
TO WIDELY SCT STORMS ALONG THE BLUE RIDGE.

LEARNED TOWARD THE WARMER MEX GUIDANCE FOR TEMPS THROUGH THE LONG
TERM PERIOD...WITH FORECAST HIGHS NEARING RECORDS FOR BLF.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM EDT MONDAY...

VFR CONDITIONS SHOULD PREVAIL THROUGH THE REST OF TODAY. A FEW
SCATTERED SHOWERS AND THUNDERSTORMS WILL POP UP LATER IN THE
AFTERNOON...BUT CHANCES ARE LOW ENOUGH THAT THUNDER WILL BE KEPT OUT
OF THE TAFS. VCSH WILL BE USED INSTEAD FOR ALL SITES. ALTHOUGH THE
THREAT OF SHOWERS WILL DISSIPATE BY MIDNIGHT...ALL GUIDANCE IS
PREDICTING THE DEVELOPMENT OF FOG DUE TO PLENTIFUL SURFACE MOISTURE.
WHETHER DENSE FOG OR LOW STRATUS CLOUDS FORMS REMAINS THE MOST
CHALLENGING ASPECT OF THIS FORECAST. FOR NOW...FOG WILL BE
FORECASTED AT LYH...ROA...BCB...AND LWB DURING THE EARLY HOURS OF
TUESDAY MORNING. IFR CONDITIONS APPEAR LIKELY FOR BCB AND LWB...SO
THE TAFS FOR THESE SITES WILL REFLECT MORE PESSIMISTIC VISIBILITIES.
MEANWHILE...CONDITIONS FOR BLF AND DAN SEEM TO SUGGEST A LOWER
PROBABILITY OF FOG...AND HAVE DECIDED TO KEEP IT OUT OF THE TAFS.
VFR CONDITIONS WILL RETURN FOR ALL SITES LATER IN THE MORNING.

THE AREA WILL REMAIN INFLUENCED BY AN UPPER LEVEL TROUGH AND WEAK
COLD FRONT UNTIL MIDWEEK...WHICH WILL BE KEEPING A THREAT OF
SHRA/TSRA AND SUB VFR WX AROUND UNTIL THEN. MAINLY VFR WX EXPECTED
FOR THU-FRI UNDER HIGH PRESSURE TO THE NORTHEAST...ALTHOUGH SOME
LATE NIGHT FOG/STRATUS IS NOT OUT OF THE QUESTION.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PW
NEAR TERM...PW
SHORT TERM...PH
LONG TERM...PH
AVIATION...KK/PW

000
FXUS61 KAKQ 211935
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
335 PM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THIS WEEK. HIGH PRESSURE BUILDS IN FOR THE UPCOMING WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
TRICKY FORECAST SCENARIO THIS AFTN AND EVNG WITH A BROAD UPR-LVL
TROF OVR THE EASTERN CONUS AND FAIRLY DISORGANIZED SFC LOW PRES.
COMBO OF WEAK CONVERG ALONG THE LO-LVL PRES TROF AND SUBTLE
PERTURBATIONS WITHIN THE FLOW ALOFT WILL BE ENOF FORCING FOR
SCATTERED SHOWERS GIVEN DEEP MOISTURE PROFILES. STRONGEST S/W TROF
IS PROGGED TO STAY OFFSHORE AND NOT AFFECT THE LOCAL AREA. ISO
TSTMS EXPECTED BUT NOT SVR DUE TO WEAK SHEAR...FORCING...AND LAPSE
RATES. BIGGEST THREAT WITH ANY STORM WILL BE HEAVY RAIN (PWAT ~1.5
IN AND WEAK STEERING FLOW ALOFT). THE RAIN MAY LINGER INTO THE
OVRNGT HRS THOUGH MUCH OF IT WILL DISSIPATE WITH THE LOSS OF
DAYTIME HEATING. FOG POSSIBLE IN SOME AREAS ERLY TUE MRNG...BUT
EXPECTING MORE IN THE WAY OF LOW STRATUS THROUGHOUT THE AREA.
TEMPS A BIT ABOVE NORMAL WITH THE CLOUD COVER IN PLACE...LOWS IN
THE LWR TO MID 60S AREAWIDE.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
UNSETTLED CONDS...NOT DUE TO TS ALBERTO...WILL CONTINUE THRU THE
SHORT TERM PERIOD WITH THE AFOREMENTIONED UPR-LVL TROF STILL IN
PLACE ALONG THE EASTERN SEABOARD. THIS WILL LEAD TO PERIODIC
CHANCES FOR SHOWERS AND STORMS AS MOIST S/SW FLOW CONTINUES. FOR
TUE...SFC TROF WILL BE SITUATED OVR WESTERN PORTIONS OF THE FA
WHERE HIGHEST POPS (50%) WERE PLACED...30-40% ELSEWHERE. TEMPS
CLIMB INTO THE UPR 70S TO LWR 80S UNDER A MSTLY CLDY SKY. RAIN MAY
LINGER INTO TUE NGT...WITH THE BEST CHC AGAIN OVR WESTERN AREAS.
UPR-LVL TROF CUTS OFF FROM THE MEAN FLOW TUE NGT INTO WED AS A
POTENT S/W DIVES DOWN THE TROF BASE. THE CENTER OF THE RESULTING
UPR-LVL LOW WILL CENTER ITSELF NEAR THE MID ATLANTIC WED INTO
THU...WITH CHANCES FOR RAIN EACH DAY. BEST CHANCE FOR RAIN DURING
THE PERIOD WILL BE WED (LIKELY POPS FOR NW QUADRANT OF FA) WITH A
SFC TROF OVR THE MID ATLANTIC...DECENT FORCING ALOFT...AND A VERY
MOIST ATM. SEASONABLE TEMPS CONTINUE WED AND THU...HIGHS STILL IN
THE UPR 70S TO LWR 80S.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE LATEST NUMERICAL GUIDANCE IS SUGGESTING THAT THE PERSISTENT
UPPER LOW MAY LINGER INTO FRIDAY. HOWEVER...AT THIS POINT NOTHING
MORE THAT A SLIGHT CHANCE POP IS NECESSARY. AN UPPER HIGH THEN
BUILDS OVER THE OHIO VALLEY FOR THE MEMORIAL DAY WEEKEND. GIVEN
WHERE THE HIGH SETS UP IT IS POSSIBLE SOME CONVECTION COULD ROUND
THE TOP OF THE RIDGE AND APPROACH THE LOCAL AREA IN MID-LEVEL NNW
FLOW. THE LARGE MAJORITY OF THE TIME IS EXPECTED TO BE DRY AND THERE
IS BASICALLY NO SKILL IN FORECASTING MCS ACTIVITY IN THE MEDIUM
RANGE. TEMPERATURES SHOULD BE ABOVE SEASONAL AVERAGES WITH HIGHS IN
THE MID 80S TO NEAR 90 (SLIGHTLY COOLER ALONG THE COASTS WITH LIGHT
ONSHORE FLOW). LOW TEMPERATURES SHOULD GENERALLY BE IN THE 60S.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
WEAK AREA OF LOW PRESSURE CENTERED OVER THE AREA AT 19Z. ISOLATED
SHOWERS WILL CONTINUE TO POP UP THROUGH THE EVENING HOURS. LIGHT
ONSHORE FLOW WILL KEEP ATMOSPHERE MOIST AND ALLOW CEILINGS TO
REMAIN SCT/BKN 2K-3K FT. IFR/LIFR CONDITIONS ARE POSSIBLE
OVERNIGHT...RAISING TO VFR AROUND 14Z FOR MOST SITES. SHOWERS AND
THUNDERSTORMS ARE POSSIBLE TUE AFTN AS UPPER TROUGH CROSSES THE
AREA.

UPPER LOW REMAINS OVER THE AREA THROUGH FRIDAY CREATING UNSETTLED
WEATHER WITH FLIGHT RESTRICTIONS POSSIBLE.

&&

.MARINE...
THE LATEST SURFACE ANALYSIS SHOWS A RATHER NEBULOUS SURFACE PATTERN
ACROSS THE LOCAL MARNIE AREA AND HENCE WEAK FLOW. THIS GENERAL FLOW
PATTERN SHOULD CONTINUE THROUGH MUCH OF THE WEEK WITH S OR SE FLOW
AOB 10KT. AN AREA OF LOW PRESSURE (NOT TS ALBERTO) PRESENTLY WELL
EAST OF THE NC COAST WILL MOVE NNE ON A TRAJECTORY TOWARD NS THROUGH
TUESDAY. WNA WAVE SHOWS SWELL ASSOCIATED WITH THIS LOW AFFECTING THE
MARINE AREA TUESDAY INTO TUESDAY NIGHT WITH SEAS AOA 5FT GENERALLY
OUT PAST 5-10NM. AN SCA FOR HAZARDOUS SEAS WILL BE RAISED FROM 6AM
TUESDAY TO 6AM WEDNESDAY. OTHERWISE...SEAS SHOULD DROP BELOW SCA FOR
THE REMAINDER OF THE WEEK. UNSETTLED CONDITIONS SHOULD PERSIST MUCH
OF THE WEEK WITH A CHANCE FOR MAINLY AFTERNOON AND EVENING
THUNDERSTORMS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...MAS
NEAR TERM...MAS
SHORT TERM...MAS
LONG TERM...AJZ
AVIATION...DAP
MARINE...AJZ

000
FXUS61 KRNK 211905
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
305 PM EDT MON MAY 21 2012

.SYNOPSIS...
A COLD FRONT WILL ARRIVE ON TUESDAY...AND THEN SLOWLY PUSH
EAST TO THE COAST BY LATE WEDNESDAY. SHOWERS AND
THUNDERSTORMS...SOME BRINGING HEAVY RAIN...WILL BE POSSIBLE
THROUGH THURSDAY. HIGH PRESSURE AND DRIER WEATHER ARRIVES LATE IN
THE WEEK.

&&

.NEAR TERM /THROUGH TUESDAY/...
AS OF 1100 AM EDT MONDAY...

CURRENTLY...THE CWA IS PINCHED IN BETWEEN AN APPROACHING COLD FRONT
OVER THE OHIO RIVER VALLEY...AND A SLOW MOVING LOW PRESSURE SYSTEM
OVER THE DELMARVA PENINSULA. NOT MUCH ADJUSTMENT WAS NEEDED FOR THE
HIGH TEMPERATURES TODAY...BUT CLOUD COVER WILL PLAY A SIGNIFICANT
ROLE. THUS...HIGHS WILL BE IN THE MID TO UPPER 70S FOR WEST OF THE
BLUE RIDGE. SOUTHSIDE VIRGINIA...THE NORTH CAROLINA PIEDMONT...AND
LOCATIONS NEAR ROANOKE VIRGINIA WILL SEE UPPER 70S TO LOWER 80S. THE
SHOWER ACTIVITY FROM EARLIER THIS MORNING HAS DISSIPATED...SO POPS
WERE LOWERED FOR THE REST OF THIS MORNING. CHANCE POPS WERE BROUGHT
IN OVER THE EASTERN VIRGINIA PIEDMONT AT THE START FROM THE SLOWLY
RETROGRADING LOW PRESSURE SYSTEM...AND LATER IN THE WESTERN
MOUNTAINS FROM THE ARRIVING COLD FRONT.

THE 12Z SOUNDING SHOWS SEVERAL CAPS IN PLACE THAT DAYTIME HEATING
WILL HAVE TO OVERCOME TO OBTAIN CONVECTION LATER IN THE AFTERNOON.
IF WE DO BREAK THESE CAPS...A POSSIBLE 1000-1500 J/KG OF CAPE COULD
BE REALIZED...AND SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE WEST OF THE BLUE RIDGE. AREAS NEAR MARTINSVILLE VIRGINIA
AND THE NORTH CAROLINA PIEDMONT HAVE THE LOWEST CHANCE BASED ON THE
LOWER THETA-E DEPICTED IN GUIDANCE AND THE OVERALL FLOW PATTERN.
WINDS ALOFT ARE VERY LIGHT...SO ANY STORM THAT DEVELOPS WILL BE SLOW
TO MOVE AND COULD PRESENT SOME HYDRO ISSUES IF TRAINING OCCURS.

TONIGHT...WITH SUN SETTING...THINKING IS THAT ORGANIZED CONVECTION
WEAKENS. HOWEVER...SFC FRONT WILL WORK ITS WAY TOWARD THE CENTRAL
APPALACHIANS BY TUESDAY MORNING AND MAY SEE AN INCREASE IN COVERAGE
TOWARD SOUTHEAST WEST VIRGINIA SOUTH INTO THE NORTH CAROLINA
MOUNTAINS BY DAYBREAK. THE MODELS ARE DIFFERENT ON THE SPEED OF THE
UPPER SYSTEM AND FRONTAL PRECIP...WITH THE NAM FASTEST IN BRINGING A
SOMEWHAT ORGANIZED LINE INTO FAR SOUTHWEST VA...WHILE THE ECMWF/GFS
KEEP IT FURTHER WEST. AGAIN...FOLLOWING SLOWER SOLUTION. LOWS
TONIGHT WILL STAY MILD WITH MID 50S TO AROUND 60 EXPECTED.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 305 PM EDT MONDAY...

AN UNSETTLED WEATHER PATTERN IS IN STORE FOR THE SHORT TERM
PERIOD...AS A SHORTWAVE TROF DIGGING INTO MISSOURI THIS AFTERNOON
IS FORECAST TO DEEPEN AND CUT OFF OVER OUR AREA BY
WEDNESDAY...BEFORE LIFTING NORTHEAST THURSDAY.

PRECIPITATION COVERAGE INCREASES WEDNESDAY AS THE UPPER LOW/COOL
POOL MOVES OVER OUR AREA. WHILE CLOUD COVER SHOULD KEEP THE
POTENTIAL FOR SEVERE WEATHER LOW...CONCERNED ABOUT LOCALIZED
FLOODING WEDNESDAY CONSIDERING FORECAST CORFIDI VECTORS WILL BE LESS
THAN 10 KTS...AND PWATS WILL BE AROUND 1.5 INCHES...WHICH IS JUST
SHY OF 2 STANDARD DEVIATIONS ABV NORMAL. THEREFORE...WILL INTRODUCE
A MENTION OF LOCALIZED FLOODING IN HWO.

MODEL GUIDANCE SHOWS A BIG DISCREPANCY FOR HIGHS WEDNESDAY...WITH
THE GFS MOS GUIDANCE 5-10 DEGREES WARMER THAN THE NAM MOS GUIDANCE.
CONSIDERING FAIRLY STEEP LAPSE RATES...CLOUDS SHOULD BE
WIDESPREAD...AND LEANED TOWARD THE COOLER NAM MOS FOR HIGHS
WEDNESDAY.

THE UPPER LOW/COOL POOL LIFTS NORTHEAST...BUT A VERY MOIST AIRMASS
REMAINS IN PLACE...AND WEAK UPSLOPE FLOW WILL GENERATE MORE SHOWERS
AND STORMS...WITH GREATEST COVERAGE IN THE ALLEGHANY HIGHLANDS
CLOSER TO THE UPPER LOW. SHOWERS AND A FEW STORMS WILL AGAIN BE SLOW
MOVING WITH CORFIDI VECTORS AGAIN LESS THAN 10 KTS.  ONCE AGAIN
LEANED TOWARD THE COOLER GUIDANCE VALUES WITH EXTENSIVE CLOUD COVER.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 305 PM EDT MONDAY...

THE MEDIUM RANGE MODELS AND ENSEMBLES ARE IN GOOD AGREEMENT
BUILDING A STRONG UPPER RIDGE...FIRST OVER THE OHIO VALLEY...THEN
ELONGATING INTO THE MID-ATLANTIC REGION SUNDAY INTO MONDAY. THIS
WILL RESULT IN TEMPERATURES WELL ABOVE NORMAL AND LESS COVERAGE IN
PRECIPITATION.

ON FRIDAY...THE LINGERING UPPER LEVEL TROF FINALLY GETS PUSHED
NORTHEAST BY A SHORTWAVE MOVING THROUGH THE GREAT LAKES. WITH A
MOIST (GREATER THAN 1.5 PWATS) AND UNSTABLE AIRMASS IN PLACE AND
WEAK LOW LEVEL CONVERGENCE AND THE SFC...WIDELY SCATTERED
THUNDERSTORMS WILL AGAIN BE POSSIBLE.

THE COVERAGE OF SHOWERS AND STORMS SHOULD DIMINISH THROUGH THE
HOLIDAY WEEKEND AS THE UPPER RIDGE BUILDS. HOWEVER...WEAK...BUT
FAIRLY DEEP EAST/SOUTHEAST UPSLOPE LOW LEVEL FLOW MAY BE ABOVE TO
OVERCOME WARMING MID LEVEL TEMPS/RISING HEIGHTS TO INITIATE ISOLATED
TO WIDELY SCT STORMS ALONG THE BLUE RIDGE.

LEARNED TOWARD THE WARMER MEX GUIDANCE FOR TEMPS THROUGH THE LONG
TERM PERIOD...WITH FORECAST HIGHS NEARING RECORDS FOR BLF.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM EDT MONDAY...

VFR CONDITIONS SHOULD PREVAIL THROUGH THE REST OF TODAY. A FEW
SCATTERED SHOWERS AND THUNDERSTORMS WILL POP UP LATER IN THE
AFTERNOON...BUT CHANCES ARE LOW ENOUGH THAT THUNDER WILL BE KEPT OUT
OF THE TAFS. VCSH WILL BE USED INSTEAD FOR ALL SITES. ALTHOUGH THE
THREAT OF SHOWERS WILL DISSIPATE BY MIDNIGHT...ALL GUIDANCE IS
PREDICTING THE DEVELOPMENT OF FOG DUE TO PLENTIFUL SURFACE MOISTURE.
WHETHER DENSE FOG OR LOW STRATUS CLOUDS FORMS REMAINS THE MOST
CHALLENGING ASPECT OF THIS FORECAST. FOR NOW...FOG WILL BE
FORECASTED AT LYH...ROA...BCB...AND LWB DURING THE EARLY HOURS OF
TUESDAY MORNING. IFR CONDITIONS APPEAR LIKELY FOR BCB AND LWB...SO
THE TAFS FOR THESE SITES WILL REFLECT MORE PESSIMISTIC VISIBILITIES.
MEANWHILE...CONDITIONS FOR BLF AND DAN SEEM TO SUGGEST A LOWER
PROBABILITY OF FOG...AND HAVE DECIDED TO KEEP IT OUT OF THE TAFS.
VFR CONDITIONS WILL RETURN FOR ALL SITES LATER IN THE MORNING.

THE AREA WILL REMAIN INFLUENCED BY AN UPPER LEVEL TROUGH AND WEAK
COLD FRONT UNTIL MIDWEEK...WHICH WILL BE KEEPING A THREAT OF
SHRA/TSRA AND SUB VFR WX AROUND UNTIL THEN. MAINLY VFR WX EXPECTED
FOR THU-FRI UNDER HIGH PRESSURE TO THE NORTHEAST...ALTHOUGH SOME
LATE NIGHT FOG/STRATUS IS NOT OUT OF THE QUESTION.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...PW/WP
SHORT TERM...PH
LONG TERM...PH
AVIATION...KK/PW

000
FXUS61 KLWX 211900
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
300 PM EDT MON MAY 21 2012

.SYNOPSIS...

SURFACE LOW PRESSURE WILL NEAR THE MID ATLANTIC COAST TONIGHT. AN
UPPER LEVEL TROUGH OF LOW PRESSURE TROUGH WILL BECOME STATIONARY
ACROSS THE MID ATLANTIC REGION WEDNESDAY. HIGH PRESSURE WILL
RETURN TO THE AREA FOR THE MEMORIAL DAY WEEKEND.

&&

.NEAR TERM /TONIGHT/...

SURFACE LOW PRESSURE WILL CONTINUE TO WEAKEN OVER VIRGINIA WHILE THE
UPPER-LEVEL LOW ASSOCIATED WITH THIS SYSTEM WEAKENS OVER OUR AREA.
AN EASTERLY FLOW AROUND THIS SYSTEM HAS USHERED IN DEEP MOISTURE
FROM THE ATLANTIC...CAUSING PLENTY OF CLOUDS ALONG WITH SHOWERS.

DEEP MOISTURE WILL COMBINE WITH FORCING FROM THE UPPER-LEVEL LOW TO
TRIGGER MORE SHOWERS THIS AFTERNOON AND EVENING. LIMITED INSTABILITY
MAY ALSO TRIGGER SOME THUNDERSTORMS LATE THIS AFTERNOON AND EVENING.
THE BEST CHANCE FOR T-STORMS WILL BE ACROSS LOCATIONS WHERE THE
MARINE LAYER MIXES OUT. THERE ARE TWO AREAS WHERE THAT IS MOST
LIKELY. THE FIRST IS ACROSS THE POTOMAC HIGHLANDS INTO CENTRAL
VIRGINIA AND THE SECOND IS NEAR AND EAST OF THE I-95 CORRIDOR WHERE
A COASTAL FRONT WILL ASSIST IN MIXING OUT THE MARINE LAYER THIS
AFTERNOON. LATEST SATELLITE IMAGERY SHOWS BREAKS IN THE CLOUD COVER
ACROSS THESE AREAS.

SHOWERS ARE EXPECTED OVERNIGHT AS DEEP MOISTURE HANGS AROUND...BUT
COVERAGE OF SHOWERS WILL DISSIPATE DUE TO THE LOSS OF DAYTIME
HEATING. LOW CLOUDS AND PATCHY FOG ARE EXPECTED OVERNIGHT. MIN TEMPS
WILL RANGE FROM THE 50S IN THE POTOMAC HIGHLANDS TO THE MID 60S IN
DOWNTOWN WASHINGTON/BALTIMORE.


&&

.SHORT TERM /TUESDAY/...

AN UPPER-LEVEL TROUGH WILL APPROACH THE REGION FROM THE WEST WHILE A
SURFACE TROUGH OF LOW PRESSURE REMAINS OVER THE REGION. LOW CLOUDS
AND PATCHY FOG WILL SLOWLY MIX OUT DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS. SOME AFTERNOON SUNSHINE IS EXPECTED AND THAT WILL
CAUSE MODERATE AMOUNTS OF INSTABILITY TO DEVELOP. MODERATE
INSTABILITY WILL COMBINE WITH FORCING FROM THE SURFACE TROUGH TO
TRIGGER SOME SHOWERS AND THUNDERSTORMS...MAINLY DURING THE AFTERNOON
HOURS. THUNDERSTORMS MAY CONTAIN LOCALLY HEAVY RAIN.

MAX TEMPS WILL BE WARMER TUESDAY COMPARED TO TODAY DUE TO MORE
AFTERNOON SUNSHINE. MAX TEMPS WILL RANGE FROM THE UPPER 60S ALONG
THE RIDGE TOPS TO THE UPPER 70S AND LOWER 80S ACROSS MOST OTHER
LOCATIONS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...

UPPER LEVEL TROUGH OF LOW PRES XPCTD TO MOVE OUT OF THE TN VLLY
TUE NGT AND BECOME A CLOSED LOW OVR THE MID ATLC WED. NOT A
PARTICULARLY DEEP CLOSED LOW...BUT STILL ENOUGH OF ONE THAT HV
PUSHED POPS ACROSS THE ENTIRE CWA TO LKLY FOR WED AFTN. THERE
CERTAINLY COULD BE THUNDER...BUT AT THIS TIME SVR THREAT LOOKS
MINIMAL. THIS LOOKS TO SLOWLY NE AWAY FM THE AREA...AND HV POPS
SLOWLY DIMINISHING AS WELL.

WED AND THU XPCT HIGH TEMPS A80 MUCH OF THE AREA. LOWS IN THE LM60S.

AFTR THE UPR LOW EXITS A PATTERN SHIFT OCCURS. UPR LVL TROF PUSHES
DOWN THE PACIFIC CST..AND IN RESPONSE HGTS START TO RISE IN THE
ERN 1/3 OF THE COUNTRY. AFTR A MUCH-ABV-NRML MAR TEMPS IN APR AND
MAY HV BEEN MORE TEMPERATE. 1000-500 HGTS MAY EXCEED 590 DM...AND
TEMPS COULD TOP 90 DEG...ESPECIALLY SUN AND MON. GIVEN THIS IS
"THE UNOFFICIAL START OF SUMMER" PLUS MEMORIAL DAY WKND WE`RE A
BIT CONCERNED OF HOW PEOPLE WL REACT TO THE CHG. WE`RE A LONG WAY
FM ISSUING ANY HEAT SPECIFIC PRODUCTS BUT WE`VE ADDED MENTION OF
THE WARMER TEMPS/HOLIDAY WKND TO THE HWO. ONLY PTNL FOR TSTMS THIS
WKND LOOKS TO BE DIURNALLY DRIVEN OVR THE MTNS. OTHERWISE SKIES
SHOULD BE M SUN DURG THE DAY.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...

MARINE LAYER HAS RESULTED IN IFR CIGS THROUGH MID-AFTERNOON. CIGS
WILL GRADUALLY IMPROVE LATE THIS AFTERNOON TO MVFR LEVELS. SHOWERS
AND ISOLATED T-STORMS ARE EXPECTED AND THIS MAY CAUSE BRIEF PERIODS
OF IFR VSBYS.

A WEAKENING AREA OF LOW PRESSURE WILL TRIGGER MORE SHOWERS TONIGHT
DUE TO THE DEEP MOISTURE ASSOCIATED WITH IT. LOW CLOUDS AND PATCHY
FOG ARE EXPECTED. IFR CIGS/VSBYS ARE EXPECTED OVERNIGHT.

LOW CIGS/VSBYS XPCTD TUE NGT THRU WED NGT W/ PDS OF RAIN/ISOLD TSTMS.
CONDS SHOULD BE IMPRVG DURG THE 2ND HALF OF THE WK INTO THE WKND
AS A LARGE AREA OF HIGH PRES SETS UP OVR THE ERN U.S.

&&

.MARINE...

LOW PRESSURE WILL CONTINUE TO WEAKEN OVER SOUTHERN VIRGINIA THROUGH
TONIGHT. AN EAST-SOUTHEAST FLOW IS EXPECTED DURING THIS TIME. WIND
GUSTS WILL BE CLOSE TO SCA CRITERIA THROUGH LATE THIS AFTERNOON.
HAVE CAPPED GUSTS AROUND 15 KNOTS FOR NOW DUE TO THE WEAKENING
PRESSURE GRADIENT. WIND SPEEDS ARE EXPECTED TO REMAIN BELOW SCA
CRITERIA TONIGHT.

SHOWERS AND ISOLATED T-STORMS ARE EXPECTED LATE THIS AFTERNOON AND
EVENING. A SURFACE TROUGH WILL REMAIN WEST OF THE WATERS TUESDAY.
WIND SPEEDS WILL REMAIN BELOW SCA CRITERIA. SHOWERS AND T-STORMS ARE
POSSIBLE...MAINLY IN THE AFTERNOON.

WINDS XPCTD TO RMN BLO SCA TUE NGT THRU THE END OF THE WORK WK.
RW/TSTMS LKLY ON WED.

&&

.TIDES/COASTAL FLOODING...

TIDAL ANOMALIES REMAIN AROUND ONE HALF TO ONE FOOT ABOVE NORMAL THIS
AFTERNOON. TIDAL ANOMALIES MAY INCREASE A LITTLE DUE TO THE ONSHORE
FLOW...BUT MINOR FLOODING IS NOT EXPECTED THROUGH LATE THIS EVENING
SINCE THE ASTRONOMICAL TIDE WILL BE THE LOWER OF THE TWO. WATER
LEVELS WILL APPROACH THRESHOLDS FOR MINOR FLOODING LATE TONIGHT INTO
TUESDAY MORNING. WILL CONTINUE TO MONITOR TIDAL ANOMALIES THIS
EVENING TO DETERMINE IF A COASTAL FLOOD ADVISORY IS NEEDED.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
PRODUCTS...BJL/WOODY!

000
FXUS61 KRNK 211747
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
147 PM EDT MON MAY 21 2012

.SYNOPSIS...
A COLD FRONT WILL ARRIVE TONIGHT INTO TUESDAY...AND WILL SLOWLY
PUSH EASTWARD TO THE COAST BY WEDNESDAY. SOME SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE FOR THE NEXT COUPLE DAYS...BEFORE
HIGH PRESSURE RETURNS BY THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM EDT MONDAY...

CURRENTLY...THE CWA IS PINCHED IN BETWEEN AN APPROACHING COLD FRONT
OVER THE OHIO RIVER VALLEY...AND A SLOW MOVING LOW PRESSURE SYSTEM
OVER THE DELMARVA PENINSULA. NOT MUCH ADJUSTMENT WAS NEEDED FOR THE
HIGH TEMPERATURES TODAY...BUT CLOUD COVER WILL PLAY A SIGNIFICANT
ROLE. THUS...HIGHS WILL BE IN THE MID TO UPPER 70S FOR WEST OF THE
BLUE RIDGE. SOUTHSIDE VIRGINIA...THE NORTH CAROLINA PIEDMONT...AND
LOCATIONS NEAR ROANOKE VIRGINIA WILL SEE UPPER 70S TO LOWER 80S. THE
SHOWER ACTIVITY FROM EARLIER THIS MORNING HAS DISSIPATED...SO POPS
WERE LOWERED FOR THE REST OF THIS MORNING. CHANCE POPS WERE BROUGHT
IN OVER THE EASTERN VIRGINIA PIEDMONT AT THE START FROM THE SLOWLY
RETROGRADING LOW PRESSURE SYSTEM...AND LATER IN THE WESTERN
MOUNTAINS FROM THE ARRIVING COLD FRONT.

THE 12Z SOUNDING SHOWS SEVERAL CAPS IN PLACE THAT DAYTIME HEATING
WILL HAVE TO OVERCOME TO OBTAIN CONVECTION LATER IN THE AFTERNOON.
IF WE DO BREAK THESE CAPS...A POSSIBLE 1000-1500 J/KG OF CAPE COULD
BE REALIZED...AND SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE WEST OF THE BLUE RIDGE. AREAS NEAR MARTINSVILLE VIRGINIA
AND THE NORTH CAROLINA PIEDMONT HAVE THE LOWEST CHANCE BASED ON THE
LOWER THETA-E DEPICTED IN GUIDANCE AND THE OVERALL FLOW PATTERN.
WINDS ALOFT ARE VERY LIGHT...SO ANY STORM THAT DEVELOPS WILL BE SLOW
TO MOVE AND COULD PRESENT SOME HYDRO ISSUES IF TRAINING OCCURS.

TONIGHT...WITH SUN SETTING...THINKING IS THAT ORGANIZED CONVECTION
WEAKENS. HOWEVER...SFC FRONT WILL WORK ITS WAY TOWARD THE CENTRAL
APPALACHIANS BY TUESDAY MORNING AND MAY SEE AN INCREASE IN COVERAGE
TOWARD SOUTHEAST WEST VIRGINIA SOUTH INTO THE NORTH CAROLINA
MOUNTAINS BY DAYBREAK. THE MODELS ARE DIFFERENT ON THE SPEED OF THE
UPPER SYSTEM AND FRONTAL PRECIP...WITH THE NAM FASTEST IN BRINGING A
SOMEWHAT ORGANIZED LINE INTO FAR SOUTHWEST VA...WHILE THE ECMWF/GFS
KEEP IT FURTHER WEST. AGAIN...FOLLOWING SLOWER SOLUTION. LOWS
TONIGHT WILL STAY MILD WITH MID 50S TO AROUND 60 EXPECTED.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 355 AM EDT MONDAY...

TUESDAY MORNING WILL START OFF WITH WIDELY SCATTERED SHOWER AND
ISOLATED THUNDERSTORM ACTIVITY...AND WILL EXPECT TO SEE COVERAGE
INCREASE BY LATE MORNING AS DAYTIME HEATING INCREASES...AND A WEAK
COLD FRONT ENTERS OUR SOUTHEAST WEST VIRGINIA AND MOUNTAIN EMPIRE
COUNTIES. BY MID AFTERNOON...THE FRONT WILL PUSH NEAR THE BLUE
RIDGE...HELPING TO FURTHER DESTABILIZE THE ATMOSPHERE ACROSS THE
PIEDMONTS. EXPECT TO SEE A FEW STRONG...AND POSSIBLY SEVERE
THUNDERSTORMS DEVELOP DURING THE EARLY EVENING EAST OF THE BLUE
RIDGE...WITH THESE STORMS CAPABLE OF PRODUCING LOCALLY GUSTY WINDS
AND LARGE HAIL. WITH WINDS BECOMING SOUTHERLY AHEAD OF THE
FRONT...WILL EXPECT TO SEE NEAR 80 DEGREE TEMPERATURES REACH AS FAR
NORTH AS BUCKINGHAM AND AMHERST COUNTIES DURING THE AFTERNOON.
FURTHER WEST...AFTERNOON TEMPERATURES CAN BE EXPECTED TO HOLD IN THE
LOW TO MID 70S. SHOWER AND THUNDERSTORM ACTIVITY WILL DIMINISH
GRADUALLY LATE TUESDAY EVENING...BUT WILL SEE THIS ACTIVITY LINGER
THROUGH THE EARLY MORNING HOURS OF WEDNESDAY.

MUCH OF THE SAME CAN BE EXPECTED FOR WEDNESDAY AND THURSDAY...AS THE
FRONTAL BOUNDARY LOSES ITS PUSH...BECOMING NOT MUCH MORE THAN A WEAK
TROUGH STALLED ACROSS THE PIEDMONT REGION. AND WITH BROAD UPPER
LEVEL TROUGHING HOLDING ALONG THE APPALACHIAN CHAIN HEADING INTO THE
END OF THE WORKWEEK...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO
INCREASE IN COVERAGE LATE EACH MORNING...AND DIMINISH LATE EACH
EVENING. BETTER COVERAGE AND GREATER INSTABILITY WILL BE FOUND EAST
OF THE BLUE RIDGE...AND EXPECT A FEW STRONG TO SEVERE STORMS EACH
EVENING. TEMPERATURES BOTH DAYS WILL BE NEAR NORMAL FOR THE SECOND
HALF OF MAY.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 AM EDT MONDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 145 PM EDT MONDAY...

VFR CONDITIONS SHOULD PREVAIL THROUGH THE REST OF TODAY. A FEW
SCATTERED SHOWERS AND THUNDERSTORMS WILL POP UP LATER IN THE
AFTERNOON...BUT CHANCES ARE LOW ENOUGH THAT THUNDER WILL BE KEPT OUT
OF THE TAFS. VCSH WILL BE USED INSTEAD FOR ALL SITES. ALTHOUGH THE
THREAT OF SHOWERS WILL DISSIPATE BY MIDNIGHT...ALL GUIDANCE IS
PREDICTING THE DEVELOPMENT OF FOG DUE TO PLENTIFUL SURFACE MOISTURE.
WHETHER DENSE FOG OR LOW STRATUS CLOUDS FORMS REMAINS THE MOST
CHALLENGING ASPECT OF THIS FORECAST. FOR NOW...FOG WILL BE
FORECASTED AT LYH...ROA...BCB...AND LWB DURING THE EARLY HOURS OF
TUESDAY MORNING. IFR CONDITIONS APPEAR LIKELY FOR BCB AND LWB...SO
THE TAFS FOR THESE SITES WILL REFLECT MORE PESSIMISTIC VISIBILITIES.
MEANWHILE...CONDITIONS FOR BLF AND DAN SEEM TO SUGGEST A LOWER
PROBABILITY OF FOG...AND HAVE DECIDED TO KEEP IT OUT OF THE TAFS.
VFR CONDITIONS WILL RETURN FOR ALL SITES LATER IN THE MORNING.

THE AREA WILL REMAIN INFLUENCED BY AN UPPER LEVEL TROUGH AND WEAK
COLD FRONT UNTIL MIDWEEK...WHICH WILL BE KEEPING A THREAT OF
SHRA/TSRA AND SUB VFR WX AROUND UNTIL THEN. MAINLY VFR WX EXPECTED
FOR THU-FRI UNDER HIGH PRESSURE TO THE NORTHEAST...ALTHOUGH SOME
LATE NIGHT FOG/STRATUS IS NOT OUT OF THE QUESTION.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...PW/WP
SHORT TERM...NF
LONG TERM...NF
AVIATION...KK/PW

000
FXUS61 KLWX 211605
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1205 PM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE WILL NEAR THE MID-ATLANTIC TODAY AND TONIGHT. A LOW
PRESSURE TROUGH WILL BECOME STATIONARY ACROSS THE MID ATLANTIC
REGION DURING THE MIDDLE PART OF THE WEEK. WEAK HIGH PRESSURE WILL
RETURN FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN EASTERLY FLOW AROUND LOW PRESSURE OVER SOUTHERN VIRGINIA HAS
ALLOWED FOR PLENTY OF CLOUDS ALONG WITH RAIN AND DRIZZLE THIS
MORNING. MOST OF THE RAIN HAS FALLEN ACROSS THE NORTHERN AND
CENTRAL CWA WHERE ISENTROPIC LIFT HAS BEEN A BIT DEEPER.

LOW PRESSURE WILL REMAIN OVER SOUTHERN VIRGINIA THIS
AFTERNOON...BUT IT WILL GRADUALLY WEAKEN. DEEP MOISTURE WILL
CONTINUE TO ADVECT INTO OUR REGION DURING THIS TIME. WEAKENING
DYNAMICS SUGGEST THAT PRECIP WOULD DIMINISH. HOWEVER...DEEP
MOISTURE WILL ALLOW FOR SOME INSTABILITY THIS AFTERNOON WHICH WILL
LEAD TO MORE SHOWERS ALONG WITH ISOLATED THUNDERSTORMS. THE BEST
CHANCE FOR SHOWERS AND T-STORMS WILL BE ACROSS LOCATIONS WHERE THE
MARINE LAYER MIXES OUT. THERE ARE TWO AREAS WHERE THAT IS MOST
LIKELY. THE FIRST IS ACROSS THE POTOMAC HIGHLANDS INTO THE CENTRAL
SHENANDOAH VALLEY AND THE SECOND IS NEAR AND EAST OF THE I-95
CORRIDOR WHERE A COASTAL FRONT MAY ASSIST IN MIXING OUT THE MARINE
LAYER THIS AFTERNOON. ANY SUNSHINE THAT DOES OCCURR WILL LEAD TO
MODERATE INSTABILITY THIS AFTERNOON...WHICH COULD CAUSE
THUNDERSTORMS TO CONTAIN LOCALLY HEAVY RAIN. SEVERE T-STORMS ARE
NOT EXPECTED DUE TO WEAK SHEAR PROFILES.

SFC TROF ENTERS POTOMAC HIGHLANDS TNGT AND PUSHES TWD BLUE RIDGE
OVNGT. BEST POPS/QPF FOCUSED ALONG/AHEAD OF THIS FEATURE...WITH LOW
LIKELY/HIGH CHC SHWR PROBS EXHIBITED FROM SHEN VLY TO I-95 CORRIDOR
OVNGT.  RMNT THUNDER FROM ANY AFTN CVCTN CUD LINGER PAST
SUNSET...BUT SHUD DIURNAL DIMINISH AFTN MIDNIGHT. MINIMA TDA WILL BE
QUITE MILD FOR LATE MAY...50S W OF BLUE RIDGE WITH L60S E.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UNSETTLED WEATHER CONDITIONS WILL CONTINUE TUESDAY INTO WEDNESDAY AS
A LOW PRESSURE TROUGH BECOMES STATIONARY ACROSS THE CWFA. THE TROUGH
WILL SERVE TO FOCUS PRECIP THROUGH THE PERIOD.

INCREASED POPS DURING THIS PERIOD. SOME INSTABILITY DURING THE
AFTERNOON...SO LEFT MENTION OF THUNDERSTORMS IN THE FORECAST INTO
THE EVENING HOURS. UPPER LEVEL STEERING WILL BE LIGHT...AND SURFACE
FLOW WILL BE FROM THE SE. THIS SHOULD ALLOW FOR THE HIGHEST PRECIP
AMOUNTS ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MOUNTAINS. AT
THIS TIME...RAINFALL AMOUNTS WILL AVERAGE BETWEEN ONE HALF AND ONE
INCH. LOCALLY HIGHER AMOUNTS ALONG EASTERN FACING HIGHER TERRAIN.
STILL BELOW 2SD FOR PWATS.

TOOK BLEND FOR TEMPS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE TROUGH SHOULD DISSIPATE BY EARLY THURSDAY. HIGH
PRESSURE SETS UP ACROSS THE DEEP SOUTH...WITH SOUTHERLY FLOW ACROSS
THE MID ATLANTIC. SOME DIFFERENCES BETWEEN THE MODELS FOR
THURSDAY...NAM IS DRIER THAN THE GFS. NO REAL FOCUS FOR THE
PRECIP...SO SAW NO REASON TO CHANGE POPS AT THIS TIME. WEAK HIGH
PRESSURE RETURNS FOR LATER THURSDAY INTO SATURDAY.

