000
FXUS61 KLWX 221405
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1005 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE PERSISTING OVER THE ATLANTIC WITH WARM AND HUMID
CONDITIONS UNTIL A COLD FRONT THURSDAY NIGHT. AN UPPER TROUGH
WILL LINGER OVER THE AREA FRIDAY WITH HIGH PRESSURE BUILDING
THROUGH SATURDAY. A FRONTAL BOUNDARY STALLS OUT ACROSS THE MID-
ATLANTIC SUNDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE BOTH AT THE UPPER-LEVELS AND THE SURFACE WILL REMAIN
OVER THE ATLANTIC OCEAN THROUGH TONIGHT. AN UPPER-LEVEL TROUGH WILL
SLOWLY SHIFT FROM THE CENTRAL CONUS INTO THE GREAT LAKES. A
SOUTHERLY FLOW AROUND THE HIGH WILL CONTINUE TO USHER IN WARM AND
HUMID CONDITIONS ACROSS OUR AREA.
LOW CLDS AND FOG ASSOCD WITH THE NOCTURNAL INVERSION LESS
PRONOUNCED THAN YDA...AND ITS BURNING AWAY QUICKER. THEREFORE...
THERE SHUD BE LESS OF A MAXT SPREAD THAN THERE WAS YDA. STILL...HV
TWEAKED I-95 CRRDR DOWN A DEGF OR TWO TO ACCNT FOR ITS IMPACT.
THE WARM AND HUMID AIRMASS IN PLACE WILL LEAD TO HIGH AMOUNTS OF
INSTABILITY. UNMODIFIED LWX RAOB REFLECTS THIS...BUT ALSO
HIGHLIGHTS THE CAPPING INHIBITION BTWN H9-8. HGTS SHUD BE DROPPING
TAFTN AS TROF AXIS CROSSES THE WRN GRTLKS. MODIFYING THE SNDG FOR
T/TD 88/68 YIELDS ARND 3000 J/KG OF SBCAPE W/O A CAP. MLCAPE MUCH
MORE RESERVED AND SLGTLY INHIBITED.
TERRAIN CIRCULATIONS AND A SURFACE TROUGH WILL ACT AS LIFTING
MECHANISMS FOR CONVECTION THIS AFTERNOON. THIS IS ALSO SIMILAR TO
TUESDAY. THEREFORE...A BETTER CHANCE FOR THUNDERSTORMS EXISTS THIS
AFTERNOON AND EVENING...ESPECIALLY NEAR AND WEST OF THE I-95
CORRIDOR. HV ADJUSTED POPS SLGTLY TO PLACE MORE EMPHASIS ON
APLCHNS AND DEEMPHASIZE INVOF CHESPK BAY. HRRR /WRF-ARW4 BOTH
SUGGEST THAT TSRA SHUD FIRE TAFTN W OF THE BLURDG...SPCLY AFTR
18Z. WL NEED TO WATCH THAT TIMING THO...AS RADAR TRENDS IN WVA
ATTM SUGGEST IT MAY BE ERLR.
ALTHOUGH WIDESPREAD SEVERE WEATHER WILL LIKELY HOLD OFF TO OUR
WEST FOR LOCATIONS CLOSER TO THE UPPER-LEVEL TROUGH...THERE IS A
THREAT FOR LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL IN ANY
THUNDERSTORMS THAT DO DEVELOP DUE TO THE HIGH INSTABILITY.
CONVECTION WILL LIKELY DISSIPATE LATER THIS EVENING DUE TO THE LOSS
OF DAYTIME HEATING. HOWEVER...AN UPPER-LEVEL DISTURBANCE IS EXPECTED
TO PASS THROUGH THE REGION LATE TONIGHT AS THE UPPER-LEVEL TROUGH
CONTINUES TO SLIDE CLOSER TO OUR AREA. PLENTY OF MOISTURE AND
FORCING FROM THE UPPER-LEVEL DISTURBANCE MAY RESULT IN SCATTERED
SHOWERS/T-STORMS TOWARD MORNING. MIN TEMPS TONIGHT WILL RANGE FROM
THE 50S IN THE MOUNTAINS TO THE LOWER AND MIDDLE 70S IN DOWNTOWN
WASHINGTON/BALTIMORE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THURSDAY LOOKS TO BE THE LAST ABOVE NORMAL TEMPERATURE DAY FOR
AWHILE AHEAD OF THE COLD FRONT THAT CROSSES THURSDAY NIGHT
TIMEFRAME. PREFRONTAL LINES/CLUSTERS OF SHOWERS/THUNDERSTORMS
PROGRESS EAST ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. GFS BUFR
SNDG FOR KIAD PROGS A 1.6 INCH PWAT WHICH IS CERTAINLY HIGH...BUT
JUST SHY OF THE 2 STDEV INDICATOR OF FLASH FLOODING. WITH
PROGRESSIVE NATURE OF THE ACTIVITY...ANY FLASH FLOODING WOULD BE
LOCALIZED. DAMAGING WIND THREAT...PARTICULARLY WITH HEATING ON
THURSDAY IS ABLE TO PEAK BEFORE ORGANIZED ACTIVITY MOVES THROUGH.
FRIDAY...UPR TROUGH DRIFTS EAST OVER THE AREA WITH BACK EDGE OF
CLOUDS SLOW TO COME IN THE AFTERNOON. GUSTY NWLY FLOW FRIDAY
CONTINUES AS HIGH PRESSURE BUILDS THROUGH SATURDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SHORTWAVE FROM TN VLY ON SUNDAY NOW LOOKS TO EXPAND EAST ACROSS THE
SOUTHERN-CENTRAL MID-ATLANTIC. CONVERGENCE ALONG THIS BOUNDARY WOULD
SET OFF SHOWERS. PATTERN IS STALLED INTO MID NEXT WEEK...SO A
PROLONGED CLOUDY/RAINY PERIOD IS POSSIBLE. THIS WOULD RESULT IN
BELOW NORMAL TEMPS.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
LOW CLOUDS BURNING OFF ATTM. MVFR AT DCA/MTN...BUT ANTICIPATE VFR
EVERYWHERE BY 15Z.
SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP AFTN...PRIMARILY
INVOF MRB. SOME OF THE THUNDERSTORMS WILL BE CAPABLE OF PRODUCING
GUSTY WINDS AND LARGE HAIL. AREAS OF LOW CLOUDS ARE POSSIBLE LATE
TONIGHT ALONG WITH SCATTERED SHOWERS/T-STORMS.
THUNDERSTORMS THURSDAY INTO THURSDAY EVENING AHEAD OF A COLD FRONT.
IFR CONDS POSSIBLE IN THE HEAVIEST ACTIVITY. SLY FLOW UNTIL A COLD
FROPA THURSDAY NIGHT. NWLY FLOW WITH GUSTS 25 TO POSSIBLY 30 KT WITH
MID LEVEL CIGS FRIDAY. NWLY FLOW CONTINUES THROUGH SATURDAY AS HIGH
PRESSURE BUILDS.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC OCEAN THROUGH TONIGHT. A
SOUTHERLY FLOW WILL CONTINUE OVER THE WATERS DURING THIS TIME. A
SMALL CRAFT ADVISORY REMAINSS IN EFFECT FOR PORTIONS OF THE WATERS
THROUGH TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE
LATER THIS AFTERNOON AND EVENING. ANY THUNDERSTORMS THAT DO
DEVELOP WILL BE CAPABLE OF PRODUCING GUSTY WINDS AND HAIL.
SLY FLOW AHEAD OF A LATE THURSDAY NIGHT COLD FRONT. SCA EXPANDED
THROUGH THURSDAY. EXPECT AN EXTENSION THURSDAY NIGHT FOR PREFRONTAL
SLY FLOW...THEN NWLY FLOW AROUND 25 KT FRIDAY THROUGH SATURDAY AS
HIGH PRESSURE BUILDS.
&&
.TIDES/COASTAL FLOODING...
A SOUTHERLY FLOW WILL CONTINUE OVER THE WATERS THROUGH THURSDAY
NIGHT...BUT THE FLOW MAY REMAIN JUST WEST OF SOUTH. TIDAL ANOMALIES
WILL LIKELY INCREASE A LITTLE...BUT WITH THE FLOW REMAINING WEST OF
SOUTH THE WATER LEVELS SHOULD REMAIN BELOW THRESHOLDS FOR MINOR
COASTAL FLOODING. THE CLOSEST WATER LEVELS WILL COME TO MINOR
FLOODING THRESHOLDS WILL BE DURING THE HIGH TIDE CYCLE LATE WEDNESDAY
NIGHT AND LATE THURSDAY NIGHT...THE HIGHER OF THE TWO HIGH TIDES.
TIDAL ANOMALIES WILL DECREASE FRIDAY BEHIND A COLD FRONT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR ANZ530-531-539.
SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM EDT THURSDAY FOR ANZ535-
538.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ532-536-540-542.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ533-534-
537-541-543.
&&
$$
SYNOPSIS...BJL
NEAR TERM...HTS/BJL
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BJL/BAJ
MARINE...KLEIN/BJL/BAJ
TIDES/COASTAL FLOODING...BJL
000
FXUS61 KLWX 220801
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
401 AM EDT WED MAY 22 2013
.SYNOPSIS...