A COLD FRONT SHOULD BEGIN TO APPROACH THE MASON DIXON LINE BY THE
END OF THE WEEKEND.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
MARINE LAYER WILL RESULT IN IFR CIGS AND MVFR/IFR VSBYS THIS
MORNING. CIGS MAY IMPROVE TO MVFR LEVELS THIS AFTERNOON.
HOWEVER...THERE IS A CONCERN THAT IFR CONDITIONS COULD PERSIST
WELL INTO THE AFTERNOON HOURS...ESPECIALLY ACROSS KMRB...KIAD AND
KCHO.

RAIN AND DRIZZLE MAY TAPER OFF LATE THIS MORNING AND EARLY
AFTERNOON...BUT SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP THIS AFTERNOON. IFR CIGS AND VSBYS ARE EXPECTED AGAIN FOR
TONIGHT ALONG WITH SOME SHOWERS.

SUB VFR CONDITIONS LIKELY TUESDAY INTO WEDNESDAY AS A LOW PRESSURE
TROUGH SETS UP ACROSS THE MID ATLANTIC. THUNDERSTORMS POSSIBLE
DURING THE AFTERNOON AND EVENING HOURS.

WEAK HIGH PRESSURE RETURNS FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.MARINE...
LOW PRESSURE WILL WEAKEN OVER SOUTHERN VIRGINIA THIS AFTERNOON. AN
EAST-SOUTHEAST FLOW WILL GUST CLOSE TO SCA CRITERIA DURING THIS
TIME. HAVE CAPPED GUSTS AROUND 15 KNOTS FOR NOW DUE TO THE
WEAKENING PRESSURE GRADIENT. WIND SPEEDS ARE EXPECTED TO REMAIN
BELOW SCA CRITERIA TONIGHT.

SHOWERS AND ISOLATED T-STORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON.

SE/S FLOW REMAINS RATHER LIGHT ACROSS THE CWFA DURING THE PERIOD. A
LOW PRESSURE TROUGH WILL SET UP JUST WEST OF THE WATERS FOR TUESDAY
INTO MUCH OF WEDNESDAY. THE TROUGH SHOULD DISSIPATE BY
THURSDAY...WITH WEAK HIGH PRESSURE RETURNING FOR FRIDAY INTO THE
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES THIS MRNG RANGE FROM 0.50-1.00 FT.
ELY FLOW WILL PERSIST TDA...CAUSING ANOMALIES TO INCREASE.
HOWEVER...AFTN/EVE HIGH TIDE IS ASTRONOMICAL LWR OF SEMIDIURNAL
CYCLE SO NO ISSUES XPCD EVEN WITH INCRG ANOMALIES. LATE TNGT/ERY
TUE...THE HIGHER ASTRONOMICAL HIGH TIDE IS EXPECTED AND MINOR
INUNDATION IS POSSIBLE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...SBK/NWL
NEAR TERM...SBK/BJL
SHORT TERM...NWL
LONG TERM...NWL
AVIATION...SBK/BJL/NWL
MARINE...SBK/BJL/NWL
TIDES/COASTAL FLOODING...BJL

000
FXUS61 KAKQ 211600
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1200 PM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST SFC ANALYSIS SHOWING CENTER OF LOW PRESSURE LOCATED NEAR
RIC AND MOVING SLOWLY W. PATTERN TODAY SUPPORTS RATHER HIGH
CHANCES FOR PRECIP CONTINUING. SKIES AVG OUT CLOUDY...WITH SOME
PARTIAL CLEARING POSSIBLE IN SOUTHERN AREAS. WILL HAVE LIKELY
POPS OVER NORTHERN PART OF FA...W/ CHC POPS REST OF AREA. ALSO
WILL HAVE ISOLATED TSTMS IN THE FCST THIS AFTN/EVENING. FAVOR
COOLER MET NUMBERS FOR HIGHS...WHICH WILL BE MAINLY IN THE UPR 70S
S...TO LWR 70S N/NE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
UNSETTLED CONDITIONS WILL DOMINATE THE WX PATTERN THROUGH
MIDWEEK...NOT DUE TO ALBERTO BUT RATHER DUE TO AN UPPER LOW THAT
WILL BE SLOW TO MOVE OUT OF THE AREA AS IT GETS CUTOFF FROM THE
MAIN STREAM OF WESTERLIES IN BETWEEN A RIDGE AMPLIFYING WELL N TO
HUDSON BAY CANADA...AND ANOTHER WELL OFF THE SE COAST NEAR
BERMUDA.

TONIGHT...WILL CARRY CHC TO LIKELY POPS MAINLY FOR THE EARLY
EVENING HRS..THEN LOOKS LIKE SOMEWHAT OF A LULL IN THE FORCING AND
WILL HAVE ONLY 20% POPS THROUGH MOST OF THE OVERNIGHT PERIOD AS
SHORTWAVE ENERGY DIVES SE FROM THE MID MS VALLEY DOWN INTO THE
DEEP SOUTH. SKIES MAY BE PARTLY CLOUDY FOR AWHILE...BUT W/ LGT
FLOW AND AMPLE LOW LEVEL MOISTURE SHOULD SEE EITHER PATCHY FOG
OR LOW STRATUS REDEVELOP PRIOR TO DAYBREAK. MILD W/ LOWS GENLY
BETWEEN 60-65.

TUE/WED...SHOULD SEE SOME GRADUAL/PARTIAL CLEARING BY LATE AM HRS
TUE AS SE FLOW DEVELOPS...BUT SKIES OVERALL AVG OUT MOSTLY CLOUDY.
INSTABILITY ON THE INCREASE BY AFTN AND WILL TEND TO HAVE A LITTLE
MORE IN THE WAY OF TSTM ACTIVITY THAN ON MON. WILL HAVE CHC POPS
FOR MOST AREAS (LIKELY OVER THE FAR WEST) BY LATE AFTN/EVENING.
AGAIN FAVORING COOLER MET GUIDANCE FOR HIGHS...A LITTLE WARMER
THAN MON W/ HIGHS GENLY IN UPPER 70S TO LOWER 80S (A LITTLE COOLER
ON THE ERN SHORE).

ON WED...GOOD CONSENSUS BETWEEN THE GFS/NAM/ECMWF AND EVEN THE
UKMET/GEM THAT UNSETTLED WX WILL PERSIST AS THE UPPER LOW BECOMES
CUTOFF AND CENTERED JUST TO OUR SW...PLACING THE MID ATLC IN A
REGION OF UPPER DIFFLUENCE AND DECENT LIFT. WENT A LITTLE HIGHER
THAN NUMERICAL GUIDANCE FOR POPS...WITH A PERIOD OF LIKELY POPS
FOR MUCH OF INTERIOR VA. HIGHS FAIRLY SIMILAR TO TUE W/ UPPER 70S
TO LOWER 80S FOR MOST (IF ENOUGH SUN COULD SEE A FEW MID 80S ACRS
SRN VA/NE NC).

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /16Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE AT 11Z APPEARED TO BE WEAKENING OVER CENTRAL VA.
IFR/LIFR CONDITIONS WERE OCCASIONALLY INTERRUPTED WITH IMPROVING
CONDITIONS OVER EASTERN PORTIONS DUE TO MIXING. EXPECT THE MAIN
IMPROVEMENT WILL ARRIVE IN THE LATE MORNING.

PCPN IS PSBL ACRS THE AREA WITH THE HIGHEST POPS AT RIC AND SBY AFT
18Z. MENTIONED SHRA AFT 18Z AT THOSE LOCATIONS TIL EARLY EVENING BUT
WITH NO RESTRICTION TO VSBY INCLUDED.

CONDITIONS MAY GO BACK DOWN MONDAY NIGHT/TUESDAY MORNING. WITH
SUPPORT FROM BOTH MET AND MAV...HAVE RIC AND SBY GOING BACK TO
IFR/LIFR AND BROUGHT THOSE TWO BACK DOWN TO IFR IN THE LATE EVENING.
THE OTHER THREE TAF SITES MAY SEE SOME LOWERING CONDITIONS TOWARD
MORNING BUT LEFT IFR OUT FOR NOW.

OUTLOOK...CONDITIONS IMPROVE ONCE AGAIN TO VFR LATE TUESDAY MORNING.
THERE WILL BE A CHANCE FOR MAINLY AFTN TSTMS BOTH TUESDAY AND AN
EVEN BETTER CHANCE FOR PCPN WEDNESDAY. NEITHER OF THESE EVENTS
SHOULD HAVE THE WIDESPREAD IFR THAT OCCURRED SUNDAY.

&&

.MARINE...
SFC LOW PRESSURE CONTINUES TO MOVE NW OVER CENTRAL VIRGINIA. WINDS
HAVE TURNED TO SOUTHERLY AND DIMINISHED BELOW SCA CRITERIA. SEAS
CONTINUE 5 FT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. SCA IN
EFFECT UNTIL 22Z AND THIS MAY BE DROPPED OVER ALL OR PORTIONS OF
THIS AREA PRIOR TO 22Z.

AS TROPICAL STORM ALBERTO MOVES NORTHEAST TO THE EAST OF THE COASTAL
WATERS TUESDAY AND WEDNESDAY...SWELLS ARE EXPECTED TO BUILD OVER THE
AREA. SURFACE WINDS AHEAD OF ALBERTO FROM WAVEWATCH LOOK SIMILAR TO
EURO (A MODEL THAT HANDLES ALBERTO FAIRLY WELL PER HPC) AND USED
WAVEWATCH FOR THE SEAS IN THE COASTAL WATERS. THIS BRINGS 5 FT SEAS
TO THE AREA TUESDAY AND TUESDAY NIGHT...ESPECIALLY OVER THE NORTHERN
COASTAL WATERS. THESE SHOULD SETTLE DOWN BY WEDNESDAY. OTHERWISE...
MARINE CONDITIONS SHOULD BE FAIRLY QUIET DURING THE
UPCOMING WEEK.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ650-
     652.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB/MAS
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...LSA
MARINE...LSA

000
FXUS61 KRNK 211508
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
1108 AM EDT MON MAY 21 2012

.SYNOPSIS...
A COLD FRONT WILL ARRIVE TONIGHT INTO TUESDAY...AND WILL SLOWLY
PUSH EASTWARD TO THE COAST BY WEDNESDAY. SOME SHOWERS AND
THUNDERSTORMS WILL BE POSSIBLE FOR THE NEXT COUPLE DAYS...BEFORE
HIGH PRESSURE RETURNS BY THURSDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM EDT MONDAY...

CURRENTLY...THE CWA IS PINCHED IN BETWEEN AN APPROACHING COLD FRONT
OVER THE OHIO RIVER VALLEY...AND A SLOW MOVING LOW PRESSURE SYSTEM
OVER THE DELMARVA PENINSULA. NOT MUCH ADJUSTMENT WAS NEEDED FOR THE
HIGH TEMPERATURES TODAY...BUT CLOUD COVER WILL PLAY A SIGNIFICANT
ROLE. THUS...HIGHS WILL BE IN THE MID TO UPPER 70S FOR WEST OF THE
BLUE RIDGE. SOUTHSIDE VIRGINIA...THE NORTH CAROLINA PIEDMONT...AND
LOCATIONS NEAR ROANOKE VIRGINIA WILL SEE UPPER 70S TO LOWER 80S. THE
SHOWER ACTIVITY FROM EARLIER THIS MORNING HAS DISSIPATED...SO POPS
WERE LOWERED FOR THE REST OF THIS MORNING. CHANCE POPS WERE BROUGHT
IN OVER THE EASTERN VIRGINIA PIEDMONT AT THE START FROM THE SLOWLY
RETROGRADING LOW PRESSURE SYSTEM...AND LATER IN THE WESTERN
MOUNTAINS FROM THE ARRIVING COLD FRONT.

THE 12Z SOUNDING SHOWS SEVERAL CAPS IN PLACE THAT DAYTIME HEATING
WILL HAVE TO OVERCOME TO OBTAIN CONVECTION LATER IN THE AFTERNOON.
IF WE DO BREAK THESE CAPS...A POSSIBLE 1000-1500 J/KG OF CAPE COULD
BE REALIZED...AND SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE WEST OF THE BLUE RIDGE. AREAS NEAR MARTINSVILLE VIRGINIA
AND THE NORTH CAROLINA PIEDMONT HAVE THE LOWEST CHANCE BASED ON THE
LOWER THETA-E DEPICTED IN GUIDANCE AND THE OVERALL FLOW PATTERN.
WINDS ALOFT ARE VERY LIGHT...SO ANY STORM THAT DEVELOPS WILL BE SLOW
TO MOVE AND COULD PRESENT SOME HYDRO ISSUES IF TRAINING OCCURS.

TONIGHT...WITH SUN SETTING...THINKING IS THAT ORGANIZED CONVECTION
WEAKENS. HOWEVER...SFC FRONT WILL WORK ITS WAY TOWARD THE CENTRAL
APPALACHIANS BY TUESDAY MORNING AND MAY SEE AN INCREASE IN COVERAGE
TOWARD SOUTHEAST WEST VIRGINIA SOUTH INTO THE NORTH CAROLINA
MOUNTAINS BY DAYBREAK. THE MODELS ARE DIFFERENT ON THE SPEED OF THE
UPPER SYSTEM AND FRONTAL PRECIP...WITH THE NAM FASTEST IN BRINGING A
SOMEWHAT ORGANIZED LINE INTO FAR SOUTHWEST VA...WHILE THE ECMWF/GFS
KEEP IT FURTHER WEST. AGAIN...FOLLOWING SLOWER SOLUTION. LOWS
TONIGHT WILL STAY MILD WITH MID 50S TO AROUND 60 EXPECTED.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 355 AM EDT MONDAY...

TUESDAY MORNING WILL START OFF WITH WIDELY SCATTERED SHOWER AND
ISOLATED THUNDERSTORM ACTIVITY...AND WILL EXPECT TO SEE COVERAGE
INCREASE BY LATE MORNING AS DAYTIME HEATING INCREASES...AND A WEAK
COLD FRONT ENTERS OUR SOUTHEAST WEST VIRGINIA AND MOUNTAIN EMPIRE
COUNTIES. BY MID AFTERNOON...THE FRONT WILL PUSH NEAR THE BLUE
RIDGE...HELPING TO FURTHER DESTABILIZE THE ATMOSPHERE ACROSS THE
PIEDMONTS. EXPECT TO SEE A FEW STRONG...AND POSSIBLY SEVERE
THUNDERSTORMS DEVELOP DURING THE EARLY EVENING EAST OF THE BLUE
RIDGE...WITH THESE STORMS CAPABLE OF PRODUCING LOCALLY GUSTY WINDS
AND LARGE HAIL. WITH WINDS BECOMING SOUTHERLY AHEAD OF THE
FRONT...WILL EXPECT TO SEE NEAR 80 DEGREE TEMPERATURES REACH AS FAR
NORTH AS BUCKINGHAM AND AMHERST COUNTIES DURING THE AFTERNOON.
FURTHER WEST...AFTERNOON TEMPERATURES CAN BE EXPECTED TO HOLD IN THE
LOW TO MID 70S. SHOWER AND THUNDERSTORM ACTIVITY WILL DIMINISH
GRADUALLY LATE TUESDAY EVENING...BUT WILL SEE THIS ACTIVITY LINGER
THROUGH THE EARLY MORNING HOURS OF WEDNESDAY.

MUCH OF THE SAME CAN BE EXPECTED FOR WEDNESDAY AND THURSDAY...AS THE
FRONTAL BOUNDARY LOSES ITS PUSH...BECOMING NOT MUCH MORE THAN A WEAK
TROUGH STALLED ACROSS THE PIEDMONT REGION. AND WITH BROAD UPPER
LEVEL TROUGHING HOLDING ALONG THE APPALACHIAN CHAIN HEADING INTO THE
END OF THE WORKWEEK...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO
INCREASE IN COVERAGE LATE EACH MORNING...AND DIMINISH LATE EACH
EVENING. BETTER COVERAGE AND GREATER INSTABILITY WILL BE FOUND EAST
OF THE BLUE RIDGE...AND EXPECT A FEW STRONG TO SEVERE STORMS EACH
EVENING. TEMPERATURES BOTH DAYS WILL BE NEAR NORMAL FOR THE SECOND
HALF OF MAY.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 AM EDT MONDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM EDT MONDAY...

VFR CONDITIONS ARE EXPECTED TODAY. SHOWERS AND A FEW THUNDERSTORMS
WILL BE POSSIBLE AREA WIDE BUT ESPECIALLY ACROSS THE PIEDMONT
NORTH OF DANVILLE AND EAST OF ROANOKE WHERE BETTER SUPPORT IN THE
UPPER LEVELS RESIDE. AFTERNOON...ANY AIRPORT COULD SEE A SHOWER OR
STORM AS HIGH MOISTURE CONTENT UNDER THE UPPER TROUGH AND WEAK
OUTFLOW COULD SPARK CONVECTION. FOR NOW WILL BE VFR OUTSIDE OF
CONVECTION. SINCE IT SHOULD BE MAINLY SCATTERED KEPT THUNDER OUT
OF THE TAFS.

TONIGHT...A LULL IN ACTIVITY ANTICIPATED ALTHOUGH A FEW SHOWERS
WILL LINGER AREAWIDE. AN ISSUE TONIGHT WILL BE AMPLE MOISTURE ON
THE GROUND VERSUS CLOUD COVER AND IF/HOW MUCH FOG AND OR LOW
STRATUS FORMS. AT THE MOMENT AM CONFIDENT ENOUGH THAT MVFR
CONDITIONS WILL OCCUR AT ALL SITES BUT BLF WHICH SHOULD STAY
VFR...AND WILL HAVE LWB SUB MVFR AFTER MIDNIGHT...WITH FOG.

THE AREA WILL REMAIN INFLUENCED BY AN UPPER TROUGH AND WEAK COLD
FRONT UNTIL MIDWEEK WHICH WILL BE KEEPING A THREAT OF SHRA/TSRA
AND SUB VFR WX AROUND UNTIL THEN. MAINLY VFR WX EXPECTED FOR THU-
FRI UNDER HIGH PRESSURE TO THE NORTHEAST...ALTHOUGH SOME LATE
NIGHT FOG/STRATUS NOT OUT OF THE QUESTION.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...PW
NEAR TERM...PW/WP
SHORT TERM...NF
LONG TERM...NF
AVIATION...KK/WP

000
FXUS61 KLWX 211505
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1105 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE WILL NEAR THE MID-ATLANTIC TODAY AND TONIGHT. A LOW
PRESSURE TROUGH WILL BECOME STATIONARY ACROSS THE MID ATLANTIC
REGION DURING THE MIDDLE PART OF THE WEEK. WEAK HIGH PRESSURE WILL
RETURN FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN EASTERLY FLOW AROUND LOW PRESSURE OVER SOUTHERN VIRGINIA HAS
ALLOWED FOR PLENTY OF CLOUDS ALONG WITH RAIN AND DRIZZLE THIS
MORNING. MOST OF THE RAIN HAS FALLEN ACROSS THE NORTHERN AND
CENTRAL CWA WHERE ISENTROPIC LIFT HAS BEEN A BIT DEEPER.

LOW PRESSURE WILL REMAIN OVER SOUTHERN VIRGINIA THIS
AFTERNOON...BUT IT WILL GRADUALLY WEAKEN. DEEP MOISTURE WILL
CONTINUE TO ADVECT INTO OUR REGION DURING THIS TIME. WEAKENING
DYNAMICS SUGGEST THAT PRECIP WOULD DIMINISH. HOWEVER...DEEP
MOISTURE WILL ALLOW FOR SOME INSTABILITY THIS AFTERNOON WHICH WILL
LEAD TO MORE SHOWERS ALONG WITH ISOLATED THUNDERSTORMS. THE BEST
CHANCE FOR SHOWERS AND T-STORMS WILL BE ACROSS LOCATIONS WHERE THE
MARINE LAYER MIXES OUT. THERE ARE TWO AREAS WHERE THAT IS MOST
LIKELY. THE FIRST IS ACROSS THE POTOMAC HIGHLANDS INTO THE CENTRAL
SHENANDOAH VALLEY AND THE SECOND IS NEAR AND EAST OF THE I-95
CORRIDOR WHERE A COASTAL FRONT MAY ASSIST IN MIXING OUT THE MARINE
LAYER THIS AFTERNOON. ANY SUNSHINE THAT DOES OCCURR WILL LEAD TO
MODERATE INSTABILITY THIS AFTERNOON...WHICH COULD CAUSE
THUNDERSTORMS TO CONTAIN LOCALLY HEAVY RAIN. SEVERE T-STORMS ARE
NOT EXPECTED DUE TO WEAK SHEAR PROFILES.

SFC TROF ENTERS POTOMAC HIGHLANDS TNGT AND PUSHES TWD BLUE RIDGE
OVNGT. BEST POPS/QPF FOCUSED ALONG/AHEAD OF THIS FEATURE...WITH LOW
LIKELY/HIGH CHC SHWR PROBS EXHIBITED FROM SHEN VLY TO I-95 CORRIDOR
OVNGT.  RMNT THUNDER FROM ANY AFTN CVCTN CUD LINGER PAST
SUNSET...BUT SHUD DIURNAL DIMINISH AFTN MIDNIGHT. MINIMA TDA WILL BE
QUITE MILD FOR LATE MAY...50S W OF BLUE RIDGE WITH L60S E.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UNSETTLED WEATHER CONDITIONS WILL CONTINUE TUESDAY INTO WEDNESDAY AS
A LOW PRESSURE TROUGH BECOMES STATIONARY ACROSS THE CWFA. THE TROUGH
WILL SERVE TO FOCUS PRECIP THROUGH THE PERIOD.

INCREASED POPS DURING THIS PERIOD. SOME INSTABILITY DURING THE
AFTERNOON...SO LEFT MENTION OF THUNDERSTORMS IN THE FORECAST INTO
THE EVENING HOURS. UPPER LEVEL STEERING WILL BE LIGHT...AND SURFACE
FLOW WILL BE FROM THE SE. THIS SHOULD ALLOW FOR THE HIGHEST PRECIP
AMOUNTS ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MOUNTAINS. AT
THIS TIME...RAINFALL AMOUNTS WILL AVERAGE BETWEEN ONE HALF AND ONE
INCH. LOCALLY HIGHER AMOUNTS ALONG EASTERN FACING HIGHER TERRAIN.
STILL BELOW 2SD FOR PWATS.

TOOK BLEND FOR TEMPS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE TROUGH SHOULD DISSIPATE BY EARLY THURSDAY. HIGH
PRESSURE SETS UP ACROSS THE DEEP SOUTH...WITH SOUTHERLY FLOW ACROSS
THE MID ATLANTIC. SOME DIFFERENCES BETWEEN THE MODELS FOR
THURSDAY...NAM IS DRIER THAN THE GFS. NO REAL FOCUS FOR THE
PRECIP...SO SAW NO REASON TO CHANGE POPS AT THIS TIME. WEAK HIGH
PRESSURE RETURNS FOR LATER THURSDAY INTO SATURDAY.

A COLD FRONT SHOULD BEGIN TO APPROACH THE MASON DIXON LINE BY THE
END OF THE WEEKEND.

&&

.AVIATION /15Z MONDAY THROUGH FRIDAY/...
MARINE LAYER WILL RESULT IN IFR CIGS AND MVFR/IFR VSBYS THIS
MORNING. CIGS MAY IMPROVE TO MVFR LEVELS THIS AFTERNOON.
HOWEVER...THERE IS A CONCERN THAT IFR CONDITIONS COULD PERSIST
WELL INTO THE AFTERNOON HOURS...ESPECIALLY ACROSS KMRB...KIAD AND
KCHO.

RAIN AND DRIZZLE MAY TAPER OFF LATE THIS MORNING AND EARLY
AFTERNOON...BUT SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP THIS AFTERNOON. IFR CIGS AND VSBYS ARE EXPECTED AGAIN FOR
TONIGHT ALONG WITH SOME SHOWERS.

SUB VFR CONDITIONS LIKELY TUESDAY INTO WEDNESDAY AS A LOW PRESSURE
TROUGH SETS UP ACROSS THE MID ATLANTIC. THUNDERSTORMS POSSIBLE
DURING THE AFTERNOON AND EVENING HOURS.

WEAK HIGH PRESSURE RETURNS FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.MARINE...
LOW PRESSURE WILL WEAKEN OVER VIRGINIA LATE THIS MORNING INTO THIS
AFTERNOON. AN EASTERLY FLOW WILL CONTINUE TO CAUSE SCA WIND GUSTS
LATE THIS MORNING. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE
MARYLAND CHESAPEAKE NORTH OF NORTH BEACH UNTIL NOON. WINDS WILL
WEAKEN TO BELOW SCA CRITERIA ACROSS ALL OF THE WATERS THIS
AFTERNOON. WIND SPEEDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA
TONIGHT.

SHOWERS AND ISOLATED T-STORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON.

SE/S FLOW REMAINS RATHER LIGHT ACROSS THE CWFA DURING THE PERIOD. A
LOW PRESSURE TROUGH WILL SET UP JUST WEST OF THE WATERS FOR TUESDAY
INTO MUCH OF WEDNESDAY. THE TROUGH SHOULD DISSIPATE BY
THURSDAY...WITH WEAK HIGH PRESSURE RETURNING FOR FRIDAY INTO THE
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES THIS MRNG RANGE FROM 0.50-1.00 FT.
ELY FLOW WILL PERSIST TDA...CAUSING ANOMALIES TO INCREASE.
HOWEVER...AFTN/EVE HIGH TIDE IS ASTRONOMICAL LWR OF SEMIDIURNAL
CYCLE SO NO ISSUES XPCD EVEN WITH INCRG ANOMALIES. LATE TNGT/ERY
TUE...THE HIGHER ASTRONOMICAL HIGH TIDE IS EXPECTED AND MINOR
INUNDATION IS POSSIBLE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>532-
     538>540.

&&

$$
SYNOPSIS...SBK/NWL
NEAR TERM...SBK/BJL
SHORT TERM...NWL
LONG TERM...NWL
AVIATION...SBK/BJL/NWL
MARINE...SBK/BJL/NWL
TIDES/COASTAL FLOODING...BJL/SBK

000
FXUS61 KAKQ 211344
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
944 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST MSAS / SFC AND RADAR OBS SHOWING CENTER OF LOW PRESSURE
CURRENTLY LOCATED OVER SE/E VA MOVING SLOWLY NW. PATTERN TODAY
SUPPORTS RATHER HIGH CHANCES FOR PRECIP CONTINUING. SKIES AVG OUT
CLOUDY THIS MORNING...WITH SOME PARTIAL CLEARING POSSIBLE IN
SOUTHERN AREAS BY LATE MRNG/EARLY AFTN. WILL HAVE LIKELY POPS OVER
NORTHERN PART OF FA FOR THE AFTN...W/ CHC POPS REST OF AREA. ALSO
WILL HAVE ISOLATED TSTMS IN THE FCST THIS AFTN/EVENING. FAVOR
COOLER MET NUMBERS FOR HIGHS...WHICH WILL BE MAINLY IN THE UPR 70S
S...TO LWR 70S N/NE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
UNSETTLED CONDITIONS WILL DOMINATE THE WX PATTERN THROUGH
MIDWEEK...NOT DUE TO ALBERTO BUT RATHER DUE TO AN UPPER LOW THAT
WILL BE SLOW TO MOVE OUT OF THE AREA AS IT GETS CUTOFF FROM THE
MAIN STREAM OF WESTERLIES IN BETWEEN A RIDGE AMPLIFYING WELL N TO
HUDSON BAY CANADA...AND ANOTHER WELL OFF THE SE COAST NEAR
BERMUDA.

TONIGHT...WILL CARRY CHC TO LIKELY POPS MAINLY FOR THE EARLY
EVENING HRS..THEN LOOKS LIKE SOMEWHAT OF A LULL IN THE FORCING AND
WILL HAVE ONLY 20% POPS THROUGH MOST OF THE OVERNIGHT PERIOD AS
SHORTWAVE ENERGY DIVES SE FROM THE MID MS VALLEY DOWN INTO THE
DEEP SOUTH. SKIES MAY BE PARTLY CLOUDY FOR AWHILE...BUT W/ LGT
FLOW AND AMPLE LOW LEVEL MOISTURE SHOULD SEE EITHER PATCHY FOG
OR LOW STRATUS REDEVELOP PRIOR TO DAYBREAK. MILD W/ LOWS GENLY
BETWEEN 60-65.

TUE/WED...SHOULD SEE SOME GRADUAL/PARTIAL CLEARING BY LATE AM HRS
TUE AS SE FLOW DEVELOPS...BUT SKIES OVERALL AVG OUT MOSTLY CLOUDY.
INSTABILITY ON THE INCREASE BY AFTN AND WILL TEND TO HAVE A LITTLE
MORE IN THE WAY OF TSTM ACTIVITY THAN ON MON. WILL HAVE CHC POPS
FOR MOST AREAS (LIKELY OVER THE FAR WEST) BY LATE AFTN/EVENING.
AGAIN FAVORING COOLER MET GUIDANCE FOR HIGHS...A LITTLE WARMER
THAN MON W/ HIGHS GENLY IN UPPER 70S TO LOWER 80S (A LITTLE COOLER
ON THE ERN SHORE).

ON WED...GOOD CONSENSUS BETWEEN THE GFS/NAM/ECMWF AND EVEN THE
UKMET/GEM THAT UNSETTLED WX WILL PERSIST AS THE UPPER LOW BECOMES
CUTOFF AND CENTERED JUST TO OUR SW...PLACING THE MID ATLC IN A
REGION OF UPPER DIFFLUENCE AND DECENT LIFT. WENT A LITTLE HIGHER
THAN NUMERICAL GUIDANCE FOR POPS...WITH A PERIOD OF LIKELY POPS
FOR MUCH OF INTERIOR VA. HIGHS FAIRLY SIMILAR TO TUE W/ UPPER 70S
TO LOWER 80S FOR MOST (IF ENOUGH SUN COULD SEE A FEW MID 80S ACRS
SRN VA/NE NC).

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE AT 11Z APPEARED TO BE WEAKENING OVER CENTRAL VA.
IFR/LIFR CONDITIONS WERE OCCASIONALLY INTERRUPTED WITH IMPROVING
CONDITIONS OVER EASTERN PORTIONS DUE TO MIXING. EXPECT THE MAIN
IMPROVEMENT WILL ARRIVE IN THE LATE MORNING.

PCPN IS PSBL ACRS THE AREA WITH THE HIGHEST POPS AT RIC AND SBY AFT
18Z. MENTIONED SHRA AFT 18Z AT THOSE LOCATIONS TIL EARLY EVENING BUT
WITH NO RESTRICTION TO VSBY INCLUDED.

CONDITIONS MAY GO BACK DOWN MONDAY NIGHT/TUESDAY MORNING. WITH
SUPPORT FROM BOTH MET AND MAV...HAVE RIC AND SBY GOING BACK TO
IFR/LIFR AND BROUGHT THOSE TWO BACK DOWN TO IFR IN THE LATE EVENING.
THE OTHER THREE TAF SITES MAY SEE SOME LOWERING CONDITIONS TOWARD
MORNING BUT LEFT IFR OUT FOR NOW.

OUTLOOK...CONDITIONS IMPROVE ONCE AGAIN TO VFR LATE TUESDAY MORNING.
THERE WILL BE A CHANCE FOR MAINLY AFTN TSTMS BOTH TUESDAY AND AN
EVEN BETTER CHANCE FOR PCPN WEDNESDAY. NEITHER OF THESE EVENTS
SHOULD HAVE THE WIDESPREAD IFR THAT OCCURRED SUNDAY.

&&

.MARINE...
SFC LOW PRESSURE CONTINUES TO MOVE NW OVER CENTRAL VIRGINIA. WINDS
HAVE TURNED TO SOUTHERLY AND DIMINISHED BELOW SCA CRITERIA. SEAS
CONTINUE 5 FT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. SCA IN
EFFECT UNTIL 22Z AND THIS MAY BE DROPPED OVER ALL OR PORTIONS OF
THIS AREA PRIOR TO 22Z.

AS TROPICAL STORM ALBERTO MOVES NORTHEAST TO THE EAST OF THE COASTAL
WATERS TUESDAY AND WEDNESDAY...SWELLS ARE EXPECTED TO BUILD OVER THE
AREA. SURFACE WINDS AHEAD OF ALBERTO FROM WAVEWATCH LOOK SIMILAR TO
EURO (A MODEL THAT HANDLES ALBERTO FAIRLY WELL PER HPC) AND USED
WAVEWATCH FOR THE SEAS IN THE COASTAL WATERS. THIS BRINGS 5 FT SEAS
TO THE AREA TUESDAY AND TUESDAY NIGHT...ESPECIALLY OVER THE NORTHERN
COASTAL WATERS. THESE SHOULD SETTLE DOWN BY WEDNESDAY. OTHERWISE...
MARINE CONDITIONS SHOULD BE FAIRLY QUIET DURING THE
UPCOMING WEEK.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ650-
     652.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB/MAS
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...LSA
MARINE...LSA

000
FXUS61 KLWX 211335
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
935 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE WILL NEAR THE MID-ATLANTIC TODAY AND TONIGHT. A LOW
PRESSURE TROUGH WILL BECOME STATIONARY ACROSS THE MID ATLANTIC
REGION DURING THE MIDDLE PART OF THE WEEK. WEAK HIGH PRESSURE WILL
RETURN FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
AN EASTERLY FLOW AROUND LOW PRESSURE OVER SOUTHERN VIRGINIA HAS
ALLOWED FOR PLENTY OF CLOUDS ALONG WITH RAIN AND DRIZZLE THIS
MORNING. MOST OF THE RAIN HAS FALLEN ACROSS THE NORTHERN AND
CENTRAL CWA WHERE ISENTROPIC LIFT HAS BEEN A BIT DEEPER.

LOW PRESSURE WILL REMAIN OVER SOUTHERN VIRGINIA THIS
AFTERNOON...BUT IT WILL GRADUALLY WEAKEN. DEEP MOISTURE WILL
CONTINUE TO ADVECT INTO OUR REGION DURING THIS TIME. WEAKENING
DYNAMICS SUGGEST THAT PRECIP WOULD DIMINISH. HOWEVER...DEEP
MOISTURE WILL ALLOW FOR SOME INSTABILITY THIS AFTERNOON WHICH WILL
LEAD TO MORE SHOWERS ALONG WITH ISOLATED THUNDERSTORMS. THE BEST
CHANCE FOR SHOWERS AND T-STORMS WILL BE ACROSS LOCATIONS WHERE THE
MARINE LAYER MIXES OUT. THERE ARE TWO AREAS WHERE THAT IS MOST
LIKELY. THE FIRST IS ACROSS THE POTOMAC HIGHLANDS INTO THE CENTRAL
SHENANDOAH VALLEY AND THE SECOND IS NEAR AND EAST OF THE I-95
CORRIDOR WHERE A COASTAL FRONT MAY ASSIST IN MIXING OUT THE MARINE
LAYER THIS AFTERNOON. ANY SUNSHINE THAT DOES OCCURR WILL LEAD TO
MODERATE INSTABILITY THIS AFTERNOON...WHICH COULD CAUSE
THUNDERSTORMS TO CONTAIN LOCALLY HEAVY RAIN. SEVERE T-STORMS ARE
NOT EXPECTED DUE TO WEAK SHEAR PROFILES.

SFC TROF ENTERS POTOMAC HIGHLANDS TNGT AND PUSHES TWD BLUE RIDGE
OVNGT. BEST POPS/QPF FOCUSED ALONG/AHEAD OF THIS FEATURE...WITH LOW
LIKELY/HIGH CHC SHWR PROBS EXHIBITED FROM SHEN VLY TO I-95 CORRIDOR
OVNGT.  RMNT THUNDER FROM ANY AFTN CVCTN CUD LINGER PAST
SUNSET...BUT SHUD DIURNAL DIMINISH AFTN MIDNIGHT. MINIMA TDA WILL BE
QUITE MILD FOR LATE MAY...50S W OF BLUE RIDGE WITH L60S E.

&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
UNSETTLED WEATHER CONDITIONS WILL CONTINUE TUESDAY INTO WEDNESDAY AS
A LOW PRESSURE TROUGH BECOMES STATIONARY ACROSS THE CWFA. THE TROUGH
WILL SERVE TO FOCUS PRECIP THROUGH THE PERIOD.

INCREASED POPS DURING THIS PERIOD. SOME INSTABILITY DURING THE
AFTERNOON...SO LEFT MENTION OF THUNDERSTORMS IN THE FORECAST INTO
THE EVENING HOURS. UPPER LEVEL STEERING WILL BE LIGHT...AND SURFACE
FLOW WILL BE FROM THE SE. THIS SHOULD ALLOW FOR THE HIGHEST PRECIP
AMOUNTS ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MOUNTAINS. AT
THIS TIME...RAINFALL AMOUNTS WILL AVERAGE BETWEEN ONE HALF AND ONE
INCH. LOCALLY HIGHER AMOUNTS ALONG EASTERN FACING HIGHER TERRAIN.
STILL BELOW 2SD FOR PWATS.

TOOK BLEND FOR TEMPS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE TROUGH SHOULD DISSIPATE BY EARLY THURSDAY. HIGH
PRESSURE SETS UP ACROSS THE DEEP SOUTH...WITH SOUTHERLY FLOW ACROSS
THE MID ATLANTIC. SOME DIFFERENCES BETWEEN THE MODELS FOR
THURSDAY...NAM IS DRIER THAN THE GFS. NO REAL FOCUS FOR THE
PRECIP...SO SAW NO REASON TO CHANGE POPS AT THIS TIME. WEAK HIGH
PRESSURE RETURNS FOR LATER THURSDAY INTO SATURDAY.

A COLD FRONT SHOULD BEGIN TO APPROACH THE MASON DIXON LINE BY THE
END OF THE WEEKEND.

&&

.AVIATION /14Z MONDAY THROUGH FRIDAY/...
MARINE LAYER WILL RESULT IN IFR CIGS AND MVFR/IFR VSBYS THIS
MORNING. CIGS MAY IMPROVE TO MVFR LEVELS THIS AFTERNOON.
HOWEVER...THERE IS A CONCERN THAT IFR CONDITIONS COULD PERSIST
WELL INTO THE AFTERNOON HOURS...ESPECIALLY ACROSS KMRB...KIAD AND
KCHO.

RAIN AND DRIZZLE MAY TAPER OFF LATE THIS MORNING AND EARLY
AFTERNOON...BUT SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED TO
DEVELOP THIS AFTERNOON. IFR CIGS AND VSBYS ARE EXPECTED AGAIN FOR
TONIGHT ALONG WITH SOME SHOWERS.

SUB VFR CONDITIONS LIKELY TUESDAY INTO WEDNESDAY AS A LOW PRESSURE
TROUGH SETS UP ACROSS THE MID ATLANTIC. THUNDERSTORMS POSSIBLE
DURING THE AFTERNOON AND EVENING HOURS.

WEAK HIGH PRESSURE RETURNS FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.MARINE...
LOW PRESSURE WILL WEAKEN OVER VIRGINIA LATE THIS MORNING INTO THIS
AFTERNOON. AN EASTERLY FLOW WILL CONTINUE TO CAUSE SCA WIND GUSTS
LATE THIS MORNING. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE
MARYLAND CHESAPEAKE NORTH OF NORTH BEACH UNTIL NOON. WINDS WILL
WEAKEN TO BELOW SCA CRITERIA ACROSS ALL OF THE WATERS THIS
AFTERNOON. WIND SPEEDS ARE EXPECTED TO REMAIN BELOW SCA CRITERIA
TONIGHT.

SHOWERS AND ISOLATED T-STORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON.

SE/S FLOW REMAINS RATHER LIGHT ACROSS THE CWFA DURING THE PERIOD. A
LOW PRESSURE TROUGH WILL SET UP JUST WEST OF THE WATERS FOR TUESDAY
INTO MUCH OF WEDNESDAY. THE TROUGH SHOULD DISSIPATE BY
THURSDAY...WITH WEAK HIGH PRESSURE RETURNING FOR FRIDAY INTO THE
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES THIS MRNG RANGE FROM 0.50-1.00 FT.
ANOMALIES WILL CAUSE WATER LEVELS TO BE AROUND THRESHOLDS FOR
MINOR COASTAL FLOODING IN ALEXANDRIA AND WASHINGTON DC NEAR HIGH
TIDE THIS MORNING. A COASTAL FLOOD ADVISORY IS IN EFFECT. ELY FLOW
WILL PERSIST TDA...CAUSING ANOMALIES TO INCREASE.
HOWEVER...AFTN/EVE HIGH TIDE IS ASTRONOMICAL LWR OF SEMIDIURNAL
CYCLE SO NO ISSUES XPCD EVEN WITH INCRG ANOMALIES. LATE TNGT/ERY
TUE...THE HIGHER ASTRONOMICAL HIGH TIDE IS EXPECTED AND MINOR
INUNDATION IS POSSIBLE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR DCZ001.
MD...NONE.
VA...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR VAZ054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ530>532-
     538>540.