HIGH PRESSURE PERSISTING OVER THE ATLANTIC WITH WARM AND HUMID
CONDITIONS UNTIL A COLD FRONT THURSDAY NIGHT. AN UPPER TROUGH
WILL LINGER OVER THE AREA FRIDAY WITH HIGH PRESSURE BUILDING
THROUGH SATURDAY. A FRONTAL BOUNDARY STALLS OUT ACROSS THE MID-
ATLANTIC SUNDAY NIGHT THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE BOTH AT THE UPPER-LEVELS AND THE SURFACE WILL REMAIN
OVER THE ATLANTIC OCEAN THROUGH TONIGHT. AN UPPER-LEVEL TROUGH WILL
SLOWLY SHIFT FROM THE CENTRAL CONUS INTO THE GREAT LAKES. A
SOUTHERLY FLOW AROUND THE HIGH WILL CONTINUE TO USHER IN WARM AND
HUMID CONDITIONS ACROSS OUR AREA.
LOW-LEVEL MOISTURE TRAPPED UNDERNEATH THE NOCTURNAL INVERSION WILL
RESULT IN PATCHY FOG ALONG WITH AREAS OF LOW CLOUDS. THE BEST CHANCE
FOR LOW CLOUDS AND FOG WILL BE EAST OF THE BLUE RIDGE MOUNTAINS AND
IN SHELTERED VALLEYS WEST OF THE BLUE RIDGE MOUNTAINS. ANY LOW
CLOUDS AND FOG SHOULD BURN OFF BY MID-MORNING. SUNSHINE AND A
SOUTHERLY FLOW WILL CAUSE MAX TEMPS TO REACH THE MID AND UPPER 80S
ACROSS MOST LOCATIONS.
THE WARM AND HUMID AIRMASS WILL LEAD TO HIGH AMOUNTS OF INSTABILITY.
NAM/GFS BUFKIT INDICATE AROUND 2000-2500 J/KG OF MLCAPE THIS
AFTERNOON...SIMILAR TO TUESDAY. TERRAIN CIRCULATION AND A SURFACE
TROUGH WILL ACT AS LIFTING MECHANISMS FOR CONVECTION THIS AFTERNOON.
THIS IS ALSO SIMILAR TO TUESDAY. HOWEVER...THE CAPPING INVERSION
WILL BE WEAKER THAN TUESDAY DUE TO HEIGHT FALLS AS THE UPPER-LEVEL
TROUGH TO OUR WEST SLOWLY SHIFTS EASTWARD. THEREFORE...A BETTER
CHANCE FOR THUNDERSTORMS EXISTS THIS AFTERNOON AND
EVENING...ESPECIALLY NEAR AND WEST OF THE I-95 CORRIDOR. ALTHOUGH
WIDESPREAD SEVERE WEATHER WILL LIKELY HOLD OFF TO OUR WEST FOR
LOCATIONS CLOSER TO THE UPPER-LEVEL TROUGH...THERE IS A THREAT FOR
LOCALLY DAMAGING WIND GUSTS AND LARGE HAIL IN ANY THUNDERSTORMS THAT
DO DEVELOP DUE TO THE HIGH INSTABILITY.
CONVECTION WILL LIKELY DISSIPATE LATER THIS EVENING DUE TO THE LOSS
OF DAYTIME HEATING. HOWEVER...AN UPPER-LEVEL DISTURBANCE IS EXPECTED
TO PASS THROUGH THE REGION LATE TONIGHT AS THE UPPER-LEVEL TROUGH
CONTINUES TO SLIDE CLOSER TO OUR AREA. PLENTY OF MOISTURE AND
FORCING FROM THE UPPER-LEVEL DISTURBANCE MAY RESULT IN SCATTERED
SHOWERS/T-STORMS TOWARD MORNING. MIN TEMPS TONIGHT WILL RANGE FROM
THE 50S IN THE MOUNTAINS TO THE LOWER AND MIDDLE 70S IN DOWNTOWN
WASHINGTON/BALTIMORE.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
THURSDAY LOOKS TO BE THE LAST ABOVE NORMAL TEMPERATURE DAY FOR
AWHILE AHEAD OF THE COLD FRONT THAT CROSSES THURSDAY NIGHT
TIMEFRAME. PREFRONTAL LINES/CLUSTERS OF SHOWERS/THUNDERSTORMS
PROGRESS EAST ACROSS THE AREA THURSDAY INTO THURSDAY NIGHT. GFS BUFR
SNDG FOR KIAD PROGS A 1.6 INCH PWAT WHICH IS CERTAINLY HIGH...BUT
JUST SHY OF THE 2 STDEV INDICATOR OF FLASH FLOODING. WITH
PROGRESSIVE NATURE OF THE ACTIVITY...ANY FLASH FLOODING WOULD BE
LOCALIZED. DAMAGING WIND THREAT...PARTICULARLY WITH HEATING ON
THURSDAY IS ABLE TO PEAK BEFORE ORGANIZED ACTIVITY MOVES THROUGH.
FRIDAY...UPR TROUGH DRIFTS EAST OVER THE AREA WITH BACK EDGE OF
CLOUDS SLOW TO COME IN THE AFTERNOON. GUSTY NWLY FLOW FRIDAY
CONTINUES AS HIGH PRESSURE BUILDS THROUGH SATURDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
SHORTWAVE FROM TN VLY ON SUNDAY NOW LOOKS TO EXPAND EAST ACROSS THE
SOUTHERN-CENTRAL MID-ATLANTIC. CONVERGENCE ALONG THIS BOUNDARY WOULD
SET OFF SHOWERS. PATTERN IS STALLED INTO MID NEXT WEEK...SO A
PROLONGED CLOUDY/RAINY PERIOD IS POSSIBLE. THIS WOULD RESULT IN
BELOW NORMAL TEMPS.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
LOW-LEVEL MOISTURE WILL BE TRAPPED UNDERNEATH THE NOCTURNAL
INVERSION EARLY THIS MORNING. THIS MAY RESULT IN LOW CLOUDS AND
AREAS OF FOG...ESPECIALLY ACROSS THE EASTERN TERMINALS. IFR
CONDITIONS ARE POSSIBLE.
ANY LOW CLOUDS WILL BURN OFF BY MID-MORNING AND VFR CONDITIONS ARE
EXPECTED THROUGH THIS EVENING. HOWEVER...SCATTERED SHOWERS AND
THUNDERSTORMS WILL DEVELOP. SOME OF THE THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING GUSTY WINDS AND LARGE HAIL. AREAS OF LOW CLOUDS
ARE POSSIBLE LATE TONIGHT ALONG WITH SCATTERED SHOWERS/T-STORMS.
THUNDERSTORMS THURSDAY INTO THURSDAY EVENING AHEAD OF A COLD FRONT.
IFR CONDS POSSIBLE IN THE HEAVIEST ACTIVITY. SLY FLOW UNTIL A COLD
FROPA THURSDAY NIGHT. NWLY FLOW WITH GUSTS 25 TO POSSIBLY 30 KT WITH
MID LEVEL CIGS FRIDAY. NWLY FLOW CONTINUES THROUGH SATURDAY AS HIGH
PRESSURE BUILDS.
&&
.MARINE...
HIGH PRESSURE WILL REMAIN OVER THE ATLANTIC OCEAN THROUGH TONIGHT. A
SOUTHERLY FLOW WILL CONTINUE OVER THE WATERS DURING THIS TIME. A
SMALL CRAFT ADVISORY IS IN EFFECT FOR PORTIONS OF THE WATERS THROUGH
TONIGHT. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATER THIS
AFTERNOON AND EVENING. ANY THUNDERSTORMS THAT DO DEVELOP WILL BE
CAPABLE OF PRODUCING GUSTY WINDS AND HAIL.
SLY FLOW AHEAD OF A LATE THURSDAY NIGHT COLD FRONT. SCA EXPANDED
THROUGH THURSDAY. EXPECT AN EXTENSION THURSDAY NIGHT FOR PREFRONTAL
SLY FLOW...THEN NWLY FLOW AROUND 25 KT FRIDAY THROUGH SATURDAY AS
HIGH PRESSURE BUILDS.
&&
.TIDES/COASTAL FLOODING...
A SOUTHERLY FLOW WILL CONTINUE OVER THE WATERS THROUGH THURSDAY
NIGHT...BUT THE FLOW MAY REMAIN JUST WEST OF SOUTH. TIDAL ANOMALIES
WILL LIKELY INCREASE A LITTLE...BUT WITH THE FLOW REMAINING WEST OF
SOUTH THE WATER LEVELS SHOULD REMAIN BELOW THRESHOLDS FOR MINOR
COASTAL FLOODING. THE CLOSEST WATER LEVELS WILL COME TO MINOR
FLOODING THRESHOLDS WILL BE DURING THE HIGH TIDE CYCLE LATE WEDNESDAY
NIGHT AND LATE THURSDAY NIGHT...THE HIGHER OF THE TWO HIGH TIDES.
TIDAL ANOMALIES WILL DECREASE FRIDAY BEHIND A COLD FRONT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM EDT
THURSDAY FOR ANZ530-531-539.
SMALL CRAFT ADVISORY FROM 9 AM TO 6 PM EDT THURSDAY FOR ANZ535-
538.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 PM EDT
THURSDAY FOR ANZ532-536-540-542.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ533-534-
537-541-543.
&&
$$
SYNOPSIS...BJL/BAJ
NEAR TERM...BJL
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/BJL
MARINE...BAJ/BJL
TIDES/COASTAL FLOODING...BJL
000
FXUS61 KLWX 220506
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
106 AM EDT WED MAY 22 2013
.SYNOPSIS...
OFFSHORE HIGH PRESSURE WILL CONTINUE TO BRING WARM MOIST SOUTHERLY
AIR INTO THE REGION THROUGH THURSDAY. AFTERNOON AND EVENING
THUNDERSTORMS ARE POSSIBLE EACH DAY. A COLD FRONT WILL PASS
THROUGH THE REGION THURSDAY NIGHT INTO FRIDAY. COOLER CONDITIONS
ARE EXPECTED OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LN OF TSTMS HAS WEAKEN OVER THE ERN PART OF THE STATE.
LGT FOG PSBL AFTR OVERNIGHT...MOST PREVALENT RIGHT B4 SUNRISE AND
THEN QUICKLY BURNING OFF. LOWS IN THE 60S XCPT L70S IN THE
CITIES.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THURSDAY/...
CWFA WL BE WARM SECTOR THRU PD...AS SFC HIGH WELL OFF ERN SEABOARD
AIDS SLY FLOW/MOISTURE ADVECTION. THUS AMS WL REMAIN UNSTBL...W/
POPS GNLY INCREASING IN RESPONSE TO DROPPING MID LVL HGTS. WL STILL
HV A DIURNAL TREND TO STORMS. THU LOOKS TO BE THE BETTER DAY IN
TERMS OF TSRA DVLPMNT AS CDFNT/UPR LOW DROPS THRU GRTLKS. HV
RAISED POPS BOTH DAYS AND INTRODUCED LKLYS ON THU.
SPC HAS WRN MD/HIGHLANDS OUTLOOKED IN SLT RISK THU AHD OF THE CD
FNT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
CFP THU NGT. AFTR THAT THE NEXT SVRL DAYS LOOKING GOOD AS CANADIAN
HIGH PRESSURE BUILDS IN WITH TEMPS 5-10 DEGREES BELOW NORMAL.
SHORTWAVE OVER THE TN VLY ON SUNDAY SHOULD REMAIN WEST OF THE LWX
CWA...WILL HAVE TO MONITOR FOR INCREASED POPS. AS OF NOW EXPECT
SOME HIGH CLOUDS SUNDAY WITH A WARMING TREND STARTING THAT
CONTINUES INTO MID NEXT WEEK.
&&
.AVIATION /05Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS AT ALL TERMINALS. XPCT AREAS OF LOW CLOUDS/FOG TO DVLP
LT TNGT...CONTG INTO THE WED MRNG PUSH BUT DISSIPATING AFTR
SUNRISE. THIS TIME HV LEANED MORE TWD FOG DVLPMNT INLAND SINCE
SKIES WL BE PRTLY CLR SUPPORTING RADL COOLING DOWN TO MOIST
DEWPTS. HWVR LOW CLDS WL BE LURKING JUST E OF DCA/BWI.
DIURNAL THUNDERSTORM ACTIVITY WED/THUR WITH IFR CONDS POSSIBLE IN
THE HEAVIEST ONES. SLY FLOW UNTIL A COLD FROPA THURSDAY NIGHT. NWLY
FLOW WITH CLEAR CONDS SATURDAY. JUST SOME HIGH CLOUDS ON SUNDAY.
&&
.MARINE...
...UPDATE TO ADD SMALL CRAFT ADVISORY OVERNIGHT AND THIS MORNING
FOR THE MARYLAND CHESAPEAKE BAY SOUTH OF NORTH BEACH AND THE LOWER
TIDAL POTOMAC RIVER SOUTH OF COBB ISLAND. THE PREVIOUS DISCUSSION
FOLLOWS...
THE PRESSURE GRADIENT WILL STRENGTHEN OVER THE REGION
WED AFTN AND NGT AS LOPRES MOVES THRU THE GREAT LAKES AND HIPRES
REMAINS PARKED OVER THE WRN ATLANTIC. SLY RETURN FLOW WILL
INCREASE ACCORDINGLY BETWEEN BOTH SYSTEMS. A SCA GOES IN EFFECT
WED AFTN FOR THE WATERS THAT ARE MOST PRONE TO SLY CHANNELING IN
THE MID CHSPK BAY AND LWR/MID TIDAL POTOMAC RVR. SCA EXPANDS WED
NGT TO INCLUDE ALL OF THE MD CHSPK BAY AS A SLY NOCTURNAL JET
DEVELOPS.
SLY FLOW WITH HIGH PRESSURE OFFSHORE AHEAD OF A COLD FRONT THAT
COMES THROUGH THURSDAY NIGHT. SLY CHANNELING TO 20 KT POSSIBLE WED
EVENING...AND THURSDAY. NWLY FLOW TO 20 KT POSSIBLE FRIDAY. LIGHT
AND VARIABLE FLOW THIS WEEKEND.
&&
.TIDES/COASTAL FLOODING...
EXPECT POSITIVE TIDAL ANOMALIES TO DEVELOP DURING THE MIDWEEK AS SLY
FLOW STRENGTHENS. CBOFS GUIDANCE...WHICH HAS VERIFIED FAIRLY WELL OF
LATE...FCST WATER LEVELS TO STAY BELOW MINOR COASTAL FLOODING
THRESHOLDS THRU AT LEAST THU MRNG.
COLD FRONT MOVES THRU ERY FRI MRNG. WLY WINDS BEHIND THE FRONT
SHOULD ERASE ANY POSITIVE TIDAL ANOMALIES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 AM EDT
THURSDAY FOR ANZ530-531-539.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 6 AM EDT
THURSDAY FOR ANZ532-536-540-542.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ533-534-
537-541-543.
&&
$$
UPDATE...LASORSA
000
FXUS61 KLWX 220021
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
821 PM EDT TUE MAY 21 2013
.SYNOPSIS...
OFFSHORE HIGH PRESSURE WILL CONTINUE TO BRING WARM MOIST SOUTHERLY
AIR INTO THE REGION THROUGH THURSDAY. AFTERNOON AND EVENING
THUNDERSTORMS ARE POSSIBLE EACH DAY. A COLD FRONT WILL PASS
THROUGH THE REGION THURSDAY NIGHT INTO FRIDAY. COOLER CONDITIONS
ARE EXPECTED OVER THE WEEKEND.
&&
.NEAR TERM /TONIGHT/...
LN OF TSTMS PRNTLY ENTERING WRN W.V. WL LKLY WEAKEN B4 GETTING TO
THE ERN PART OF THE STATE.
LGT FOG PSBL AFTR MDNGT...MOST PREVALENT RIGHT B4 SUNRISE AND THEN
QUICKLY BURNING OFF. LOWS IN THE 60S XCPT L70S IN THE CITIES.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
CWFA WL BE WARM SECTOR THRU PD...AS SFC HIGH WELL OFF ERN SEABOARD
AIDS SLY FLOW/MOISTURE ADVECTION. THUS AMS WL REMAIN UNSTBL...W/
POPS GNLY INCREASING IN RESPONSE TO DROPPING MID LVL HGTS. WL STILL
HV A DIURNAL TREND TO STORMS. THU LOOKS TO BE THE BETTER DAY IN
TERMS OF TSRA DVLPMNT AS CDFNT/UPR LOW DROPS THRU GRTLKS. HV
RAISED POPS BOTH DAYS AND INTRODUCED LKLYS ON THU.
SPC HAS WRN MD/HIGHLANDS OUTLOOKED IN SLT RISK THU AHD OF THE CD
FNT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
CFP THU NGT. AFTR THAT THE NEXT SVRL DAYS LOOKING GOOD AS CANADIAN
HIGH PRESSURE BUILDS IN WITH TEMPS 5-10 DEGREES BELOW NORMAL.
SHORTWAVE OVER THE TN VLY ON SUNDAY SHOULD REMAIN WEST OF THE LWX
CWA...WILL HAVE TO MONITOR FOR INCREASED POPS. AS OF NOW EXPECT
SOME HIGH CLOUDS SUNDAY WITH A WARMING TREND STARTING THAT
CONTINUES INTO MID NEXT WEEK.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS AT ALL TERMINALS. XPCT AREAS OF LOW CLOUDS/FOG TO DVLP
LT TNGT...CONTG INTO THE WED MRNG PUSH BUT DISSIPATING AFTR
SUNRISE. THIS TIME HV LEANED MORE TWD FOG DVLPMNT INLAND SINCE
SKIES WL BE PRTLY CLR SUPPORTING RADL COOLING DOWN TO MOIST
DEWPTS. HWVR LOW CLDS WL BE LURKING JUST E OF DCA/BWI.