&&

$$
SYNOPSIS...SBK/NWL
NEAR TERM...BJL/SBK
SHORT TERM...NWL
LONG TERM...NWL
AVIATION...SBK/BJL/NWL
MARINE...SBK/BJL/NWL
TIDES/COASTAL FLOODING...BJL

000
FXUS61 KLWX 211204
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
804 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE WILL NEAR THE MID-ATLANTIC TODAY AND TONIGHT. A LOW
PRESSURE TROUGH WILL BECOME STATIONARY ACROSS THE MID ATLANTIC
REGION DURING THE MIDDLE PART OF THE WEEK. WEAK HIGH PRESSURE WILL
RETURN FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC LOPRES NEAR MOUTH OF CHESAPEAKE ERY THIS MRNG WILL DRIFT
NWWD/WEAKEN TDA AS STRONGER LOPRES DVLPS FURTHER IN ATLC. CLOSED
ULVL LOPRES OVR CAROLINAS WILL GRADUALLY BE ABSORBED BY NRN STREAM
LONGWAVE TROF...WHICH WILL BE DIGGING THRU GREAT LAKES TDA/TNGT.
ULVL TROFS ATTENDANT SFC TROF WILL APPROACH APLCNS TDA AND INTO WRN
CWA TDA.

MAIN MOISTURE PLUME WILL GRADUALLY MOVE N OF RGN THIS
AFTERNOON...THUS POPS RANGE FROM CATEGORICAL N TO CHC S/W. OVC
CONDS WILL KEEP INSTABILITY MINIMAL...BUT ISOLATED THUNDER IS PSBL
THIS AFTN WITH AMPLE LIFT AND ABUNDANT MOISTURE IN PLACE.
TEMPS...REGULATED BY CLOUDS/PCPN...WILL STRUGGLE TO REACH L/M70S
THIS AFTN...DESPITE STARTING OFF ALREADY IN M60S.

SFC TROF ENTERS POTOMAC HIGHLANDS TNGT AND PUSHES TWD BLUE RIDGE
OVNGT. BEST POPS/QPF FOCUSED ALONG/AHEAD OF THIS FEATURE...WITH LOW
LIKELY/HIGH CHC SHWR PROBS EXHIBITED FROM SHEN VLY TO I-95 CORRIDOR
OVNGT.  RMNT THUNDER FROM ANY AFTN CVCTN CUD LINGER PAST
SUNSET...BUT SHUD DIURNAL DIMINISH AFTN MIDNIGHT. MINIMA TDA WILL BE
QUITE MILD FOR LATE MAY...50S W OF BLUE RIDGE WITH L60S E.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
UNSETTLED WEATHER CONDITIONS WILL CONTINUE TUESDAY INTO WEDNESDAY AS
A LOW PRESSURE TROUGH BECOMES STATIONARY ACROSS THE CWFA. THE TROUGH
WILL SERVE TO FOCUS PRECIP THROUGH THE PERIOD.

INCREASED POPS DURING THIS PERIOD. SOME INSTABILITY DURING THE
AFTERNOON...SO LEFT MENTION OF THUNDERSTORMS IN THE FORECAST INTO
THE EVENING HOURS. UPPER LEVEL STEERING WILL BE LIGHT...AND SURFACE
FLOW WILL BE FROM THE SE. THIS SHOULD ALLOW FOR THE HIGHEST PRECIP
AMOUNTS ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MOUNTAINS. AT
THIS TIME...RAINFALL AMOUNTS WILL AVERAGE BETWEEN ONE HALF AND ONE
INCH. LOCALLY HIGHER AMOUNTS ALONG EASTERN FACING HIGHER TERRAIN.
STILL BELOW 2SD FOR PWATS.

TOOK BLEND FOR TEMPS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE TROUGH SHOULD DISSIPATE BY EARLY THURSDAY. HIGH
PRESSURE SETS UP ACROSS THE DEEP SOUTH...WITH SOUTHERLY FLOW ACROSS
THE MID ATLANTIC. SOME DIFFERENCES BETWEEN THE MODELS FOR
THURSDAY...NAM IS DRIER THAN THE GFS. NO REAL FOCUS FOR THE
PRECIP...SO SAW NO REASON TO CHANGE POPS AT THIS TIME. WEAK HIGH
PRESSURE RETURNS FOR LATER THURSDAY INTO SATURDAY.

A COLD FRONT SHOULD BEGIN TO APPROACH THE MASON DIXON LINE BY THE
END OF THE WEEKEND.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
IFR CIGS/MVFR VSBY NOW IMPACTING MOST TERMINALS...AND RESTRICTIONS
SHUD PERSIST INTO MID-MRNG AS EASTERLY FLOW ADVECTS MOISTURE FROM
ATLC INTO RGN. SCT/NUM SHWRS WILL IMPACT TERMINALS DURG THIS
PERIOD...WITH HIGHEST CVRG FOR URBAN CORRIDOR AIRPORTS. LT
MRNG...SHWRS DIMINISH AT LEAST SOMEWHAT...VCSH STILL WARRANTED...AND
CIGS SHUD IMPROVE TO MVFR. ISOLATED TSTMS PSBL THIS AFTN/EVE...THO
RISK TO LOW TO DISPLAY IN TAFS ATTM. SCT SHRA STILL PERSIST
TNGT...WITH VSBY/CIGS GRADUALLY DEGRADING AFTER MIDNIGHT. WINDS THRU
TNGT MOSTLY NE AND LGT.

SUB VFR CONDITIONS LIKELY TUESDAY INTO WEDNESDAY AS A LOW PRESSURE
TROUGH SETS UP ACROSS THE MID ATLANTIC. THUNDERSTORMS POSSIBLE
DURING THE AFTERNOON AND EVENING HOURS.

WEAK HIGH PRESSURE RETURNS FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.MARINE...
NE FLOW CONTS AROUND LOPRES NEAR MOUTH OF BAY ERY THIS MRNG...WITH
GUSTS NEAR 20KTS BEING REALIZED ACRS PORTIONS OF WATERS WHERE ADZY
IN EFFECT UNTIL 14Z...BUT LOPRES SHUD WEAKEN AND FLOW RELAXES
LATER THIS MRNG. THEREAFTER...LGT NE FLOW WILL GRADUALLY BCM ELY.
SCT/NUM SHWRS...PSBLY TSTMS...WILL RESIDE IN VICINITY OF WATERS
THRU TNGT AS GENERAL LOPRES DOMINATES.

SE/S FLOW REMAINS RATHER LIGHT ACROSS THE CWFA DURING THE PERIOD. A
LOW PRESSURE TROUGH WILL SET UP JUST WEST OF THE WATERS FOR TUESDAY
INTO MUCH OF WEDNESDAY. THE TROUGH SHOULD DISSIPATE BY
THURSDAY...WITH WEAK HIGH PRESSURE RETURNING FOR FRIDAY INTO THE
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES THIS MRNG RANGE FROM 0.50-1.00 FT.
ANOMALIES WILL CAUSE WATER LEVELS TO BE NEAR THRESHOLDS FOR MINOR
COASTAL FLOODING IN ALEXANDRIA AND WASHINGTON DC NEAR HIGH TIDE
THIS MORNING. A COASTAL FLOOD ADVISORY IS IN EFFECT. ELY FLOW
WILL PERSIST TDA...CAUSING ANOMALIES TO INCREASE.
HOWEVER...AFTN/EVE HIGH TIDE IS ASTRONOMICAL LWR OF SEMIDIURNAL
CYCLE SO NO ISSUES XPCD EVEN WITH INCRG ANOMALIES. LATE TNGT/ERY
TUE...THE HIGHER ASTRONOMICAL HIGH TIDE IS EXPECTED AND MINOR
INUNDATION IS POSSIBLE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR DCZ001.
MD...NONE.
VA...COASTAL FLOOD ADVISORY UNTIL 11 AM EDT THIS MORNING FOR VAZ054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR
     ANZ530>534-537>543.

&&

$$
SYNOPSIS...SBK/NWL
NEAR TERM...SBK/BJL
SHORT TERM...NWL
LONG TERM...NWL
AVIATION...SBK/NWL
MARINE...SBK/NWL
TIDES/COASTAL FLOODING...SBK/BJL

000
FXUS61 KRNK 211139
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
739 AM EDT MON MAY 21 2012

.SYNOPSIS...
BROAD AREA OF LOW PRESSURE WILL LINGER OVER THE EAST THROUGH
TUESDAY. A FRONT ARRIVES TUESDAY AND WILL SLOWLY PUSH EAST TO THE
COAST LATER WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 655 AM EDT MONDAY...

HAVE MADE SOME ADJUSTMENTS TO POPS THIS MORNING ADDING SLIGHT
CHANCE ACROSS SE WV WITH LIGHT RETURNS ON RADAR SHOWING UP WEST OF
LWB. OTHERWISE...THE FORECAST IS ON TRACK WITH MORE CLOUDS IN THE
EAST THIS MORNING WITH MORE SUN IN THE WEST.

HIGHER MOISTURE-LADEN AIR IS ENTERING THE FORECAST AREA FROM THE
EAST THIS MORNING PER DEWPOINTS IN THE LOWER 60S JUST AT THE CWA
BORDER. WILL SEE INCREASING CLOUDINESS AS WELL...AND ALREADY GETTING
MOSTLY CLOUDY TO OVERCAST SKIES ACROSS THE PIEDMONT...BUT STILL
SCT-BKN IN THE WEST. RADAR HAS BEEN SHOWING VERY LIGHT RETURNS
BETWEEN LYNCHBURG-DANVILLE AND REIDSVILLE. MODELS HAVE NOT
INITIALIZED THAT WELL WITH THIS...WHICH WILL LEAD TO SOME LOW
CONFIDENCE IN THE FORECAST. THE UPPER TROUGH THAT IS COVERING THE
SOUTHEAST WILL REMAIN IN THE GENERAL AREA THROUGH TONIGHT...AND WILL
HAVE TO SEE WHERE INDIVIDUAL PIECES OF UPPER ENERGY MOVE IN
CONJUNCTION WITH SFC BOUNDARIES.

FOLLOWED CLOSER TO THE LOCAL WRF THIS MORNING...THEN BLENDING OF THE
PREVIOUS FORECAST WITH THE SREF/ECMWF. WILL KEEP CHANCE POPS IN THE
EAST THIS MORNING WITH SLIGHT CHANCES AS FAR WEST AS THE GREENBRIER
VALLEY WITH A WAVE PIVOTING NW ACROSS THE NORTHERN VA. THE SOUTHWEST
FORECAST AREA SHOULD BE MAINLY DRY THIS MORNING...PINCHED BETWEEN
HIGHER THETA-E AIR TO THE EAST AND OVER THE OHIO VALLEY INTO THE MID
MISSISSIPPI VALLEY. THIS AFTERNOON...THE ENTIRE AREA SHOULD SEE
AMPLE MOISTURE AND ENOUGH HEATING WITH SUPPORT IN THE UPPER LEVELS
THAT SHOWERS AND STORMS WILL DEVELOP. TRYING TO DETERMINE WHERE BEST
COVERAGE WILL BE IS TRICKY...BUT HEDGING TOWARD THE NORTHERN
FORECAST AREA BETWEEN LWB-LYH...WHERE THE UPPER SUPPORT APPEARS
GREATEST. THE INCREASE IN CLOUD COVER AND SFC DEWPOINTS SHOULD KEEP
HIGH TEMPS A FEW DEGREES COOLER THAN SUNDAYS...WITH MID TO UPPER 70S
EXPECTED MOST PLACES.

TONIGHT...WITH SUN SETTING...THINKING IS THAT ORGANIZED CONVECTION
WEAKENS. HOWEVER...SFC FRONT WILL WORK ITS WAY TOWARD THE CENTRAL
APPALACHIANS BY TUESDAY MORNING AND MAY SEE AN INCREASE IN COVERAGE
TOWARD SOUTHEAST WEST VIRGINIA SOUTH INTO THE NORTH CAROLINA
MOUNTAINS BY DAYBREAK. THE MODELS ARE DIFFERENT ON THE SPEED OF THE
UPPER SYSTEM AND FRONTAL PRECIP...WITH THE NAM FASTEST IN BRINGING A
SOMEWHAT ORGANIZED LINE INTO FAR SOUTHWEST VA...WHILE THE ECMWF/GFS
KEEP IT FURTHER WEST. AGAIN...FOLLOWING SLOWER SOLUTION. LOWS
TONIGHT WILL STAY MILD WITH MID 50S TO AROUND 60 EXPECTED.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 355 AM EDT MONDAY...

TUESDAY MORNING WILL START OFF WITH WIDELY SCATTERED SHOWER AND
ISOLATED THUNDERSTORM ACTIVITY...AND WILL EXPECT TO SEE COVERAGE
INCREASE BY LATE MORNING AS DAYTIME HEATING INCREASES...AND A WEAK
COLD FRONT ENTERS OUR SOUTHEAST WEST VIRGINIA AND MOUNTAIN EMPIRE
COUNTIES. BY MID AFTERNOON...THE FRONT WILL PUSH NEAR THE BLUE
RIDGE...HELPING TO FURTHER DESTABILIZE THE ATMOSPHERE ACROSS THE
PIEDMONTS. EXPECT TO SEE A FEW STRONG...AND POSSIBLY SEVERE
THUNDERSTORMS DEVELOP DURING THE EARLY EVENING EAST OF THE BLUE
RIDGE...WITH THESE STORMS CAPABLE OF PRODUCING LOCALLY GUSTY WINDS
AND LARGE HAIL. WITH WINDS BECOMING SOUTHERLY AHEAD OF THE
FRONT...WILL EXPECT TO SEE NEAR 80 DEGREE TEMPERATURES REACH AS FAR
NORTH AS BUCKINGHAM AND AMHERST COUNTIES DURING THE AFTERNOON.
FURTHER WEST...AFTERNOON TEMPERATURES CAN BE EXPECTED TO HOLD IN THE
LOW TO MID 70S. SHOWER AND THUNDERSTORM ACTIVITY WILL DIMINISH
GRADUALLY LATE TUESDAY EVENING...BUT WILL SEE THIS ACTIVITY LINGER
THROUGH THE EARLY MORNING HOURS OF WEDNESDAY.

MUCH OF THE SAME CAN BE EXPECTED FOR WEDNESDAY AND THURSDAY...AS THE
FRONTAL BOUNDARY LOSES ITS PUSH...BECOMING NOT MUCH MORE THAN A WEAK
TROUGH STALLED ACROSS THE PIEDMONT REGION. AND WITH BROAD UPPER
LEVEL TROUGHING HOLDING ALONG THE APPALACHIAN CHAIN HEADING INTO THE
END OF THE WORKWEEK...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO
INCREASE IN COVERAGE LATE EACH MORNING...AND DIMINISH LATE EACH
EVENING. BETTER COVERAGE AND GREATER INSTABILITY WILL BE FOUND EAST
OF THE BLUE RIDGE...AND EXPECT A FEW STRONG TO SEVERE STORMS EACH
EVENING. TEMPERATURES BOTH DAYS WILL BE NEAR NORMAL FOR THE SECOND
HALF OF MAY.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 AM EDT MONDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM EDT MONDAY...

VFR CONDITIONS ARE EXPECTED TODAY. SHOWERS AND A FEW THUNDERSTORMS
WILL BE POSSIBLE AREA WIDE BUT ESPECIALLY ACROSS THE PIEDMONT
NORTH OF DANVILLE AND EAST OF ROANOKE WHERE BETTER SUPPORT IN THE
UPPER LEVELS RESIDE. AFTERNOON...ANY AIRPORT COULD SEE A SHOWER OR
STORM AS HIGH MOISTURE CONTENT UNDER THE UPPER TROUGH AND WEAK
OUTFLOW COULD SPARK CONVECTION. FOR NOW WILL BE VFR OUTSIDE OF
CONVECTION. SINCE IT SHOULD BE MAINLY SCATTERED KEPT THUNDER OUT
OF THE TAFS.

TONIGHT...A LULL IN ACTIVITY ANTICIPATED ALTHOUGH A FEW SHOWERS
WILL LINGER AREAWIDE. AN ISSUE TONIGHT WILL BE AMPLE MOISTURE ON
THE GROUND VERSUS CLOUD COVER AND IF/HOW MUCH FOG AND OR LOW
STRATUS FORMS. AT THE MOMENT AM CONFIDENT ENOUGH THAT MVFR
CONDITIONS WILL OCCUR AT ALL SITES BUT BLF WHICH SHOULD STAY
VFR...AND WILL HAVE LWB SUB MVFR AFTER MIDNIGHT...WITH FOG.

THE AREA WILL REMAIN INFLUENCED BY AN UPPER TROUGH AND WEAK COLD
FRONT UNTIL MIDWEEK WHICH WILL BE KEEPING A THREAT OF SHRA/TSRA
AND SUB VFR WX AROUND UNTIL THEN. MAINLY VFR WX EXPECTED FOR THU-
FRI UNDER HIGH PRESSURE TO THE NORTHEAST...ALTHOUGH SOME LATE
NIGHT FOG/STRATUS NOT OUT OF THE QUESTION.



&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...NF
LONG TERM...NF
AVIATION...WP

000
FXUS61 KAKQ 211121
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
721 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST MSAS / SFC AND RADAR OBS SHOWING CENTER OF LOW PRESSURE
CURRENTLY LOCATED OVER SE/E VA MOVING SLOWLY NW. PATTERN TODAY
SUPPORTS RATHER HIGH CHANCES FOR PRECIP CONTINUING. FOR THE NEXT
FEW HRS...GENLY ONLY SPOTTY LIGHT SHOWERS/DRIZZLE ACRS MOST OF THE
AREA...BUT CAN SEE THE NEXT BATCH OFF THE COAST POISED TO
OVERSPREAD THE ERN SHORE BY AROUND DAYBREAK. SKIES AVG OUT CLOUDY
THIS MORNING...WITH SOME PARTIAL CLEARING POSSIBLE IN SOUTHERN
AREAS BY LATE MRNG/EARLY AFTN. WILL HAVE LIKELY POPS ON THE ERN
SHORE FOR MOST OF THE DAY...AND FOR MUCH OF VA FOR THE AFTN...W/
CHC POPS IN THE FAR SOUTH. ALOS WILL HAVE ISOLATED TSTMS IN THE
FCST THIS AFTN/EVENING. FAVOR COOLER MET NUMBERS FOR HIGHS...WHICH
WILL BE MAINLY IN THE UPR 70S S...TO LWR 70S N/NE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
UNSETTLED CONDITIONS WILL DOMINATE THE WX PATTERN THROUGH
MIDWEEK...NOT DUE TO ALBERTO BUT RATHER DUE TO AN UPPER LOW THAT
WILL BE SLOW TO MOVE OUT OF THE AREA AS IT GETS CUTOFF FROM THE
MAIN STREAM OF WESTERLIES IN BETWEEN A RIDGE AMPLIFYING WELL N TO
HUDSON BAY CANADA...AND ANOTHER WELL OFF THE SE COAST NEAR
BERMUDA.

TONIGHT...WILL CARRY CHC TO LIKELY POPS MAINLY FOR THE EARLY
EVENING HRS..THEN LOOKS LIKE SOMEWHAT OF A LULL IN THE FORCING AND
WILL HAVE ONLY 20% POPS THROUGH MOST OF THE OVERNIGHT PERIOD AS
SHORTWAVE ENERGY DIVES SE FROM THE MID MS VALLEY DOWN INTO THE
DEEP SOUTH. SKIES MAY BE PARTLY CLOUDY FOR AWHILE...BUT W/ LGT
FLOW AND AMPLE LOW LEVEL MOISTURE SHOULD SEE EITHER PATCHY FOG
OR LOW STRATUS REDEVELOP PRIOR TO DAYBREAK. MILD W/ LOWS GENLY
BETWEEN 60-65.

TUE/WED...SHOULD SEE SOME GRADUAL/PARTIAL CLEARING BY LATE AM HRS
TUE AS SE FLOW DEVELOPS...BUT SKIES OVERALL AVG OUT MOSTLY CLOUDY.
INSTABILITY ON THE INCREASE BY AFTN AND WILL TEND TO HAVE A LITTLE
MORE IN THE WAY OF TSTM ACTIVITY THAN ON MON. WILL HAVE CHC POPS
FOR MOST AREAS (LIKELY OVER THE FAR WEST) BY LATE AFTN/EVENING.
AGAIN FAVORING COOLER MET GUIDANCE FOR HIGHS...A LITTLE WARMER
THAN MON W/ HIGHS GENLY IN UPPER 70S TO LOWER 80S (A LITTLE COOLER
ON THE ERN SHORE).

ON WED...GOOD CONSENSUS BETWEEN THE GFS/NAM/ECMWF AND EVEN THE
UKMET/GEM THAT UNSETTLED WX WILL PERSIST AS THE UPPER LOW BECOMES
CUTOFF AND CENTERED JUST TO OUR SW...PLACING THE MID ATLC IN A
REGION OF UPPER DIFFLUENCE AND DECENT LIFT. WENT A LITTLE HIGHER
THAN NUMERICAL GUIDANCE FOR POPS...WITH A PERIOD OF LIKELY POPS
FOR MUCH OF INTERIOR VA. HIGHS FAIRLY SIMILAR TO TUE W/ UPPER 70S
TO LOWER 80S FOR MOST (IF ENOUGH SUN COULD SEE A FEW MID 80S ACRS
SRN VA/NE NC).

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE AT 11Z APPEARED TO BE WEAKENING OVER CENTRAL VA.
IFR/LIFR CONDITIONS WERE OCCASIONALLY INTERRUPTED WITH IMPROVING
CONDITIONS OVER EASTERN PORTIONS DUE TO MIXING. EXPECT THE MAIN
IMPROVEMENT WILL ARRIVE IN THE LATE MORNING.

PCPN IS PSBL ACRS THE AREA WITH THE HIGHEST POPS AT RIC AND SBY AFT
18Z. MENTIONED SHRA AFT 18Z AT THOSE LOCATIONS TIL EARLY EVENING BUT
WITH NO RESTRICTION TO VSBY INCLUDED.

CONDITIONS MAY GO BACK DOWN MONDAY NIGHT/TUESDAY MORNING. WITH
SUPPORT FROM BOTH MET AND MAV...HAVE RIC AND SBY GOING BACK TO
IFR/LIFR AND BROUGHT THOSE TWO BACK DOWN TO IFR IN THE LATE EVENING.
THE OTHER THREE TAF SITES MAY SEE SOME LOWERING CONDITIONS TOWARD
MORNING BUT LEFT IFR OUT FOR NOW.

OUTLOOK...CONDITIONS IMPROVE ONCE AGAIN TO VFR LATE TUESDAY MORNING.
THERE WILL BE A CHANCE FOR MAINLY AFTN TSTMS BOTH TUESDAY AND AN
EVEN BETTER CHANCE FOR PCPN WEDNESDAY. NEITHER OF THESE EVENTS
SHOULD HAVE THE WIDESPREAD IFR THAT OCCURRED SUNDAY.

&&

.MARINE...
SFC LOW PRESSURE CONTINUES TO MOVE NW OVER CENTRAL VIRGINIA. WINDS
HAVE TURNED TO SOUTHERLY AND DIMINISHED BELOW SCA CRITERIA. SEAS
CONTINUE 5 FT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. SCA IN
EFFECT UNTIL 22Z AND THIS MAY BE DROPPED OVER ALL OR PORTIONS OF
THIS AREA PRIOR TO 22Z.

AS TROPICAL STORM ALBERTO MOVES NORTHEAST TO THE EAST OF THE COASTAL
WATERS TUESDAY AND WEDNESDAY...SWELLS ARE EXPECTED TO BUILD OVER THE
AREA. SURFACE WINDS AHEAD OF ALBERTO FROM WAVEWATCH LOOK SIMILAR TO
EURO (A MODEL THAT HANDLES ALBERTO FAIRLY WELL PER HPC) AND USED
WAVEWATCH FOR THE SEAS IN THE COASTAL WATERS. THIS BRINGS 5 FT SEAS
TO THE AREA TUESDAY AND TUESDAY NIGHT...ESPECIALLY OVER THE NORTHERN
COASTAL WATERS. THESE SHOULD SETTLE DOWN BY WEDNESDAY. OTHERWISE...
MARINE CONDITIONS SHOULD BE FAIRLY QUIET DURING THE
UPCOMING WEEK.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ650-
     652-654.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...LSA
MARINE...LSA

000
FXUS61 KAKQ 210809
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
409 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE AND UNSETTLED CONDITIONS WILL PERSIST ACROSS THE AREA
THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LATEST MSAS / SFC AND RADAR OBS SHOWING CENTER OF LOW PRESSURE
CURRENTLY LOCATED OVER SE/E VA MOVING SLOWLY NW. PATTERN TODAY
SUPPORTS RATHER HIGH CHANCES FOR PRECIP CONTINUING. FOR THE NEXT
FEW HRS...GENLY ONLY SPOTTY LIGHT SHOWERS/DRIZZLE ACRS MOST OF THE
AREA...BUT CAN SEE THE NEXT BATCH OFF THE COAST POISED TO
OVERSPREAD THE ERN SHORE BY AROUND DAYBREAK. SKIES AVG OUT CLOUDY
THIS MORNING...WITH SOME PARTIAL CLEARING POSSIBLE IN SOUTHERN
AREAS BY LATE MRNG/EARLY AFTN. WILL HAVE LIKELY POPS ON THE ERN
SHORE FOR MOST OF THE DAY...AND FOR MUCH OF VA FOR THE AFTN...W/
CHC POPS IN THE FAR SOUTH. ALOS WILL HAVE ISOLATED TSTMS IN THE
FCST THIS AFTN/EVENING. FAVOR COOLER MET NUMBERS FOR HIGHS...WHICH
WILL BE MAINLY IN THE UPR 70S S...TO LWR 70S N/NE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
UNSETTLED CONDITIONS WILL DOMINATE THE WX PATTERN THROUGH
MIDWEEK...NOT DUE TO ALBERTO BUT RATHER DUE TO AN UPPER LOW THAT
WILL BE SLOW TO MOVE OUT OF THE AREA AS IT GETS CUTOFF FROM THE
MAIN STREAM OF WESTERLIES IN BETWEEN A RIDGE AMPLIFYING WELL N TO
HUDSON BAY CANADA...AND ANOTHER WELL OFF THE SE COAST NEAR
BERMUDA.

TONIGHT...WILL CARRY CHC TO LIKELY POPS MAINLY FOR THE EARLY
EVENING HRS..THEN LOOKS LIKE SOMEWHAT OF A LULL IN THE FORCING AND
WILL HAVE ONLY 20% POPS THROUGH MOST OF THE OVERNIGHT PERIOD AS
SHORTWAVE ENERGY DIVES SE FROM THE MID MS VALLEY DOWN INTO THE
DEEP SOUTH. SKIES MAY BE PARTLY CLOUDY FOR AWHILE...BUT W/ LGT
FLOW AND AMPLE LOW LEVEL MOISTURE SHOULD SEE EITHER PATCHY FOG
OR LOW STRATUS REDEVELOP PRIOR TO DAYBREAK. MILD W/ LOWS GENLY
BETWEEN 60-65.

TUE/WED...SHOULD SEE SOME GRADUAL/PARTIAL CLEARING BY LATE AM HRS
TUE AS SE FLOW DEVELOPS...BUT SKIES OVERALL AVG OUT MOSTLY CLOUDY.
INSTABILITY ON THE INCREASE BY AFTN AND WILL TEND TO HAVE A LITTLE
MORE IN THE WAY OF TSTM ACTIVITY THAN ON MON. WILL HAVE CHC POPS
FOR MOST AREAS (LIKELY OVER THE FAR WEST) BY LATE AFTN/EVENING.
AGAIN FAVORING COOLER MET GUIDANCE FOR HIGHS...A LITTLE WARMER
THAN MON W/ HIGHS GENLY IN UPPER 70S TO LOWER 80S (A LITTLE COOLER
ON THE ERN SHORE).

ON WED...GOOD CONSENSUS BETWEEN THE GFS/NAM/ECMWF AND EVEN THE
UKMET/GEM THAT UNSETTLED WX WILL PERSIST AS THE UPPER LOW BECOMES
CUTOFF AND CENTERED JUST TO OUR SW...PLACING THE MID ATLC IN A
REGION OF UPPER DIFFLUENCE AND DECENT LIFT. WENT A LITTLE HIGHER
THAN NUMERICAL GUIDANCE FOR POPS...WITH A PERIOD OF LIKELY POPS
FOR MUCH OF INTERIOR VA. HIGHS FAIRLY SIMILAR TO TUE W/ UPPER 70S
TO LOWER 80S FOR MOST (IF ENOUGH SUN COULD SEE A FEW MID 80S ACRS
SRN VA/NE NC).

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE AT 05Z IN VICINITY OF PHF AS INDICATED BY SURFACE WINDS
AND MOVING SLOWLY NW. THERE ARE WIDESPREAD IFR/LIFR CONDITIONS IN
ASSOCIATION WITH THE LOW ALONG WITH AREAS OF LIGHT RAIN AND
DRIZZLE.

IFR OR LOWER SHOULD PERSIST THROUGH MID MORNING. THERE ARE A FEW
LOCATIONS NEAR THE COAST THAT IMPROVED SHORTLY AFTER MIDNIGHT...
ESPECIALLY EAST OF ECG...BUT THERE IS LITTLE CONFIDENCE IN ANY OF
THE TAF SITES HAVING SIGNIFICANT IMPROVEMENT FOR AT LEAST THE
FIRST SIX HOURS OF THE 06Z TAF.

MOS AND BUFR SOUNDINGS ALL SUPPORT IFR ENDING AT EACH OF THE SITES
BETWEEN 14 AND 18Z. CONDITIONS MAY GO BACK DOWN MONDAY NIGHT/TUESDAY
MORNING. SINCE BOTH MET AND MAV HAVE RIC AND SBY GOING BACK TO
IFR/LIFR...(RATHER THAN JUST THE MET) BROUGHT THOSE TWO BACK DOWN TO
IFR IN THE LATE EVENING. TOO EARLY TO SAY ABOUT THE THREE TAF SITES
BUT WOULD PROBABLY BE AFT 06Z IF IT OCCURS AND WILL TAKE A LOOK
AGAIN WITH THE 12Z ISSUANCE.

OUTLOOK...CONDITIONS IMPROVE ONCE AGAIN TO VFR LATE TUESDAY MORNING.
THERE WILL BE A CHANCE FOR MAINLY AFTN TSTMS BOTH TUESDAY AND AN
EVEN BETTER CHANCE FOR PCPN WEDNESDAY. NEITHER OF THESE EVENTS
SHOULD HAVE THE WIDESPREAD IFR THAT OCCURRED SUNDAY.

&&

.MARINE...
SFC LOW PRESSURE CONTINUES TO MOVE NW OVER CENTRAL VIRGINIA. WINDS
HAVE TURNED TO SOUTHERLY AND DIMINISHED BELOW SCA CRITERIA. SEAS
CONTINUE 5 FT OVER THE COASTAL WATERS NORTH OF CAPE CHARLES. SCA IN
EFFECT UNTIL 22Z AND THIS MAY BE DROPPED OVER ALL OR PORTIONS OF
THIS AREA PRIOR TO 22Z.

AS TROPICAL STORM ALBERTO MOVES NORTHEAST TO THE EAST OF THE COASTAL
WATERS TUESDAY AND WEDNESDAY...SWELLS ARE EXPECTED TO BUILD OVER THE
AREA. SURFACE WINDS AHEAD OF ALBERTO FROM WAVEWATCH LOOK SIMILAR TO
EURO (A MODEL THAT HANDLES ALBERTO FAIRLY WELL PER HPC) AND USED
WAVEWATCH FOR THE SEAS IN THE COASTAL WATERS. THIS BRINGS 5 FT SEAS
TO THE AREA TUESDAY AND TUESDAY NIGHT...ESPECIALLY OVER THE NORTHERN
COASTAL WATERS. THESE SHOULD SETTLE DOWN BY WEDNESDAY. OTHERWISE...
MARINE CONDITIONS SHOULD BE FAIRLY QUIET DURING THE
UPCOMING WEEK.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ650-
     652-654.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...LSA
MARINE...LSA

000
FXUS61 KRNK 210803
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
403 AM EDT MON MAY 21 2012

.SYNOPSIS...
BROAD AREA OF LOW PRESSURE WILL LINGER OVER THE EAST THROUGH
TUESDAY. A FRONT ARRIVES TUESDAY AND WILL SLOWLY PUSH EAST TO THE
COAST LATER WEDNESDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 355 AM EDT MONDAY...

HIGHER MOISTURE-LADEN AIR IS ENTERING THE FORECAST AREA FROM THE
EAST THIS MORNING PER DEWPOINTS IN THE LOWER 60S JUST AT THE CWA
BORDER. WILL SEE INCREASING CLOUDINESS AS WELL...AND ALREADY GETTING
MOSTLY CLOUDY TO OVERCAST SKIES ACROSS THE PIEDMONT...BUT STILL
SCT-BKN IN THE WEST. RADAR HAS BEEN SHOWING VERY LIGHT RETURNS
BETWEEN LYNCHBURG-DANVILLE AND REIDSVILLE. MODELS HAVE NOT
INITIALIZED THAT WELL WITH THIS...WHICH WILL LEAD TO SOME LOW
CONFIDENCE IN THE FORECAST. THE UPPER TROUGH THAT IS COVERING THE
SOUTHEAST WILL REMAIN IN THE GENERAL AREA THROUGH TONIGHT...AND WILL
HAVE TO SEE WHERE INDIVIDUAL PIECES OF UPPER ENERGY MOVE IN
CONJUNCTION WITH SFC BOUNDARIES.

FOLLOWED CLOSER TO THE LOCAL WRF THIS MORNING...THEN BLENDING OF THE
PREVIOUS FORECAST WITH THE SREF/ECMWF. WILL KEEP CHANCE POPS IN THE
EAST THIS MORNING WITH SLIGHT CHANCES AS FAR WEST AS THE GREENBRIER
VALLEY WITH A WAVE PIVOTING NW ACROSS THE NORTHERN VA. THE SOUTHWEST
FORECAST AREA SHOULD BE MAINLY DRY THIS MORNING...PINCHED BETWEEN
HIGHER THETA-E AIR TO THE EAST AND OVER THE OHIO VALLEY INTO THE MID
MISSISSIPPI VALLEY. THIS AFTERNOON...THE ENTIRE AREA SHOULD SEE
AMPLE MOISTURE AND ENOUGH HEATING WITH SUPPORT IN THE UPPER LEVELS
THAT SHOWERS AND STORMS WILL DEVELOP. TRYING TO DETERMINE WHERE BEST
COVERAGE WILL BE IS TRICKY...BUT HEDGING TOWARD THE NORTHERN
FORECAST AREA BETWEEN LWB-LYH...WHERE THE UPPER SUPPORT APPEARS
GREATEST. THE INCREASE IN CLOUD COVER AND SFC DEWPOINTS SHOULD KEEP
HIGH TEMPS A FEW DEGREES COOLER THAN SUNDAYS...WITH MID TO UPPER 70S
EXPECTED MOST PLACES.

TONIGHT...WITH SUN SETTING...THINKING IS THAT ORGANIZED CONVECTION
WEAKENS. HOWEVER...SFC FRONT WILL WORK ITS WAY TOWARD THE CENTRAL
APPALACHIANS BY TUESDAY MORNING AND MAY SEE AN INCREASE IN COVERAGE
TOWARD SOUTHEAST WEST VIRGINIA SOUTH INTO THE NORTH CAROLINA
MOUNTAINS BY DAYBREAK. THE MODELS ARE DIFFERENT ON THE SPEED OF THE
UPPER SYSTEM AND FRONTAL PRECIP...WITH THE NAM FASTEST IN BRINGING A
SOMEWHAT ORGANIZED LINE INTO FAR SOUTHWEST VA...WHILE THE ECMWF/GFS
KEEP IT FURTHER WEST. AGAIN...FOLLOWING SLOWER SOLUTION. LOWS
TONIGHT WILL STAY MILD WITH MID 50S TO AROUND 60 EXPECTED.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 355 AM EDT MONDAY...

TUESDAY MORNING WILL START OFF WITH WIDELY SCATTERED SHOWER AND
ISOLATED THUNDERSTORM ACTIVITY...AND WILL EXPECT TO SEE COVERAGE
INCREASE BY LATE MORNING AS DAYTIME HEATING INCREASES...AND A WEAK
COLD FRONT ENTERS OUR SOUTHEAST WEST VIRGINIA AND MOUNTAIN EMPIRE
COUNTIES. BY MID AFTERNOON...THE FRONT WILL PUSH NEAR THE BLUE
RIDGE...HELPING TO FURTHER DESTABILIZE THE ATMOSPHERE ACROSS THE
PIEDMONTS. EXPECT TO SEE A FEW STRONG...AND POSSIBLY SEVERE
THUNDERSTORMS DEVELOP DURING THE EARLY EVENING EAST OF THE BLUE
RIDGE...WITH THESE STORMS CAPABLE OF PRODUCING LOCALLY GUSTY WINDS
AND LARGE HAIL. WITH WINDS BECOMING SOUTHERLY AHEAD OF THE
FRONT...WILL EXPECT TO SEE NEAR 80 DEGREE TEMPERATURES REACH AS FAR
NORTH AS BUCKINGHAM AND AMHERST COUNTIES DURING THE AFTERNOON.
FURTHER WEST...AFTERNOON TEMPERATURES CAN BE EXPECTED TO HOLD IN THE
LOW TO MID 70S. SHOWER AND THUNDERSTORM ACTIVITY WILL DIMINISH
GRADUALLY LATE TUESDAY EVENING...BUT WILL SEE THIS ACTIVITY LINGER
THROUGH THE EARLY MORNING HOURS OF WEDNESDAY.

MUCH OF THE SAME CAN BE EXPECTED FOR WEDNESDAY AND THURSDAY...AS THE
FRONTAL BOUNDARY LOSES ITS PUSH...BECOMING NOT MUCH MORE THAN A WEAK
TROUGH STALLED ACROSS THE PIEDMONT REGION. AND WITH BROAD UPPER
LEVEL TROUGHING HOLDING ALONG THE APPALACHIAN CHAIN HEADING INTO THE
END OF THE WORKWEEK...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS TO
INCREASE IN COVERAGE LATE EACH MORNING...AND DIMINISH LATE EACH
EVENING. BETTER COVERAGE AND GREATER INSTABILITY WILL BE FOUND EAST
OF THE BLUE RIDGE...AND EXPECT A FEW STRONG TO SEVERE STORMS EACH
EVENING. TEMPERATURES BOTH DAYS WILL BE NEAR NORMAL FOR THE SECOND
HALF OF MAY.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 345 AM EDT MONDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AS OF 130 AM EDT MONDAY...

FLIGHT CONDITIONS SHOULD START TO WORSEN AT LEAST EAST OF LYH/DAN
LINE THIS MORNING WITH INCREASING LOW LVL MOISTURE PUSHING
WESTWARD FROM THE VIRGINIA COAST. WILL SEE MVFR CIGS AT LYH/DAN
WITH SOME LIGHT SHOWER ACTIVITY BETWEEN 08Z-11Z. FURTHER
WEST...THE VFR CONDITIONS WILL HANG AROUND LONGER EXCEPT FOR FOG
POTENTIAL AT BCB WHERE A PERIOD OF MVFR VSBYS EXPECTED BEFORE DAWN.

THE SYSTEM OFF THE COAST IS EXPECTED TO MEANDER AT LEAST ACROSS
THE DELMARVA AND TIDEWATER INTO THIS AFTERNOON. A PUSH WESTWARD OF
THE UPPER TROUGH MAY WORK MORE SHOWERS ACROSS THE PIEDMONT AND
NORTH OF ROANOKE AND LWB THIS AFTERNOON.