DIURNAL THUNDERSTORM ACTIVITY WED/THUR WITH IFR CONDS POSSIBLE IN
THE HEAVIEST ONES. SLY FLOW UNTIL A COLD FROPA THURSDAY NIGHT. NWLY
FLOW WITH CLEAR CONDS SATURDAY. JUST SOME HIGH CLOUDS ON SUNDAY.
&&
.MARINE...
THE PRESSURE GRADIENT WILL STRENGTHEN OVER THE REGION WED AFTN AND
NGT AS LOPRES MOVES THRU THE GREAT LAKES AND HIPRES REMAINS PARKED
OVER THE WRN ATLANTIC. SLY RETURN FLOW WILL INCREASE ACCORDINGLY
BETWEEN BOTH SYSTEMS. A SCA GOES IN EFFECT WED AFTN FOR THE WATERS
THAT ARE MOST PRONE TO SLY CHANNELING IN THE MID CHSPK BAY AND
LWR/MID TIDAL POTOMAC RVR. SCA EXPANDS WED NGT TO INCLUDE ALL OF THE
MD CHSPK BAY AS A SLY NOCTURNAL JET DEVELOPS.
SLY FLOW WITH HIGH PRESSURE OFFSHORE AHEAD OF A COLD FRONT THAT
COMES THROUGH THURSDAY NIGHT. SLY CHANNELING TO 20 KT POSSIBLE WED
EVENING...AND THURSDAY. NWLY FLOW TO 20 KT POSSIBLE FRIDAY. LIGHT
AND VARIABLE FLOW THIS WEEKEND.
&&
.TIDES/COASTAL FLOODING...
EXPECT POSITIVE TIDAL ANOMALIES TO DEVELOP DURING THE MIDWEEK AS SLY
FLOW STRENGTHENS. CBOFS GUIDANCE...WHICH HAS VERIFIED FAIRLY WELL OF
LATE...FCST WATER LEVELS TO STAY BELOW MINOR COASTAL FLOODING
THRESHOLDS THRU AT LEAST THU MRNG.
COLD FRONT MOVES THRU ERY FRI MRNG. WLY WINDS BEHIND THE FRONT
SHOULD ERASE ANY POSITIVE TIDAL ANOMALIES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ530-531-539.
SMALL CRAFT ADVISORY FROM 2 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ532>534-536-537-540>543.
&&
$$
UPDATE...WOODY!
000
FXUS61 KLWX 212137
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
537 PM EDT TUE MAY 21 2013
.SYNOPSIS...
OFFSHORE HIGH PRESSURE WILL CONTINUE TO BRING WARM MOIST SOUTHERLY
AIR INTO THE REGION THROUGH THURSDAY. AFTERNOON AND EVENING
THUNDERSTORMS ARE POSSIBLE EACH DAY. A COLD FRONT WILL PASS
THROUGH THE REGION THURSDAY NIGHT INTO FRIDAY. COOLER CONDITIONS
ARE EXPECTED OVER THE WEEKEND.
&&
.NEAR TERM /TONIGHT/...
ISOLD TSTMS PSBL OVR THE MTNS THRU MID EVE. THESE MAY PRODUCE
BRIEFLY HEAVY RAINS. UPR LVL WIND FIELD IS VERY LGT.
LGT FOG PSBL AFTR MDNGT...MOST PREVALENT RIGHT B4 SUNRISE AND THEN
QUICKLY BURNING OFF. LOWS IN THE 60S XCPT L70S IN THE CITIES.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
CWFA WL BE WARM SECTOR THRU PD...AS SFC HIGH WELL OFF ERN SEABOARD
AIDS SLY FLOW/MOISTURE ADVECTION. THUS AMS WL REMAIN UNSTBL...W/
POPS GNLY INCREASING IN RESPONSE TO DROPPING MID LVL HGTS. WL STILL
HV A DIURNAL TREND TO STORMS. THU LOOKS TO BE THE BETTER DAY IN
TERMS OF TSRA DVLPMNT AS CDFNT/UPR LOW DROPS THRU GRTLKS. HV
RAISED POPS BOTH DAYS AND INTRODUCED LKLYS ON THU.
SPC HAS WRN MD/HIGHLANDS OUTLOOKED IN SLT RISK THU AHD OF THE CD
FNT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
CFP THU NGT. AFTR THAT THE NEXT SVRL DAYS LOOKING GOOD AS CANADIAN
HIGH PRESSURE BUILDS IN WITH TEMPS 5-10 DEGREES BELOW NORMAL.
SHORTWAVE OVER THE TN VLY ON SUNDAY SHOULD REMAIN WEST OF THE LWX
CWA...WILL HAVE TO MONITOR FOR INCREASED POPS. AS OF NOW EXPECT
SOME HIGH CLOUDS SUNDAY WITH A WARMING TREND STARTING THAT
CONTINUES INTO MID NEXT WEEK.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
VFR CONDS AT ALL TERMINALS. XPCT AREAS OF LOW CLOUDS/FOG TO DVLP
LT TNGT...CONTG INTO THE WED MRNG PUSH BUT DISSIPATING AFTR
SUNRISE. THIS TIME HV LEANED MORE TWD FOG DVLPMNT INLAND SINCE
SKIES WL BE PRTLY CLR SUPPORTING RADL COOLING DOWN TO MOIST
DEWPTS. HWVR LOW CLDS WL BE LURKING JUST E OF DCA/BWI.
DIURNAL THUNDERSTORM ACTIVITY WED/THUR WITH IFR CONDS POSSIBLE IN
THE HEAVIEST ONES. SLY FLOW UNTIL A COLD FROPA THURSDAY NIGHT. NWLY
FLOW WITH CLEAR CONDS SATURDAY. JUST SOME HIGH CLOUDS ON SUNDAY.
&&
.MARINE...
THE PRESSURE GRADIENT WILL STRENGTHEN OVER THE REGION WED AFTN AND
NGT AS LOPRES MOVES THRU THE GREAT LAKES AND HIPRES REMAINS PARKED
OVER THE WRN ATLANTIC. SLY RETURN FLOW WILL INCREASE ACCORDINGLY
BETWEEN BOTH SYSTEMS. A SCA GOES IN EFFECT WED AFTN FOR THE WATERS
THAT ARE MOST PRONE TO SLY CHANNELING IN THE MID CHSPK BAY AND
LWR/MID TIDAL POTOMAC RVR. SCA EXPANDS WED NGT TO INCLUDE ALL OF THE
MD CHSPK BAY AS A SLY NOCTURNAL JET DEVELOPS.
SLY FLOW WITH HIGH PRESSURE OFFSHORE AHEAD OF A COLD FRONT THAT
COMES THROUGH THURSDAY NIGHT. SLY CHANNELING TO 20 KT POSSIBLE WED
EVENING...AND THURSDAY. NWLY FLOW TO 20 KT POSSIBLE FRIDAY. LIGHT
AND VARIABLE FLOW THIS WEEKEND.
&&
.TIDES/COASTAL FLOODING...
EXPECT POSITIVE TIDAL ANOMALIES TO DEVELOP DURING THE MIDWEEK AS SLY
FLOW STRENGTHENS. CBOFS GUIDANCE...WHICH HAS VERIFIED FAIRLY WELL OF
LATE...FCST WATER LEVELS TO STAY BELOW MINOR COASTAL FLOODING
THRESHOLDS THRU AT LEAST THU MRNG.
COLD FRONT MOVES THRU ERY FRI MRNG. WLY WINDS BEHIND THE FRONT
SHOULD ERASE ANY POSITIVE TIDAL ANOMALIES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ530-531-539.
SMALL CRAFT ADVISORY FROM 2 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ532>534-536-537-540>543.
&&
$$
UPDATE...WOODY!
000
FXUS61 KLWX 211859
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
259 PM EDT TUE MAY 21 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO AID A SOUTHERLY
FLOW THROUGH THURSDAY...BRINGING WARM AND HUMID CONDITIONS.
AFTERNOON AND EVENING THUNDERSTORMS ARE POSSIBLE EACH DAY. A
COLD FRONT WILL PASS THROUGH THE REGION THURSDAY NIGHT INTO
FRIDAY. COOLER CONDITIONS ARE EXPECTED OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
H5 TROF HAS WEAKENED AND SLID SE OF CWFA. THAT LEAVES CWFA W/IN
SLY FLOW FM RDGG SFC-H5. AMS REMAINS UNSTBL BUT CAPPED...W/ SHEN
VLY/PTMC HIGHLANDS LKLY NEAREST CONVECTIVE TEMPS IN THE UPR 80S.
FORTUNATELY SEE NO SIGNS OF DVLPMNT THRU THE OHVLY...AND HV SCALED
POPS BACK BY ABT 10 PCT. AM STILL HOLDING ONTO CHC POPS SINCE WERE
CLOSE TO BREAKING CAP IN THE W...AND THERE/S PLENTY OF CAPE TO
FEED OFF OF ONCE WE DO. ANY ACTIVITY WL BE FAIRLY UNORGANIZED...
SINCE TRRN CURCULATIONS/DIFF HEATING BNDRYS WL BE BEST TRIGGERS.