FORECAST CONFIDENCE IS LOW ON THE EXTENT OF HOW LONG THE LOWER
CLOUDS LINGER IN THE EAST...BUT GIVEN ITS LATE MAY THINK THE
STRONGER SUN AND ENOUGH MIXING MAY SCATTER OUT THE MVFR CIGS BY MIDDAY.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR TUESDAY...AND THIS IS POSSIBLE
AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF US. DRIER AIR WILL
HEAD INTO OUR REGION TOWARDS THE END OF THE WEEK INTO NEXT
WEEKEND.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...NF
LONG TERM...NF/DW
AVIATION...KK/WP

000
FXUS61 KLWX 210743
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
343 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE WILL NEAR THE MID-ATLANTIC TODAY AND TONIGHT. A LOW
PRESSURE TROUGH WILL BECOME STATIONARY ACROSS THE MID ATLANTIC
REGION DURING THE MIDDLE PART OF THE WEEK. WEAK HIGH PRESSURE WILL
RETURN FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC LOPRES NEAR MOUTH OF CHESAPEAKE ERY THIS MRNG WILL DRIFT
NWWD/WEAKEN TDA AS STRONGER LOPRES DVLPS FURTHER IN ATLC. CLOSED
ULVL LOPRES OVR CAROLINAS WILL GRADUALLY BE ABSORBED BY NRN STREAM
LONGWAVE TROF...WHICH WILL BE DIGGING THRU GREAT LAKES TDA/TNGT.
ULVL TROFS ATTENDANT SFC TROF WILL APPROACH APLCNS TDA AND INTO WRN
CWA TDA.

AT 7Z...RADAR DEPICTS SCT MOSTLY LGT SHWRS SPREADING WWD INTO ERN
CWA...A RESULT OF MOISTURE FETCH ON N SIDE OF AFOREMENTIONED SFC
LOPRES.  XPCT THIS ACTIVITY TO INCRG IN CVRG AND BEGIN TO IMPACT
AREAS W OF BLUE RIDGE BEFORE DAWN...WITH SOME ENHANCEMENT DUE TO
UPSLOPE NATURE OF FLOW.  QPF WILL BE LOW...MOST AREAS HAVING ONE
TENTH OR LESS PCPN THRU THIS MRNG.  MAIN MOISTURE PLUME WILL
GRADUALLY MOVE N OF RGN TDA...THUS POPS RANGE FROM CATEGORICAL   N
TO CHC S/W. OVC CONDS WILL KEEP INSTABILITY MINIMAL...BUT ISOLATED
THUNDER IS PSBL THIS AFTN WITH AMPLE LIFT AND ABUNDANT MOISTURE IN
PLACE. TEMPS...REGULATED BY CLOUDS/PCPN...WILL STRUGGLE TO REACH
L/M70S THIS AFTN...DESPITE STARTING OFF ALREADY IN M60S.

SFC TROF ENTERS POTOMAC HIGHLANDS TNGT AND PUSHES TWD BLUE RIDGE
OVNGT. BEST POPS/QPF FOCUSED ALONG/AHEAD OF THIS FEATURE...WITH LOW
LIKELY/HIGH CHC SHWR PROBS EXHIBITED FROM SHEN VLY TO I-95 CORRIDOR
OVNGT.  RMNT THUNDER FROM ANY AFTN CVCTN CUD LINGER PAST
SUNSET...BUT SHUD DIURNAL DIMINISH AFTN MIDNIGHT. MINIMA TDA WILL BE
QUITE MILD FOR LATE MAY...50S W OF BLUE RIDGE WITH L60S E.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
UNSETTLED WEATHER CONDITIONS WILL CONTINUE TUESDAY INTO WEDNESDAY AS
A LOW PRESSURE TROUGH BECOMES STATIONARY ACROSS THE CWFA. THE TROUGH
WILL SERVE TO FOCUS PRECIP THROUGH THE PERIOD.

INCREASED POPS DURING THIS PERIOD. SOME INSTABILITY DURING THE
AFTERNOON...SO LEFT MENTION OF THUNDERSTORMS IN THE FORECAST INTO
THE EVENING HOURS. UPPER LEVEL STEERING WILL BE LIGHT...AND SURFACE
FLOW WILL BE FROM THE SE. THIS SHOULD ALLOW FOR THE HIGHEST PRECIP
AMOUNTS ALONG THE EASTERN SLOPES OF THE BLUE RIDGE MOUNTAINS. AT
THIS TIME...RAINFALL AMOUNTS WILL AVERAGE BETWEEN ONE HALF AND ONE
INCH. LOCALLY HIGHER AMOUNTS ALONG EASTERN FACING HIGHER TERRAIN.
STILL BELOW 2SD FOR PWATS.

TOOK BLEND FOR TEMPS.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
LOW PRESSURE TROUGH SHOULD DISSIPATE BY EARLY THURSDAY. HIGH
PRESSURE SETS UP ACROSS THE DEEP SOUTH...WITH SOUTHERLY FLOW ACROSS
THE MID ATLANTIC. SOME DIFFERENCES BETWEEN THE MODELS FOR
THURSDAY...NAM IS DRIER THAN THE GFS. NO REAL FOCUS FOR THE
PRECIP...SO SAW NO REASON TO CHANGE POPS AT THIS TIME. WEAK HIGH
PRESSURE RETURNS FOR LATER THURSDAY INTO SATURDAY.

A COLD FRONT SHOULD BEGIN TO APPROACH THE MASON DIXON LINE BY THE
END OF THE WEEKEND.

&&

.AVIATION /08Z MONDAY THROUGH FRIDAY/...
IFR CIGS/MVFR VSBY NOW IMPACTING MOST TERMINALS...AND RESTRICTIONS
SHUD PERSIST INTO MID-MRNG AS EASTERLY FLOW ADVECTS MOISTURE FROM
ATLC INTO RGN. SCT/NUM SHWRS WILL IMPACT TERMINALS DURG THIS
PERIOD...WITH HIGHEST CVRG FOR URBAN CORRIDOR AIRPORTS. LT
MRNG...SHWRS DIMINISH AT LEAST SOMEWHAT...VCSH STILL WARRANTED...AND
CIGS SHUD IMPROVE TO MVFR. ISOLATED TSTMS PSBL THIS AFTN/EVE...THO
RISK TO LOW TO DISPLAY IN TAFS ATTM. SCT SHRA STILL PERSIST
TNGT...WITH VSBY/CIGS GRADUALLY DEGRADING AFTER MIDNIGHT. WINDS THRU
TNGT MOSTLY NE AND LGT.

SUB VFR CONDITIONS LIKELY TUESDAY INTO WEDNESDAY AS A LOW PRESSURE
TROUGH SETS UP ACROSS THE MID ATLANTIC. THUNDERSTORMS POSSIBLE
DURING THE AFTERNOON AND EVENING HOURS.

WEAK HIGH PRESSURE RETURNS FOR THE END OF THE WEEK INTO THE WEEKEND.

&&

.MARINE...
NE FLOW CONTS AROUND LOPRES NEAR MOUTH OF BAY ERY THIS MRNG...WITH
GUSTS NEAR 20KTS BEING REALIZED ACRS PORTIONS OF WATERS WHERE ADZY
IN EFFECT UNTIL 10Z.  WILL MONITOR FOR PSBL TEMPORAL XTNSN...BUT
LOPRES SHUD WEAKEN AND FLOW RELAXES LATER THIS MRNG.
THEREAFTER...LGT NE FLOW WILL GRADUALLY BCM ELY. SCT/NUM
SHWRS...PSBLY TSTMS...WILL RESIDE IN VICINITY OF WATERS THRU TNGT AS
GENERAL LOPRES DOMINATES.

SE/S FLOW REMAINS RATHER LIGHT ACROSS THE CWFA DURING THE PERIOD. A
LOW PRESSURE TROUGH WILL SET UP JUST WEST OF THE WATERS FOR TUESDAY
INTO MUCH OF WEDNESDAY. THE TROUGH SHOULD DISSIPATE BY
THURSDAY...WITH WEAK HIGH PRESSURE RETURNING FOR FRIDAY INTO THE
WEEKEND.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES THIS MRNG RANGE FROM 0.25-0.75 FT...NOT
HIGH ENUF FOR COASTAL FLOOD CONCERNS FOR INITIAL TIDE OF DAY. NELY
FLOW WILL PERSIST TDA...BUT AFTN/EVE HIGH TIDE IS ASTRONOMICAL LWR
OF SEMIDIURNAL CYCLE SO NO ISSUES XPCD EVEN WITH INCRG ANOMALIES.
LATE TNGT/ERY TUE...WINDS BCM MORE ELY AND LOPRES CONTS OVR WATERS.
THESE FACTORS MAY COMBINE TO PRODUCE MINOR TIDAL INUNDATION CLOSE TO
TUES FIRST HIGH TIDES.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
     ANZ530>534-537>543.

&&

$$
SYNOPSIS...KONARIK/LISTEMAA
NEAR TERM...KONARIK
SHORT TERM...LISTEMAA
LONG TERM...LISTEMAA
AVIATION...KONARIK/LISTEMAA
MARINE...KONARIK/LISTEMAA
TIDES/COASTAL FLOODING...KONARIK

000
FXUS61 KAKQ 210609
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
209 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE DRIFTS SLOWLY NORTHWEST ACROSS VIRGINIA THROUGH
MONDAY. THE LOW WILL PERSIST ACROSS THE AREA THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST MSAS / SFC AND RADAR OBS SHOWING CENTER OF LOW PRESSURE
CURRENTLY LOCATED OVER THE SOUTHERN MOST PART OF CHES BAY AND
MOVING SLOWLY NW. RUC/WRF/SREF SHOW THIS TRACK CONINUING FOR THE
REST OF TONIGHT. PRECIP NOW MAINLY LIGHT RAIN / DRIZZLE BUT
COVERAGE HAS EXPANDED TO MOST OF THE AREA NORTH OF THE VA/NC
BORDER PAST FEW HOURS. THUS..HAVE BUMBED UP POPS TO CATEGORICAL
MAINLY EAST OF I95 CORRIDOR AND NORTH OF BORDER. MODELS SHOW THE
HIGHEST COVERAGE OF PRECIP MOVING INTO NORTHERN HALF OF FA AFTER
MIDNIGHT. SO GRIDS WILL SHOW LIKELY POPS AFTER 06Z NORTHERN HALF
OF FA WITH CHC ACROSS THE SOUTH. LOWS 59-63.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
WX CONDS RMN UNSETTLED THROUGH MIDWEEK. TROUGH ALOFT RMNS IN PLCS
OVR THE SE AND MDATLC RGNS. A REINFORCING PIECE OF ENERGY ARRIVES
INTO THE TROUGH TUE...THEN PROGRESSES ACRS NC/VA TUE AFTN INTO
WED.

XPCG VRBL CLDNS OR MCLDY CONDS THROUGH THE PD. POP FORECAST IS
DIFFICULT...AND LIKELY TO BCM MR DIURNAL IN NATURE BY MIDWEEK.
SOMETHING TO WATCH IS WHEN THE NEW PIECE OF ENERGY IN THE TROUGH
TRACKS THROUGH THE RGN (TUE AFTN INTO TUE NGT)...MAY SEE A MR
ORGANIZED AREA OF CNVTN.

FOR HI TEMPS NEXT SVRL DAYS...LEANED A FEW DEGS F BLO GUID. HI
TEMPS MON FM ARND 70F AT THE CST...TO L/M70S ELSW. HI TEMPS TUE
AND WED FM THE 70S TO L80S. LO TEMPS EACH NGT MNLY IN THE L/M60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE AT 05Z IN VICINITY OF PHF AS INDICATED BY SURFACE WINDS
AND MOVING SLOWLY NW. THERE ARE WIDESPREAD IFR/LIFR CONDITIONS IN
ASSOCIATION WITH THE LOW ALONG WITH AREAS OF LIGHT RAIN AND
DRIZZLE.

IFR OR LOWER SHOULD PERSIST THROUGH MID MORNING. THERE ARE A FEW
LOCATIONS NEAR THE COAST THAT IMPROVED SHORTLY AFTER MIDNIGHT...
ESPECIALLY EAST OF ECG...BUT THERE IS LITTLE CONFIDENCE IN ANY OF
THE TAF SITES HAVING SIGNIFICANT IMPROVEMENT FOR AT LEAST THE
FIRST SIX HOURS OF THE 06Z TAF.

MOS AND BUFR SOUNDINGS ALL SUPPORT IFR ENDING AT EACH OF THE SITES
BETWEEN 14 AND 18Z. CONDITIONS MAY GO BACK DOWN MONDAY NIGHT/TUESDAY
MORNING. SINCE BOTH MET AND MAV HAVE RIC AND SBY GOING BACK TO
IFR/LIFR...(RATHER THAN JUST THE MET) BROUGHT THOSE TWO BACK DOWN TO
IFR IN THE LATE EVENING. TOO EARLY TO SAY ABOUT THE THREE TAF SITES
BUT WOULD PROBABLY BE AFT 06Z IF IT OCCURS AND WILL TAKE A LOOK
AGAIN WITH THE 12Z ISSUANCE.

OUTLOOK...CONDITIONS IMPROVE ONCE AGAIN TO VFR LATE TUESDAY MORNING.
THERE WILL BE A CHANCE FOR MAINLY AFTN TSTMS BOTH TUESDAY AND AN
EVEN BETTER CHANCE FOR PCPN WEDNESDAY. NEITHER OF THESE EVENTS
SHOULD HAVE THE WIDESPREAD IFR THAT OCCURRED SUNDAY.

&&

.MARINE...
SFC LOW PRESSURE WAS OVER THE LOWER CHESAPEAKE BAY AT MIDNIGHT AND
WILL CONTINUE TO MOVE SLOWLY WEST AND NORTHWEST. WINDS OF AROUND
15 KNOTS IN THE NORTHERN BAY WILL SLOWLY DIMINISH. WINDS ARE LIGHT
AND VARIABLE IN THE SOUTHERN BAY.

SCA REMAINS OVER THE COASTAL WATERS BUT SCA HAVE BEEN CANCELLED
ELSEWHERE. SEAS OF 5-7 FT WILL CONTINUE ON THE COASTAL WATERS
THROUGH JUST AFTER DAYBREAK MONDAY MORNING...THEN WILL DROP BELOW
5 FT SOUTH OF CAPE CHARLES LIGHT. HAVE ENDED THE SOUTHERN TWO
COASTAL ZONES AT 7 AM MON. HAVE MAINTAINED SCA`S FOR THE REMAINDER
OF THE COASTAL WATERS THROUGH MONDAY AFTERNOON AS SEAS WILL BE
SLOWER TO DROP BELOW 5 FT THERE.

WILL HAVE TO WATCH WHAT BECOMES OF ALBERTO BY TUESDAY MORNING AS
THE CURRENT NHC FORECAST PASSES IT WELL EAST OF THE NC OUTER
BANKS. WE MAY NEED TO BRING SEAS BACK UP AGAIN TO ACCOUNT FOR
ALBERTO`S PASSAGE.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ650-
     652-654.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656-
     658.

&&

$$
SYNOPSIS...ALB
NEAR TERM...MPR
SHORT TERM...ALB
LONG TERM...JDM
AVIATION...LSA
MARINE...JDM/LSA

000
FXUS61 KRNK 210544
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
144 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID-ATLANTIC COAST WILL DRIFT SLOWLY NORTH
AND WEST TONIGHT AND MONDAY WITH INCREASING RAIN CHANCES WHILE A
COLD FRONT APPROACHES FROM THE WEST BY TUESDAY WITH MORE SHOWERS
POSSIBLE. TROPICAL STORM ALBERTO IS FORECAST TO REMAIN NEARLY
STATIONARY OFF THE SOUTHEAST COAST THE NEXT DAY OR SO AND THEN
TRACK OFF TO THE NORTHEAST BY MID-WEEK.

&&

.NEAR TERM /THROUGH TODAY/...
AS OF 105 AM EDT MONDAY...

HAVE MADE SOME ADJUSTMENTS TO POPS THIS MORNING GIVEN LACK OF
RADAR SIGNATURES. WILL FOLLOW CLOSER TO THE LOCAL WRF/HRRR WITH
SLOWLY INCREASING POPS ACROSS THE NE CWA THRU DAWN. OVERALL SHOULD
SEE LESS CLOUD COVER WEST OF THE BLUE RIDGE INTO SUNRISE. WITH
INCREASING DEWPOINTS KEPT LOWS AS PREVIOUSLY FORECASTED.

AS COLUMN BECOMES INCREASINGLY SATURATED EXPECT CONCOMITANT
INCREASE IN CLOUDS/POPS MAINLY BEGINNING LATE TONIGHT/EARLY MONDAY
IN THE EAST WITH HIGHEST CHC POPS BY LATE AFTERNOON IN THE
NORTHEASTERN CWA CLOSEST TO THE INFLUENCE OF THE COASTAL LOW.
MEANWHILE FROM THE WEST...A COLD FRONT OVER THE MID- MISSISSIPPI
VALLEY WILL BE SLOWLY APPROACHING THE AREA BY LATE MONDAY WITH
PRECIPITATION CHANCES ALONG AND AHEAD OF THIS BOUNDARY ALSO
INCREASING...HOWEVER MAIN EFFECTS OF THIS FRONT LOOK TO BE BEYOND
THE NEAR-TERM FORECAST PERIOD. TEMPS WILL BE SOMEWHAT WARMER
TONIGHT THAN THE PREVIOUS FEW AS AFOREMENTIONED CLOUDS MOVE IN
HOLDING LOWS TOMORROW MORNING TO NEAR 6O IN THE EAST AND MID-50S
WEST. TROPICAL STORM ALBERTO IS NOT EXPECTED TO HAVE ANY REAL
INFLUENCE ON OUR WEATHER IN THE SOUTHERN APPALACHIANS AS THE STORM
WILL REMAIN OFFSHORE AND EVENTUALLY TRACK OFF TO THE NORTHEAST.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM EDT SUNDAY...

APPROACH OF UPPER TROF FROM THE WEST...AND BUILDING UPPER RIDGE OFF
THE ATLANTIC COAST WILL HELP TO CAUSE RETROGRESSION OF WEAK CLOSED
LOW CURRENTLY OFF THE MID ATLANTIC COAST...TRAPPING SYSTEM OVER OR
NEAR THE BLACKSBURG FORECAST AREA THROUGH THE ENTIRE SHORT TERM
PERIOD.

COMBINATION OF ATLANTIC MOISTURE AND SLIGHTLY COOLER MID LEVEL AIR
ASSOCIATED WITH THIS SYSTEM SHOULD MAINTAIN SUFFICIENT THERMODYNAMIC
PROFILE TO SUPPORT MAINLY DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS
THROUGH THE PERIOD...WHICH MIGHT VERY WELL LINGER WELL INTO EACH
NIGHT WHERE UPSLOPE IS MAXIMIZED SINCE CORFIDI VECTORS ARE FORECAST
TO BE VERY WEAK AND ALIGNED NEARLY PARALLEL TO RIDGE LINES.

EXTENT OF CLOUD COVER WILL STRONGLY INFLUENCE EXTENT OF DAYTIME
HEATING EACH DAY...AND AS WOULD BE EXPECTED UNDER SUCH
CIRCUMSTANCES...LARGE SPREAD IN MOS GUIDANCE EXISTS WITH MAV-BASED
MOS MUCH WARMER THAN MET-BASED MOS AND LOCALLY RUN MOS-MOS GUIDANCE.
CONSIDERING SUPERIOR PERFORMANCE OF MOS-MOS GUIDANCE RECENTLY...WILL
CONTINUE TO GIVE STRONG WEIGHTING TO IT THROUGHOUT SHORT TERM PERIOD
FOR DAYTIME HIGHS AS WELL AS OVERNIGHT LOWS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 130 AM EDT MONDAY...

FLIGHT CONDITIONS SHOULD START TO WORSEN AT LEAST EAST OF LYH/DAN
LINE THIS MORNING WITH INCREASING LOW LVL MOISTURE PUSHING
WESTWARD FROM THE VIRGINIA COAST. WILL SEE MVFR CIGS AT LYH/DAN
WITH SOME LIGHT SHOWER ACTIVITY BETWEEN 08Z-11Z. FURTHER
WEST...THE VFR CONDITIONS WILL HANG AROUND LONGER EXCEPT FOR FOG
POTENTIAL AT BCB WHERE A PERIOD OF MVFR VSBYS EXPECTED BEFORE DAWN.

THE SYSTEM OFF THE COAST IS EXPECTED TO MEANDER AT LEAST ACROSS
THE DELMARVA AND TIDEWATER INTO THIS AFTERNOON. A PUSH WESTWARD OF
THE UPPER TROUGH MAY WORK MORE SHOWERS ACROSS THE PIEDMONT AND
NORTH OF ROANOKE AND LWB THIS AFTERNOON.

FORECAST CONFIDENCE IS LOW ON THE EXTENT OF HOW LONG THE LOWER
CLOUDS LINGER IN THE EAST...BUT GIVEN ITS LATE MAY THINK THE
STRONGER SUN AND ENOUGH MIXING MAY SCATTER OUT THE MVFR CIGS BY MIDDAY.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR TUESDAY...AND THIS IS POSSIBLE
AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF US. DRIER AIR WILL
HEAD INTO OUR REGION TOWARDS THE END OF THE WEEK INTO NEXT
WEEKEND.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/WP
SHORT TERM...WERT
LONG TERM...WERT
AVIATION...KK/WP

000
FXUS61 KAKQ 210428
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1228 AM EDT MON MAY 21 2012

.SYNOPSIS...
LOW PRESSURE DRIFTS SLOWLY NORTHWEST ACROSS VIRGINIA THROUGH
MONDAY. THE LOW WILL PERSIST ACROSS THE AREA THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LATEST MSAS / SFC AND RADAR OBS SHOWING CENTER OF LOW PRESSURE
CURRENTLY LOCATED OVER THE SOUTHERN MOST PART OF CHES BAY AND
MOVING SLOWLY NW. RUC/WRF/SREF SHOW THIS TRACK CONINUING FOR THE
REST OF TONIGHT. PRECIP NOW MAINLY LIGHT RAIN / DRIZZLE BUT
COVERAGE HAS EXPANDED TO MOST OF THE AREA NORTH OF THE VA/NC
BORDER PAST FEW HOURS. THUS..HAVE BUMBED UP POPS TO CATEGORICAL
MAINLY EAST OF I95 CORRIDOR AND NORTH OF BORDER. MODELS SHOW THE
HIGHEST COVERAGE OF PRECIP MOVING INTO NORTHERN HALF OF FA AFTER
MIDNIGHT. SO GRIDS WILL SHOW LIKELY POPS AFTER 06Z NORTHERN HALF
OF FA WITH CHC ACROSS THE SOUTH. LOWS 59-63.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY/...
WX CONDS RMN UNSETTLED THROUGH MIDWEEK. TROUGH ALOFT RMNS IN PLCS
OVR THE SE AND MDATLC RGNS. A REINFORCING PIECE OF ENERGY ARRIVES
INTO THE TROUGH TUE...THEN PROGRESSES ACRS NC/VA TUE AFTN INTO
WED.

XPCG VRBL CLDNS OR MCLDY CONDS THROUGH THE PD. POP FORECAST IS
DIFFICULT...AND LIKELY TO BCM MR DIURNAL IN NATURE BY MIDWEEK.
SOMETHING TO WATCH IS WHEN THE NEW PIECE OF ENERGY IN THE TROUGH
TRACKS THROUGH THE RGN (TUE AFTN INTO TUE NGT)...MAY SEE A MR
ORGANIZED AREA OF CNVTN.

FOR HI TEMPS NEXT SVRL DAYS...LEANED A FEW DEGS F BLO GUID. HI
TEMPS MON FM ARND 70F AT THE CST...TO L/M70S ELSW. HI TEMPS TUE
AND WED FM THE 70S TO L80S. LO TEMPS EACH NGT MNLY IN THE L/M60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AREA OF LOW PRESSURE CENTERED OFF THE VA/NC COAST WILL CONTINUE TO
SLOWLY MOVE W THROUGH MON. NE FLOW WILL USHER IN LOW CEILINGS AND
-RA EAST TO WEST OVERNIGHT WITH SOME IFR TO LIFR CONDITIONS
POSSIBLE. THE PRESSURE GRADIENT WILL REMAIN THE TIGHTEST IN THE
NORTHERN PORTION OF THE FA BETWEEN HIGH PRESSURE OVER WESTERN NEW
ENGLAND AND THE LOW OFF THE COAST. THIS WILL CAUSE NE/E WINDS WINDS
TO REMAIN GUSTY TO AROUND 20 KT.

FLIGHT RESTRICTIONS ARE LIKELY THROUGH TUE AS THE LOW MOVES OVER THE
AREA BEFORE A COLD FRONT APPROACHES THE AREA ON TUE. ANY AFFECTS FROM
TROPICAL STORM ALBERTO SHOULD BE NEGLIGIBLE AT ANY TAF SITE DUE TO
THE CURRENT TRACK TO THE STORM BEING A CONSIDERABLE DISTANCE OFF
THE COAST.

&&

.MARINE...
SFC LOW PRESSURE WAS OVER THE LOWER CHESAPEAKE BAY AT MIDNIGHT AND
WILL CONTINUE TO MOVE SLOWLY WEST AND NORTHWEST. WINDS OF AROUND
15 KNOTS IN THE NORTHERN BAY WILL SLOWLY DIMINISH. WINDS ARE LIGHT
AND VARIABLE IN THE SOUTHERN BAY.

SCA REMAINS OVER THE COASTAL WATERS BUT SCA HAVE BEEN CANCELLED
ELSEWHERE. SEAS OF 5-7 FT WILL CONTINUE ON THE COASTAL WATERS
THROUGH JUST AFTER DAYBREAK MONDAY MORNING...THEN WILL DROP BELOW
5 FT SOUTH OF CAPE CHARLES LIGHT. HAVE ENDED THE SOUTHERN TWO
COASTAL ZONES AT 7 AM MON. HAVE MAINTAINED SCA`S FOR THE REMAINDER
OF THE COASTAL WATERS THROUGH MONDAY AFTERNOON AS SEAS WILL BE
SLOWER TO DROP BELOW 5 FT THERE.

WILL HAVE TO WATCH WHAT BECOMES OF ALBERTO BY TUESDAY MORNING AS
THE CURRENT NHC FORECAST PASSES IT WELL EAST OF THE NC OUTER
BANKS. WE MAY NEED TO BRING SEAS BACK UP AGAIN TO ACCOUNT FOR
ALBERTO`S PASSAGE.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ650-
     652-654.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT THIS MORNING FOR ANZ656-
     658.

&&

$$
SYNOPSIS...ALB
NEAR TERM...MPR
SHORT TERM...ALB
LONG TERM...JDM
AVIATION...DAP
MARINE...JDM/LSA

000
FXUS61 KAKQ 210152
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
952 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE DRIFTS SLOWLY NORTHWEST ACROSS VIRGINIA THROUGH
MONDAY. THE LOW WILL PERSIST ACROSS THE AREA THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
LATEST MSAS / SFC AND RADAR OBS SHOWING CENTER OF LOW PRESSURE
CURRENTLY LOCATED OVER THE SOUTHERN MOST PART OF CHES BAY AND
MOVING SLOWLY NW. RUC/WRF/SREF SHOW THIS TRACK CONINUING FOR THE
REST OF TONIGHT. PRECIP NOW MAINLY LIGHT RAIN / DRIZZLE BUT
COVERAGE HAS EXPANDED TO MOST OF THE AREA NORTH OF THE VA/NC
BORDER PAST FEW HOURS. THUS..HAVE BUMBED UP POPS TO CATEGORICAL
MAINLY EAST OF I95 CORRIDOR AND NORTH OF BORDER. MODELS SHOW THE
HIGHEST COVERAGE OF PRECIP MOVING INTO NORTHERN HALF OF FA AFTER
MIDNIGHT. SO GRIDS WILL SHOW LIKELY POPS AFTER 06Z NORTHERN HALF
OF FA WITH CHC ACROSS THE SOUTH. LOWS 59-63.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
WX CONDS RMN UNSETTLED THROUGH MIDWEEK. TROUGH ALOFT RMNS IN PLCS
OVR THE SE AND MDATLC RGNS. A REINFORCING PIECE OF ENERGY ARRIVES
INTO THE TROUGH TUE...THEN PROGRESSES ACRS NC/VA TUE AFTN INTO
WED.

XPCG VRBL CLDNS OR MCLDY CONDS THROUGH THE PD. POP FORECAST IS
DIFFICULT...AND LIKELY TO BCM MR DIURNAL IN NATURE BY MIDWEEK.
SOMETHING TO WATCH IS WHEN THE NEW PIECE OF ENERGY IN THE TROUGH
TRACKS THROUGH THE RGN (TUE AFTN INTO TUE NGT)...MAY SEE A MR
ORGANIZED AREA OF CNVTN.

FOR HI TEMPS NEXT SVRL DAYS...LEANED A FEW DEGS F BLO GUID. HI
TEMPS MON FM ARND 70F AT THE CST...TO L/M70S ELSW. HI TEMPS TUE
AND WED FM THE 70S TO L80S. LO TEMPS EACH NGT MNLY IN THE L/M60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
AREA OF LOW PRESSURE CENTERED OFF THE VA/NC COAST WILL CONTINUE TO
SLOWLY MOVE W THROUGH MON. NE FLOW WILL USHER IN LOW CEILINGS AND
-RA EAST TO WEST OVERNIGHT WITH SOME IFR TO LIFR CONDITIONS
POSSIBLE. THE PRESSURE GRADIENT WILL REMAIN THE TIGHTEST IN THE
NORTHERN PORTION OF THE FA BETWEEN HIGH PRESSURE OVER WESTERN NEW
ENGLAND AND THE LOW OFF THE COAST. THIS WILL CAUSE NE/E WINDS WINDS
TO REMAIN GUSTY TO AROUND 20 KT.

FLIGHT RESTRICTIONS ARE LIKELY THROUGH TUE AS THE LOW MOVES OVER THE
AREA BEFORE A COLD FRONT APPROACHES THE AREA ON TUE. ANY AFFECTS FROM
TROPICAL STORM ALBERTO SHOULD BE NEGLIGIBLE AT ANY TAF SITE DUE TO
THE CURRENT TRACK TO THE STORM BEING A CONSIDERABLE DISTANCE OFF
THE COAST.

&&

.MARINE...
SFC LOW PRESSURE WILL MOVE WESTWARD INTO EASTERN VA WITHIN THE NEXT
6-8 HRS. DURING THIS TIME...SUSTAINED NE WINDS WILL AVERAGE 15-20 KT
OVER THE WATERS...EXCEPT SUBSIDING TO 10-15 KT SOUTH OF THE NC
BORDER AROUND SUNSET. AS THE LOW MOVES INLAND THIS EVENING...WINDS
WILL TURN E-ESE AND LESSEN TO BETWEEN 5-10 KT OVERNIGHT. SCA ARE
STILL SET TO END ON THE LOWER JAMES RIVER AT 7PM...THE CURRITUCK
SOUND AT 10PM...AND ALL OF THE CHES BAY AT MIDNIGHT. WAVES ON THE
CHES BAY WILL CONTINUE BETWEEN 3-4 FT THROUGH THIS EVENING BEFORE
SUBSIDING. SEAS OF 5-7 FT WILL CONTINUE ON THE COASTAL WATERS
THROUGH JUST AFTER DAYBREAK MONDAY MORNING...THEN WILL DROP BELOW
5 FT SOUTH OF CAPE CHARLES LIGHT. HAVE ENDED THE SOUTHERN TWO
COASTAL ZONES AT 7 AM MON. HAVE MAINTAINED SCA`S FOR THE REMAINDER
OF THE COASTAL WATERS THROUGH MONDAY AFTERNOON AS SEAS WILL BE
SLOWER TO DROP BELOW 5 FT THERE. WILL HAVE TO WATCH WHAT BECOMES
OF ALBERTO BY TUESDAY MORNING AS THE CURRENT NHC FORECAST PASSES
IT WELL EAST OF THE NC OUTER BANKS. WE MAY NEED TO BRING SEAS BACK
UP AGAIN TO ACCOUNT FOR ALBERTO`S PASSAGE.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ630>632-
     634.
    SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654.
    SMALL CRAFT ADVISORY UNTIL 7 AM EDT MONDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...ALB
LONG TERM...JDM
AVIATION...DAP
MARINE...JDM

000
FXUS61 KRNK 210128
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
928 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID-ATLANTIC COAST WILL DRIFT SLOWLY NORTH
AND WEST TONIGHT AND MONDAY WITH INCREASING RAIN CHANCES WHILE A
COLD FRONT APPROACHES FROM THE WEST BY TUESDAY WITH MORE SHOWERS
POSSIBLE. TROPICAL STORM ALBERTO IS FORECAST TO REMAIN NEARLY
STATIONARY OFF THE SOUTHEAST COAST THE NEXT DAY OR SO AND THEN
TRACK OFF TO THE NORTHEAST BY MID-WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 925 PM EDT SUNDAY...

LOCAL RADAR WAS SHOWING ISOLATED SHOWERS IN THE SOUTHEAST COUNTY
WARNING AREA. EXPECT PERIODIC SHOWERS WITH SIMILAR AREAL COVERAGE
THROUGH MIDNIGHT THEN PRECIPITATION BECOMING MORE WIDESPREAD IN
THE NORTHEAST DURING THE EARLY MORNING HOURS. LITTLE TO NO CHANGE
NEEDED TO THE OVERNIGHT LOW TEMPERATURES.

AS OF 455 PM EDT SUNDAY...

HAVE UPDATED PROBABILITY OF PRECIPITATION TO ACCOUNT FOR BAND OF
SHOWERS MOVING WEST INTO THE FOOTHILLS. MORE WIDESPREAD
PRECIPITATION STILL NOT EXPECTED UNTIL LATER TONIGHT.

AS OF 310 PM EDT SUNDAY...

RIBBON OF DRIER AIR IN PLACE ACROSS THE RNK CWA WILL BE ERODING FROM
BOTH EAST AND WEST OVER THE NEXT 24 HOURS. FROM THE EAST A 1015 MB
LOW PRESSURE CENTER LOCATED THIS AFTERNOON OFF THE VA/NC COAST HAS
BEEN SPREADING MID-LEVEL CLOUDS WESTWARD ALL DAY WHICH HAVE
FINALLY REACHED OUR EASTERN COUNTIES. THE PERSISTENT EASTERLY FLOW
AROUND THIS LOW WILL CONTINUE AND STEADILY MOISTEN THE AIR MASS...AS
CURRENT PWAT VALUES GENERALLY IN THE 0.60-0.70 INCH RANGE ARE
FORECAST IN VARIOUS BUFKIT MODELS TO INCREASE TO 1.00 TO 1.25 INCH
RANGE BY MONDAY AFTERNOON. AS COLUMN BECOME INCREASINGLY SATURATED
EXPECT CONCOMITANT INCREASE IN CLOUDS/POPS MAINLY BEGINNING LATE
TONIGHT/EARLY MONDAY IN THE EAST WITH HIGHEST CHC POPS BY LATE
AFTERNOON IN THE NORTHEASTERN CWA CLOSEST TO THE INFLUENCE OF THE
COASTAL LOW. MEANWHILE FROM THE WEST...A COLD FRONT OVER THE MID-
MISSISSIPPI VALLEY WILL BE SLOWLY APPROACHING THE AREA BY LATE
MONDAY WITH PRECIPITATION CHANCES ALONG AND AHEAD OF THIS
BOUNDARY ALSO INCREASING...HOWEVER MAIN EFFECTS OF THIS FRONT
LOOK TOBE BEYOND THE NEAR-TERM FORECAST PERIOD. TEMPS WILL BE
SOMEWHAT WARMER TONIGHT THAN THE PREVIOUS FEW AS AFOREMENTIONED
CLOUDS MOVE IN HOLDING LOWS TOMORROW MORNING TO NEAR 6O IN THE EAST
AND MID-50S WEST. TROPICAL STORM ALBERTO CURRENTLY LOCATED
SOUTHEAST OF SAVANNAH GA WITH MAXIMUM 45 MPH WINDS IS NOT EXPECTED
TO HAVE ANY REAL INFLUENCE ON OUR WEATHER IN THE SOUTHERN
APPALACHIANS AS THE STORM WILL REMAIN OFFSHORE AND EVENTUALLY
TRACK OFF TO THE NORTHEAST.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM EDT SUNDAY...

APPROACH OF UPPER TROF FROM THE WEST...AND BUILDING UPPER RIDGE OFF
THE ATLANTIC COAST WILL HELP TO CAUSE RETROGRESSION OF WEAK CLOSED
LOW CURRENTLY OFF THE MID ATLANTIC COAST...TRAPPING SYSTEM OVER OR
NEAR THE BLACKSBURG FORECAST AREA THROUGH THE ENTIRE SHORT TERM
PERIOD.

COMBINATION OF ATLANTIC MOISTURE AND SLIGHTLY COOLER MID LEVEL AIR
ASSOCIATED WITH THIS SYSTEM SHOULD MAINTAIN SUFFICIENT THERMODYNAMIC
PROFILE TO SUPPORT MAINLY DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS
THROUGH THE PERIOD...WHICH MIGHT VERY WELL LINGER WELL INTO EACH
NIGHT WHERE UPSLOPE IS MAXIMIZED SINCE CORFIDI VECTORS ARE FORECAST
TO BE VERY WEAK AND ALIGNED NEARLY PARALLEL TO RIDGE LINES.

EXTENT OF CLOUD COVER WILL STRONGLY INFLUENCE EXTENT OF DAYTIME
HEATING EACH DAY...AND AS WOULD BE EXPECTED UNDER SUCH
CIRCUMSTANCES...LARGE SPREAD IN MOS GUIDANCE EXISTS WITH MAV-BASED
MOS MUCH WARMER THAN MET-BASED MOS AND LOCALLY RUN MOS-MOS GUIDANCE.
CONSIDERING SUPERIOR PERFORMANCE OF MOS-MOS GUIDANCE RECENTLY...WILL
CONTINUE TO GIVE STRONG WEIGHTING TO IT THROUGHOUT SHORT TERM PERIOD
FOR DAYTIME HIGHS AS WELL AS OVERNIGHT LOWS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /02Z MONDAY THROUGH FRIDAY/...
AS OF 730 PM EDT SUNDAY...

KFCX 88D LOOP SHOWED BAND OF SHOWERS MOVING WEST ACROSS CWA THIS
EVENING. EXPECT THIS CONVECTION TO DIMINISH WITH THE LOSS OF SOLAR
HEATING IN NEXT HOUR OR TWO. MID AND HIGH LEVEL CLOUDS WILL SPREAD
WEST THIS EVENING INTO TONIGHT IN ASSOCIATION WITH THE SURFACE LOW
CENTERED OFF THE MID- ATLANTIC COAST.

OVERNIGHT EXPECT SLOWLY LOWERING/THICKENING OF CLOUDS OVER THE
EASTERN HALF AS PERSISTENT EAST TO NORTHEAST FLOW RESULTS IN
INCREASING MOISTURE. KEPT FOG/BR AND LOW STRATUS OUT OF THE WESTERN
TAFS (ESP LWB) WHERE HIGHER CLOUDS MAY IMPEDE FOG FORMATION BUT WILL
HAVE TO WATCH FOR POSSIBLE FORMATION IF IT REMAINS CLEAR. PRECIP
CHANCES ALSO INCREASE FROM EAST TO WEST BY MONDAY AFTERNOON.
LYH HAS THE BEST CHANCE FOR SHOWERS MONDAY AFTERNOON INTO MONDAY
EVENING.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR LATER MONDAY INTO TUESDAY...AND
THIS IS POSSIBLE AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF US.
DRIER AIR WILL HEAD INTO OUR REGION TOWARDS THE END OF THE WEEK INTO
NEXT WEEKEND.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/PC
SHORT TERM...WERT
LONG TERM...WERT
AVIATION...KK/PC

000
FXUS61 KLWX 210031
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
831 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE WEST INTO SOUTHERN VIRGINIA
TONIGHT THROUGH MONDAY. A COLD FRONT WILL STALL OUT OVER THE REGION
DURING THE MIDDLE PORTION OF THE WEEK. UNSETTLED CONDITIONS ARE
EXPECTED DURING THIS TIME. UPPER-LEVEL HIGH PRESSURE WILL BUILD OVER
THE AREA LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE WEAKENING EARLY THIS EVNG WHILE LOW PRESSURE
RETROGRADES WESTWARD TOWARD THE VIRGINIA/NORTH CAROLINA COAST.
TROPICAL STORM ALBERTO REMAINS OFF THE SOUTH CAROLINA COAST...BUT
IT WILL NOT HAVE AN IMPACT ON OUR WEATHER.

A NORTHEAST FLOW AROUND THE LOW HAS CAUSED MOISTURE FROM THE
ATLANTIC TO MOVE INTO CWFA...SPCLY SOUTHEASTERN PARTS OF THE
AREA. MOISTURE WILL CONTINUE TO INCREASE ACROSS THE ENTIRE AREA
TONIGHT AS THE LOW MOVES ONSHORE. CLOUDS WILL INCREASE AND SHOWERS
ARE LIKELY ACROSS THE REGION. LOW CLDS/WIDELY SCT RADAR RETURNS
ALREADY NOTED ON THE EASTERN SHORE/HAMPTON ROADS/APPROACHING SRN
MD...MOVING WWD. LGT SHOWERS WILL OVERSPREAD THE RGN TNGT. HV
ADJUSTED POPS A BIT...PUSHING HIEST VALUES MORE TWD PRE-DAWN WHEN
COLUMN WL BE MORE SATD. QPF SHOULD BE MINIMAL.