ONCE DAYTIME HEATING WANES...RISK DIMINISHES...AND HV SCALED BACK
POPS FOR THE OVNGT HRS. DEWPTS HIGH ENUF THAT W/ PARTLY CLR SKIES
PATCHY FOG SHUD DVLP.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY/...
CWFA WL BE WARM SECTOR THRU PD...AS SFC HIGH WELL OFF ERN SEABOARD
AIDS SLY FLOW/MOISTURE ADVECTION. THUS AMS WL REMAIN UNSTBL...W/
POPS GNLY INCREASING IN RESPONSE TO DROPPING MID LVL HGTS. WL STILL
HV A DIURNAL TREND TO STORMS. THU LOOKS TO BE THE BETTER DAY IN
TERMS OF TSRA DVLPMNT AS CDFNT/UPR LOW DROPS THRU GRTLKS. HV
RAISED POPS BOTH DAYS AND INTRODUCED LKLYS ON THU.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
CFP THU NGT. CANADIAN HIGH PRESSURE BUILDS IN WITH TEMPS 5-10
DEGREES BELOW NORMAL. SHORTWAVE OVER THE TN VLY ON SUNDAY SHOULD
REMAIN WEST OF THE LWX CWA...WILL HAVE TO MONITOR FOR INCREASED
POPS. AS OF NOW EXPECT SOME HIGH CLOUDS SUNDAY WITH A WARMING
TREND STARTING THAT CONTINUES INTO MID NEXT WEEK.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW-LEVEL MOISTURE HAS FINALLY SCOURED OUT...LEAVING VFR CONDS AT
ALL TERMINALS. ISOLD SHOWERS AND T-STORMS ARE STILL POSSIBLE THIS
AFTERNOON AND EVENING...PARTICULARLY FOR MRB/CHO...BUT THREAT WAY
TOO SLIM FOR TAF INCLUSION. XPCT AREAS OF LOW CLOUDS/FOG TO DVLP
AGN LT TNGT...CONTG INTO THE WED MRNG PUSH. THIS TIME HV LEANED
MORE TWD FOG DVLPMNT INLAND SINCE SKIES WL BE PRTLY CLR SUPPORTING
RADL COOLING DOWN TO MOIST DEWPTS. HWVR LOW CLDS WL BE LURKING
JUST E OF DCA/BWI.
DIURNAL THUNDERSTORM ACTIVITY WED/THUR WITH IFR CONDS POSSIBLE IN
THE HEAVIEST ONES. SLY FLOW UNTIL A COLD FROPA THURSDAY NIGHT. NWLY
FLOW WITH CLEAR CONDS SATURDAY. JUST SOME HIGH CLOUDS ON SUNDAY.
&&
.MARINE...
THE PRESSURE GRADIENT WILL STRENGTHEN OVER THE REGION WED AFTN AND
NGT AS LOPRES MOVES THRU THE GREAT LAKES AND HIPRES REMAINS PARKED
OVER THE WRN ATLANTIC. SLY RETURN FLOW WILL INCREASE ACCORDINGLY
BETWEEN BOTH SYSTEMS. A SCA GOES IN EFFECT WED AFTN FOR THE WATERS
THAT ARE MOST PRONE TO SLY CHANNELING IN THE MID CHSPK BAY AND
LWR/MID TIDAL POTOMAC RVR. SCA EXPANDS WED NGT TO INCLUDE ALL OF THE
MD CHSPK BAY AS A SLY NOCTURNAL JET DEVELOPS.
SLY FLOW WITH HIGH PRESSURE OFFSHORE AHEAD OF A COLD FRONT THAT
COMES THROUGH THURSDAY NIGHT. SLY CHANNELING TO 20 KT POSSIBLE WED
EVENING...AND THURSDAY. NWLY FLOW TO 20 KT POSSIBLE FRIDAY. LIGHT
AND VARIABLE FLOW THIS WEEKEND.
&&
.TIDES/COASTAL FLOODING...
DESPITE SLY WINDS...WATER LEVELS THIS AFTN ARE NEAR ASTRONOMICAL
TIDE AND EVEN A FEW INCHES BELOW NORMAL IN THE TIDAL POTOMAC. DO
EXPECT POSITIVE TIDAL ANOMALIES TO DEVELOP DURING THE MIDWEEK AS SLY
FLOW STRENGTHENS. CBOFS GUIDANCE...WHICH HAS VERIFIED FAIRLY WELL OF
LATE...FCST WATER LEVELS TO STAY COMFORTABLY BELOW MINOR COASTAL
FLOODING THRESHOLDS THRU AT LEAST THU MRNG.
COLD FRONT MOVES THRU ERY FRI MRNG. WLY WINDS BEHIND THE FRONT
SHOULD ERASE ANY POSITIVE TIDAL ANOMALIES.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ530-531-539.
SMALL CRAFT ADVISORY FROM 2 PM WEDNESDAY TO 6 AM EDT THURSDAY
FOR ANZ532>534-536-537-540>543.
&&
$$
000
FXUS61 KLWX 211416
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1016 AM EDT TUE MAY 21 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO AID A SOUTHERLY
FLOW THROUGH THURSDAY...BRINGING WARM AND HUMID CONDITIONS.
AFTERNOON AND EVENING THUNDERSTORMS ARE POSSIBLE EACH DAY. A
COLD FRONT WILL PASS THROUGH THE REGION THURSDAY NIGHT INTO
FRIDAY. COOLER CONDITIONS ARE EXPECTED OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK UPPER-LEVEL LOW PRESSURE REMAINS OVER SOUTHERN VIRGINIA INTO
THE CAROLINAS THIS MORNING WHILE SURFACE HIGH PRESSURE REMAINS
CENTERED OVER THE ATLANTIC OCEAN. PLENTY OF CLDS BANKED UP ALONG
AND EAST OF THE BLURDG...WHILE MOSUN SKIES PREVAIL TO THE W. 12Z
LWX RAOB INDICATES AN INVERSION ASSOCD W/ THE LOW CLDS UP TO ABT
H9. ABV THAT SNDG UNSTBL...W/ APPROX 1850 J/KG CAPE. HWVR CNVCTV
TEMPS /89F/ WL BE HARD TO REACH UNDER THE CLD CVR.
LAMP TEMPS RUNNING LWR THAN FCST MAXT. WHILE LAMP HAS HAD A GOOD
FEEL FOR ERODING LOW CLDS PAST CPL DAYS AND LIKE ITS HANDLING TDA
/SCT OUT LLVL MSTR BTWN 15-18Z/...TEMP HV BEEN RUNNING A LTL ON
THE COOL SIDE. INDEED...OUR OBSVD SNDG CUD WARM UP IN A HURRY.
THEREFORE...WL BE HOLDING ONTO GOING TEMP FCST.
THAT LEADS TO THE PCPN FCST. THE WARM AND HUMID AIR WILL LEAD TO
HIGH AMOUNTS OF INSTABILITY. NAM/GFS BUFKIT ARE INDICATING AROUND
2000-2500 J/KG OF MLCAPE THIS AFTERNOON. GOT SIMLR RSLTS IN SBCAPE
MODIFYING OBSVD SNDG TO 85/65. HWVR...THERE WAS ALSO ABT 50 J/KG
CINH. THIS INHIBITION WILL MAKE IT DIFFICULT FOR CONVECTION TO
DEVELOP. LIKE PRVS FCST...WHICH CONCENTRATED ON TERRAIN
CIRCULATIONS...A SURFACE TROUGH AND THE UPPER-LEVEL LOW ACTING AS
LIFTING MECHANISMS. MAIN PREMISE OF POPS REMAIN UNCHGD. WILL ALSO
HAVE TO MONITOR CONVECTION OVER THE MIDWEST. THIS MAY SURVIVE OFF
ITS COLD POOL AND BRING A THREAT FOR MORE WIDESPREAD CONVECTION
ALONG THE ALLEGHENY AND POTOMAC HIGHLANDS THIS EVENING. THE
HIGHEST POPS ARE LOCATED ACROSS THESE AREAS FOR THAT REASON.
THE THREAT FOR SEVERE T-STORMS THIS AFTERNOON AND EVENING SHOULD BE
LOW DUE TO THE STRONG CAPPING INVERSION. HOWEVER...IF THE LIFTING
MECHANISMS END UP BEING STRONG ENOUGH TO ERODE THE INVERSION...THEN
GUSTY WINDS AND HAIL ARE POSSIBLE.
ANY LEFTOVER CONVECTION WILL DISSIPATE OVERNIGHT DUE TO THE LOSS OF
DAYTIME HEATING. LOW CLOUDS AND AREAS OF FOG MAY DEVELOP AS MOISTURE
GETS TRAPPED UNDERNEATH THE NOCTURNAL INVERSION. HOWEVER...LOW
CLOUDS/FOG SHOULD NOT BE AS WIDESPREAD AS RECENT NIGHTS DUE TO A
HIGHER TEMP/DEWPOINT DEPRESSION AND A STRONGER GRADIENT. MIN TEMPS
WILL BE IN THE 60S ACROSS MOST AREAS TO THE LOWER 70S IN DOWNTOWN
WASHINGTON/BALTIMORE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
CNTRL MID-ATLANTIC IN WARM SECTOR OF MIDWEST LOW UNTIL A COLD FRONT
IN THE THURSDAY NIGHT TIMEFRAME. SFC HIGH WELL OFF ERN SEABOARD AIDS
SLY FLOW/MOISTURE ADVECTION. TEMPS ABOUT 10 DEGREES ABOVE NORMAL
WITH UPR 60S TO NEAR 70F DEWPOINTS. EXPECT A DIURNAL TREND IN PRECIP
COVERAGE WITH PREFRONTAL FORCING ENTERING THE AREA THURSDAY. SLIGHT
RISK FOR WEDNESDAY DUE TO POTENTIAL FOR STRAIGHT LINE WINDS FROM
ONGOING MCS ACTIVITY OVER THE OHIO VALLEY PUSHING EAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
12Z ECMWF PROGS THE CD FROPA AS THURSDAY NIGHT (THERE HAS BEEN
FLUCTUATION FROM LATE THURSDAY TO FRIDAY MORNING). CANADIAN HIGH
PRESSURE BUILDS IN WITH A CRYSTAL CLEAR AND COOL WITH TEMPS 5-10
DEGREES BELOW NORMAL. SHORTWAVE OVER THE TN VLY ON SUNDAY SHOULD
REMAIN WEST OF THE LWX CWA...WILL HAVE TO MONITOR FOR INCREASED
POPS. AS OF NOW EXPECT SOME HIGH CLOUDS SUNDAY WITH A WARMING TREND
STARTING THAT CONTINUES INTO MID NEXT WEEK.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
LOW-LEVEL MOISTURE IS TRAPPED UNDERNEATH THE STILL PRESENT
NOCTURNAL INVERSION. LOW CLOUDS AND FOG JUST BGNG TO ERODE...AND
WILL IMPROVE TO VFR BY/ARND NOON. ISOLD SHOWERS AND T-STORMS ARE
POSSIBLE THIS AFTERNOON AND EVENING. THREAT TOO SLIM FOR TAF
INCLUSION. AREAS OF LOW CLOUDS/FOG MAY IMPACT THE TERMINALS LATE
TONIGHT.
DIURNAL THUNDERSTORM ACTIVITY WED/THUR WITH IFR CONDS POSSIBLE IN
THE HEAVIEST ONES. SLY FLOW UNTIL A COLD FROPA THURSDAY NIGHT. NWLY
FLOW WITH CLEAR CONDS SATURDAY. JUST SOME HIGH CLOUDS ON SUNDAY.
&&
.MARINE...
SOUTHERLY WINDS ARE EXPECTED OVER THE WATERS THROUGH TONIGHT. WIND
GUSTS WILL BE CLOSE TO SCA CRITERIA THIS AFTERNOON AND TONIGHT. HAVE
CAPPED GUSTS AROUND 15 KNOTS FOR NOW DUE TO THE RELATIVELY COOLER
WATERS. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AND EVENING.
SLY FLOW WITH HIGH PRESSURE OFFSHORE AHEAD OF A COLD FRONT THAT
COMES THROUGH THURSDAY NIGHT. SLY CHANNELING TO 20 KT POSSIBLE WED
EVENING...AND THURSDAY. NWLY FLOW TO 20 KT POSSIBLE FRIDAY. LIGHT
AND VARIABLE FLOW THIS WEEKEND.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES HAVE INCREASED TO AROUND ONE QUARTER FOOT ABOVE
NORMAL. ANOMALIES MAY INCREASE A BIT MORE DUE TO THE SOUTHERLY
FLOW...BUT WATER LEVELS SHOULD REMAIN BELOW THRESHOLDS FOR MINOR
FLOODING THROUGH TONIGHT. WILL HAVE TO WATCH SOUTHERLY FLOW
WEDNESDAY AND THURSDAY AS IT MAY SUPPORT AN INCREASE IN DEPARTURES
AGAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BJL
NEAR TERM...HTS/BJL
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BJL/BAJ
MARINE...BAJ/BJL
TIDES/COASTAL FLOODING...BJL
000
FXUS61 KLWX 210758
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
358 AM EDT TUE MAY 21 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE ATLANTIC WILL CONTINUE TO AID A SOUTHERLY
FLOW THROUGH THURSDAY...BRINGING WARM AND HUMID CONDITIONS. AFTERNOON
AND EVENING THUNDERSTORMS ARE POSSIBLE EACH DAY. A COLD FRONT
WILL PASS THROUGH THE REGION THURSDAY NIGHT INTO FRIDAY. COOLER
CONDITIONS ARE EXPECTED OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WEAK UPPER-LEVEL LOW PRESSURE REMAINS OVER SOUTHERN VIRGINIA INTO
THE CAROLINAS EARLY THIS MORNING WHILE SURFACE HIGH PRESSURE REMAINS
CENTERED OVER THE ATLANTIC OCEAN.
A SOUTHERLY FLOW AROUND THE SURFACE HIGH HAS CAUSED WARM AND HUMID
CONDITIONS EARLY THIS MORNING. PLENTY OF MOISTURE IS TRAPPED
UNDERNEATH THE NOCTURNAL INVERSION AND THIS WILL CAUSE LOW CLOUDS
ALONG WITH AREAS OF FOG EARLY. FOG MAY BE LOCALLY DENSE IN VALLEYS
AND RURAL AREAS.
LOW CLOUDS AND FOG WILL MIX OUT BY MID-MORNING AND A SOUTHERLY FLOW
WILL CONTINUE TO USHER IN WARM AND HUMID CONDITIONS. MAX TEMPS TODAY
SHOULD BE SEVERAL DEGREES WARMER THAN MONDAY...RANGING FROM THE 70S
IN THE MOUNTAINS TO THE MID AND UPPER 80S ACROSS MOST OTHER
LOCATIONS. LEANED CLOSER TO THE MAV GUIDANCE FOR MAX TEMPS WHICH IS
A BIT WARMER THAN OTHER GUIDANCE. THE MAV HAS BEEN PERFORMING WELL
AND THERE SHOULD BE ENOUGH SUNSHINE AND MIXING FOR HIGHER TEMPS.
THE WARM AND HUMID AIR WILL LEAD TO HIGH AMOUNTS OF INSTABILITY.
NAM/GFS BUFKIT ARE INDICATING AROUND 2000-2500 J/KG OF MLCAPE THIS
AFTERNOON. A CAPPING INVERSION AROUND 5KFT WILL MAKE IT DIFFICULT
FOR CONVECTION TO DEVELOP. DID ALLOW FOR A CHANCE FOR
SHOWERS/T-STORMS ANYWAY DUE TO TERRAIN CIRCULATION...A SURFACE
TROUGH AND THE UPPER-LEVEL LOW ACTING AS LIFTING MECHANISMS. WILL
ALSO HAVE TO MONITOR CONVECTION OVER THE MIDWEST. THIS MAY SURVIVE
OFF ITS COLD POOL AND BRING A THREAT FOR MORE WIDESPREAD CONVECTION
ALONG THE ALLEGHENY AND POTOMAC HIGHLANDS THIS EVENING. THE HIGHEST
POPS ARE LOCATED ACROSS THESE AREAS FOR THAT REASON.
THE THREAT FOR SEVERE T-STORMS THIS AFTERNOON AND EVENING SHOULD BE
LOW DUE TO THE STRONG CAPPING INVERSION. HOWEVER...IF THE LIFTING
MECHANISMS END UP BEING STRONG ENOUGH TO ERODE THE INVERSION...THEN
GUSTY WINDS AND HAIL ARE POSSIBLE.
ANY LEFTOVER CONVECTION WILL DISSIPATE OVERNIGHT DUE TO THE LOSS OF
DAYTIME HEATING. LOW CLOUDS AND AREAS OF FOG MAY DEVELOP AS MOISTURE
GETS TRAPPED UNDERNEATH THE NOCTURNAL INVERSION. HOWEVER...LOW
CLOUDS/FOG SHOULD NOT BE AS WIDESPREAD AS RECENT NIGHTS DUE TO A
HIGHER TEMP/DEWPOINT DEPRESSION AND A STRONGER GRADIENT. MIN TEMPS
WILL BE IN THE 60S ACROSS MOST AREAS TO THE LOWER 70S IN DOWNTOWN
WASHINGTON/BALTIMORE.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
CNTRL MID-ATLANTIC IN WARM SECTOR OF MIDWEST LOW UNTIL A COLD FRONT
IN THE THURSDAY NIGHT TIMEFRAME. SFC HIGH WELL OFF ERN SEABOARD AIDS
SLY FLOW/MOISTURE ADVECTION. TEMPS ABOUT 10 DEGREES ABOVE NORMAL
WITH UPR 60S TO NEAR 70F DEWPOINTS. EXPECT A DIURNAL TREND IN PRECIP
COVERAGE WITH PREFRONTAL FORCING ENTERING THE AREA THURSDAY. SLIGHT
RISK FOR WEDNESDAY DUE TO POTENTIAL FOR STRAIGHT LINE WINDS FROM
ONGOING MCS ACTIVITY OVER THE OHIO VALLEY PUSHING EAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
12Z ECMWF PROGS THE CD FROPA AS THURSDAY NIGHT (THERE HAS BEEN
FLUCTUATION FROM LATE THURSDAY TO FRIDAY MORNING). CANADIAN HIGH
PRESSURE BUILDS IN WITH A CRYSTAL CLEAR AND COOL WITH TEMPS 5-10
DEGREES BELOW NORMAL. SHORTWAVE OVER THE TN VLY ON SUNDAY SHOULD
REMAIN WEST OF THE LWX CWA...WILL HAVE TO MONITOR FOR INCREASED
POPS. AS OF NOW EXPECT SOME HIGH CLOUDS SUNDAY WITH A WARMING TREND
STARTING THAT CONTINUES INTO MID NEXT WEEK.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
LOW-LEVEL MOISTURE IS TRAPPED UNDERNEATH THE NOCTURNAL INVERSION.