CLOUD COVER AND INCREASED DEWPOINTS WILL ALLOW FOR MILDER
CONDITIONS COMPARED TO RECENT NIGHTS. MIN TEMPS WILL RANGE FROM
THE 50S ACROSS THE POTOMAC HIGHLANDS TO THE UPPER 50S AND LOWER
60S ACROSS MOST OTHER LOCATIONS.

SURFACE LOW PRESSURE WILL MOVE INTO SOUTHERN VIRGINIA MONDAY BEFORE
WEAKENING LATE IN THE DAY. AN ONSHORE FLOW WILL BRING PLENTY OF
CLOUDS AND A GOOD CHANCE FOR SHOWERS. MAX TEMPS WILL BE COOLER
COMPARED TO RECENT DAYS DUE TO THE CLOUD COVER. MAX TEMPS WILL RANGE
FROM THE 60S IN THE MOUNTAINS TO THE LOWER AND MIDDLE 70S ACROSS
MOST OTHER LOCATIONS.

DESPITE WEAK DYNAMICS...DEEP MOISTURE OFF THE ATLANTIC OCEAN MAY
PROVIDE ENOUGH INSTABILITY FOR SOME THUNDERSTORMS MONDAY AFTERNOON.
ANY SUNSHINE WILL COMBINE WITH THE DEEP MOISTURE TO PROVIDE MODERATE
AMOUNTS OF INSTABILITY. WILL CARRY AT LEAST THE SLIGHT CHANCE FOR
T-STORMS ACROSS THE ENTIRE AREA...BUT THERE ARE TWO FAVORED AREAS
WHERE T-STORMS ARE MOST LIKELY. THE FIRST IS ACROSS THE POTOMAC
HIGHLANDS INTO THE CENTRAL SHENANDOAH VALLEY WHERE THE MARINE LAYER
IS MOST LIKELY TO MIX OUT. THE SECOND IS NEAR AND EAST OF THE I-95
CORRIDOR WHERE A COASTAL FRONT WILL ALSO HELP MIX OUT THE MARINE
LAYER. GIVEN THE LIGHT FLOW ALOFT AND DEEP MOISTURE...ANY T-STORMS
THAT DO DEVELOP MAY PRODUCE LOCALLY HEAVY RAIN.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
REMNANT PRECIP FROM A COASTAL LOW PRESSURE SYSTEM WILL DIMINISH MON
NIGHT WHILE A COLD FRONT AND UPPER-LEVEL TROUGH APPROACH FROM THE
CENTER OF THE COUNTRY. GUIDANCE DEPICTS TROPICAL STROM ALBERTO
DRIFTING OUT TO SEA THROUGH MIDWEEK THEREFORE NOT HAVING A
SIGNIFICANT IMPACT ON THE CWA.

THE APPROACHING FRONT WILL PRODUCE ANOTHER ROUND OF SHOWERS WITH
AFTERNOON CONVECTION TUES. THE PRESENCE OF WEAK STEERING FLOW COULD
LEAD TO HEAVY RAIN WITH SOME OF THESE SHOWERS. SLIGHTLY WARMER THEN
AVERAGE DAYTIME TEMPS TUE AND WED NEAR 80 DEGREES ARE CONTINGENT
UPON CLOUD BREAKS FORMING THROUGHOUT THE DAY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A CUTOFF UPPER-LEVEL LOW WILL DEVELOP INTO THURS AS A RIDGE BUILDS
ACROSS THE CENTRAL CONUS. THIS LOW WILL SLOWLY DRIFT EASTWARD ACROSS
THE AREA THROUGH FRI. THE PRESENCE OF SOUTHERLY TO EASTERLY FLOW
DURING THE WEEK WILL ENTRAIN HUMID MARINE AIR INTO THE REGION. THIS
WILL LEAD TO CONTINUED SHOWER AND THUNDERSTORM CHANCES INTO FRI.
MODELS DISAGREE AS TO THE TIMING OF HIGHEST POPS AND WITH SUCH A
SLOW MOVING PATTERN...CONFIDENCE IN THE EXACT TIMING OF PRECIP IS
LOW. WITH PREVAILING SOUTHEAST FLOW...A MARINE AIR MASS AND CLOUD
DECK COULD BECOME LODGED AGAINST THE EASTERN SLOPES OF THE BLUE
RIDGE. THIS COULD LEAD TO CLOUDY SKIES OVER EASTERN AREAS WITH
CLEARING OVER WESTERN LOCATIONS DURING THE END OF THE WEEK.

FRI AND INTO THE WEEKEND LOOK TO BEGIN A DRYING TREND AS THE
UPPER-LOW MOVES OFF THE EASTERN SEABOARD. CLEARING SKIES COULD LEAD
TO SOME OF THE WARMEST TEMPS SEEN SO FAR THIS YEAR WITH HIGHS
APPROACHING 90 DEGREES SAT AND SUN.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE WILL MOVE ONSHORE TONIGHT AND THEN INTO SOUTHERN
VIRGINIA MONDAY BEFORE WEAKENING. ALTHO VFR FLGT CONDS PREVAIL
ACRS THE TERMINALS...IFR CIGS LURK ALONG THE ATLC SEABOARD. WITH
PERSISTENT ENELY FLOW OVNGT...ITS REASONABLE TO XPCT THAT THESE
CLDS WL SPREAD WWD. PREMISE OF PRVS TAFS WERE KEPT IN TERMS OF
RESTRICTIONS...ALTHO WND DIR/SPD WERE CLEANED UP A BIT. WHILE LGT
PCPN PLAUSIBLE...DONT FORSEE VSBY RESTRICTIONS TO BE NEARLY AS
PROBLEMATIC AS CIGS.

IFR CIGS WILL SLOWLY IMPROVE TO MVFR LEVELS LATER MONDAY MORNING
INTO MONDAY AFTERNOON. MORE SHOWERS ARE LIKELY ALONG WITH POSSIBLE
T-STORMS. THE BEST CHANCE FOR T-STORMS WILL BE ACROSS THE EASTERN
TERMINALS.

VISBY AND CIG RESTRICTIONS MAY BE NEEDED IN SHOWERS AND
THUNDERSTORMS. A MARINE AIR MASS INTRUSION COULD LEAD TO LOW LEVEL
CIGS INTO FRI.

&&

.MARINE...
LOW PRESSURE WILL RETROGRADE WESTWARD INTO VIRGINIA/NORTH CAROLINA
TONIGHT BEFORE WEAKENING OVER SOUTHERN VIRGINIA MONDAY. THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS WILL SUPPORT WIND GUSTS TO 20 KT
INTO THIS EVENING. OBS AT DCA AND BTWN RTE 301 BRIDGE AND COBB
ISLAND SUPPORTED AN EXTENSION OF ADVYS...THROUGH 10 PM AND 1 AM
RESPECTIVELY.

A LLJ INCREASE ACRS THE NRN WATERS TNGT...KEEPING SCA THREAT GOING
THERE OVNGT. PREDAWN WNDS IN NRN BAY PROGGED TO BE GREATER THAN
MID BAY/LWR PTMC. HV ALSO EXPANDED SCA FOR NRN WATERS FOR THE
OVNGT HRS TO MATCH PREVIOUSLY ISSUED HAZARD. ATTM WONT ATTEMPT
FURTHER SEGMENTATION OF ADVY.

NORTHEAST WINDS WILL CONTINUE MONDAY MORNING BEFORE TURNING TOWARD
THE EAST-SOUTHEAST MONDAY AFTERNOON. WIND GUSTS WILL APPROACH SCA
CRITERIA...ESPECIALLY MONDAY MORNING. HAVE NOT ISSUED AN SCA AT THIS
TIME SINCE THE PRESSURE GRADIENT IS EXPECTED TO WEAKEN.

OVERALL WEAK PRESSURE GRADIENT FOR THE LONG TERM WILL LEAD TO LIGHT
WINDS OVER MARINE AREAS. VISIBILITY RESTRICTIONS COULD OCCUR IN
SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK.

&&

.TIDES/COASTAL FLOODING...
A PROLONGED NORTHEAST FLOW HAS CONTINUED TO SUPPORT ELEVATED
WATER LEVELS. HOWEVER...THE ONSHORE FLOW HAS NOT BEEN STRONG
ENOUGH THUS FAR TO CAUSE WATER LEVELS TO EXCEED THRESHOLDS FOR
MINOR COASTAL FLOODING. TIDAL ANOMALIES MAY INCREASE SOME MORE
LATE TONIGHT AND MONDAY AS LOW PRESSURE MOVES ONSHORE AND NELY
WNDS INCREASE. WATER LEVELS WILL APPROACH THRESHOLDS FOR MINOR
FLOODING. FOR MOST SITES...ANOMOLIES NEED TO EXCEED 1 FT FOR ANY
CONCERN. ANNAPOLIS WL BE THE EXCEPTION...REQUIRING ONLY 3/4 FT. DO
NOT THINK DEPARTURES WILL REACH 1 FT. THUS...ANNAPOLIS THE ONLY
PLACE ON THE EDGE. HIGH TIDE NOT TIL 530 AM...SO WE HV TIME FOR
CONTD MONITORING.

FLOW PATTERN WL SUPPORT CONTD NEAR ISSUES THROUGH TUE.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ530>534-
     537>543.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ535.
     SMALL CRAFT ADVISORY UNTIL 1 AM EDT MONDAY FOR ANZ536.

&&

$$

SYNOPSIS...BJL
NEAR TERM...HTS/BJL
SHORT TERM...CLS
LONG TERM...CLS
AVIATION...HTS/BJL/CLS
MARINE...HTS/BJL/CLS
TIDES/COASTAL FLOODING...HTS/BJL

000
FXUS61 KRNK 202333
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
733 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID-ATLANTIC COAST WILL DRIFT SLOWLY NORTH
AND WEST TONIGHT AND MONDAY WITH INCREASING RAIN CHANCES WHILE A
COLD FRONT APPROACHES FROM THE WEST BY TUESDAY WITH MORE SHOWERS
POSSIBLE. TROPICAL STORM ALBERTO IS FORECAST TO REMAIN NEARLY
STATIONARY OFF THE SOUTHEAST COAST THE NEXT DAY OR SO AND THEN
TRACK OFF TO THE NORTHEAST BY MID-WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 455 PM EDT SUNDAY...

HAVE UPDATED PROBABILITY OF PRECIPITATION TO ACCOUNT FOR BAND OF
SHOWERS MOVING WEST INTO THE FOOTHILLS. MORE WIDESPREAD
PRECIPITATION STILL NOT EXPECTED UNTIL LATER TONIGHT.

AS OF 310 PM EDT SUNDAY...

RIBBON OF DRIER AIR IN PLACE ACROSS THE RNK CWA WILL BE ERODING FROM
BOTH EAST AND WEST OVER THE NEXT 24 HOURS. FROM THE EAST A 1015 MB
LOW PRESSURE CENTER LOCATED THIS AFTERNOON OFF THE VA/NC COAST HAS
BEEN SPREADING MID-LEVEL CLOUDS WESTWARD ALL DAY WHICH HAVE
FINALLY REACHED OUR EASTERN COUNTIES. THE PERSISTENT EASTERLY FLOW
AROUND THIS LOW WILL CONTINUE AND STEADILY MOISTEN THE AIR MASS...AS
CURRENT PWAT VALUES GENERALLY IN THE 0.60-0.70 INCH RANGE ARE
FORECAST IN VARIOUS BUFKIT MODELS TO INCREASE TO 1.00 TO 1.25 INCH
RANGE BY MONDAY AFTERNOON. AS COLUMN BECOME INCREASINGLY SATURATED
EXPECT CONCOMITANT INCREASE IN CLOUDS/POPS MAINLY BEGINNING LATE
TONIGHT/EARLY MONDAY IN THE EAST WITH HIGHEST CHC POPS BY LATE
AFTERNOON IN THE NORTHEASTERN CWA CLOSEST TO THE INFLUENCE OF THE
COASTAL LOW. MEANWHILE FROM THE WEST...A COLD FRONT OVER THE MID-
MISSISSIPPI VALLEY WILL BE SLOWLY APPROACHING THE AREA BY LATE
MONDAY WITH PRECIPITATION CHANCES ALONG AND AHEAD OF THIS
BOUNDARY ALSO INCREASING...HOWEVER MAIN EFFECTS OF THIS FRONT
LOOK TOBE BEYOND THE NEAR-TERM FORECAST PERIOD. TEMPS WILL BE
SOMEWHAT WARMER TONIGHT THAN THE PREVIOUS FEW AS AFOREMENTIONED
CLOUDS MOVE IN HOLDING LOWS TOMORROW MORNING TO NEAR 6O IN THE EAST
AND MID-50S WEST. TROPICAL STORM ALBERTO CURRENTLY LOCATED
SOUTHEAST OF SAVANNAH GA WITH MAXIMUM 45 MPH WINDS IS NOT EXPECTED
TO HAVE ANY REAL INFLUENCE ON OUR WEATHER IN THE SOUTHERN
APPALACHIANS AS THE STORM WILL REMAIN OFFSHORE AND EVENTUALLY
TRACK OFF TO THE NORTHEAST.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM EDT SUNDAY...

APPROACH OF UPPER TROF FROM THE WEST...AND BUILDING UPPER RIDGE OFF
THE ATLANTIC COAST WILL HELP TO CAUSE RETROGRESSION OF WEAK CLOSED
LOW CURRENTLY OFF THE MID ATLANTIC COAST...TRAPPING SYSTEM OVER OR
NEAR THE BLACKSBURG FORECAST AREA THROUGH THE ENTIRE SHORT TERM
PERIOD.

COMBINATION OF ATLANTIC MOISTURE AND SLIGHTLY COOLER MID LEVEL AIR
ASSOCIATED WITH THIS SYSTEM SHOULD MAINTAIN SUFFICIENT THERMODYNAMIC
PROFILE TO SUPPORT MAINLY DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS
THROUGH THE PERIOD...WHICH MIGHT VERY WELL LINGER WELL INTO EACH
NIGHT WHERE UPSLOPE IS MAXIMIZED SINCE CORFIDI VECTORS ARE FORECAST
TO BE VERY WEAK AND ALIGNED NEARLY PARALLEL TO RIDGE LINES.

EXTENT OF CLOUD COVER WILL STRONGLY INFLUENCE EXTENT OF DAYTIME
HEATING EACH DAY...AND AS WOULD BE EXPECTED UNDER SUCH
CIRCUMSTANCES...LARGE SPREAD IN MOS GUIDANCE EXISTS WITH MAV-BASED
MOS MUCH WARMER THAN MET-BASED MOS AND LOCALLY RUN MOS-MOS GUIDANCE.
CONSIDERING SUPERIOR PERFORMANCE OF MOS-MOS GUIDANCE RECENTLY...WILL
CONTINUE TO GIVE STRONG WEIGHTING TO IT THROUGHOUT SHORT TERM PERIOD
FOR DAYTIME HIGHS AS WELL AS OVERNIGHT LOWS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 730 PM EDT SUNDAY...

KFCX 88D LOOP SHOWED BAND OF SHOWERS MOVING WEST ACROSS CWA THIS
EVENING. EXPECT THIS CONVECTION TO DIMINISH WITH THE LOSS OF SOLAR
HEATING IN NEXT HOUR OR TWO. MID AND HIGH LEVEL CLOUDS WILL SPREAD
WEST THIS EVENING INTO TONIGHT IN ASSOCIATION WITH THE SURFACE LOW
CENTERED OFF THE MID- ATLANTIC COAST.

OVERNIGHT EXPECT SLOWLY LOWERING/THICKENING OF CLOUDS OVER THE
EASTERN HALF AS PERSISTENT EAST TO NORTHEAST FLOW RESULTS IN
INCREASING MOISTURE. KEPT FOG/BR AND LOW STRATUS OUT OF THE WESTERN
TAFS (ESP LWB) WHERE HIGHER CLOUDS MAY IMPEDE FOG FORMATION BUT WILL
HAVE TO WATCH FOR POSSIBLE FORMATION IF IT REMAINS CLEAR. PRECIP
CHANCES ALSO INCREASE FROM EAST TO WEST BY MONDAY AFTERNOON.
LYH HAS THE BEST CHANCE FOR SHOWERS MONDAY AFTERNOON INTO MONDAY
EVENING.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR LATER MONDAY INTO TUESDAY...AND
THIS IS POSSIBLE AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF US.
DRIER AIR WILL HEAD INTO OUR REGION TOWARDS THE END OF THE WEEK INTO
NEXT WEEKEND.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/PC
SHORT TERM...WERT
LONG TERM...WERT
AVIATION...KK/PC

000
FXUS61 KAKQ 202325
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
725 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID ATLANTIC COAST GRADUALLY DRIFTS
WESTWARD INTO MONDAY. LOW PRESSURE WILL PERSIST ACROSS THE
AREA THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
FORECAST ON TRACK AS BANDS OF SHOWERS ASSOCIATED WITH LOW PRESSURE
APPROACHING THE COAST MOVES WEST. INITIAL BATCH OF SHOWERS NOW
APPROACHING THE SWRN COUNTIES WHILE MAIN BATCH OF SHOWERS MOVING
ONSHORE ACROSS THE LOWER DELMARVA. THIS TREND EXPECTED TO CONTINUE
THOUGH THE NIGHT AS THE LOW MOVES ONSHORE. MOST IF ALL THUNDER HAS
DISSIPATED BUT KEPT THE CHC OF THUNDER IN ACROSS EASTERN SHORE AS
MAIN BATCH OF SHOWERS MOVES OFFSHORE NEXT FEW HOURS.

PREV DISCUSSION:
EXTRA TROPICAL LO PRES E OF THE CST CONTS ITS MOVEMENT W TWD THE
CST THIS AFTN. SHRAS HAVE ARRIVED ON SCHEDULE IN SE QTR OF FA.
CLDNS HAS ALSO BCM WDSPRD AND WELL INLAND ACRS FA. LOWEST CIGS
RIGHT NR THE CST FM THE ERN SHR TO ORF/NTU AND ECG/OUTER BANKS.
WATCHING CNVTN N OF THE LO AND CURRENTLY E OF THE ERN SHR. XPCG
CONTD CLDS/SHRAS TO MOV INLAND AS THE LO DRIFTS CLSR TO LAND. WL
INCLD CHC T OVR PORTIONS OF THE ERN SHR DESPITE MARITIME AMS IN
PLC. DURG OVRNGT HRS...REFLECTION OF THAT SFC LO CONTS TO DRIFT
WNW AND INLAND...EVENTUALLY TO REACH NRN VA/SRN MD BY (ERY) MON
MRNG. WL HAVE CHC POPS ALL AREAS FOR THE NGT...W/ LIKELY TO CAT
(60-80%) ACRS NE PORTIONS. LO TEMPS MNLY IN THE L/M60S.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
WX CONDS RMN UNSETTLED THROUGH MIDWEEK. TROUGH ALOFT RMNS IN PLCS
OVR THE SE AND MDATLC RGNS. A REINFORCING PIECE OF ENERGY ARRIVES
INTO THE TROUGH TUE...THEN PROGRESSES ACRS NC/VA TUE AFTN INTO
WED.

XPCG VRBL CLDNS OR MCLDY CONDS THROUGH THE PD. POP FORECAST IS
DIFFICULT...AND LIKELY TO BCM MR DIURNAL IN NATURE BY MIDWEEK.
SOMETHING TO WATCH IS WHEN THE NEW PIECE OF ENERGY IN THE TROUGH
TRACKS THROUGH THE RGN (TUE AFTN INTO TUE NGT)...MAY SEE A MR
ORGANIZED AREA OF CNVTN.

FOR HI TEMPS NEXT SVRL DAYS...LEANED A FEW DEGS F BLO GUID. HI
TEMPS MON FM ARND 70F AT THE CST...TO L/M70S ELSW. HI TEMPS TUE
AND WED FM THE 70S TO L80S. LO TEMPS EACH NGT MNLY IN THE L/M60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /23Z SUNDAY THROUGH FRIDAY/...
AREA OF LOW PRESSURE CENTERED OFF THE VA/NC COAST WILL CONTINUE TO
SLOWLY MOVE W THROUGH MON. NE FLOW WILL USHER IN LOW CEILINGS AND
-RA EAST TO WEST OVERNIGHT WITH SOME IFR TO LIFR CONDITIONS
POSSIBLE. THE PRESSURE GRADIENT WILL REMAIN THE TIGHTEST IN THE
NORTHERN PORTION OF THE FA BETWEEN HIGH PRESSURE OVER WESTERN NEW
ENGLAND AND THE LOW OFF THE COAST. THIS WILL CAUSE NE/E WINDS WINDS
TO REMAIN GUSTY TO AROUND 20 KT.

FLIGHT RESTRICTIONS ARE LIKELY THROUGH TUE AS THE LOW MOVES OVER THE
AREA BEFORE A COLD FRONT APPROACHES THE AREA ON TUE. ANY AFFECTS FROM
TROPICAL STORM ALBERTO SHOULD BE NEGLIGIBLE AT ANY TAF SITE DUE TO
THE CURRENT TRACK TO THE STORM BEING A CONSIDERABLE DISTANCE OFF
THE COAST.

&&

.MARINE...
SFC LOW PRESSURE WILL MOVE WESTWARD INTO EASTERN VA WITHIN THE NEXT
6-8 HRS. DURING THIS TIME...SUSTAINED NE WINDS WILL AVERAGE 15-20 KT
OVER THE WATERS...EXCEPT SUBSIDING TO 10-15 KT SOUTH OF THE NC
BORDER AROUND SUNSET. AS THE LOW MOVES INLAND THIS EVENING...WINDS
WILL TURN E-ESE AND LESSEN TO BETWEEN 5-10 KT OVERNIGHT. SCA ARE
STILL SET TO END ON THE LOWER JAMES RIVER AT 7PM...THE CURRITUCK
SOUND AT 10PM...AND ALL OF THE CHES BAY AT MIDNIGHT. WAVES ON THE
CHES BAY WILL CONTINUE BETWEEN 3-4 FT THROUGH THIS EVENING BEFORE
SUBSIDING. SEAS OF 5-7 FT WILL CONTINUE ON THE COASTAL WATERS
THROUGH JUST AFTER DAYBREAK MONDAY MORNING...THEN WILL DROP BELOW
5 FT SOUTH OF CAPE CHARLES LIGHT. HAVE ENDED THE SOUTHERN TWO
COASTAL ZONES AT 7 AM MON. HAVE MAINTAINED SCA`S FOR THE REMAINDER
OF THE COASTAL WATERS THROUGH MONDAY AFTERNOON AS SEAS WILL BE
SLOWER TO DROP BELOW 5 FT THERE. WILL HAVE TO WATCH WHAT BECOMES
OF ALBERTO BY TUESDAY MORNING AS THE CURRENT NHC FORECAST PASSES
IT WELL EAST OF THE NC OUTER BANKS. WE MAY NEED TO BRING SEAS BACK
UP AGAIN TO ACCOUNT FOR ALBERTO`S PASSAGE.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ630>632-
     634.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT MONDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/MPR
SHORT TERM...ALB
LONG TERM...JDM
AVIATION...DAP
MARINE...JDM

000
FXUS61 KRNK 202101
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
501 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID-ATLANTIC COAST WILL DRIFT SLOWLY NORTH
AND WEST TONIGHT AND MONDAY WITH INCREASING RAIN CHANCES WHILE A
COLD FRONT APPROACHES FROM THE WEST BY TUESDAY WITH MORE SHOWERS
POSSIBLE. TROPICAL STORM ALBERTO IS FORECAST TO REMAIN NEARLY
STATIONARY OFF THE SOUTHEAST COAST THE NEXT DAY OR SO AND THEN
TRACK OFF TO THE NORTHEAST BY MID-WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 455 PM EDT SUNDAY...

HAVE UPDATED PROBABILITY OF PRECIPITATION TO ACCOUNT FOR BAND OF
SHOWERS MOVING WEST INTO THE FOOTHILLS. MORE WIDESPREAD
PRECIPITATION STILL NOT EXPECTED UNTIL LATER TONIGHT.

AS OF 310 PM EDT SUNDAY...

RIBBON OF DRIER AIR IN PLACE ACROSS THE RNK CWA WILL BE ERODING FROM
BOTH EAST AND WEST OVER THE NEXT 24 HOURS. FROM THE EAST A 1015 MB
LOW PRESSURE CENTER LOCATED THIS AFTERNOON OFF THE VA/NC COAST HAS
BEEN SPREADING MID-LEVEL CLOUDS WESTWARD ALL DAY WHICH HAVE
FINALLY REACHED OUR EASTERN COUNTIES. THE PERSISTENT EASTERLY FLOW
AROUND THIS LOW WILL CONTINUE AND STEADILY MOISTEN THE AIR MASS...AS
CURRENT PWAT VALUES GENERALLY IN THE 0.60-0.70 INCH RANGE ARE
FORECAST IN VARIOUS BUFKIT MODELS TO INCREASE TO 1.00 TO 1.25 INCH
RANGE BY MONDAY AFTERNOON. AS COLUMN BECOME INCREASINGLY SATURATED
EXPECT CONCOMITANT INCREASE IN CLOUDS/POPS MAINLY BEGINNING LATE
TONIGHT/EARLY MONDAY IN THE EAST WITH HIGHEST CHC POPS BY LATE
AFTERNOON IN THE NORTHEASTERN CWA CLOSEST TO THE INFLUENCE OF THE
COASTAL LOW. MEANWHILE FROM THE WEST...A COLD FRONT OVER THE MID-
MISSISSIPPI VALLEY WILL BE SLOWLY APPROACHING THE AREA BY LATE
MONDAY WITH PRECIPITATION CHANCES ALONG AND AHEAD OF THIS
BOUNDARY ALSO INCREASING...HOWEVER MAIN EFFECTS OF THIS FRONT
LOOK TOBE BEYOND THE NEAR-TERM FORECAST PERIOD. TEMPS WILL BE
SOMEWHAT WARMER TONIGHT THAN THE PREVIOUS FEW AS AFOREMENTIONED
CLOUDS MOVE IN HOLDING LOWS TOMORROW MORNING TO NEAR 6O IN THE EAST
AND MID-50S WEST. TROPICAL STORM ALBERTO CURRENTLY LOCATED
SOUTHEAST OF SAVANNAH GA WITH MAXIMUM 45 MPH WINDS IS NOT EXPECTED
TO HAVE ANY REAL INFLUENCE ON OUR WEATHER IN THE SOUTHERN
APPALACHIANS AS THE STORM WILL REMAIN OFFSHORE AND EVENTUALLY
TRACK OFF TO THE NORTHEAST.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM EDT SUNDAY...

APPROACH OF UPPER TROF FROM THE WEST...AND BUILDING UPPER RIDGE OFF
THE ATLANTIC COAST WILL HELP TO CAUSE RETROGRESSION OF WEAK CLOSED
LOW CURRENTLY OFF THE MID ATLANTIC COAST...TRAPPING SYSTEM OVER OR
NEAR THE BLACKSBURG FORECAST AREA THROUGH THE ENTIRE SHORT TERM
PERIOD.

COMBINATION OF ATLANTIC MOISTURE AND SLIGHTLY COOLER MID LEVEL AIR
ASSOCIATED WITH THIS SYSTEM SHOULD MAINTAIN SUFFICIENT THERMODYNAMIC
PROFILE TO SUPPORT MAINLY DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS
THROUGH THE PERIOD...WHICH MIGHT VERY WELL LINGER WELL INTO EACH
NIGHT WHERE UPSLOPE IS MAXIMIZED SINCE CORFIDI VECTORS ARE FORECAST
TO BE VERY WEAK AND ALIGNED NEARLY PARALLEL TO RIDGE LINES.

EXTENT OF CLOUD COVER WILL STRONGLY INFLUENCE EXTENT OF DAYTIME
HEATING EACH DAY...AND AS WOULD BE EXPECTED UNDER SUCH
CIRCUMSTANCES...LARGE SPREAD IN MOS GUIDANCE EXISTS WITH MAV-BASED
MOS MUCH WARMER THAN MET-BASED MOS AND LOCALLY RUN MOS-MOS GUIDANCE.
CONSIDERING SUPERIOR PERFORMANCE OF MOS-MOS GUIDANCE RECENTLY...WILL
CONTINUE TO GIVE STRONG WEIGHTING TO IT THROUGHOUT SHORT TERM PERIOD
FOR DAYTIME HIGHS AS WELL AS OVERNIGHT LOWS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIR MASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
AS OF 140 PM EDT SUNDAY...

MID-LEVEL BKN-OVC DECK CONTINUE ADVANCING FROM EAST TO WEST IN
ASSOCIATION WITH THE SURFACE LOW CENTERED OFF THE MID-ATLANTIC COAST
THIS AFTERNOON. HAVE SEEN SOME MIXING OUT AND THINNING OF CLOUDS
AS THEY ENCOUNTER DRIER AIR OVER CENTRAL AND WESTERN VIRGINIA SO
SHOWED ONLY BROKEN MID-LEVEL CLOUDS COMING IN AT AT EASTERN TAF
SITES (DAN/LYH) BY EVENING. OVERNIGHT EXPECT SLOWLY
LOWERING/THICKENING OF CLOUDS OVER THE EASTERN HALF AS PERSISTENT
EAST TO NORTHEAST FLOW RESULTS IN INCREASING MOISTURE. KEPT FOG/BR
AND LOW STRATUS OUT OF THE WESTERN TAFS (ESP LWB) WHERE HIGHER
CLOUDS MAY IMPEDE FOG FORMATION BUT WILL HAVE TO WATCH FOR
POSSIBLE FORMATION IF IT REMAINS CLEAR. PRECIP CHANCES ALSO
INCREASE FROM EAST TO WEST BUT ONLY BROUGHT PREVAILING SHOWERS AS
FAR WEST AS LYH AND NOT UNTIL EARLY AFTERNOON MONDAY.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR LATER MONDAY INTO TUESDAY...AND
THIS IS POSSIBLE AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF
US.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/PC
SHORT TERM...WERT
LONG TERM...WERT
AVIATION...PC/WP

000
FXUS61 KAKQ 202017
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
417 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID ATLANTIC COAST GRADUALLY DRIFTS
WESTWARD INTO MONDAY. LOW PRESSURE WILL PERSIST ACROSS THE
AREA THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HAVE ADDED T (THROUGH EVE HRS) TO PORTIONS OF SE VA/CSTL NE NC
BASED ON DVLPMNT OF CLUSTER OF STMS MOVG ONSHR.

PREV DISCUSSION:
EXTRA TROPICAL LO PRES E OF THE CST CONTS ITS MOVEMENT W TWD THE
CST THIS AFTN. SHRAS HAVE ARRIVED ON SCHEDULE IN SE QTR OF FA.
CLDNS HAS ALSO BCM WDSPRD AND WELL INLAND ACRS FA. LOWEST CIGS
RIGHT NR THE CST FM THE ERN SHR TO ORF/NTU AND ECG/OUTER BANKS.
WATCHING CNVTN N OF THE LO AND CURRENTLY E OF THE ERN SHR. XPCG
CONTD CLDS/SHRAS TO MOV INLAND AS THE LO DRIFTS CLSR TO LAND. WL
INCLD CHC T OVR PORTIONS OF THE ERN SHR DESPITE MARITIME AMS IN
PLC. DURG OVRNGT HRS...REFLECTION OF THAT SFC LO CONTS TO DRIFT
WNW AND INLAND...EVENTUALLY TO REACH NRN VA/SRN MD BY (ERY) MON
MRNG. WL HAVE CHC POPS ALL AREAS FOR THE NGT...W/ LIKELY TO CAT
(60-80%) ACRS NE PORTIONS. LO TEMPS MNLY IN THE L/M60S.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
WX CONDS RMN UNSETTLED THROUGH MIDWEEK. TROUGH ALOFT RMNS IN PLCS
OVR THE SE AND MDATLC RGNS. A REINFORCING PIECE OF ENERGY ARRIVES
INTO THE TROUGH TUE...THEN PROGRESSES ACRS NC/VA TUE AFTN INTO
WED.

XPCG VRBL CLDNS OR MCLDY CONDS THROUGH THE PD. POP FORECAST IS
DIFFICULT...AND LIKELY TO BCM MR DIURNAL IN NATURE BY MIDWEEK.
SOMETHING TO WATCH IS WHEN THE NEW PIECE OF ENERGY IN THE TROUGH
TRACKS THROUGH THE RGN (TUE AFTN INTO TUE NGT)...MAY SEE A MR
ORGANIZED AREA OF CNVTN.

FOR HI TEMPS NEXT SVRL DAYS...LEANED A FEW DEGS F BLO GUID. HI
TEMPS MON FM ARND 70F AT THE CST...TO L/M70S ELSW. HI TEMPS TUE
AND WED FM THE 70S TO L80S. LO TEMPS EACH NGT MNLY IN THE L/M60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
AREA OF LOW PRESSURE CENTERED OFF THE VA/NC COAST WILL CONTINUE TO
SLOWLY MOVE W THROUGH MON. NE FLOW WILL USHER IN LOW CEILINGS AND
-RA EAST TO WEST OVERNIGHT WITH SOME IFR TO LIFR CONDITIONS
POSSIBLE. THE PRESSURE GRADIENT WILL REMAIN THE TIGHTEST IN THE
NORTHERN PORTION OF THE FA BETWEEN HIGH PRESSURE OVER WESTERN NEW
ENGLAND AND THE LOW OFF THE COAST. THIS WILL CAUSE NE/E WINDS WINDS
TO REMAIN GUSTY TO AROUND 20 KT.

FLIGHT RESTRICTIONS ARE LIKELY THROUGH TUE AS THE LOW MOVES OVER THE
AREA BEFORE A COLD FRONT APPROACHES THE AREA ON TUE. ANY AFFECTS FROM
TROPICAL STORM ALBERTO SHOULD BE NEGLIGIBLE AT ANY TAF SITE DUE TO
THE CURRENT TRACK TO THE STORM BEING A CONSIDERABLE DISTANCE OFF
THE COAST.

&&

.MARINE...
SFC LOW PRESSURE WILL MOVE WESTWARD INTO EASTERN VA WITHIN THE NEXT
6-8 HRS. DURING THIS TIME...SUSTAINED NE WINDS WILL AVERAGE 15-20 KT
OVER THE WATERS...EXCEPT SUBSIDING TO 10-15 KT SOUTH OF THE NC
BORDER AROUND SUNSET. AS THE LOW MOVES INLAND THIS EVENING...WINDS
WILL TURN E-ESE AND LESSEN TO BETWEEN 5-10 KT OVERNIGHT. SCA ARE
STILL SET TO END ON THE LOWER JAMES RIVER AT 7PM...THE CURRITUCK
SOUND AT 10PM...AND ALL OF THE CHES BAY AT MIDNIGHT. WAVES ON THE
CHES BAY WILL CONTINUE BETWEEN 3-4 FT THROUGH THIS EVENING BEFORE
SUBSIDING. SEAS OF 5-7 FT WILL CONTINUE ON THE COASTAL WATERS
THROUGH JUST AFTER DAYBREAK MONDAY MORNING...THEN WILL DROP BELOW
5 FT SOUTH OF CAPE CHARLES LIGHT. HAVE ENDED THE SOUTHERN TWO
COASTAL ZONES AT 7 AM MON. HAVE MAINTAINED SCA`S FOR THE REMAINDER
OF THE COASTAL WATERS THROUGH MONDAY AFTERNOON AS SEAS WILL BE
SLOWER TO DROP BELOW 5 FT THERE. WILL HAVE TO WATCH WHAT BECOMES
OF ALBERTO BY TUESDAY MORNING AS THE CURRENT NHC FORECAST PASSES
IT WELL EAST OF THE NC OUTER BANKS. WE MAY NEED TO BRING SEAS BACK
UP AGAIN TO ACCOUNT FOR ALBERTO`S PASSAGE.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ630>632-
     634.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633.
     SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ638.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT MONDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...JDM
AVIATION...DAP
MARINE...JDM

000
FXUS61 KRNK 201925
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
325 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID-ATLANTIC COAST WILL DRIFT SLOWLY NORTH
AND WEST TONIGHT AND MONDAY WITH INCREASING RAIN CHANCES WHILE A
COLD FRONT APPROACHES FROM THE WEST BY TUESDAY WITH MORE SHOWERS
POSSIBLE. TROPICAL STORM ALBERTO IS FORECAST TO REMAIN NEARLY
STATIONARY OFF THE SOUTHEAST COAST THE NEXT DAY OR SO AND THEN
TRACK OFF TO THE NORTHEAST BY MID-WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
AS OF 310 PM EDT SUNDAY...

RIBBON OF DRIER AIR IN PLACE ACROSS THE RNK CWA WILL BE ERODING FROM
BOTH EAST AND WEST OVER THE NEXT 24 HOURS. FROM THE EAST A 1015 MB
LOW PRESSURE CENTER LOCATED THIS AFTERNOON OFF THE VA/NC COAST HAS
BEEN SPREADING MID-LEVEL CLOUDS WESTWARD ALL DAY WHICH HAVE
FINALLY REACHED OUR EASTERN COUNTIES. THE PERSISTENT EASTERLY FLOW
AROUND THIS LOW WILL CONTINUE AND STEADILY MOISTEN THE AIR MASS...AS
CURRENT PWAT VALUES GENERALLY IN THE 0.60-0.70 INCH RANGE ARE
FORECAST IN VARIOUS BUFKIT MODELS TO INCREASE TO 1.00 TO 1.25 INCH
RANGE BY MONDAY AFTERNOON. AS COLUMN BECOME INCREASINGLY SATURATED
EXPECT CONCOMITANT INCREASE IN CLOUDS/POPS MAINLY BEGINNING LATE
TONIGHT/EARLY MONDAY IN THE EAST WITH HIGHEST CHC POPS BY LATE
AFTERNOON IN THE NORTHEASTERN CWA CLOSEST TO THE INFLUENCE OF THE
COASTAL LOW. MEANWHILE FROM THE WEST...A COLD FRONT OVER THE MID-
MISSISSIPPI VALLEY WILL BE SLOWLY APPROACHING THE AREA BY LATE
MONDAY WITH PRECIPITATION CHANCES ALONG AND AHEAD OF THIS
BOUNDARY ALSO INCREASING...HOWEVER MAIN EFFECTS OF THIS FRONT
LOOK TOBE BEYOND THE NEAR-TERM FORECAST PERIOD. TEMPS WILL BE
SOMEWHAT WARMER TONIGHT THAN THE PREVIOUS FEW AS AFOREMENTIONED
CLOUDS MOVE IN HOLDING LOWS TOMORROW MORNING TO NEAR 6O IN THE EAST
AND MID-50S WEST. TROPICAL STORM ALBERTO CURRENTLY LOCATED
SOUTHEAST OF SAVANNAH GA WITH MAXIMUM 45 MPH WINDS IS NOT EXPECTED
TO HAVE ANY REAL INFLUENCE ON OUR WEATHER IN THE SOUTHERN
APPALACHIANS AS THE STORM WILL REMAIN OFFSHORE AND EVENTUALLY
TRACK OFF TO THE NORTHEAST.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM EDT SUNDAY...

APPROACH OF UPPER TROF FROM THE WEST...AND BUILDING UPPER RIDGE OFF
THE ATLANTIC COAST WILL HELP TO CAUSE RETROGRESSION OF WEAK CLOSED
LOW CURRENTLY OFF THE MID ATLANTIC COAST...TRAPPING SYSTEM OVER OR
NEAR THE BLACKSBURG FORECAST AREA THROUGH THE ENTIRE SHORT TERM
PERIOD.

COMBINATION OF ATLANTIC MOISTURE AND SLIGHTLY COOLER MID LEVEL AIR
ASSOCIATED WITH THIS SYSTEM SHOULD MAINTAIN SUFFICIENT THERMODYNAMIC
PROFILE TO SUPPORT MAINLY DIURNALLY DRIVEN SHOWERS/THUNDERSTORMS
THROUGH THE PERIOD...WHICH MIGHT VERY WELL LINGER WELL INTO EACH
NIGHT WHERE UPSLOPE IS MAXIMIZED SINCE CORFIDI VECTORS ARE FORECAST
TO BE VERY WEAK AND ALIGNED NEARLY PARALLEL TO RIDGE LINES.