LOW CLOUDS AND FOG ARE EXPECTED WITH IFR/SUBIFR CONDITIONS EARLY
THIS MORNING. CIGS/VSBYS WILL IMPROVE BY MID MORNING AND SOUTHERLY
WINDS ARE EXPECTED THIS AFTERNOON WITH GUSTS AROUND 15 KNOTS
EXPECTED. SCATTERED SHOWERS AND T-STORMS ARE POSSIBLE THIS AFTERNOON
AND EVENING. AREAS OF LOW CLOUDS/FOG MAY IMPACT THE TERMINALS LATE
TONIGHT.
DIURNAL THUNDERSTORM ACTIVITY WED/THUR WITH IFR CONDS POSSIBLE IN
THE HEAVIEST ONES. SLY FLOW UNTIL A COLD FROPA THURSDAY NIGHT. NWLY
FLOW WITH CLEAR CONDS SATURDAY. JUST SOME HIGH CLOUDS ON SUNDAY.
&&
.MARINE...
SOUTHERLY WINDS ARE EXPECTED OVER THE WATERS THROUGH TONIGHT. WIND
GUSTS WILL BE CLOSE TO SCA CRITERIA THIS AFTERNOON AND TONIGHT. HAVE
CAPPED GUSTS AROUND 15 KNOTS FOR NOW DUE TO THE RELATIVELY COOLER
WATERS. SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON AND EVENING.
SLY FLOW WITH HIGH PRESSURE OFFSHORE AHEAD OF A COLD FRONT THAT
COMES THROUGH THURSDAY NIGHT. SLY CHANNELING TO 20 KT POSSIBLE WED
EVENING...AND THURSDAY. NWLY FLOW TO 20 KT POSSIBLE FRIDAY. LIGHT
AND VARIABLE FLOW THIS WEEKEND.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES HAVE INCREASED TO AROUND ONE QUARTER FOOT ABOVE
NORMAL. ANOMALIES MAY INCREASE A BIT MORE DUE TO THE SOUTHERLY
FLOW...BUT WATER LEVELS SHOULD REMAIN BELOW THRESHOLDS FOR MINOR
FLOODING THROUGH TONIGHT. WILL HAVE TO WATCH SOUTHERLY FLOW
WEDNESDAY AND THURSDAY AS IT MAY SUPPORT AN INCREASE IN DEPARTURES
AGAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/BJL
MARINE...BAJ/BJL
TIDES/COASTAL FLOODING...BJL
000
FXUS61 KLWX 202354
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
754 PM EDT MON MAY 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE ATLANTIC WILL PROVIDE A SOUTHERLY FLOW FOR
TUESDAY AND WEDNESDAY...BRINGING WARM AND HUMID CONDITIONS.
MEANWHILE...AND UPPER LEVEL DISTURBANCE WILL CROSS THE REGION. A
COLD FRONT WILL PASS THROUGH THE AREA THURSDAY AFTERNOON AND
EVENING. COOLER CONDITIONS WILL RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
ALTHO NOT QUITE AS WARM...WINDWISE IT FEELS SOMEWHAT LK MID-SUMMER
GIVEN HOW LGT THE WIND FIELD IS. CELLS WHICH PRODUCE ISOLD FLDG IN
AUGUSTA CO. IN LATE AFTN ARE BEGINNING TO WEAKEN.
ONCE DAYTIME HEATING WANES...SHRA/TSRA CVRG SHUD DIMINISH. AM
RUNNING WITH A DRY FCST OVNGT. ITS PSBL THAT THERE MAY BE A STRAY
STORM OR TWO...BUT CANNOT PINPOINT WHERE...AND WUD RATHER NOT
BLANKET LOW POPS OVER A LARGE AREA.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
MID-ATLANTIC WILL BE ON THE WARM SIDE OF THINGS DURING MID-WEEK.
THIS WILL ALLOW FOR A WARM UP TUESDAY-WEDNESDAY...WITH HIGHS IN
THE MID 80S. IF THERE IS MORE SUNSHINE...TEMPS COULD REACH UPPER
80S IN SOME LOCATIONS.
THERE WL BE TRRN CIRCULATIONS AND DIURNAL HEATING BNDRYS. HV CHC
POPS CENTERED UPON TIME OF PEAK HTG TUE AFTN. AM TAKING THAT ROUND
EWD IN THE EVNG INVOF H5 AXIS.
THE MID LVL RDG AXIS BREAKS DOWN WED WHICH WL PROVIDE ITS OWN TSRA
SUPPORT. WED AFTN POPS SEEM ADEQUATE IN THE 30-40 PCT RANGE...BUT
HV INCREASE EVNG CVRG AS HGTS FALL. NWRN CORNER OF CWFA TOUCHING
SPC DAY 3 SLGT RISK...AND ISOL SVR CRVG TO APPROX THE BLURDG IN
CONJUNCTION WITH THIS THREAT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
SLIGHT HEIGHT FALLS ARE FORECAST TOWARD THE END OF THE WEEK AS AN
UPPER TROUGH APPROACHES...IN TANDEM WITH A COLD FRONT. THERE IS SOME
QUESTION REGARDING TIMING OF THE FROPA...LATEST GUIDANCE SUGGESTING
LATE THURSDAY INTO EARLY FRIDAY. DUE TO UNCERTAINTY HAVE CHANCE POPS
IN THE THURSDAY THROUGH FRIDAY TIME FRAME...AND WE CAN FINE TUNE THE
TIMING AS WE GET CLOSER.
THERE IS GOOD AGREEMENT THAT THE FRONT WILL HAVE MOVED THROUGH THE
AREA BY THE WEEKEND...FAVORING A COOLER/DRIER AIR MASS. FORECAST
REFLECTS MOSTLY CLEAR SKIES AND TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR CONDS PREVAIL AT ALL SITES. FOG MAY FORM AFTR MDNGT..AND HV
3SM IN SVRL OF THE TAFS..BUT GIVEN TEMPS AT SVRL SITES HAD A POST
5 PM MAX AM UNCERTAIN THIS LATE DAY WARMTH WAS FIGURED INTO THE MDLS.
EXPECT FOG/STRATUS EARLY TUESDAY AS LOW LEVEL MOISTURE REMAINS.
ONCE THIS MSTR BURNS OFF...VFR EXPECTED TO PREVAIL THE BALANCE OF
TUESDAY. CHANCE OF THUNDERSTORMS RETURNS IN THE AFTN...BUT CVRG
ISSUES REDUCE CONFIDENCE IF AIRFIELDS WL BE IMPACTED. A REPEAT
PERFORMANCE POSSIBLE WED...AND AGAIN THU. GREATEST CVRG ASSOCD
WITH CFP LT THU.
&&
.MARINE...
SLY WNDS 10-15 KT OVRNGT.
SLY WINDS ARE EXPECTED TUE-WED UNTIL A COLD FRONT MOVES THROUGH
THU SWITCHING WINDS TO THE NORTHWEST. THERES A DAILY TSRA RISK...
SPCLY IN THE AFTN/EVE.
SOUTHERLY CHANNELLING UP THE BAY COULD BRING MARGINAL SCA
CONDITIONS...PARTICULARLY DURING THE LATE AFTERNOON/EVENINGS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES REMAIN NEAR NORMAL. WILL HAVE TO WATCH SOUTHERLY
FLOW DURING THE MID-WEEK AS IT MAY SUPPORT AN INCREASE IN
DEPARTURES AGAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...WOODY!
PRVS...HTS
000
FXUS61 KLWX 201907
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
307 PM EDT MON MAY 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE ATLANTIC WILL PROVIDE A SOUTHERLY FLOW FOR
TUESDAY AND WEDNESDAY...BRINGING WARM AND HUMID CONDITIONS.