EXTENT OF CLOUD COVER WILL STRONGLY INFLUENCE EXTENT OF DAYTIME
HEATING EACH DAY...AND AS WOULD BE EXPECTED UNDER SUCH
CIRCUMSTANCES...LARGE SPREAD IN MOS GUIDANCE EXISTS WITH MAV-BASED
MOS MUCH WARMER THAN MET-BASED MOS AND LOCALLY RUN MOS-MOS GUIDANCE.
CONSIDERING SUPERIOR PERFORMANCE OF MOS-MOS GUIDANCE RECENTLY...WILL
CONTINUE TO GIVE STRONG WEIGHTING TO IT THROUGHOUT SHORT TERM PERIOD
FOR DAYTIME HIGHS AS WELL AS OVERNIGHT LOWS.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 300 PM EDT SUNDAY...

LONG TERM PERIOD WILL BE CHARACTERIZED BY GRADUAL REPLACEMENT OF
EAST COAST CLOSED LOW/TROFFING WITH ESTABLISHMENT OF UPPER RIDGE
OVER THE TENNESSEE AND OHIO VALLEYS...PLACING BLACKSBURG FORECAST
AREA IN INCREASINGLY WARM AIRMASS WITH LIGHT SURFACE FLOW AND WITH
NORTHWESTERLY FLOW ALOFT.

PLACEMENT ON NORTHEASTERN PERIPHERY OF UPPER RIDGE IMPLIES
SUSCEPTIBILITY TO ANY SHORT WAVE/MCS RIDGE RUNNERS THAT TURN
SOUTHEAST OUT OF THE UPPER GREAT LAKES ON PERIPHERY OF UPPER RIDGE
INTO SOUTHERN NEW ENGLAND...BUT AT THE PRESENT TIME ALL OF THE
LONGER RANGE MODELS FAIRLY CONSISTENT IN MAINTAINING SUFFICIENT
STRENGTH AND BREADTH OF UPPER RIDGE TO DEFLECT ANY SHORT WAVE
ACTIVITY AND BACKDOOR COOL FRONTS OUT OF THE BLACKSBURG AREA UNTIL
AT LEAST SUNDAY NIGHT OR MONDAY...JUST BEYOND THIS LONG TERM
FORECAST PERIOD.

DESPITE TREND TOWARDS A DRIER REGIME BY THE END OF THE WEEK INTO
NEXT WEEKEND...CAPPING INVERSION ON EASTERN PERIPHERY OF RIDGE NOT
EXPECTED TO BE STRONG ENOUGH TO OFFSET STRONG DAYTIME HEATING AND
LOCALIZED CONFLUENCE RESULTING FROM DIFFERENTIAL HEATING ALONG/NEAR
HIGHER TERRAIN AND WHERE LOCALIZED UPSLOPE IS REALIZED. WITH MOIST
GROUND IN MANY AREAS...AND EVAPOTRANSPIRATION IN FULL SWING...
MOISTURE IN LOWER TROPOSPHERIC SHOULD BE SUFFICIENT WHERE LIFT IS
MAXIMIZED TO SUPPORT MAINLY DIURNALLY DRIVEN ISOLATED TO WIDELY
SCATTERED SHOWERS/STORMS THROUGH THE PERIOD...MAXIMIZED OVER THE
MOUNTAINS AND FOOTHILLS.

500 MILLIBAR HEIGHTS AND 850 MILLIBAR TEMPERATURES FORECAST TO
GRADUALLY RISE FROM 585 DM TO 591 DM AND FROM 18C TO 22C...
RESPECTIVELY...BETWEEN FRIDAY AND SUNDAY. AS A RESULT...EXPECT HIGH
TEMPERATURES BY NEXT WEEKEND TO RISE INTO THE MID 70S TO MID 80S IN
THE MOUNTAINS WITH UPPER 80S TO AROUND 90F ACROSS THE PIEDMONT...WITH
MID 50S TO LOWER 60S IN THE MOUNTAINS TO MAINLY 60S ACROSS THE
PIEDMONT AT NIGHT.

HPC BIAS CORRECTED GUIDANCE USED TO POPULATE LONG RANGE GRIDDED
FIELDS...WITH ONLY SUBTLE TWEAKS TO REFLECT TOPOGRAPHICALLY DRIVEN
LOCAL CLIMATOLOGICAL BIASES AS/WHERE APPROPRIATE.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AS OF 140 PM EDT SUNDAY...

MID-LEVEL BKN-OVC DECK CONTINUE ADVANCING FROM EAST TO WEST IN
ASSOCIATION WITH THE SURFACE LOW CENTERED OFF THE MID-ATLANTIC COAST
THIS AFTERNOON. HAVE SEEN SOME MIXING OUT AND THINNING OF CLOUDS
AS THEY ENCOUNTER DRIER AIR OVER CENTRAL AND WESTERN VIRGINIA SO
SHOWED ONLY BROKEN MID-LEVEL CLOUDS COMING IN AT AT EASTERN TAF
SITES (DAN/LYH) BY EVENING. OVERNIGHT EXPECT SLOWLY
LOWERING/THICKENING OF CLOUDS OVER THE EASTERN HALF AS PERSISTENT
EAST TO NORTHEAST FLOW RESULTS IN INCREASING MOISTURE. KEPT FOG/BR
AND LOW STRATUS OUT OF THE WESTERN TAFS (ESP LWB) WHERE HIGHER
CLOUDS MAY IMPEDE FOG FORMATION BUT WILL HAVE TO WATCH FOR
POSSIBLE FORMATION IF IT REMAINS CLEAR. PRECIP CHANCES ALSO
INCREASE FROM EAST TO WEST BUT ONLY BROUGHT PREVAILING SHOWERS AS
FAR WEST AS LYH AND NOT UNTIL EARLY AFTERNOON MONDAY.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR LATER MONDAY INTO TUESDAY...AND
THIS IS POSSIBLE AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF
US.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...PC
SHORT TERM...WERT
LONG TERM...WERT
AVIATION...PC/WP

000
FXUS61 KAKQ 201918
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
318 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID ATLANTIC COAST GRADUALLY DRIFTS
WESTWARD INTO MONDAY. LOW PRESSURE WILL PERSIST ACROSS THE
AREA THROUGH MIDWEEK.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
EXTRA TROPICAL LO PRES E OF THE CST CONTS ITS MOVEMENT W TWD THE
CST THIS AFTN. SHRAS HAVE ARRIVED ON SCHEDULE IN SE QTR OF FA.
CLDNS HAS ALSO BCM WDSPRD AND WELL INLAND ACRS FA. LOWEST CIGS
RIGHT NR THE CST FM THE ERN SHR TO ORF/NTU AND ECG/OUTER BANKS.
WATCHING CNVTN N OF THE LO AND CURRENTLY E OF THE ERN SHR. XPCG
CONTD CLDS/SHRAS TO MOV INLAND AS THE LO DRIFTS CLSR TO LAND. WL
INCLD CHC T OVR PORTIONS OF THE ERN SHR DESPITE MARITIME AMS IN
PLC. DURG OVRNGT HRS...REFLECTION OF THAT SFC LO CONTS TO DRIFT
WNW AND INLAND...EVENTUALLY TO REACH NRN VA/SRN MD BY (ERY) MON
MRNG. WL HAVE CHC POPS ALL AREAS FOR THE NGT...W/ LIKELY TO CAT
(60-80%) ACRS NE PORTIONS. LO TEMPS MNLY IN THE L/M60S.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY/...
WX CONDS RMN UNSETTLED THROUGH MIDWEEK. TROUGH ALOFT RMNS IN PLCS
OVR THE SE AND MDATLC RGNS. A REINFORCING PIECE OF ENERGY ARRIVES
INTO THE TROUGH TUE...THEN PROGRESSES ACRS NC/VA TUE AFTN INTO
WED.

XPCG VRBL CLDNS OR MCLDY CONDS THROUGH THE PD. POP FORECAST IS
DIFFICULT...AND LIKELY TO BCM MR DIURNAL IN NATURE BY MIDWEEK.
SOMETHING TO WATCH IS WHEN THE NEW PIECE OF ENERGY IN THE TROUGH
TRACKS THROUGH THE RGN (TUE AFTN INTO TUE NGT)...MAY SEE A MR
ORGANIZED AREA OF CNVTN.

FOR HI TEMPS NEXT SVRL DAYS...LEANED A FEW DEGS F BLO GUID. HI
TEMPS MON FM ARND 70F AT THE CST...TO L/M70S ELSW. HI TEMPS TUE
AND WED FM THE 70S TO L80S. LO TEMPS EACH NGT MNLY IN THE L/M60S.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION THROUGH THURSDAY...BEFORE DRIFTING SOUTHEAST AND OFF THE
COAST THURSDAY NIGHT/FRIDAY MORNING. GIVEN THE EXPECTED POSITION OF
THE UPPER LOW OVERHEAD...WILL MAINTAIN CHC POPS (30%) ON THURSDAY.
BY FRIDAY...THE LOW WILL BE OFFSHORE AND OTHER THAN A SPOTTY SHOWER
ACROSS EASTERN AREAS...FRIDAY SHOULD BE DRY. HEIGHTS WILL BE ON THE
INCREASE ACROSS THE MID-ATLANTIC FRIDAY AS THE H5 RIDGE OVER THE
MIDWEST/TN VALLEY BEGINS TO SPILL EAST. THE H5 RIDGE AXIS REMAINS TO
OUR WEST NEXT WEEKEND BUT AN INCREASE IN HEIGHTS TO BETWEEN 588-590
DM WILL ALLOW FOR A SPELL OF WARM/HOT TEMPERATURES. NW FLOW ALOFT
WILL LEAVE THE DOOR OPEN FOR CONVECTION TO DRIFT SOUTHWARD OVER THE
TOP OF THE RIDGE AND POSSIBLY INTO THE MID-ATLANTIC REGION NEXT
WEEKEND. WILL CARRY SLIGHT CHC POPS (20%) FOR NOW AND SEE HOW THINGS
DEVELOP. TEMPS THURSDAY WILL BE IN THE UPR 70S TO LOW 80S. WARMING
FRIDAY-SUNDAY WITH SOME 90 DEG READINGS POSSIBLE FOR CENTRAL VA
SAT/SUN. KEPT COOLEST MAX TEMPS (LOW/MID 80S) ALONG THE COAST WHERE
A SEABREEZE MAY DEVELOP BOTH DAYS NEXT WEEKEND.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AREA OF LOW PRESSURE CENTERED OFF THE VA/NC COAST WILL CONTINUE TO
SLOWLY MOVE W THROUGH MON. NE FLOW WILL USHER IN LOW CEILINGS AND
-RA EAST TO WEST OVERNIGHT WITH SOME IFR TO LIFR CONDITIONS
POSSIBLE. THE PRESSURE GRADIENT WILL REMAIN THE TIGHTEST IN THE
NORTHERN PORTION OF THE FA BETWEEN HIGH PRESSURE OVER WESTERN NEW
ENGLAND AND THE LOW OFF THE COAST. THIS WILL CAUSE NE/E WINDS WINDS
TO REMAIN GUSTY TO AROUND 20 KT.

FLIGHT RESTRICTIONS ARE LIKELY THROUGH TUE AS THE LOW MOVES OVER THE
AREA BEFORE A COLD FRONT APPROACHES THE AREA ON TUE. ANY AFFECTS FROM
TROPICAL STORM ALBERTO SHOULD BE NEGLIGIBLE AT ANY TAF SITE DUE TO
THE CURRENT TRACK TO THE STORM BEING A CONSIDERABLE DISTANCE OFF
THE COAST.

&&

.MARINE...
SFC LOW PRESSURE WILL MOVE WESTWARD INTO EASTERN VA WITHIN THE NEXT
6-8 HRS. DURING THIS TIME...SUSTAINED NE WINDS WILL AVERAGE 15-20 KT
OVER THE WATERS...EXCEPT SUBSIDING TO 10-15 KT SOUTH OF THE NC
BORDER AROUND SUNSET. AS THE LOW MOVES INLAND THIS EVENING...WINDS
WILL TURN E-ESE AND LESSEN TO BETWEEN 5-10 KT OVERNIGHT. SCA ARE
STILL SET TO END ON THE LOWER JAMES RIVER AT 7PM...THE CURRITUCK
SOUND AT 10PM...AND ALL OF THE CHES BAY AT MIDNIGHT. WAVES ON THE
CHES BAY WILL CONTINUE BETWEEN 3-4 FT THROUGH THIS EVENING BEFORE
SUBSIDING. SEAS OF 5-7 FT WILL CONTINUE ON THE COASTAL WATERS
THROUGH JUST AFTER DAYBREAK MONDAY MORNING...THEN WILL DROP BELOW
5 FT SOUTH OF CAPE CHARLES LIGHT. HAVE ENDED THE SOUTHERN TWO
COASTAL ZONES AT 7 AM MON. HAVE MAINTAINED SCA`S FOR THE REMAINDER
OF THE COASTAL WATERS THROUGH MONDAY AFTERNOON AS SEAS WILL BE
SLOWER TO DROP BELOW 5 FT THERE. WILL HAVE TO WATCH WHAT BECOMES
OF ALBERTO BY TUESDAY MORNING AS THE CURRENT NHC FORECAST PASSES
IT WELL EAST OF THE NC OUTER BANKS. WE MAY NEED TO BRING SEAS BACK
UP AGAIN TO ACCOUNT FOR ALBERTO`S PASSAGE.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ630>632-
     634.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633.
     SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ638.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT MONDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB
SHORT TERM...ALB
LONG TERM...JDM
AVIATION...DAP
MARINE...JDM

000
FXUS61 KLWX 201903
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
303 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO MOVE WEST INTO SOUTHERN VIRGINIA
TONIGHT THROUGH MONDAY. A COLD FRONT WILL STALL OUT OVER THE REGION
DURING THE MIDDLE PORTION OF THE WEEK. UNSETTLED CONDITIONS ARE
EXPECTED DURING THIS TIME. UPPER-LEVEL HIGH PRESSURE WILL BUILD OVER
THE AREA LATE IN THE WEEK.

&&

.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE WILL REMAIN OVER THE REGION LATE THIS AFTERNOON WHILE
LOW PRESSURE RETROGRADES WESTWARD TOWARD THE VIRGINIA/NORTH CAROLINA
COAST. TROPICAL STORM ALBERTO REMAINS OFF THE SOUTH CAROLINA
COAST...BUT IT WILL NOT HAVE AN IMPACT ON OUR WEATHER.

A NORTHEAST FLOW AROUND THE LOW HAS CAUSED MOISTURE FROM THE
ATLANTIC TO MOVE INTO SOUTHEASTERN PARTS OF THE AREA. MOISTURE WILL
CONTINUE TO INCREASE ACROSS THE ENTIRE AREA TONIGHT AS THE LOW MOVES
ONSHORE. CLOUDS WILL INCREASE AND SHOWERS ARE LIKELY ACROSS THE
REGION. SHOWERS WILL OVERSPREAD LOWER SOUTHERN MARYLAND LATE THIS
AFTERNOON INTO THIS EVENING BEFORE MOVING ACROSS THE REST OF THE
AREA LATE THIS EVENING AND OVERNIGHT. DESPITE RAINFALL
TONIGHT...CLOUD COVER AND INCREASED DEWPOINTS WILL ALLOW FOR MILDER
CONDITIONS COMPARED TO RECENT NIGHTS. MIN TEMPS WILL RANGE FROM THE
50S ACROSS THE POTOMAC HIGHLANDS TO THE UPPER 50S AND LOWER 60S
ACROSS MOST OTHER LOCATIONS.

SURFACE LOW PRESSURE WILL MOVE INTO SOUTHERN VIRGINIA MONDAY BEFORE
WEAKENING LATE IN THE DAY. AN ONSHORE FLOW WILL BRING PLENTY OF
CLOUDS AND A GOOD CHANCE FOR SHOWERS. MAX TEMPS WILL BE COOLER
COMPARED TO RECENT DAYS DUE TO THE CLOUD COVER. MAX TEMPS WILL RANGE
FROM THE 60S IN THE MOUNTAINS TO THE LOWER AND MIDDLE 70S ACROSS
MOST OTHER LOCATIONS.

DESPITE WEAK DYNAMICS...DEEP MOISTURE OFF THE ATLANTIC OCEAN MAY
PROVIDE ENOUGH INSTABILITY FOR SOME THUNDERSTORMS MONDAY AFTERNOON.
ANY SUNSHINE WILL COMBINE WITH THE DEEP MOISTURE TO PROVIDE MODERATE
AMOUNTS OF INSTABILITY. WILL CARRY AT LEAST THE SLIGHT CHANCE FOR
T-STORMS ACROSS THE ENTIRE AREA...BUT THERE ARE TWO FAVORED AREAS
WHERE T-STORMS ARE MOST LIKELY. THE FIRST IS ACROSS THE POTOMAC
HIGHLANDS INTO THE CENTRAL SHENANDOAH VALLEY WHERE THE MARINE LAYER
IS MOST LIKELY TO MIX OUT. THE SECOND IS NEAR AND EAST OF THE I-95
CORRIDOR WHERE A COASTAL FRONT WILL ALSO HELP MIX OUT THE MARINE
LAYER. GIVEN THE LIGHT FLOW ALOFT AND DEEP MOISTURE...ANY T-STORMS
THAT DO DEVELOP MAY PRODUCE LOCALLY HEAVY RAIN.

&&

.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
REMNANT PRECIP FROM A COASTAL LOW PRESSURE SYSTEM WILL DIMINISH MON
NIGHT WHILE A COLD FRONT AND UPPER-LEVEL TROUGH APPROACH FROM THE
CENTER OF THE COUNTRY. GUIDANCE DEPICTS TROPICAL STROM ALBERTO
DRIFTING OUT TO SEA THROUGH MIDWEEK THEREFORE NOT HAVING A
SIGNIFICANT IMPACT ON THE CWA.

THE APPROACHING FRONT WILL PRODUCE ANOTHER ROUND OF SHOWERS WITH
AFTERNOON CONVECTION TUES. THE PRESENCE OF WEAK STEERING FLOW COULD
LEAD TO HEAVY RAIN WITH SOME OF THESE SHOWERS. SLIGHTLY WARMER THEN
AVERAGE DAYTIME TEMPS TUE AND WED NEAR 80 DEGREES ARE CONTINGENT
UPON CLOUD BREAKS FORMING THROUGHOUT THE DAY.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
A CUTOFF UPPER-LEVEL LOW WILL DEVELOP INTO THURS AS A RIDGE BUILDS
ACROSS THE CENTRAL CONUS. THIS LOW WILL SLOWLY DRIFT EASTWARD ACROSS
THE AREA THROUGH FRI. THE PRESENCE OF SOUTHERLY TO EASTERLY FLOW
DURING THE WEEK WILL ENTRAIN HUMID MARINE AIR INTO THE REGION. THIS
WILL LEAD TO CONTINUED SHOWER AND THUNDERSTORM CHANCES INTO FRI.
MODELS DISAGREE AS TO THE TIMING OF HIGHEST POPS AND WITH SUCH A
SLOW MOVING PATTERN...CONFIDENCE IN THE EXACT TIMING OF PRECIP IS
LOW. WITH PREVAILING SOUTHEAST FLOW...A MARINE AIR MASS AND CLOUD
DECK COULD BECOME LODGED AGAINST THE EASTERN SLOPES OF THE BLUE
RIDGE. THIS COULD LEAD TO CLOUDY SKIES OVER EASTERN AREAS WITH
CLEARING OVER WESTERN LOCATIONS DURING THE END OF THE WEEK.

FRI AND INTO THE WEEKEND LOOK TO BEGIN A DRYING TREND AS THE
UPPER-LOW MOVES OFF THE EASTERN SEABOARD. CLEARING SKIES COULD LEAD
TO SOME OF THE WARMEST TEMPS SEEN SO FAR THIS YEAR WITH HIGHS
APPROACHING 90 DEGREES SAT AND SUN.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
LOW PRESSURE WILL MOVE ONSHORE TONIGHT AND THEN INTO SOUTHERN
VIRGINIA MONDAY BEFORE WEAKENING. CLOUDS WILL INCREASE LATE THIS
AFTERNOON AND EVENING. CIGS WILL LOWER TO MVFR LEVELS LATER THIS
EVENING ACROSS MOST OF THE TERMINALS BEFORE DROPPING TO IFR LEVELS
LATE TONIGHT. SHOWERS ARE LIKELY LATE THIS EVENING AND OVERNIGHT.

IFR CIGS WILL SLOWLY IMPROVE TO MVFR LEVELS LATER MONDAY MORNING
INTO MONDAY AFTERNOON. MORE SHOWERS ARE LIKELY ALONG WITH POSSIBLE
T-STORMS. THE BEST CHANCE FOR T-STORMS WILL BE ACROSS THE EASTERN
TERMINALS.

VISBY AND CIG RESTRICTIONS MAY BE NEEDED IN SHOWERS AND
THUNDERSTORMS. A MARINE AIR MASS INTRUSION COULD LEAD TO LOW LEVEL
CIGS INTO FRI.

&&

.MARINE...
LOW PRESSURE WILL RETROGRADE WESTWARD INTO VIRGINIA/NORTH CAROLINA
TONIGHT BEFORE WEAKENING OVER SOUTHERN VIRGINIA MONDAY. THE PRESSURE
GRADIENT BETWEEN THESE TWO SYSTEMS WILL CAUSE WIND GUSTS AROUND 20
KNOTS ACROSS THE WATERS THIS AFTERNOON AND EARLY EVENING. A SMALL
CRAFT ADVISORY IS IN EFFECT DURING THIS TIME. THE SMALL CRAFT
ADVISORY CONTINUES THROUGH TONIGHT FOR THE MARYLAND CHESAPEAKE BAY
SOUTH OF SANDY POINT AND THE LOWER TIDAL POTOMAC RIVER FROM COBB
ISLAND TO SMITH POINT.

NORTHEAST WINDS WILL CONTINUE MONDAY MORNING BEFORE TURNING TOWARD
THE EAST-SOUTHEAST MONDAY AFTERNOON. WIND GUSTS WILL APPROACH SCA
CRITERIA...ESPECIALLY MONDAY MORNING. HAVE NOT ISSUED AN SCA AT THIS
TIME SINCE THE PRESSURE GRADIENT IS EXPECTED TO WEAKEN.

OVERALL WEAK PRESSURE GRADIENT FOR THE LONG TERM WILL LEAD TO LIGHT
WINDS OVER MARINE AREAS. VISIBILITY RESTRICTIONS COULD OCCUR IN
SHOWERS AND THUNDERSTORMS THROUGHOUT THE WEEK.

&&

.TIDES/COASTAL FLOODING...
A PROLONGED NORTHEAST FLOW HAS CAUSED ELEVATED WATER LEVELS.
HOWEVER...THE ONSHORE FLOW HAS NOT BEEN STRONG ENOUGH TO CAUSE WATER
LEVELS TO EXCEED THRESHOLDS FOR MINOR COASTAL FLOODING. TIDAL
ANOMALIES MAY INCREASE SOME MORE LATE TONIGHT AND MONDAY AS LOW
PRESSURE MOVES ONSHORE. HOWEVER...THE FLOW WILL WEAKEN DURING THIS
TIME. WATER LEVELS WILL APPROACH THRESHOLDS FOR MINOR FLOODING...BUT
A COASTAL FLOOD ADVISORY HAS NOT BEEN ISSUED DUE TO LOW CONFIDENCE
FROM THE WEAKENING FLOW. WILL CONTINUE TO MONITOR TIDAL ANOMALIES
TONIGHT.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ530-
     531-535-536-538-539.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ532>534-537-
     540>543.

&&

$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...CLS
LONG TERM...CLS
AVIATION...CLS/BJL
MARINE...CLS/BJL
TIDES/COASTAL FLOODING...BJL

000
FXUS61 KAKQ 201833
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
233 PM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID ATLANTIC COAST GRADUALLY DRIFTS
WESTWARD INTO MONDAY. LOW PRESSURE WILL PERSIST ACROSS THE
AREA THROUGH MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WX CONTG TO DETERIORATE FM E TO W RIGHT NOW...AND WL KP DOING SO
THROUGH THE MIDDAY INTO THE AFTN HRS AS EXTRA-TROPICAL SFC LO PRES
E OF VA CST SLOLY MOVS W. WDSPRD LO CLDNS (CIGS FM ABT 700-2000FT)
HAS OVERSPREAD ERN PORTION OF THE FA (WHICH ARE NOT RELATED IN ANY
WAY W/ TRPCL SYS OFF SC/GA CST)...AND SPOTTY LGT RA INDCTD ON RDR
MOVG INLAND. XPCG CLDNS TO SPRD W ACRS MOST (IF NOT ALL) OF THE FA
BY THIS AFTN. SOME EROSION IN THE CLDNS PSBL OVR THE FAR WRN
FRINGE (AND KEPT THAT AREA PSNY/WRMR FOR NOW). W/ THE CLDS...AND
CONTG NNE WNDS (GUSTY TO 25-30 MPH)...TEMPS WILL BE HELD IN CHECK
FM BASICALLY I95 ON TO THE CST (GENLY A GRADIENT FM E TO W FM THE
60S TO L70S). FOR AREAS OF THE PDMNT (W OF RIC/PTB)...HI TEMPS
STILL XPCD TO REACH THE U70S.

BETTER SUPPORT FOR MORE WIDESPREAD PRECIP ARRIVES THIS EVENING...AND
WILL CARRY LIKELY POPS ACRS MUCH OF THE CWA...ESPECIALLY THE ERN
SHORE AND NRN ZONES...W/ CHC POPS ELSEWHERE. COULD EVEN SEE SOME
ELEVATED TSTMS LATER TONIGHT ALONG THE COAST BUT THINK BULK OF
THIS STAYS OFFSHORE SO WILL NOT INCLUDE ATTM. W/ CLOUDS AND HIGHER
DEW PTS IT WILL BE MILDER TONIGHT W/ LOWS MAINLY IN THE UPR 50S
WELL INLAND TO THE LWR 60S FARTHER EAST.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
FOR DETAILS ON THE TRACK FCST FOR TROPICAL SYSTEM ALBERTO SEE THE
LATEST ADSY FROM TPC/NHC. FOR AKQ CWA THE DOMINANT WX FEATURE WILL
NOT BE TROPICAL...ALTHOUGH UNSETTLED CONDITIONS CAN BE EXPECTED
UNDER THE INFLUENCE OF A CUTOFF UPPER LOW THAT EVENTUALLY GETS
ENGULFED BY A UPPER LEVEL TROUGH/SHORTWAVE MOVING SE FROM THE UPPER
MIDWEST. THIS TROUGH WILL CONTINUE TO LINGER ACRS THE MID ATLC/SE
STATES INTO TUE AND BEYOND. ON MON...WILL CARRY HIGHEST POPS ACRS
THE NORTHERN/CENTRAL AREAS (60%)...BUT EVEN IN SOUTHERN ZONES WILL
CONTINUE W/ HI CHC POPS (50%). SOME MODEST INSTABILITY BY AFTN SO
WILL CONTINUE W/ SLIGHT CHC FOR AFTN TSTMS. HIGH TEMPS RANGING FROM
THE UPR 70S S TO AROUND 70 ON THE ERN SHORE...AGAIN FAVORING A BLEND
OF GUIDANCE...A LITTLE MORE WEIGHTED TO THE COOLER MET/NAM NUMBERS
DUE TO MOSTLY CLOUDY SKIES. COULD SEE SOME LULL IN THE OVERALL
PRECIP COVERAGE MON NIGHT/EARLY TUE IN BETWEEN ALBERTO WELL OFF
THE COAST TO OUR SE AND THE APPROACHING UPR LEVEL TROUGH FROM THE
NW (ALTHOUGH KEEPING CHC POPS GOING). MILD W/ LOWS GENLY IN THE
60-65 RANGE. FOR TUE...LOW LEVEL FLOW LIKELY TURNS MORE SW BOTH AT
THE SFC AND ALOFT...WHICH MAY TEMPORARILY LEAD TO PARTIAL
CLEARING. STILL THINK MAV TEMPS ARE TOO WARM BUT EVEN SO...DO
EXPECT HIGHS TO REACH INTO THE UPR 70S NORTH TO LWR 80S
CENTRAL/SOUTH. BUMPED POPS UP TO 50% FOR THE AFTN AND EVENING HRS
ALONG/W OF I-95...A LITTLE LOWER TOWARDS THE COAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION TUESDAY NIGHT THROUGH FRIDAY...BEFORE DRIFTING SOUTHEAST
AND OFF THE SERN COAST LATE FRIDAY INTO NEXT WEEKEND. WILL
MAINTAIN CHANCE/SLIGHT CHANCE POPS OVER THE AREA THROUGH FRIDAY
GIVEN THE POSITION OF THE UPPER LOW. MODELS STARTING TO COME INTO
BETTER AGREEMENT ABOUT THE UPPER LOW DRIFTING SE OF THE AREA BY
NEXT WEEKEND WHICH WOULD LEAD TO WARMER TEMPERATURES AND DRY WX AS
AN UPPER RIDGE BUILDS OVER THE REGION. HAVE MAINTAINED SLIGHT CHC
POPS NEXT SATURDAY UNTIL CONFIDENCE INCREASES THAT THE
AFOREMENTIONED UPPER LOW ACTUALLY MOVES OFFSHORE. TEMPS WILL
CHANGE LITTLE WED/THURS WITH HIGHS IN THE UPR 70S TO LOW 80S.
WARMING INTO THE LOW/MID 80S MOST AREAS FRI/SAT...WITH UPR 80S
POSSIBLE WESTERN AREAS BY SAT.

&&

.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
AREA OF LOW PRESSURE CENTERED OFF THE VA/NC COAST WILL CONTINUE TO
SLOWLY MOVE W THROUGH MON. NE FLOW WILL USHER IN LOW CEILINGS AND
-RA EAST TO WEST OVERNIGHT WITH SOME IFR TO LIFR CONDITIONS
POSSIBLE. THE PRESSURE GRADIENT WILL REMAIN THE TIGHTEST IN THE
NORTHERN PORTION OF THE FA BETWEEN HIGH PRESSURE OVER WESTERN NEW
ENGLAND AND THE LOW OFF THE COAST. THIS WILL CAUSE NE/E WINDS WINDS
TO REMAIN GUSTY TO AROUND 20 KT.

FLIGHT RESTRICTIONS ARE LIKELY THROUGH TUE AS THE LOW MOVES OVER THE
AREA BEFORE A COLD FRONT APPROACHES THE AREA ON TUE. ANY AFFECTS FROM
TROPICAL STORM ALBERTO SHOULD BE NEGLIGIBLE AT ANY TAF SITE DUE TO
THE CURRENT TRACK TO THE STORM BEING A CONSIDERABLE DISTANCE OFF
THE COAST.

&&

.MARINE...
AFTER A BRIEF LULL SATURDAY NIGHT/EARLY SUNDAY MORNING...NE WINDS
ARE FORECAST TO STRENGTHEN ONCE MORE TODAY WITH SOLID SCA WIND
VELOCITIES IN THE BAY AND COASTAL WATERS WITH MARGINAL SCA WINDS
OVER THE SOUND AND LOWER JAMES RIVER. AS LOW PRESSURE OFF THE COAST
MOVES TOWARD THE MID ATLANTIC STATES...WINDS WILL DIMINISH THIS
EVENING. ALL SCA END AT MIDNIGHT OR BEFORE EXCEPT OVER THE COASTAL
WATERS.

SWELLS ARE EXPECTED TO KEEP SEAS AT 5 FT OR HIGHER FOR A WHILE
LONGER AND HAVE EXTENDED SCA THROUGH LATE MONDAY. CURRENT FORECAST
HAS SEAS STAYING UP THROUGH TUESDAY. SWAN AND WAVEWATCH HAVE THE
SEAS DROPPING BELOW SCA CRITERIA BY MONDAY MORNING BUT THIS DOES NOT
SEEM REALISTIC. THE MODELS THEN HAVE THE SEAS BACK UP TO 5 FT OVER
MOST OF THE COASTAL WATERS (ESPECIALLY NORTHERN PORTIONS) BY
TUESDAY MORNING. DID A BLEND OF PREVIOUS FORECAST WAVE HEIGHTS AND
THAT OF WAVEWATCH.

AS FOR TIDES...NOT EXPECTING ANY FLOODING THRESHOLDS TO BE
MET...BUT TIDES ACRS SE VA/NE NC RUNNING ABOUT 1 FT ABOVE NORMAL
AND HAVE A MENTION OF THIS IN HWO FOR ZONES ALONG THE YORK/JAMES/LOWER
BAY AND SRN CSTL WATERS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ630>632-
     634.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR ANZ633.
     SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ANZ638.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654.
     SMALL CRAFT ADVISORY UNTIL 7 AM EDT MONDAY FOR ANZ656-658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...DAP
MARINE...LSA

000
FXUS61 KRNK 201747
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
147 PM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN SITUATED OVER THE REGION TODAY BETWEEN TROPICAL
STORM ALBERTO OFF THE SOUTH CAROLINA/GEORGIA COAST AND ANOTHER LOW
OFF THE VIRGINIA COAST. ALBERTO IS EXPECTED TO STAY OFF THE COAST
THROUGH TUESDAY WITH A COLD FRONT MOVING INTO OUR AREA BY THEN.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 145 AM EDT SUNDAY...

GOING FORECAST ON TRACK...WATCHING MID- AND HIGH CLOUDS
ERODING/MIXING OUT AS THEY MOVE WESTWARD FROM THE COASTAL LOW DUE
TO DRIER AIR IN PLACE ACROSS THE CWA...17Z MESO-ANALYSIS SHOWS AXIS
OF PWATS BELOW 0.7 INCHES ACROSS THE CENTRAL CWA. NO CONVECTION SO
FAR WITH NEAREST ACTIVITY WELL TO THE WEST OVER TN VALLEY.

PREVIOUS DISCUSSION AT 340 AM...

OVERALL TONIGHT WILL BE MILD WITH CLOUDINESS INCREASING IN THE EAST
WHILE SUBSIDENCE OVER THE WEST KEEPS SKIES WITH LESS CLOUDINESS
ALTHOUGH SOME HIGH CLOUDS ARE POSSIBLE FROM THE COASTAL SYSTEMS. THE
SHOWERS TONIGHT WILL BE INCREASING TOWARD THE PIEDMONT AS THE
NON-TROPICAL LOW THAT IS OFF THE VA COAST SHIFTS NORTHWEST INTO THE
EASTERN SHORE OF MARYLAND. SHOULD SEE AT LEAST 30 POPS ACROSS A
LYNCHBURG TO SOUTH BOSTON LINE AND EAST BY SUNRISE MONDAY...WITH
ISOLATED SHOWERS AS FAR WEST AS THE BLUE RIDGE. WITH INCREASING
MOISTURE/CLOUDS/DEWPOINTS LOWS TONIGHT WILL RANGE FROM THE UPPER 50S
IN THE EAST TO THE LOWER 50S OVER THE MTNS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 345 AM EDT SUNDAY...

SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE DURING THE LATE
MORNING ON MONDAY THANKS TO THE COMBINATION OF INCREASING DAYTIME
HEATING...AND INCREASING INSTABILITY ASSOCIATED WITH AN APPROACHING
WEAK COLD FRONT. BEST CHANCES FOR THUNDERSTORM ACTIVITY WILL BE
FOUND ACROSS THE MOUNTAINS...PARTICULARLY IN NORTH CAROLINA AND THE
MOUNTAIN EMPIRE...WHERE ONE OR TWO STORMS WILL LIKELY BECOME SEVERE
DURING THE EVENING...WITH LARGE HAIL AND LOCALLY STRONG WINDS
POSSIBLE. INSTABILITY DECREASES FURTHER TO THE EAST WHERE HIGH
PRESSURE IS MORE ESTABLISHED...AND EXPECT TO SEE ONLY ISOLATED
THUNDERSTORM ACTIVITY ACROSS THE PIEDMONT. WITH HIGH PRESSURE
WEAKENING AS THE COLD FRONT APPROACHES...AND WINDS BECOMING MORE
SOUTHERLY THROUGH THE DAY...EXPECT TO SEE AFTERNOON TEMPERATURES
CLIMB INTO THE UPPER 70S TO THE LOW 80S ACROSS THE PIEDMONT...WHILE
HIGHS ACROSS THE MOUNTAINS WILL REACH INTO THE LOW TO MID
70S...WHERE CLOUD COVER WILL BE GREATER.

THE COLD FRONT WILL MAKE ITS WAY ACROSS THE MOUNTAINS ON TUESDAY
MORNING...BEFORE PUSHING EAST OF THE BLUE RIDGE DURING THE
AFTERNOON. AND WHILE SHOWER AND THUNDERSTORM ACTIVITY WILL BE SPREAD
ALL ACROSS THE REGION ON TUESDAY...EXPECT TO SEE THE AREA OF
GREATEST INSTABILITY TRANSITION INTO THE PIEDMONT BY AFTERNOON...
AHEAD OF THE COLD FRONT. LOOK FOR SCATTERED STRONG STORMS TO DEVELOP
EAST OF THE BLUE RIDGE BY MID AFTERNOON...AGAIN WITH A FEW STORMS
BECOMING SEVERE BY EARLY EVENING. BEST CHANCES FOR STRONG STORMS
WILL BE FOUND EAST OF A DANVILLE TO LYNCHBURG LINE. BY LATE TUESDAY
NIGHT THE COLD FRONT WILL SLIDE EAST OF OUR AREA...WITH SHOWER AND
THUNDERSTORM ACTIVITY DECREASING DURING THE LATE EVENING WITH THE
LOSS OF DAYTIME HEATING.

SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL LINGER INTO
WEDNESDAY...MORE SO ACROSS THE EASTERN HALF OF THE FORECAST AREA...
AS THE COLD FRONT STALLS ACROSS THE COASTAL PLAIN. AS SUCH...DO NOT
ANTICIPATE MUCH THREAT FOR SEVERE THUNDERSTORM ACTIVITY...MAINLY JUST
HIT AND MISS VARIETY SHOWERS AND THUNDERSTORMS THAT WILL DIMINISH
QUICKLY AFTER SUNSET. HIGH PRESSURE WILL BUILD INTO THE AREA
WEDNESDAY NIGHT...AND WITH LIGHT WINDS AND DECREASED CLOUD COVER
EXPECTED...MAY HAVE A DECENT SETUP FOR WIDESPREAD FOG AFTER MIDNIGHT.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 345 AM EDT SUNDAY...

LOOKING INTO THURSDAY...THE BEST RAIN CHANCES WILL AGAIN BE FOCUSED
ACROSS THE EASTERN HALF OF THE AREA...GIVEN THE AREA OF LOW PRESSURE
AND THE STALLED COLD FRONT. BY FRIDAY...THE FRONT IS EXPECTED TO
CONTINUE EAST...AND AN AREA OF HIGH PRESSURE IS EXPECTED TO MOVE
OVER THE SPINE OF THE APPALACHIANS BEHIND THE DEPARTING LOW PRESSURE
SYSTEM. LOW LEVEL FLOW ACROSS THE AREA WILL TURN EASTERLY TO
SOUTHEASTERLY AROUND THE RIDGE AXIS...WITH THIS TRAJECTORY TAPPING
INTO ATLANTIC MOISTURE. THE RESULT WILL BE SCATTERED SHOWERS AND
STORMS PRIMARILY FOCUSED ALONG THE UPSLOPE AREAS OF THE SPINE OF THE
APPALACHIANS AND POINTS EASTWARD. CONVECTION SHOULD NOT BE TOO DEEP
AS AN UPPER RIDGE BUILDS OVER THE AREA AS WELL. THIS WILL BRING
INCREASED HEIGHTS AND HIGHER 850 MB TEMPS TO THE AREA. ANTICIPATE
MODERATING TEMPERATURES HEADING INTO THE START OF THE MEMORIAL DAY
WEEKEND.

&&

.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 140 PM EDT SUNDAY...

MID-LEVEL BKN-OVC DECK CONTINUE ADVANCING FROM EAST TO WEST IN
ASSOCIATION WITH THE SURFACE LOW CENTERED OFF THE MID-ATLANTIC COAST
THIS AFTERNOON. HAVE SEEN SOME MIXING OUT AND THINNING OF CLOUDS
AS THEY ENCOUNTER DRIER AIR OVER CENTRAL AND WESTERN VIRGINIA SO
SHOWED ONLY BROKEN MID-LEVEL CLOUDS COMING IN AT AT EASTERN TAF
SITES (DAN/LYH) BY EVENING. OVERNIGHT EXPECT SLOWLY
LOWERING/THICKENING OF CLOUDS OVER THE EASTERN HALF AS PERSISTENT
EAST TO NORTHEAST FLOW RESULTS IN INCREASING MOISTURE. KEPT FOG/BR
AND LOW STRATUS OUT OF THE WESTERN TAFS (ESP LWB) WHERE HIGHER
CLOUDS MAY IMPEDE FOG FORMATION BUT WILL HAVE TO WATCH FOR
POSSIBLE FORMATION IF IT REMAINS CLEAR. PRECIP CHANCES ALSO
INCREASE FROM EAST TO WEST BUT ONLY BROUGHT PREVAILING SHOWERS AS
FAR WEST AS LYH AND NOT UNTIL EARLY AFTERNOON MONDAY.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR LATER MONDAY INTO TUESDAY...AND
THIS IS POSSIBLE AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF
US.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/PC/WP
SHORT TERM...NF
LONG TERM...NF
AVIATION...KK/WP

000
FXUS61 KLWX 201510
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1110 AM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRES OVR NRN NEW ENGLAND CONTINUES TO NOSE DOWN THE ERN
SEABOARD THIS AFTERNOON. THE ARE TWO AREAS OF LOW PRESSURE - A
WEAK SYSTEM WELL E OF VIRGINIA BEACH AND TROPICAL STORM ALBERTO -
OFF THE SOUTH CAROLINA COAST. LOW PRESSURE WILL GRADUALLY LIFT
NORTHEASTWARD MONDAY THROUGH THE MID-ATLANTIC...AS A FRONT MOVES
IN FROM THE WEST FOR TUESDAY AND WEDNESDAY. HIGH PRESSURE SLOWLY
BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY WHILE LOW PRESSURE
RETROGRADES WESTWARD TOWARD THE NORTH CAROLINA COAST. TROPICAL
STORM ALBERTO REMAINS OFF THE SOUTH CAROLINA COAST...BUT IT WILL
NOT HAVE AN IMPACT ON OUR WEATHER.

MOISTURE WILL WRAP AROUND THE LOW OFF THE NORTH CAROLINA
COAST...CAUSING CLOUDS TO INCREASE ESPECIALLY ACROSS LOWER
SOUTHERN MARYLAND INTO CENTRAL VIRGINIA. ELSEWHERE...PLENTY OF
SUNSHINE IS EXPECTED ALONG WITH DRY CONDITIONS. MAX TEMPS WILL
RANGE FROM THE MID 70S ACROSS LOWER SOUTHERN MARYLAND WHERE MORE
CLOUD COVER IS EXPECTED...TO THE LOWER AND MIDDLE 80S ACROSS MOST
OTHER LOCATIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
FOR TNGT MDLS..ESPECIALLY THE NAM...SEEM SOMEWHAT AGGRESSIVE ON
BRINGING RAFL INTO THE RGN IN ASSO W/ THE NRN CSTL LOW (NOT
ALBERTO...WHICH IS RMNG FURTHER S). IT`S INTERESTING TO NOTE THAT
THE HRRR IS SHOWING EVEN NOW A FAIRLY DVLPD SPIRAL BANDING OF PCPN
OFF THE DELMARVA...BUT ON IR STLT IT LOOKS AS IF THERE`S BARELY
EVEN ANY CLD IN ASSO W/ IT. SREF SHOWS THE LOW APRCHG THE CST LN
THIS EVE WHILE WEAKENING ERLY ONSHORE FLOW WL ADVECT SOME MOISTURE
INTO CWA. QUSTN THEN IS HOW FAR W AND HOW MUCH? AND WL ALBERTO
TAKE ENERGY FM THE NRN LOW? I HV CUT BACK ON QPF...AND PUSHED
BACK THE TIMING ABT 6 HRS...PSBLY LGT RA REACHING DC BY 06Z.
WOULDN`T BE SURPRISED IF NO PCPN OCCURS W OF THE BLUE RDG...AND HV
CUT WRN CWA POPS TO LO CHC. BEST CHC FOR RAFL OVRNGT WL LKLY BE LWR
SRN MD.

LOWS IN THE 50S XCPT L60S IN THE CITIES/ALONG THE BAY.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
STACKED LOPRES...MOSTLY UNRELATED TO TROPICAL STORM ALBERTO...WILL CONT WWD
DRIFT INTO MID-ATLC MON. HIGH CHC/LOW LIKELY SHWRS AND ISOLATED
THUNDER FOR MON...WITH DIURNAL PEAK IN CNVCTN. MON NGT PCPN WANES AS
CLOSED LOW OPENS AND IS PULLED NEWD/ABSORBED BY APPROACHING NRN
STREAM ULVL TROF. TROF WILL BE BLOCKED BY STRONG BERMUDA RDGG AND
DRAW STATIONARY TUE...EVOLVING INTO CLOSED LOPRES CNTRD S OF RGN ON
WED. AT SFC...TROF/CDFNT WILL CROSS APLCNS TUE...INDUCING SCT/NUM
SHWRS/TSTMS.  TEMPS SHUD BE REGULATED BY XTNSV CLOUD COVER
MON...SUPPRESSING MAXIMA TO L/M70S. TUE SHUD HAVE SOME BREAKS IN
CLOUDS...ALLOWING TEMPS TO REACH AOA 80F MOST RGN...THUS THE BETTER
TSTM CHCS.  CONFIDENCE IN AFOREMENTIONED IS LOW...AS GUIDANCE IS NOT
IN AGREEMENT AND ALBERTO IS ESPECIALLY NOT WELL HANDLED BY MODELS
ATTM.

WITH M/ULVL LOPRES S/W OF RGN TUE NGT/WED...SFC TROF AXIS WILL
MEANDER THRU CWA AND GRADUALLY WASH OUT...WITH PLENTY MOISTURE IN
PLACE...CHC POPS WARRANTED.  GUIDANCE SUGGESTS THAT ANOTHER NRN
BRANCH TROF WILL BCM DOMINATE ACRS PLAINS THU/FRI...ALLOWING SWLY
FLOW TO ESTABLISH ACRS ERN CONUS. WITH THIS...BERMUDA RIDGE WOULD
BUILD INTO ERN CONUS...TRIGGERING DRIER/WARMER CONDS FOR MID-ATLC
FOR WKS END. STILL...LLVL MOISTURE WILL BE DECENT...SO ISOLATED/SCT
MAINLY DIURNAL CNVCTN CANT BE RULED OUT THRU XTDD FCST.

&&

.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDS TDA. CLDS XPCTD TO BEGIN TO LOWER TNGT...W/ CIGS DROPPING
INTO THE MVFR RANGE OVERNIGHT. IFR CIGS ARE POSSIBLE AS WELL. LGT
RAIN MAY IMPACT THE TERMINALS OVERNIGHT.

SCT/NUM SHWRS/PSBLY TSTMS WILL IMPACT TERMINALS MON THRU WED.
HIGHLY UNCERTAIN AS TO EXTENT OF PREVAILING FLIGHT
RESTRICTIONS...BUT AT LEAST PERIODS OF SUB-VFR CIGS/VBSYS APPEAR
PLAUSIBLE WITH MOIST ELY FLOW IN PLACE. POPS GRADUALLY DIMINISH FOR
SECOND HALF OF WEEK...AS HIPRES BUILDS IN.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THIS AFTERNOON...BUT LOW
PRESSURE WILL RETROGRADE INTO NORTH CAROLINA THROUGH TONIGHT. THE
PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS WILL CAUSE WIND GUSTS
AROUND 20 KNOTS ACROSS THE WATERS THIS AFTERNOON AND EARLY
EVENING. A SMALL CRAFT ADVISORY IS IN EFFECT DURING THIS TIME. THE
SMALL CRAFT ADVISORY CONTINUES THROUGH TONIGHT FOR THE MARYLAND
CHESAPEAKE BAY SOUTH OF SANDY POINT AND THE LOWER TIDAL POTOMAC
RIVER FROM COBB ISLAND TO SMITH POINT.

NELY FLOW CONTS MON/TUE. GUSTS ON MON MAY APPROACH SCA
THRESHOLD...BUT CONFIDENCE TO LOW ATTM FOR EXTENSION OF HEADLINES.
LOPRES RMNS IN VICINITY THRU MIDWK...WITH SCT/NUM SHWRS/TSTMS XPCD.
SFC TROF/CDFNT APPROACHES TUE NGT/WED...WITH HIPRES SLOWLY BUILDING
IN THEREAFTER.

&&

.TIDES/COASTAL FLOODING...
WITH PROLONGED ELY FLOW AND LWRG PRESSURE ACRS CHESAPEAKE BAY...
MINOR COASTAL FLOODING LOOKS LIKELY WITH MON MRNGS HIGH TIDE.
FAVORABLE FLOW WILL CONT MON INTO TUE...SO ADDITIONAL COASTAL
FLOODING OF SENSITIVE LOCATIONS IS POSSIBLE AGAIN DURING HIGH
TIDES THIS PERIOD.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR ANZ530-
     531-535-536-538-539.
     SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ532>534-537-
     540>543.

&&

$$
PRODUCTS...LASORSA/WOODY!/SBK

000
FXUS61 KAKQ 201415
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
1015 AM EDT SUN MAY 20 2012

.SYNOPSIS...
LOW PRESSURE OFF THE MID ATLANTIC COAST GRADUALLY DRIFTS
WESTWARD INTO MONDAY. LOW PRESSURE WILL PERSIST ACROSS THE
AREA THROUGH MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
WX CONTG TO DETERIORATE FM E TO W RIGHT NOW...AND WL KP DOING SO
THROUGH THE MIDDAY INTO THE AFTN HRS AS EXTRA-TROPICAL SFC LO PRES
E OF VA CST SLOLY MOVS W. WDSPRD LO CLDNS (CIGS FM ABT 700-2000FT)
HAS OVERSPREAD ERN PORTION OF THE FA (WHICH ARE NOT RELATED IN ANY
WAY W/ TRPCL SYS OFF SC/GA CST)...AND SPOTTY LGT RA INDCTD ON RDR
MOVG INLAND. XPCG CLDNS TO SPRD W ACRS MOST (IF NOT ALL) OF THE FA
BY THIS AFTN. SOME EROSION IN THE CLDNS PSBL OVR THE FAR WRN
FRINGE (AND KEPT THAT AREA PSNY/WRMR FOR NOW). W/ THE CLDS...AND
CONTG NNE WNDS (GUSTY TO 25-30 MPH)...TEMPS WILL BE HELD IN CHECK
FM BASICALLY I95 ON TO THE CST (GENLY A GRADIENT FM E TO W FM THE
60S TO L70S). FOR AREAS OF THE PDMNT (W OF RIC/PTB)...HI TEMPS
STILL XPCD TO REACH THE U70S.

BETTER SUPPORT FOR MORE WIDESPREAD PRECIP ARRIVES THIS EVENING...AND
WILL CARRY LIKELY POPS ACRS MUCH OF THE CWA...ESPECIALLY THE ERN
SHORE AND NRN ZONES...W/ CHC POPS ELSEWHERE. COULD EVEN SEE SOME
ELEVATED TSTMS LATER TONIGHT ALONG THE COAST BUT THINK BULK OF
THIS STAYS OFFSHORE SO WILL NOT INCLUDE ATTM. W/ CLOUDS AND HIGHER
DEW PTS IT WILL BE MILDER TONIGHT W/ LOWS MAINLY IN THE UPR 50S
WELL INLAND TO THE LWR 60S FARTHER EAST.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
FOR DETAILS ON THE TRACK FCST FOR TROPICAL SYSTEM ALBERTO SEE THE
LATEST ADSY FROM TPC/NHC. FOR AKQ CWA THE DOMINANT WX FEATURE WILL
NOT BE TROPICAL...ALTHOUGH UNSETTLED CONDITIONS CAN BE EXPECTED
UNDER THE INFLUENCE OF A CUTOFF UPPER LOW THAT EVENTUALLY GETS
ENGULFED BY A UPPER LEVEL TROUGH/SHORTWAVE MOVING SE FROM THE UPPER
MIDWEST. THIS TROUGH WILL CONTINUE TO LINGER ACRS THE MID ATLC/SE
STATES INTO TUE AND BEYOND. ON MON...WILL CARRY HIGHEST POPS ACRS
THE NORTHERN/CENTRAL AREAS (60%)...BUT EVEN IN SOUTHERN ZONES WILL
CONTINUE W/ HI CHC POPS (50%). SOME MODEST INSTABILITY BY AFTN SO
WILL CONTINUE W/ SLIGHT CHC FOR AFTN TSTMS. HIGH TEMPS RANGING FROM
THE UPR 70S S TO AROUND 70 ON THE ERN SHORE...AGAIN FAVORING A BLEND
OF GUIDANCE...A LITTLE MORE WEIGHTED TO THE COOLER MET/NAM NUMBERS
DUE TO MOSTLY CLOUDY SKIES. COULD SEE SOME LULL IN THE OVERALL
PRECIP COVERAGE MON NIGHT/EARLY TUE IN BETWEEN ALBERTO WELL OFF
THE COAST TO OUR SE AND THE APPROACHING UPR LEVEL TROUGH FROM THE
NW (ALTHOUGH KEEPING CHC POPS GOING). MILD W/ LOWS GENLY IN THE
60-65 RANGE. FOR TUE...LOW LEVEL FLOW LIKELY TURNS MORE SW BOTH AT
THE SFC AND ALOFT...WHICH MAY TEMPORARILY LEAD TO PARTIAL
CLEARING. STILL THINK MAV TEMPS ARE TOO WARM BUT EVEN SO...DO
EXPECT HIGHS TO REACH INTO THE UPR 70S NORTH TO LWR 80S
CENTRAL/SOUTH. BUMPED POPS UP TO 50% FOR THE AFTN AND EVENING HRS
ALONG/W OF I-95...A LITTLE LOWER TOWARDS THE COAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION TUESDAY NIGHT THROUGH FRIDAY...BEFORE DRIFTING SOUTHEAST
AND OFF THE SERN COAST LATE FRIDAY INTO NEXT WEEKEND. WILL
MAINTAIN CHANCE/SLIGHT CHANCE POPS OVER THE AREA THROUGH FRIDAY
GIVEN THE POSITION OF THE UPPER LOW. MODELS STARTING TO COME INTO
BETTER AGREEMENT ABOUT THE UPPER LOW DRIFTING SE OF THE AREA BY
NEXT WEEKEND WHICH WOULD LEAD TO WARMER TEMPERATURES AND DRY WX AS
AN UPPER RIDGE BUILDS OVER THE REGION. HAVE MAINTAINED SLIGHT CHC
POPS NEXT SATURDAY UNTIL CONFIDENCE INCREASES THAT THE
AFOREMENTIONED UPPER LOW ACTUALLY MOVES OFFSHORE. TEMPS WILL
CHANGE LITTLE WED/THURS WITH HIGHS IN THE UPR 70S TO LOW 80S.
WARMING INTO THE LOW/MID 80S MOST AREAS FRI/SAT...WITH UPR 80S
POSSIBLE WESTERN AREAS BY SAT.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
LOW CLOUDS HAVE ALREADY ARRIVED OVER COASTAL AREAS AND WAS DEPICTED
WELL BY STLT FOG PRODUCT. CONDITIONS HAVE LOWERED MORE QUICKLY THAN
THE MET GUIDANCE.

THIS MAY BE INTERMITTENT THIS MORNING BUT WITH TIME SHOULD BECOME
MORE CONTINUOUS IFR. TIMING OF IFR IS DIFFICULT TO PIN POINT. IFR IS
IN THE TAF DURING PORTIONS OF THE FIRST SIX HOURS AT SBY AND ECG
WITH CONDITIONS BEING REPORTED JUST TO THE EAST.

PCPN NOT DETECTED NEARBY AT 11Z BUT SHOULD DEVELOP LATE TODAY AND
TONIGHT ACROSS MOST OF THE AREA. LEFT PCPN OUT OF FCST AT RIC AS IT
WILL MOST LIKELY HOLD OFF THERE TIL DURING THE DAY MONDAY. PCPN
SHOULD BE LIGHT WITH LARGEST IMPACT DURING THE NEXT 24 HOURS IS
EXPECTED TO BE THE CEILING.

PERIODS OF LOW CEILINGS AND RAIN ARE EXPECTED THROUGH TUESDAY.
ALBERTO IS NOT EXPECTED TO HAVE A DIRECT IMPACT ON THE TAF SITES.
WEAK COLD FRONT ARRIVES ON WEDNESDAY...BUT LOOKS TO STALL OVER THE
REGION AND COULD BE A FOCUS FOR CONVECTION WEDNESDAY INTO THURSDAY.

&&

.MARINE...
AFTER A BRIEF LULL SATURDAY NIGHT/EARLY SUNDAY MORNING...NE WINDS
ARE FORECAST TO STRENGTHEN ONCE MORE TODAY WITH SOLID SCA WIND
VELOCITIES IN THE BAY AND COASTAL WATERS WITH MARGINAL SCA WINDS
OVER THE SOUND AND LOWER JAMES RIVER. AS LOW PRESSURE OFF THE COAST
MOVES TOWARD THE MID ATLANTIC STATES...WINDS WILL DIMINISH THIS
EVENING. ALL SCA END AT MIDNIGHT OR BEFORE EXCEPT OVER THE COASTAL
WATERS.

SWELLS ARE EXPECTED TO KEEP SEAS AT 5 FT OR HIGHER FOR A WHILE
LONGER AND HAVE EXTENDED SCA THROUGH LATE MONDAY. CURRENT FORECAST
HAS SEAS STAYING UP THROUGH TUESDAY. SWAN AND WAVEWATCH HAVE THE
SEAS DROPPING BELOW SCA CRITERIA BY MONDAY MORNING BUT THIS DOES NOT
SEEM REALISTIC. THE MODELS THEN HAVE THE SEAS BACK UP TO 5 FT OVER
MOST OF THE COASTAL WATERS (ESPECIALLY NORTHERN PORTIONS) BY
TUESDAY MORNING. DID A BLEND OF PREVIOUS FORECAST WAVE HEIGHTS AND
THAT OF WAVEWATCH.

AS FOR TIDES...NOT EXPECTING ANY FLOODING THRESHOLDS TO BE
MET...BUT TIDES ACRS SE VA/NE NC RUNNING ABOUT 1 FT ABOVE NORMAL
AND HAVE A MENTION OF THIS IN HWO FOR ZONES ALONG THE YORK/JAMES/LOWER
BAY AND SRN CSTL WATERS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ634.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
     ANZ630>633.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ638.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654-
     656-658.

&&

$$
SYNOPSIS...ALB/LKB
NEAR TERM...ALB/LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...LSA
MARINE...LSA

000
FXUS61 KRNK 201353
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
953 AM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN SITUATED OVER THE REGION TODAY BETWEEN TROPICAL
STORM ALBERTO OFF THE SOUTH CAROLINA/GEORGIA COAST AND ANOTHER LOW
OFF THE VIRGINIA COAST. ALBERTO IS EXPECTED TO STAY OFF THE COAST
THROUGH TUESDAY WITH A COLD FRONT MOVING INTO OUR AREA BY THEN.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT SUNDAY...

ONLY MINOR ADJUSTMENTS TO GRIDS AS WEATHER REMAINS TRANQUIL.
MAINTAINED THE TREND OF THINNING OUT THE CIRRUS DECK AS THE DAY
PROGRESSES. THESE CLOUD HAVE MAINLY COVERED THE WESTERN THIRD
OF THE FORECAST AREA THIS MORNING. STILL NO POPS IN FCST AS AIR
MASS REMAINS QUITE DRY AND NO REAL TRIGGERS FOR CONVECTION. TEMPS STILL
FORECAST TO TOP OUT NEAR SEASONAL NORMS FROM LOW 70S NW TO NEAR 80
IN THE SOUTHEAST. EXPECT LOWER CLOUDS FROM THE LOW OFF THE VA
CAPES TO STAY EAST OF THE CWA TODAY AS WELL.

PREVIOUS DISCUSSION AT 340 AM...

OVERALL TONIGHT WILL BE MILD WITH CLOUDINESS INCREASING IN THE EAST
WHILE SUBSIDENCE OVER THE WEST KEEPS SKIES WITH LESS CLOUDINESS
ALTHOUGH SOME HIGH CLOUDS ARE POSSIBLE FROM THE COASTAL SYSTEMS. THE
SHOWERS TONIGHT WILL BE INCREASING TOWARD THE PIEDMONT AS THE
NON-TROPICAL LOW THAT IS OFF THE VA COAST SHIFTS NORTHWEST INTO THE
EASTERN SHORE OF MARYLAND. SHOULD SEE AT LEAST 30 POPS ACROSS A
LYNCHBURG TO SOUTH BOSTON LINE AND EAST BY SUNRISE MONDAY...WITH
ISOLATED SHOWERS AS FAR WEST AS THE BLUE RIDGE. WITH INCREASING
MOISTURE/CLOUDS/DEWPOINTS LOWS TONIGHT WILL RANGE FROM THE UPPER 50S
IN THE EAST TO THE LOWER 50S OVER THE MTNS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 345 AM EDT SUNDAY...

SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE DURING THE LATE
MORNING ON MONDAY THANKS TO THE COMBINATION OF INCREASING DAYTIME
HEATING...AND INCREASING INSTABILITY ASSOCIATED WITH AN APPROACHING
WEAK COLD FRONT. BEST CHANCES FOR THUNDERSTORM ACTIVITY WILL BE
FOUND ACROSS THE MOUNTAINS...PARTICULARLY IN NORTH CAROLINA AND THE
MOUNTAIN EMPIRE...WHERE ONE OR TWO STORMS WILL LIKELY BECOME SEVERE
DURING THE EVENING...WITH LARGE HAIL AND LOCALLY STRONG WINDS
POSSIBLE. INSTABILITY DECREASES FURTHER TO THE EAST WHERE HIGH
PRESSURE IS MORE ESTABLISHED...AND EXPECT TO SEE ONLY ISOLATED
THUNDERSTORM ACTIVITY ACROSS THE PIEDMONT. WITH HIGH PRESSURE
WEAKENING AS THE COLD FRONT APPROACHES...AND WINDS BECOMING MORE
SOUTHERLY THROUGH THE DAY...EXPECT TO SEE AFTERNOON TEMPERATURES
CLIMB INTO THE UPPER 70S TO THE LOW 80S ACROSS THE PIEDMONT...WHILE
HIGHS ACROSS THE MOUNTAINS WILL REACH INTO THE LOW TO MID
70S...WHERE CLOUD COVER WILL BE GREATER.

THE COLD FRONT WILL MAKE ITS WAY ACROSS THE MOUNTAINS ON TUESDAY
MORNING...BEFORE PUSHING EAST OF THE BLUE RIDGE DURING THE
AFTERNOON. AND WHILE SHOWER AND THUNDERSTORM ACTIVITY WILL BE SPREAD
ALL ACROSS THE REGION ON TUESDAY...EXPECT TO SEE THE AREA OF
GREATEST INSTABILITY TRANSITION INTO THE PIEDMONT BY AFTERNOON...
AHEAD OF THE COLD FRONT. LOOK FOR SCATTERED STRONG STORMS TO DEVELOP
EAST OF THE BLUE RIDGE BY MID AFTERNOON...AGAIN WITH A FEW STORMS
BECOMING SEVERE BY EARLY EVENING. BEST CHANCES FOR STRONG STORMS
WILL BE FOUND EAST OF A DANVILLE TO LYNCHBURG LINE. BY LATE TUESDAY
NIGHT THE COLD FRONT WILL SLIDE EAST OF OUR AREA...WITH SHOWER AND
THUNDERSTORM ACTIVITY DECREASING DURING THE LATE EVENING WITH THE
LOSS OF DAYTIME HEATING.

SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL LINGER INTO
WEDNESDAY...MORE SO ACROSS THE EASTERN HALF OF THE FORECAST AREA...
AS THE COLD FRONT STALLS ACROSS THE COASTAL PLAIN. AS SUCH...DO NOT
ANTICIPATE MUCH THREAT FOR SEVERE THUNDERSTORM ACTIVITY...MAINLY JUST
HIT AND MISS VARIETY SHOWERS AND THUNDERSTORMS THAT WILL DIMINISH
QUICKLY AFTER SUNSET. HIGH PRESSURE WILL BUILD INTO THE AREA
WEDNESDAY NIGHT...AND WITH LIGHT WINDS AND DECREASED CLOUD COVER
EXPECTED...MAY HAVE A DECENT SETUP FOR WIDESPREAD FOG AFTER MIDNIGHT.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 345 AM EDT SUNDAY...

LOOKING INTO THURSDAY...THE BEST RAIN CHANCES WILL AGAIN BE FOCUSED
ACROSS THE EASTERN HALF OF THE AREA...GIVEN THE AREA OF LOW PRESSURE
AND THE STALLED COLD FRONT. BY FRIDAY...THE FRONT IS EXPECTED TO
CONTINUE EAST...AND AN AREA OF HIGH PRESSURE IS EXPECTED TO MOVE
OVER THE SPINE OF THE APPALACHIANS BEHIND THE DEPARTING LOW PRESSURE
SYSTEM. LOW LEVEL FLOW ACROSS THE AREA WILL TURN EASTERLY TO
SOUTHEASTERLY AROUND THE RIDGE AXIS...WITH THIS TRAJECTORY TAPPING
INTO ATLANTIC MOISTURE. THE RESULT WILL BE SCATTERED SHOWERS AND
STORMS PRIMARILY FOCUSED ALONG THE UPSLOPE AREAS OF THE SPINE OF THE
APPALACHIANS AND POINTS EASTWARD. CONVECTION SHOULD NOT BE TOO DEEP
AS AN UPPER RIDGE BUILDS OVER THE AREA AS WELL. THIS WILL BRING
INCREASED HEIGHTS AND HIGHER 850 MB TEMPS TO THE AREA. ANTICIPATE
MODERATING TEMPERATURES HEADING INTO THE START OF THE MEMORIAL DAY
WEEKEND.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
AS OF 725 AM EDT SUNDAY...

SOME MVFR FOG AT BCB WILL BE GONE BY 12Z...AS IT IS MAINLY GROUND
FOG. OTHERWISE...LOOK FOR VFR UNDER SOME CIRRUS/FEW AC
TODAY...WITH SCATTER CU IN THE MOUNTAINS THIS AFTERNOON. WINDS
PICK UP FROM THE EAST AND NORTHEAST AT 10 TO 15 KNOTS AT
TIMES...ESPECIALLY ACROSS DAN/LYH.

MODELS SHOWING INCREASING LOW LEVEL MOISTURE AFTER MIDNIGHT
TONIGHT ACROSS THE LYH/DAN CORRIDOR...AND WILL INTRODUCE SOME MVFR
CIGS...DESPITE MODELS SHOWING IFR OR WORSE. WILL HAVE TO SEE HOW
THIS TRANSPIRES WITH SHOWERS POSSIBLY MOVING INTO THE LYH/DAN AREA
BY 12Z MONDAY.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR MONDAY INTO TUESDAY...AND THIS IS
POSSIBLE AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF US.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/PC/WP
SHORT TERM...NF
LONG TERM...NF
AVIATION...KK/WP

000
FXUS61 KLWX 201331
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
931 AM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRES OVR NRN NEW ENGLAND CONTINUES TO NOSE DOWN THE ERN
SEABOARD THIS AFTERNOON. THE ARE TWO AREAS OF LOW PRESSURE - A
WEAK SYSTEM WELL E OF VIRGINIA BEACH AND TROPICAL STORM ALBERTO -
OFF THE SOUTH CAROLINA COAST. LOW PRESSURE WILL GRADUALLY LIFT
NORTHEASTWARD MONDAY THROUGH THE MID-ATLANTIC...AS A FRONT MOVES
IN FROM THE WEST FOR TUESDAY AND WEDNESDAY. HIGH PRESSURE SLOWLY
BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL REMAIN OVER THE REGION TODAY WHILE LOW PRESSURE
RETROGRADES WESTWARD TOWARD THE NORTH CAROLINA COAST. TROPICAL
STORM ALBERTO REMAINS OFF THE SOUTH CAROLINA COAST...BUT IT WILL
NOT HAVE AN IMPACT ON OUR WEATHER.

MOISTURE WILL WRAP AROUND THE LOW OFF THE NORTH CAROLINA
COAST...CAUSING CLOUDS TO INCREASE ESPECIALLY ACROSS LOWER
SOUTHERN MARYLAND INTO CENTRAL VIRGINIA. ELSEWHERE...PLENTY OF
SUNSHINE IS EXPECTED ALONG WITH DRY CONDITIONS. MAX TEMPS WILL
RANGE FROM THE MID 70S ACROSS LOWER SOUTHERN MARYLAND WHERE MORE
CLOUD COVER IS EXPECTED...TO THE LOWER AND MIDDLE 80S ACROSS MOST
OTHER LOCATIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
FOR TNGT MDLS..ESPECIALLY THE NAM...SEEM SOMEWHAT AGGRESSIVE ON
BRINGING RAFL INTO THE RGN IN ASSO W/ THE NRN CSTL LOW (NOT
ALBERTO...WHICH IS RMNG FURTHER S). IT`S INTERESTING TO NOTE THAT
THE HRRR IS SHOWING EVEN NOW A FAIRLY DVLPD SPIRAL BANDING OF PCPN
OFF THE DELMARVA...BUT ON IR STLT IT LOOKS AS IF THERE`S BARELY
EVEN ANY CLD IN ASSO W/ IT. SREF SHOWS THE LOW APRCHG THE CST LN
THIS EVE WHILE WEAKENING ERLY ONSHORE FLOW WL ADVECT SOME MOISTURE
INTO CWA. QUSTN THEN IS HOW FAR W AND HOW MUCH? AND WL ALBERTO
TAKE ENERGY FM THE NRN LOW? I HV CUT BACK ON QPF...AND PUSHED
BACK THE TIMING ABT 6 HRS...PSBLY LGT RA REACHING DC BY 06Z.
WOULDN`T BE SURPRISED IF NO PCPN OCCURS W OF THE BLUE RDG...AND HV
CUT WRN CWA POPS TO LO CHC. BEST CHC FOR RAFL OVRNGT WL LKLY BE LWR
SRN MD.

LOWS IN THE 50S XCPT L60S IN THE CITIES/ALONG THE BAY.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
STACKED LOPRES...MOSTLY UNRELATED TO TROPICAL STORM ALBERTO...WILL CONT WWD
DRIFT INTO MID-ATLC MON. HIGH CHC/LOW LIKELY SHWRS AND ISOLATED
THUNDER FOR MON...WITH DIURNAL PEAK IN CNVCTN. MON NGT PCPN WANES AS
CLOSED LOW OPENS AND IS PULLED NEWD/ABSORBED BY APPROACHING NRN
STREAM ULVL TROF. TROF WILL BE BLOCKED BY STRONG BERMUDA RDGG AND
DRAW STATIONARY TUE...EVOLVING INTO CLOSED LOPRES CNTRD S OF RGN ON
WED. AT SFC...TROF/CDFNT WILL CROSS APLCNS TUE...INDUCING SCT/NUM
SHWRS/TSTMS.  TEMPS SHUD BE REGULATED BY XTNSV CLOUD COVER
MON...SUPPRESSING MAXIMA TO L/M70S. TUE SHUD HAVE SOME BREAKS IN
CLOUDS...ALLOWING TEMPS TO REACH AOA 80F MOST RGN...THUS THE BETTER
TSTM CHCS.  CONFIDENCE IN AFOREMENTIONED IS LOW...AS GUIDANCE IS NOT
IN AGREEMENT AND ALBERTO IS ESPECIALLY NOT WELL HANDLED BY MODELS
ATTM.

WITH M/ULVL LOPRES S/W OF RGN TUE NGT/WED...SFC TROF AXIS WILL
MEANDER THRU CWA AND GRADUALLY WASH OUT...WITH PLENTY MOISTURE IN
PLACE...CHC POPS WARRANTED.  GUIDANCE SUGGESTS THAT ANOTHER NRN
BRANCH TROF WILL BCM DOMINATE ACRS PLAINS THU/FRI...ALLOWING SWLY
FLOW TO ESTABLISH ACRS ERN CONUS. WITH THIS...BERMUDA RIDGE WOULD
BUILD INTO ERN CONUS...TRIGGERING DRIER/WARMER CONDS FOR MID-ATLC
FOR WKS END. STILL...LLVL MOISTURE WILL BE DECENT...SO ISOLATED/SCT
MAINLY DIURNAL CNVCTN CANT BE RULED OUT THRU XTDD FCST.

&&

.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
VFR CONDS TDA. CLDS XPCTD TO BEGIN TO LOWER TNGT...W/ CIGS DROPPING
INTO THE MVFR RANGE OVERNIGHT. IFR CIGS ARE POSSIBLE AS WELL. LGT
RAIN MAY IMPACT THE TERMINALS OVERNIGHT.

SCT/NUM SHWRS/PSBLY TSTMS WILL IMPACT TERMINALS MON THRU WED.
HIGHLY UNCERTAIN AS TO EXTENT OF PREVAILING FLIGHT
RESTRICTIONS...BUT AT LEAST PERIODS OF SUB-VFR CIGS/VBSYS APPEAR
PLAUSIBLE WITH MOIST ELY FLOW IN PLACE. POPS GRADUALLY DIMINISH FOR
SECOND HALF OF WEEK...AS HIPRES BUILDS IN.

&&

.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE WATERS THIS AFTERNOON...BUT LOW
PRESSURE WILL RETROGRADE ONTO THE NORTH CAROLINA COAST INTO
TONIGHT. THE PRESSURE GRADIENT BETWEEN THESE TWO SYSTEMS WILL
CAUSE WIND GUSTS AROUND 20 KNOTS ACROSS THE MIDDLE PORTION OF THE
BAY AND LOWER TIDAL POTOMAC RIVER. A SMALL CRAFT ADVISORY IS IN
EFFECT FOR THESE AREAS THROUGH TONIGHT.

NELY FLOW CONTS MON/TUE. GUSTS ON MON MAY APPROACH SCA
THRESHOLD...BUT CONFIDENCE TO LOW ATTM FOR EXTENSION OF HEADLINES.
LOPRES RMNS IN VICINITY THRU MIDWK...WITH SCT/NUM SHWRS/TSTMS XPCD.
SFC TROF/CDFNT APPROACHES TUE NGT/WED...WITH HIPRES SLOWLY BUILDING
IN THEREAFTER.

&&

.TIDES/COASTAL FLOODING...
WITH PROLONGED ELY FLOW AND LWRG PRESSURE ACRS CHESAPEAKE BAY...
MINOR COASTAL FLOODING LOOKS LIKELY WITH MON MRNGS HIGH TIDE.
FAVORABLE FLOW WILL CONT MON INTO TUE...SO ADDITIONAL COASTAL
FLOODING OF SENSITIVE LOCATIONS IS POSSIBLE AGAIN DURING HIGH
TIDES THIS PERIOD.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ532>534-537-
     540>543.

&&

$$
PRODUCTS...LASORSA/WOODY!/SBK

000
FXUS61 KAKQ 201137
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
737 AM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRESSURE SLIDES OFF THE NEW ENGLAND COAST TODAY INTO
MONDAY...AS LOW PRESSURE OFF THE MID ATLANTIC COAST GRADUALLY
DRIFTS WESTWARD. LOW PRESSURE WILL PERSIST ACROSS THE AREA
THROUGH MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS SHOWS TROPICAL SYSTEM ALBERTO OFF THE SC/GA
COAST...WITH EXTRA-TROPICAL SFC LOW PRESSURE OFF THE VA COAST. FOR
TODAY...MAIN TREND WILL BE FOR INCREASING CLOUDINESS FROM EAST TO
WEST (DUE TO THE LOW OFF THE VA COAST/NOT ALBERTO). LOW CLOUDS
ALREADY OVERSPREADING MUCH OF THE COASTAL SECTIONS BUT PRECIP
STILL LOOKS RATHER LIMITED FOR THE NEXT SEVERAL HRS ALONG THE
COAST AND NOT UNTIL LATE AFTN/EVENING FARTHER INLAND AS DEEP
MOISTURE WILL BE LACKING DESPITE THE MORE RAPID INCREASE IN
CLOUDS/LOW LEVEL MOISTURE. HIGHS WILL BE HELD DOWN TODAY...ESPECIALLY
CLOSER TO THE COAST...FAVOR THE NAM/MET GUIDANCE FOR HIGHS
(ALTHOUGH NOT QUITE THAT COOL)...W/ HIGHS IN THE UPR 60S/AROUND 70
AT THE COAST TO AROUND 80 IN THE PIEDMONT (WHERE SUNSHINE WILL
PREVAIL UNTIL MID AFTN). BETTER SUPPORT FOR MORE WIDESPREAD PRECIP
ARRIVES THIS EVENING...AND WILL CARRY LIKELY POPS ACRS MUCH OF THE
CWA...ESPECIALLY THE ERN SHORE AND NRN ZONES...W/ CHC POPS
ELSEWHERE. COULD EVEN SEE SOME ELEVATED TSTMS LATER TONIGHT ALONG
THE COAST BUT THINK BULK OF THIS STAYS OFFSHORE SO WILL NOT
INCLUDE ATTM. W/ CLOUDS AND HIGHER DEW PTS IT WILL BE MILDER
TONIGHT W/ LOWS MAINLY IN THE UPR 50S WELL INLAND TO THE LWR 60S
FARTHER EAST.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
FOR DETAILS ON THE TRACK FCST FOR TROPICAL SYSTEM ALBERTO SEE THE
LATEST ADSY FROM TPC/NHC. FOR AKQ CWA THE DOMINANT WX FEATURE WILL
NOT BE TROPICAL...ALTHOUGH UNSETTLED CONDITIONS CAN BE EXPECTED
UNDER THE INFLUENCE OF A CUTOFF UPPER LOW THAT EVENTUALLY GETS
ENGULFED BY A UPPER LEVEL TROUGH/SHORTWAVE MOVING SE FROM THE UPPER
MIDWEST. THIS TROUGH WILL CONTINUE TO LINGER ACRS THE MID ATLC/SE
STATES INTO TUE AND BEYOND. ON MON...WILL CARRY HIGHEST POPS ACRS
THE NORTHERN/CENTRAL AREAS (60%)...BUT EVEN IN SOUTHERN ZONES WILL
CONTINUE W/ HI CHC POPS (50%). SOME MODEST INSTABILITY BY AFTN SO
WILL CONTINUE W/ SLIGHT CHC FOR AFTN TSTMS. HIGH TEMPS RANGING FROM
THE UPR 70S S TO AROUND 70 ON THE ERN SHORE...AGAIN FAVORING A BLEND
OF GUIDANCE...A LITTLE MORE WEIGHTED TO THE COOLER MET/NAM NUMBERS
DUE TO MOSTLY CLOUDY SKIES. COULD SEE SOME LULL IN THE OVERALL
PRECIP COVERAGE MON NIGHT/EARLY TUE IN BETWEEN ALBERTO WELL OFF
THE COAST TO OUR SE AND THE APPROACHING UPR LEVEL TROUGH FROM THE
NW (ALTHOUGH KEEPING CHC POPS GOING). MILD W/ LOWS GENLY IN THE
60-65 RANGE. FOR TUE...LOW LEVEL FLOW LIKELY TURNS MORE SW BOTH AT
THE SFC AND ALOFT...WHICH MAY TEMPORARILY LEAD TO PARTIAL
CLEARING. STILL THINK MAV TEMPS ARE TOO WARM BUT EVEN SO...DO
EXPECT HIGHS TO REACH INTO THE UPR 70S NORTH TO LWR 80S
CENTRAL/SOUTH. BUMPED POPS UP TO 50% FOR THE AFTN AND EVENING HRS
ALONG/W OF I-95...A LITTLE LOWER TOWARDS THE COAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION TUESDAY NIGHT THROUGH FRIDAY...BEFORE DRIFTING SOUTHEAST
AND OFF THE SERN COAST LATE FRIDAY INTO NEXT WEEKEND. WILL
MAINTAIN CHANCE/SLIGHT CHANCE POPS OVER THE AREA THROUGH FRIDAY
GIVEN THE POSITION OF THE UPPER LOW. MODELS STARTING TO COME INTO
BETTER AGREEMENT ABOUT THE UPPER LOW DRIFTING SE OF THE AREA BY
NEXT WEEKEND WHICH WOULD LEAD TO WARMER TEMPERATURES AND DRY WX AS
AN UPPER RIDGE BUILDS OVER THE REGION. HAVE MAINTAINED SLIGHT CHC
POPS NEXT SATURDAY UNTIL CONFIDENCE INCREASES THAT THE
AFOREMENTIONED UPPER LOW ACTUALLY MOVES OFFSHORE. TEMPS WILL
CHANGE LITTLE WED/THURS WITH HIGHS IN THE UPR 70S TO LOW 80S.
WARMING INTO THE LOW/MID 80S MOST AREAS FRI/SAT...WITH UPR 80S
POSSIBLE WESTERN AREAS BY SAT.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
LOW CLOUDS HAVE ALREADY ARRIVED OVER COASTAL AREAS AND WAS DEPICTED
WELL BY STLT FOG PRODUCT. CONDITIONS HAVE LOWERED MORE QUICKLY THAN
THE MET GUIDANCE.

THIS MAY BE INTERMITTENT THIS MORNING BUT WITH TIME SHOULD BECOME
MORE CONTINUOUS IFR. TIMING OF IFR IS DIFFICULT TO PIN POINT. IFR IS
IN THE TAF DURING PORTIONS OF THE FIRST SIX HOURS AT SBY AND ECG
WITH CONDITIONS BEING REPORTED JUST TO THE EAST.

PCPN NOT DETECTED NEARBY AT 11Z BUT SHOULD DEVELOP LATE TODAY AND
TONIGHT ACROSS MOST OF THE AREA. LEFT PCPN OUT OF FCST AT RIC AS IT
WILL MOST LIKELY HOLD OFF THERE TIL DURING THE DAY MONDAY. PCPN
SHOULD BE LIGHT WITH LARGEST IMPACT DURING THE NEXT 24 HOURS IS
EXPECTED TO BE THE CEILING.

PERIODS OF LOW CEILINGS AND RAIN ARE EXPECTED THROUGH TUESDAY.
ALBERTO IS NOT EXPECTED TO HAVE A DIRECT IMPACT ON THE TAF SITES.
WEAK COLD FRONT ARRIVES ON WEDNESDAY...BUT LOOKS TO STALL OVER THE
REGION AND COULD BE A FOCUS FOR CONVECTION WEDNESDAY INTO THURSDAY.

&&

.MARINE...
AFTER A BRIEF LULL SATURDAY NIGHT/EARLY SUNDAY MORNING...NE WINDS
ARE FORECAST TO STRENGTHEN ONCE MORE TODAY WITH SOLID SCA WIND
VELOCITIES IN THE BAY AND COASTAL WATERS WITH MARGINAL SCA WINDS
OVER THE SOUND AND LOWER JAMES RIVER. AS LOW PRESSURE OFF THE COAST
MOVES TOWARD THE MID ATLANTIC STATES...WINDS WILL DIMINISH THIS
EVENING. ALL SCA END AT MIDNIGHT OR BEFORE EXCEPT OVER THE COASTAL
WATERS.

SWELLS ARE EXPECTED TO KEEP SEAS AT 5 FT OR HIGHER FOR A WHILE
LONGER AND HAVE EXTENDED SCA THROUGH LATE MONDAY. CURRENT FORECAST
HAS SEAS STAYING UP THROUGH TUESDAY. SWAN AND WAVEWATCH HAVE THE
SEAS DROPPING BELOW SCA CRITERIA BY MONDAY MORNING BUT THIS DOES NOT
SEEM REALISTIC. THE MODELS THEN HAVE THE SEAS BACK UP TO 5 FT OVER
MOST OF THE COASTAL WATERS (ESPECIALLY NORTHERN PORTIONS) BY
TUESDAY MORNING. DID A BLEND OF PREVIOUS FORECAST WAVE HEIGHTS AND
THAT OF WAVEWATCH.

AS FOR TIDES...NOT EXPECTING ANY FLOODING THRESHOLDS TO BE
MET...BUT TIDES ACRS SE VA/NE NC RUNNING ABOUT 1 FT ABOVE NORMAL
AND HAVE A MENTION OF THIS IN HWO FOR ZONES ALONG THE YORK/JAMES/LOWER
BAY AND SRN CSTL WATERS.

&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ634.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
     ANZ630>633.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ638.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654-
     656-658.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...LSA
MARINE...LSA

000
FXUS61 KRNK 201134
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
734 AM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN SITUATED OVER THE REGION TODAY BETWEEN TROPICAL
STORM ALBERTO OFF THE SOUTH CAROLINA/GEORGIA COAST AND ANOTHER LOW
OFF THE VIRGINIA COAST. ALBERTO IS EXPECTED TO STAY OFF THE COAST
THROUGH TUESDAY WITH A COLD FRONT MOVING INTO OUR AREA BY THEN.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM EDT SUNDAY...

CIRRUS AROUND THE WESTERN FORECAST AREA THIS MORNING IS EXPECTED
TO BE MAINLY THINNING OUT...SO AT THE MOMENT THINK MOSTLY SUNNY
SKIES WILL PREVAIL. PATCHY FOG IN THE VALLEYS SHOULD ALSO DISPERSE SHORTLY.

PREVIOUS DISCUSSION AT 340 AM...

SURFACE HIGH WILL BE PINCHED BETWEEN TWO STORM SYSTEMS
TODAY...WITH THE HIGH MAINLY IN CONTROL OF OUR WEATHER TODAY. TS
ALBERTO OFF THE SOUTH CAROLINA/GEORGIA COAST ALONG WITH ANOTHER
SURFACE LOW EAST OF THE OUTER BANKS WILL KEEP THE COASTAL AREAS
CLOUDY WITH SHOWERS TODAY. FURTHER WEST...A FRONTAL BOUNDARY WILL
BE SITUATED FROM THE WESTERN GREAT LAKES SOUTH INTO THE LOWER
MISSOURI VALLEY AND THE SOUTHERN PLAINS. WILL HAVE TO WATCH FOR
ANY HIGHER THETA-E AIR SITUATED OVER THE TENNESSEE VALLEY
ADVECTING INTO THE CENTRAL APPALACHIANS THIS AFTERNOON...SIMILAR
TO WHAT HAPPENED SATURDAY WITH ISOLATED SHOWERS OVER SE WV. THE
THREAT REMAINS LOW...SO LEFT IT OUT OF THE FORECAST. WILL SEE
MAINLY SOME HIGH CLOUDS AT TIMES TODAY WITH SOME CU/SC DEVELOPING
ACROSS THE MOUNTAINS THIS AFTERNOON AND MORE CLOUDS ARRIVING IN
THE PIEDMONT. THE UPPER LOW OFF THE COAST MAY RETROGRADE ENOUGH TO
THE WEST TO BRING A THREAT OF SHOWERS TO THE PIEDMONT BY EARLY
EVENING. HAVE LOWERED POPS TODAY FROM PREVIOUS FORECAST...DELAYING
ONSET TIL LATE TODAY INTO TONIGHT. WITH LESS CLOUD COVER
TODAY...WILL SEE HIGHS REACH THE LOWER 80S ACROSS THE FOOTHILLS
INTO THE ROANOKE AND SOUTHERN SHENANDOAH VALLEY. WITH 70S WEST AND
FAR EAST.

OVERALL TONIGHT WILL BE MILD WITH CLOUDINESS INCREASING IN THE EAST
WHILE SUBSIDENCE OVER THE WEST KEEPS SKIES WITH LESS CLOUDINESS
ALTHOUGH SOME HIGH CLOUDS ARE POSSIBLE FROM THE COASTAL SYSTEMS. THE
SHOWERS TONIGHT WILL BE INCREASING TOWARD THE PIEDMONT AS THE
NON-TROPICAL LOW THAT IS OFF THE VA COAST SHIFTS NORTHWEST INTO THE
EASTERN SHORE OF MARYLAND. SHOULD SEE AT LEAST 30 POPS ACROSS A
LYNCHBURG TO SOUTH BOSTON LINE AND EAST BY SUNRISE MONDAY...WITH
ISOLATED SHOWERS AS FAR WEST AS THE BLUE RIDGE. WITH INCREASING
MOISTURE/CLOUDS/DEWPOINTS LOWS TONIGHT WILL RANGE FROM THE UPPER 50S
IN THE EAST TO THE LOWER 50S OVER THE MTNS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 345 AM EDT SUNDAY...

SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE DURING THE LATE
MORNING ON MONDAY THANKS TO THE COMBINATION OF INCREASING DAYTIME
HEATING...AND INCREASING INSTABILITY ASSOCIATED WITH AN APPROACHING
WEAK COLD FRONT. BEST CHANCES FOR THUNDERSTORM ACTIVITY WILL BE
FOUND ACROSS THE MOUNTAINS...PARTICULARLY IN NORTH CAROLINA AND THE
MOUNTAIN EMPIRE...WHERE ONE OR TWO STORMS WILL LIKELY BECOME SEVERE
DURING THE EVENING...WITH LARGE HAIL AND LOCALLY STRONG WINDS
POSSIBLE. INSTABILITY DECREASES FURTHER TO THE EAST WHERE HIGH
PRESSURE IS MORE ESTABLISHED...AND EXPECT TO SEE ONLY ISOLATED
THUNDERSTORM ACTIVITY ACROSS THE PIEDMONT. WITH HIGH PRESSURE
WEAKENING AS THE COLD FRONT APPROACHES...AND WINDS BECOMING MORE
SOUTHERLY THROUGH THE DAY...EXPECT TO SEE AFTERNOON TEMPERATURES
CLIMB INTO THE UPPER 70S TO THE LOW 80S ACROSS THE PIEDMONT...WHILE
HIGHS ACROSS THE MOUNTAINS WILL REACH INTO THE LOW TO MID
70S...WHERE CLOUD COVER WILL BE GREATER.

THE COLD FRONT WILL MAKE ITS WAY ACROSS THE MOUNTAINS ON TUESDAY
MORNING...BEFORE PUSHING EAST OF THE BLUE RIDGE DURING THE
AFTERNOON. AND WHILE SHOWER AND THUNDERSTORM ACTIVITY WILL BE SPREAD
ALL ACROSS THE REGION ON TUESDAY...EXPECT TO SEE THE AREA OF
GREATEST INSTABILITY TRANSITION INTO THE PIEDMONT BY AFTERNOON...
AHEAD OF THE COLD FRONT. LOOK FOR SCATTERED STRONG STORMS TO DEVELOP
EAST OF THE BLUE RIDGE BY MID AFTERNOON...AGAIN WITH A FEW STORMS
BECOMING SEVERE BY EARLY EVENING. BEST CHANCES FOR STRONG STORMS
WILL BE FOUND EAST OF A DANVILLE TO LYNCHBURG LINE. BY LATE TUESDAY
NIGHT THE COLD FRONT WILL SLIDE EAST OF OUR AREA...WITH SHOWER AND
THUNDERSTORM ACTIVITY DECREASING DURING THE LATE EVENING WITH THE
LOSS OF DAYTIME HEATING.

SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL LINGER INTO
WEDNESDAY...MORE SO ACROSS THE EASTERN HALF OF THE FORECAST AREA...
AS THE COLD FRONT STALLS ACROSS THE COASTAL PLAIN. AS SUCH...DO NOT
ANTICIPATE MUCH THREAT FOR SEVERE THUNDERSTORM ACTIVITY...MAINLY JUST
HIT AND MISS VARIETY SHOWERS AND THUNDERSTORMS THAT WILL DIMINISH
QUICKLY AFTER SUNSET. HIGH PRESSURE WILL BUILD INTO THE AREA
WEDNESDAY NIGHT...AND WITH LIGHT WINDS AND DECREASED CLOUD COVER
EXPECTED...MAY HAVE A DECENT SETUP FOR WIDESPREAD FOG AFTER MIDNIGHT.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 345 AM EDT SUNDAY...

LOOKING INTO THURSDAY...THE BEST RAIN CHANCES WILL AGAIN BE FOCUSED
ACROSS THE EASTERN HALF OF THE AREA...GIVEN THE AREA OF LOW PRESSURE
AND THE STALLED COLD FRONT. BY FRIDAY...THE FRONT IS EXPECTED TO
CONTINUE EAST...AND AN AREA OF HIGH PRESSURE IS EXPECTED TO MOVE
OVER THE SPINE OF THE APPALACHIANS BEHIND THE DEPARTING LOW PRESSURE
SYSTEM. LOW LEVEL FLOW ACROSS THE AREA WILL TURN EASTERLY TO
SOUTHEASTERLY AROUND THE RIDGE AXIS...WITH THIS TRAJECTORY TAPPING
INTO ATLANTIC MOISTURE. THE RESULT WILL BE SCATTERED SHOWERS AND
STORMS PRIMARILY FOCUSED ALONG THE UPSLOPE AREAS OF THE SPINE OF THE
APPALACHIANS AND POINTS EASTWARD. CONVECTION SHOULD NOT BE TOO DEEP
AS AN UPPER RIDGE BUILDS OVER THE AREA AS WELL. THIS WILL BRING
INCREASED HEIGHTS AND HIGHER 850 MB TEMPS TO THE AREA. ANTICIPATE
MODERATING TEMPERATURES HEADING INTO THE START OF THE MEMORIAL DAY
WEEKEND.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 725 AM EDT SUNDAY...

SOME MVFR FOG AT BCB WILL BE GONE BY 12Z...AS IT IS MAINLY GROUND
FOG. OTHERWISE...LOOK FOR VFR UNDER SOME CIRRUS/FEW AC
TODAY...WITH SCATTER CU IN THE MOUNTAINS THIS AFTERNOON. WINDS
PICK UP FROM THE EAST AND NORTHEAST AT 10 TO 15 KNOTS AT
TIMES...ESPECIALLY ACROSS DAN/LYH.

MODELS SHOWING INCREASING LOW LEVEL MOISTURE AFTER MIDNIGHT
TONIGHT ACROSS THE LYH/DAN CORRIDOR...AND WILL INTRODUCE SOME MVFR
CIGS...DESPITE MODELS SHOWING IFR OR WORSE. WILL HAVE TO SEE HOW
THIS TRANSPIRES WITH SHOWERS POSSIBLY MOVING INTO THE LYH/DAN AREA
BY 12Z MONDAY.

DEPENDING ON THE COASTAL SYSTEM...THERE COULD BE A PERIOD OF SUB
VFR WEATHER INTO TUESDAY...WITH ANOTHER FRONT MOVING IN FROM THE
WEST. AT THE MOMENT CONFIDENCE IS SOMEWHAT HIGH THAT SUB VFR CIGS
WILL OCCUR ACROSS THE REGION FOR MONDAY INTO TUESDAY...AND THIS IS
POSSIBLE AS WELL ON WEDNESDAY AS THE FRONT MOVES EAST OF US.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/WP
SHORT TERM...NF
LONG TERM...NF
AVIATION...KK/WP

000
FXUS61 KAKQ 200819
AFDAKQ

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE WAKEFIELD VA
419 AM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRESSURE REMAINS ANCHORED OVER THE NORTHEAST STATES TODAY AND
MONDAY SLIDES OFF THE NEW ENGLAND COAST BY EARLY MONDAY.
MEANWHILE...LOW PRESSURE SITTING OFF THE MID ATLANTIC COAST GRADUALLY
DRIFT WESTWARD TODAY INTO MONDAY. THE SYSTEM IS EXPECTED TO THEN
LINGER OVER THE AREA THROUGH MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
LATEST WX ANALYSIS SHOWS TROPICAL SYSTEM ALBERTO OFF THE SC/GA
COAST...WITH EXTRA-TROPICAL SFC LOW PRESSURE OFF THE VA COAST. FOR
TODAY...MAIN TREND WILL BE FOR INCREASING CLOUDINESS FROM EAST TO
WEST (ALREADY BECMG MOSTLY CLOUDY ALONG THE IMMEDIATE COAST).
PRECIP MAY BE RATHER LIMITED UNTIL LATE MRNG ALONG THE COAST AND
NOT UNTIL LATE AFTN/EVENING W OF I-95 AS DEEP MOISTURE WILL BE
LACKING DESPITE THE MORE RAPID INCREASE IN CLOUDS/LOW LEVEL
MOISTURE. HIGHS WILL BE HELD DOWN TODAY...ESPECIALLY CLOSER TO THE
COAST...FAVOR THE NAM/MET GUIDANCE FOR HIGHS (ALTHOUGH NOT QUITE
THAT COOL)...W/ HIGHS AROUND 70 AT THE COAST TO AROUND 80 IN THE
PIEDMONT. BETTER SUPPORT FOR MORE WIDESPREAD PRECIP ARRIVES THIS
EVENING...AND WILL CARY LIKELY POPS ACRS MUCH OF THE ERN SHORE AND
NRN ZONES...W/ CHC POPS ELSEWHERE. COULD EVEN SEE SOME ELEVATED
TSTMS LATER TONIGHT ALONG THE COAST BUT WILL NOT INCLUDE ATTM.
MILDER TONIGHT W/ LOWS MAINLY IN THE UPR 50S WELL INLAND TO THE
LWR 60S FARTHER EAST.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
FOR DETAILS ON THE TRACK FCST FOR TROPICAL SYSTEM ALBERTO SEE THE
LATEST ADSY FROM TPC/NHC. FOR AKQ CWA THE DOMINANT WX FEATURE WILL
NOT BE TROPICAL...ALTHOUGH UNSETTLED CONDITIONS CAN BE EXPECTED
UNDER THE INFLUENCE OF A CUTOFF UPPER LOW THAT EVENTUALLY GETS
ENGULFED BY A UPPER LEVEL TROUGH/SHORTWAVE MOVING SE FROM THE UPPER
MIDWEST. THIS TROUGH WILL CONTINUE TO LINGER ACRS THE MID ATLC/SE
STATES INTO TUE AND BEYOND. ON MON...WILL CARRY HIGHEST POPS ACRS
THE NORTHERN/CENTRAL AREAS (60%)...BUT EVEN IN SOUTHERN ZONES WILL
CONTINUE W/ HI CHC POPS (50%). SOME MODEST INSTABILITY BY AFTN SO
WILL CONTINUE W/ SLIGHT CHC FOR AFTN TSTMS. HIGH TEMPS RANGING FROM
THE UPR 70S S TO AROUND 70 ON THE ERN SHORE...AGAIN FAVORING A BLEND
OF GUIDANCE...A LITTLE MORE WEIGHTED TO THE COOLER MET/NAM NUMBERS
DUE TO MOSTLY CLOUDY SKIES. COULD SEE SOME LULL IN THE OVERALL
PRECIP COVERAGE MON NIGHT/EARLY TUE IN BETWEEN ALBERTO WELL OFF
THE COAST TO OUR SE AND THE APPROACHING UPR LEVEL TROUGH FROM THE
NW (ALTHOUGH KEEPING CHC POPS GOING). MILD W/ LOWS GENLY IN THE
60-65 RANGE. FOR TUE...LOW LEVEL FLOW LIKELY TURNS MORE SW BOTH AT
THE SFC AND ALOFT...WHICH MAY TEMPORARILY LEAD TO PARTIAL
CLEARING. STILL THINK MAV TEMPS ARE TOO WARM BUT EVEN SO...DO
EXPECT HIGHS TO REACH INTO THE UPR 70S NORTH TO LWR 80S
CENTRAL/SOUTH. BUMPED POPS UP TO 50% FOR THE AFTN AND EVENING HRS
ALONG/W OF I-95...A LITTLE LOWER TOWARDS THE COAST.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AN UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO IMPACT THE
REGION TUESDAY NIGHT THROUGH FRIDAY...BEFORE DRIFTING SOUTHEAST
AND OFF THE SERN COAST LATE FRIDAY INTO NEXT WEEKEND. WILL
MAINTAIN CHANCE/SLIGHT CHANCE POPS OVER THE AREA THROUGH FRIDAY
GIVEN THE POSITION OF THE UPPER LOW. MODELS STARTING TO COME INTO
BETTER AGREEMENT ABOUT THE UPPER LOW DRIFTING SE OF THE AREA BY
NEXT WEEKEND WHICH WOULD LEAD TO WARMER TEMPERATURES AND DRY WX AS
AN UPPER RIDGE BUILDS OVER THE REGION. HAVE MAINTAINED SLIGHT CHC
POPS NEXT SATURDAY UNTIL CONFIDENCE INCREASES THAT THE
AFOREMENTIONED UPPER LOW ACTUALLY MOVES OFFSHORE. TEMPS WILL
CHANGE LITTLE WED/THURS WITH HIGHS IN THE UPR 70S TO LOW 80S.
WARMING INTO THE LOW/MID 80S MOST AREAS FRI/SAT...WITH UPR 80S
POSSIBLE WESTERN AREAS BY SAT.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SFC LOW PRESSURE...ENTRAINED IN A BROAD UPPER LEVEL LOW PRESSURE
SYSTEM...CONTINUES TO SPIN OFF THE MID ATLANTIC COAST. NAM AND GFS
BOTH SHOW THAT THIS LOW WILL SLOWLY RETROGRADE AND SLIDE OVER THE
COASTAL AREAS SUNDAY. LOW LEVEL MOISTURE WILL INCREASE ON NE TO E
FLOW AND LOWERED CEILINGS A BIT EARLIER THAN PREVIOUS FORECAST.
RUC/NAM BOTH SHOW NEAR SATURATED CONDITIONS AS LOW AS 975 MB
DEVELOPING OVER EASTERN AREAS IN THE MORNING. CONFIDENCE IN THE
TIMING OF THE LOWER CONDITIONS IS NOT HIGH. WENT CLOSE TO THE FASTER
NAM MOS GUIDANCE BUT FOR NOW DID NOT INCLUDE IFR AT RIC. TIMING OF
PCPN IS UNCERTAIN AS WELL BUT IS EXPECTED TO BE LIGHT.  THE LARGEST
IMPACT DURING THE NEXT 24 HOURS IS EXPECTED TO BE THE CEILING.

FROM MONDAY THROUGH THURSDAY...MOISTURE WITH THE ONSHORE FLOW AND
UPPER LOW CONTINUES TO LINGER INTO TUESDAY. ALBERTO IS NOT EXPECTED
TO HAVE AN IMPACT ON THE TAF SITES. WEAK COLD FRONT ARRIVES ON
WEDNESDAY...BUT LOOKS TO STALL OVER THE REGION AND COULD BE A FOCUS
FOR CONVECTION WEDNESDAY INTO THURSDAY.

&&

.MARINE...
AFTER A BRIEF LULL SATURDAY NIGHT/EARLY SUNDAY MORNING...NE WINDS
ARE FORECAST TO STRENGTHEN ONCE MORE TODAY WITH SOLID SCA WIND
VELOCITIES IN THE BAY AND COASTAL WATERS WITH MARGINAL SCA WINDS
OVER THE SOUND AND LOWER JAMES RIVER. AS LOW PRESSURE OFF THE COAST
MOVES TOWARD THE MID ATLANTIC STATES...WINDS WILL DIMINISH THIS
EVENING. ALL SCA END AT MIDNIGHT OR BEFORE EXCEPT OVER THE COASTAL
WATERS.

SWELLS ARE EXPECTED TO KEEP SEAS AT 5 FT OR HIGHER FOR A WHILE
LONGER AND HAVE EXTENDED SCA THROUGH LATE MONDAY. CURRENT FORECAST
HAS SEAS STAYING UP THROUGH TUESDAY. SWAN AND WAVEWATCH HAVE THE
SEAS DROPPING BELOW SCA CRITERIA BY MONDAY MORNING BUT THIS DOES NOT
SEEM REALISTIC. THE MODELS THEN HAVE THE SEAS BACK UP TO 5 FT OVER
MOST OF THE COASTAL WATERS (ESPECIALLY NORTHERN PORTIONS) BY
TUESDAY MORNING. DID A BLEND OF PREVIOUS FORECAST WAVE HEIGHTS AND
THAT OF WAVEWATCH.


&&

.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ634.
     SMALL CRAFT ADVISORY UNTIL 10 PM EDT THIS EVENING FOR
     ANZ630>633.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ638.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ650-652-654-
     656-658.

&&

$$
SYNOPSIS...LKB
NEAR TERM...LKB
SHORT TERM...LKB
LONG TERM...JDM
AVIATION...LSA
MARINE...LSA

000
FXUS61 KRNK 200800
AFDRNK

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BLACKSBURG VA
400 AM EDT SUN MAY 20 2012

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN SITUATED OVER THE REGION TODAY BETWEEN TROPICAL
STORM ALBERTO OFF THE SOUTH CAROLINA/GEORGIA COAST AND ANOTHER LOW
OFF THE VIRGINIA COAST. ALBERTO IS EXPECTED TO STAY OFF THE COAST
THROUGH TUESDAY WITH A COLD FRONT MOVING INTO OUR AREA BY THEN.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM EDT SUNDAY...

SURFACE HIGH WILL BE PINCHED BETWEEN TWO STORM SYSTEMS TODAY...WITH
THE HIGH MAINLY IN CONTROL OF OUR WEATHER TODAY. TS ALBERTO OFF THE
SOUTH CAROLINA/GEORGIA COAST ALONG WITH ANOTHER SURFACE LOW EAST OF
THE OUTER BANKS WILL KEEP THE COASTAL AREAS CLOUDY WITH SHOWERS
TODAY. FURTHER WEST...A FRONTAL BOUNDARY WILL BE SITUATED FROM THE
WESTERN GREAT LAKES SOUTH INTO THE LOWER MISSOURI VALLEY AND THE
SOUTHERN PLAINS. WILL HAVE TO WATCH FOR ANY HIGHER THETA-E AIR
SITUATED OVER THE TENNESSEE VALLEY ADVECTING INTO THE CENTRAL
APPALACHIANS THIS AFTERNOON...SIMILAR TO WHAT HAPPENED SATURDAY WITH
ISOLATED SHOWERS OVER SE WV. THE THREAT REMAINS LOW...SO LEFT IT OUT
OF THE FORECAST. WILL SEE MAINLY SOME HIGH CLOUDS AT TIMES TODAY
WITH SOME CU/SC DEVELOPING ACROSS THE MOUNTAINS THIS AFTERNOON AND
MORE CLOUDS ARRIVING IN THE PIEDMONT. THE UPPER LOW OFF THE COAST
MAY RETROGRADE ENOUGH TO THE WEST TO BRING A THREAT OF SHOWERS TO
THE PIEDMONT BY EARLY EVENING. HAVE LOWERED POPS TODAY FROM PREVIOUS
FORECAST...DELAYING ONSET TIL LATE TODAY INTO TONIGHT. WITH LESS
CLOUD COVER TODAY...WILL SEE HIGHS REACH THE LOWER 80S ACROSS THE
FOOTHILLS INTO THE ROANOKE AND SOUTHERN SHENANDOAH VALLEY. WITH 70S
WEST AND FAR EAST.

OVERALL TONIGHT WILL BE MILD WITH CLOUDINESS INCREASING IN THE EAST
WHILE SUBSIDENCE OVER THE WEST KEEPS SKIES WITH LESS CLOUDINESS
ALTHOUGH SOME HIGH CLOUDS ARE POSSIBLE FROM THE COASTAL SYSTEMS. THE
SHOWERS TONIGHT WILL BE INCREASING TOWARD THE PIEDMONT AS THE
NON-TROPICAL LOW THAT IS OFF THE VA COAST SHIFTS NORTHWEST INTO THE
EASTERN SHORE OF MARYLAND. SHOULD SEE AT LEAST 30 POPS ACROSS A
LYNCHBURG TO SOUTH BOSTON LINE AND EAST BY SUNRISE MONDAY...WITH
ISOLATED SHOWERS AS FAR WEST AS THE BLUE RIDGE. WITH INCREASING
MOISTURE/CLOUDS/DEWPOINTS LOWS TONIGHT WILL RANGE FROM THE UPPER 50S
IN THE EAST TO THE LOWER 50S OVER THE MTNS.

&&

.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 345 AM EDT SUNDAY...

SHOWER AND THUNDERSTORM ACTIVITY WILL INCREASE DURING THE LATE
MORNING ON MONDAY THANKS TO THE COMBINATION OF INCREASING DAYTIME
HEATING...AND INCREASING INSTABILITY ASSOCIATED WITH AN APPROACHING
WEAK COLD FRONT. BEST CHANCES FOR THUNDERSTORM ACTIVITY WILL BE
FOUND ACROSS THE MOUNTAINS...PARTICULARLY IN NORTH CAROLINA AND THE
MOUNTAIN EMPIRE...WHERE ONE OR TWO STORMS WILL LIKELY BECOME SEVERE
DURING THE EVENING...WITH LARGE HAIL AND LOCALLY STRONG WINDS
POSSIBLE. INSTABILITY DECREASES FURTHER TO THE EAST WHERE HIGH
PRESSURE IS MORE ESTABLISHED...AND EXPECT TO SEE ONLY ISOLATED
THUNDERSTORM ACTIVITY ACROSS THE PIEDMONT. WITH HIGH PRESSURE
WEAKENING AS THE COLD FRONT APPROACHES...AND WINDS BECOMING MORE
SOUTHERLY THROUGH THE DAY...EXPECT TO SEE AFTERNOON TEMPERATURES
CLIMB INTO THE UPPER 70S TO THE LOW 80S ACROSS THE PIEDMONT...WHILE
HIGHS ACROSS THE MOUNTAINS WILL REACH INTO THE LOW TO MID
70S...WHERE CLOUD COVER WILL BE GREATER.

THE COLD FRONT WILL MAKE ITS WAY ACROSS THE MOUNTAINS ON TUESDAY
MORNING...BEFORE PUSHING EAST OF THE BLUE RIDGE DURING THE
AFTERNOON. AND WHILE SHOWER AND THUNDERSTORM ACTIVITY WILL BE SPREAD
ALL ACROSS THE REGION ON TUESDAY...EXPECT TO SEE THE AREA OF
GREATEST INSTABILITY TRANSITION INTO THE PIEDMONT BY AFTERNOON...
AHEAD OF THE COLD FRONT. LOOK FOR SCATTERED STRONG STORMS TO DEVELOP
EAST OF THE BLUE RIDGE BY MID AFTERNOON...AGAIN WITH A FEW STORMS
BECOMING SEVERE BY EARLY EVENING. BEST CHANCES FOR STRONG STORMS
WILL BE FOUND EAST OF A DANVILLE TO LYNCHBURG LINE. BY LATE TUESDAY
NIGHT THE COLD FRONT WILL SLIDE EAST OF OUR AREA...WITH SHOWER AND
THUNDERSTORM ACTIVITY DECREASING DURING THE LATE EVENING WITH THE
LOSS OF DAYTIME HEATING.

SHOWER AND ISOLATED THUNDERSTORM ACTIVITY WILL LINGER INTO
WEDNESDAY...MORE SO ACROSS THE EASTERN HALF OF THE FORECAST AREA...
AS THE COLD FRONT STALLS ACROSS THE COASTAL PLAIN. AS SUCH...DO NOT
ANTICIPATE MUCH THREAT FOR SEVERE THUNDERSTORM ACTIVITY...MAINLY JUST
HIT AND MISS VARIETY SHOWERS AND THUNDERSTORMS THAT WILL DIMINISH
QUICKLY AFTER SUNSET. HIGH PRESSURE WILL BUILD INTO THE AREA
WEDNESDAY NIGHT...AND WITH LIGHT WINDS AND DECREASED CLOUD COVER
EXPECTED...MAY HAVE A DECENT SETUP FOR WIDESPREAD FOG AFTER MIDNIGHT.

&&

.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 345 AM EDT SUNDAY...

LOOKING INTO THURSDAY...THE BEST RAIN CHANCES WILL AGAIN BE FOCUSED
ACROSS THE EASTERN HALF OF THE AREA...GIVEN THE AREA OF LOW PRESSURE
AND THE STALLED COLD FRONT. BY FRIDAY...THE FRONT IS EXPECTED TO
CONTINUE EAST...AND AN AREA OF HIGH PRESSURE IS EXPECTED TO MOVE
OVER THE SPINE OF THE APPALACHIANS BEHIND THE DEPARTING LOW PRESSURE
SYSTEM. LOW LEVEL FLOW ACROSS THE AREA WILL TURN EASTERLY TO
SOUTHEASTERLY AROUND THE RIDGE AXIS...WITH THIS TRAJECTORY TAPPING
INTO ATLANTIC MOISTURE. THE RESULT WILL BE SCATTERED SHOWERS AND
STORMS PRIMARILY FOCUSED ALONG THE UPSLOPE AREAS OF THE SPINE OF THE
APPALACHIANS AND POINTS EASTWARD. CONVECTION SHOULD NOT BE TOO DEEP
AS AN UPPER RIDGE BUILDS OVER THE AREA AS WELL. THIS WILL BRING
INCREASED HEIGHTS AND HIGHER 850 MB TEMPS TO THE AREA. ANTICIPATE
MODERATING TEMPERATURES HEADING INTO THE START OF THE MEMORIAL DAY
WEEKEND.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
AS OF 125 AM EDT SUNDAY...

VFR CONDITIONS WILL PREVAIL THIS PERIOD...ALTHOUGH SOME MVFR FOG
AT LWB/BCB POSSIBLE THIS MORNING BEFORE OR AT DAWN.

NORTHEAST WINDS SHOULD INCREASE THIS AFTERNOON WITH SOME GUSTS TO
20 KNOTS IN DANVILLE.

FLIGHT CONDITIONS DETERIORATE BEYOND 24 HOURS AS CLOUDS/POPS
INCREASE IN ASSOCIATION WITH THE COASTAL LOW AND SLOWLY
APPROACHING FRONT FROM THE WEST. MVFR CONVECTION IS POSSIBLE
SUNDAY NIGHT INTO MONDAY. BRIEF IFR POSSIBLE IN THUNDERSTORMS
MONDAY AFTERNOON INTO MIDWEEK.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...WP
NEAR TERM...AMS/WP
SHORT TERM...NF
LONG TERM...NF
AVIATION...KK/WP

000
FXUS61 KLWX 200729
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
329 AM EDT SUN MAY 20 2012

.SYNOPSIS...

HIGH PRES OVR NRN NEW ENGLAND CONTINUES TO NOSE DOWN THE ERN
SEABOARD TDA. THE ARE TWO AREAS OF LOW PRESSURE - A WEAK SYSTEM
WELL E OF VIRGINIA BEACH AND TROPICAL STORM ALBERTO - OFF THE
SOUTH CAROLINA COAST. LOW PRESSURE WILL GRADUALLY LIFT
NORTHEASTWARD MONDAY THROUGH THE MID-ATLANTIC...AS A FRONT MOVES
IN FROM THE WEST FOR TUESDAY AND WEDNESDAY. HIGH PRESSURE SLOWLY
BUILDS IN FOR THE END OF THE WEEK.

&&

.NEAR TERM /TODAY/...

WX SURE HAS BEEN NICE FOR THE PAST SVRL DAYS...40S DWPTS HV MADE
THINGS VERY COMFORTABLE. TDA SHOULD BE ANOTHER FINE DAY OF
WX...ALTHO DWPTS HV CREPT BACK INTO THE 50S. HIGH PRES WHICH HAS
BEEN RESPONSIBLE FOR THIS HAS DONE A SLOW CRAWL OVR THE PAST 48
HRS FM NY STATE TO CT AND NOW TO NRN NH. TDA A WK AREA OF LOW
PRES HAS FORMED E OF ORF...AND IN A REAL RARITY TS ALBERTO HAS
DVLPD OFF THE S CAROLINA CST. FOR TDA ALL THESE SHOULD DO FOR MID
ATLC IS CONT TO PRODUCE CI. YDA TEMPS REACHED LM80S ACROSS MUCH OF
THE AREA. LK LAST NGT WE`LL BE BEGINNING THE DAY FM A HIGHER TEMP
STARTING PT THAN DURG THE LAST DAYS OF THE WORKWEEK...SO WE CAN
XPCT TO SEE LM80S AGN THIS AFTN.

&&

.SHORT TERM /TONIGHT/...

FOR TNGT MDLS..ESPECIALLY THE NAM...SEEM SOMEWHAT AGGRESSIVE ON
BRINGING RAFL INTO THE RGN IN ASSO W/ THE NRN CSTL LOW (NOT
ALBERTO...WHICH IS RMNG FURTHER S). IT`S INTERESTING TO NOTE THAT
THE HRRR IS SHOWING EVEN NOW A FAIRLY DVLPD SPIRAL BANDING OF PCPN
OFF THE DELMARVA...BUT ON IR STLT IT LOOKS AS IF THERE`S BARELY
EVEN ANY CLD IN ASSO W/ IT. SREF SHOWS THE LOW APRCHG THE CST LN
THIS EVE WHILE WEAKENING ERLY ONSHORE FLOW WL ADVECT SOME MOISTURE
INTO CWA. QUSTN THEN IS HOW FAR W AND HOW MUCH? AND WL ALBERTO
TAKE ENERGY FM THE NRN LOW? I HV CUT BACK ON QPF...AND PUSHED
BACK THE TIMING ABT 6 HRS...PSBLY LGT RA REACHING DC BY 06Z.
WOULDN`T BE SURPRISED IF NO PCPN OCCURS W OF THE BLUE RDG...AND HV
CUT WRN CWA POPS TO LO CHC. BEST CHC FOR RAFL OVRNGT WL LKLY BE LWR
SRN MD.

LOWS IN THE 50S XCPT L60S IN THE CITIES/ALONG THE BAY.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...

STACKED LOPRES...MOSTLY UNRELATED TO TROPICAL STORM ALBERTO...WILL CONT WWD
DRIFT INTO MID-ATLC MON. HIGH CHC/LOW LIKELY SHWRS AND ISOLATED
THUNDER FOR MON...WITH DIURNAL PEAK IN CNVCTN. MON NGT PCPN WANES AS
CLOSED LOW OPENS AND IS PULLED NEWD/ABSORBED BY APPROACHING NRN
STREAM ULVL TROF. TROF WILL BE BLOCKED BY STRONG BERMUDA RDGG AND
DRAW STATIONARY TUE...EVOLVING INTO CLOSED LOPRES CNTRD S OF RGN ON
WED. AT SFC...TROF/CDFNT WILL CROSS APLCNS TUE...INDUCING SCT/NUM
SHWRS/TSTMS.  TEMPS SHUD BE REGULATED BY XTNSV CLOUD COVER
MON...SUPPRESSING MAXIMA TO L/M70S. TUE SHUD HAVE SOME BREAKS IN
CLOUDS...ALLOWING TEMPS TO REACH AOA 80F MOST RGN...THUS THE BETTER
TSTM CHCS.  CONFIDENCE IN AFOREMENTIONED IS LOW...AS GUIDANCE IS NOT
IN AGREEMENT AND ALBERTO IS ESPECIALLY NOT WELL HANDLED BY MODELS
ATTM.

WITH M/ULVL LOPRES S/W OF RGN TUE NGT/WED...SFC TROF AXIS WILL
MEANDER THRU CWA AND GRADUALLY WASH OUT...WITH PLENTY MOISTURE IN
PLACE...CHC POPS WARRANTED.  GUIDANCE SUGGESTS THAT ANOTHER NRN
BRANCH TROF WILL BCM DOMINATE ACRS PLAINS THU/FRI...ALLOWING SWLY
FLOW TO ESTABLISH ACRS ERN CONUS. WITH THIS...BERMUDA RIDGE WOULD
BUILD INTO ERN CONUS...TRIGGERING DRIER/WARMER CONDS FOR MID-ATLC
FOR WKS END. STILL...LLVL MOISTURE WILL BE DECENT...SO ISOLATED/SCT
MAINLY DIURNAL CNVCTN CANT BE RULED OUT THRU XTDD FCST.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...

VFR CONDS TDA. CLDS XPCTD TO BEGIN TO LOWER TNGT...W/ CIGS PSBLY
DROPPING INTO THE MVFR RANGE LATE THIS EVE. LGT RA PSBL OVRNGT BUT
NOT XPCTD TO CAUSE A REDUCTION TO VSBY.

SCT/NUM SHWRS/PSBLY TSTMS WILL IMPACT TERMINALS MON THRU WED.
HIGHLY UNCERTAIN AS TO EXTENT OF PREVAILING FLIGHT
RESTRICTIONS...BUT AT LEAST PERIODS OF SUB-VFR CIGS/VBSYS APPEAR
PLAUSIBLE WITH MOIST ELY FLOW IN PLACE. POPS GRADUALLY DIMINISH FOR
SECOND HALF OF WEEK...AS HIPRES BUILDS IN.

&&

.MARINE...

WINDS HV BEEN BLO SCA LVLS IN EVEN OUR LWR PTMC/BAY..SO HV PUSHED
THE START TIME OF THE SCA TO 8 AM. AS OFFSHORE LOW MOVES CLOSER TO
THE CST XPCT TO SEE MORE 20 KT NRLY GUSTS TDA FM S CHES BAY OF
SANDY PT AND TDL PTMC E OF COBB ISLAND.

NELY FLOW CONTS MON/TUE. GUSTS ON MON MAY APPROACH SCA
THRESHOLD...BUT CONFIDENCE TO LOW ATTM FOR EXTENSION OF HEADLINES.
LOPRES RMNS IN VICINITY THRU MIDWK...WITH SCT/NUM SHWRS/TSTMS XPCD.
SFC TROF/CDFNT APPROACHES TUE NGT/WED...WITH HIPRES SLOWLY BUILDING
IN THEREAFTER.

&&

.TIDES/COASTAL FLOODING...

WITH PROLONGED ELY FLOW AND LWRG PRESSURE ACRS CHESAPEAKE BAY...
MINOR COASTAL FLOODING LOOKS LIKELY WITH MON MRNGS HIGH TIDE.
FAVORABLE FLOW WILL CONT MON INTO TUE...SO ADDITIONAL COASTAL
FLOODING OF SENSITIVE LOCATIONS IS POSSIBLE AGAIN DURING HIGH
TIDES THIS PERIOD.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 6 AM EDT MONDAY
     FOR ANZ532>534-537-540>543.

&&

$$
PRODUCTS...WOODY!/SBK