MEANWHILE...AND UPPER LEVEL DISTURBANCE WILL CROSS THE REGION. A
COLD FRONT WILL PASS THROUGH THE AREA THURSDAY AFTERNOON AND
EVENING. COOLER CONDITIONS WILL RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
CWFA WITHIN WARM SECTOR TAFTN...BUT LOTSA CLDCVR HAS HELD TEMPS
DOWN...WHICH IN TURN HAS LIMITED AMT IN INSTBY GENERATED. CUTOFF
H5 TROF AXIS UNDER L/WV RDGG HAS ASSISTED IN FOCUSING SHRA/TSRA
ACTIVITY ACRS WVA/WRN VA/CENTRL NC. SINCE THESE STORMS ARE W/IN A
RDG AXIS...FWD MOTION HAS BEEN SLOW...AND MUCH OF THIS ACTIVITY
LKLY WONT REACH CWFA E OF THE SHEN VLY. GREATER INSTBY ALSO CAN BE
FOUND IN SERN VA/ERN NC DUE TO MORE AMPLE HEATING...AND SOME OF
THESE STORMS WL APPROACH SRN MD AND THE NRN NECK OF VA. POPS HIEST
IN THESE TWO AREAS. AM HANGING ONTO CHC POPS ELSW TIL ABT SUNSET.
PWAT ALMOST UP TO 1.5 INCHES...SO HVY RAIN SHUD BE THE BIGGEST
THREAT.
ONCE DAYTIME HEATING WANES...THINK SHRA/TSRA CVRG SHUD DIMINISH.
AM RUNNING WITH A DRY FCST OVNGT. ITS PSBL THAT THERE MAY BE A
STRAY STORM OR TWO...BUT CANNOT PINPOINT WHERE...AND WUD RATHER
NOT BLANKET SMALL POPS OVER A LARGE AREA. INSTEAD...THE NEARLY
SATD LLVLS SHUD LEAD TO MORE LOW CLDS/FOG FOR THE OVNGT HRS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
MID-ATLANTIC WILL RESIDE IN A WARM SECTOR DURING THE MID-WEEK. THIS
WILL ALLOW FOR A WARM UP TUESDAY THROUGH WEDNESDAY...WITH MAXIMA IN
THE MID 80S. IF THERE IS MORE SUNSHINE...THEN MAXIMA COULD EVEN
REACH UPPER 80S IN SOME LOCATIONS.
TUESDAY MORNING MAY START OFF WITH SOME FOG/STRATUS...BUT CLOUDS
SHOULD BREAK FOR SOME SUNSHINE DURING THE AFTERNOON. GREATER
INSTBY IN PLACE AND H5 TROF AXIS SHUD STILL BE LINGERING...MUCH
LIKE SSIDE VA/NC TAFTN. PLUS...THERE WL BE TRRN BASED
CIRCULATIONS AND DIURNAL HEATING BNDRYS. AM THEREFORE
UNCOMFORTABLE WITH A DRY FCST...AND HV ADDED CHC POPS CENTERED
UPON TIME OF PEAK HTG TUE AFTN. AM TAKING THAT ROUND EWD IN THE
EVNG INVOF H5 AXIS.
THE MID LVL RDG AXIS BREAKS DOWN WED WHICH WL PROVIDE ITS OWN TSRA
SUPPORT. WED AFTN POPS SEEM ADEQUATE IN THE 30-40 PCT RANGE...BUT
HV INCREASE EVNG CVRG AS HGTS FALL. NWRN CORNER OF CWFA TOUCHING
SPC DAY 3 SLGT RISK...AND ISOL SVR CRVG TO APPROX THE BLURDG IN
CONJUNCTION WITH THIS THREAT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SLIGHT HEIGHT FALLS ARE FORECAST TOWARD THE END OF THE WEEK AS AN
UPPER TROUGH APPROACHES...IN TANDEM WITH A COLD FRONT. THERE IS SOME
QUESTION REGARDING TIMING OF THE FROPA...LATEST GUIDANCE SUGGESTING
LATE THURSDAY INTO EARLY FRIDAY. DUE TO UNCERTAINTY HAVE CHANCE POPS
IN THE THURSDAY THROUGH FRIDAY TIME FRAME...AND WE CAN FINE TUNE THE
TIMING AS WE GET CLOSER.
THERE IS GOOD AGREEMENT THAT THE FRONT WILL HAVE MOVED THROUGH THE
AREA BY THE WEEKEND...FAVORING A COOLER/DRIER AIR MASS. FORECAST
REFLECTS MOSTLY CLEAR SKIES AND TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
CIGS HV LIFTED...AND VFR CONDS PREVAIL AT ALL SITES XCPT MTN.
TSRA/SHRA CHCS THRU SUNSET SLIM...BUT NONZERO. UNLKLY THAT A CELL
WL AFFECT AN AIRFIELD...BUT CHO WL BE NEAREST AIRPORT.
EXPECT FOG/STRATUS EARLY TUESDAY AS LOW LEVEL MOISTURE REMAINS.
ONCE THIS MSTR BURNS OFF...VFR EXPECTED TO PREVAIL THE BALANCE OF
TUESDAY. CHANCE OF THUNDERSTORMS RETURNS IN THE AFTN...BUT CVRG
ISSUES REDUCE CONFIDENCE IF AIRFIELDS WL BE IMPACTED. A REPEAT
PERFORMANCE POSSIBLE WED...AND AGAIN THU. GREATEST CVRG ASSOCD
WITH CFP LT THU.
&&
.MARINE...
SLY WNDS TAFTN...BUT AOB 10 KT. THERE MAY BE A FEW SHRA/TSRA...
SPCLY IN THE MID BAY/LWR PTMC WHICH WUD PRODUCE LCLLY HIER WNDS.
SLY WINDS ARE EXPECTED TUE-WED UNTIL A COLD FRONT MOVES THROUGH
THU SWITCHING WINDS TO THE NORTHWEST. THERES A DAILY TSRA RISK...
SPCLY IN THE AFTN/EVE.
SOUTHERLY CHANNELLING UP THE BAY COULD BRING MARGINAL SCA
CONDITIONS...PARTICULARLY DURING THE LATE AFTERNOON/EVENINGS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES REMAIN NEAR NORMAL. WILL HAVE TO WATCH SOUTHERLY
FLOW DURING THE MID-WEEK AS IT MAY SUPPORT AN INCREASE IN
DEPARTURES AGAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
000
FXUS61 KLWX 201427
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1027 AM EDT MON MAY 20 2013
.SYNOPSIS...
A WARM FRONT WILL PASS THROUGH THE AREA TODAY WHILE AN UPPER-LEVEL
DISTURBANCE MOVES THROUGH THE AREA. HIGH PRESSURE OVER THE ATLANTIC
WILL PROVIDE A SOUTHERLY FLOW FOR TUESDAY THROUGH THURSDAY...
BRINGING WARM AND HUMID CONDITIONS. A COLD FRONT WILL PASS THROUGH
THE AREA LATE IN THE WEEK AND COOLER CONDITIONS WILL RETURN FOR
NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
WK WMFNT ALONG OR NEAR THE PTMC RIVER THIS MRNG. LWX RAOB MOIST
BUT NOT SATD. LIKE SNDGS FM SIMLR SECTOR YDA...ITS ALSO MARGINALLY
UNSTBL. CNVCTV TEMPS UP IN THE UPR 70S...WHICH PER LAMP WUD BE
REACHABLE. IN ADDITION...AN UPR LOW MVG THRU THE TN VLY TWD WRN
VA/SRN WVA CAN BE A TRIGGERING MECHANISM.
THEREFORE...XPCT SHRA/TSRA TO DVLP TAFTN IN THE WARM AMS. PWAT
ARND 1.40 IN AND CAPE VALUES 500-1000 J/KG SUGGESTS THAT HVY
RAINERS WL BE THE BIGGER CONCERN...NOT WND GUSTS. IN FACT...SHEAR
LESS THAN 10 KT. HELD ONTO GLIMMER OF LKLY POPS FOR CENTRL VA AND
UPR PTMC HIGHLANDS...OTRW CVRG WL BE SCT AT BEST. RADAR DEPICTION
WL BE PRTLY CONTROLLED BY MESOSCALE FEATURES SUCH AS THE DIFF
HEATING BNDRY PRESENT IN SHEN VLY/PTMC HIGHLANDS ATTM.
WARM AND HUMID CONDITIONS WILL PERSIST OVERNIGHT WITH MIN TEMPS
HOLDING IN THE 60S FOR MOST AREAS. PLENTY OF MOISTURE UNDERNEATH THE
NOCTURNAL INVERSION WILL RESULT IN AREAS OF LOW CLOUDS/FOG.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
MID-ATLANTIC WILL RESIDE IN A WARM SECTOR DURING THE MID-WEEK. THIS
WILL ALLOW FOR A WARM UP TUESDAY THROUGH WEDNESDAY...WITH MAXIMA IN
THE MID 80S. IF THERE IS MORE SUNSHINE...THEN MAXIMA COULD EVEN
REACH UPPER 80S IN SOME LOCATIONS.
TUESDAY MORNING MAY START OFF WITH SOME FOG/STRATUS...BUT CLOUDS
SHOULD BREAK FOR SOME SUNSHINE DURING THE AFTERNOON. MODELS SHOW
MOISTURE IN PLACE...AND SOME INSTABILITY AS WELL HOWEVER AM HAVING
TROUBLE FINDING ANY GOOD FORCING/FOCUSING MECHANISMS FOR CONVECTION
THEREFORE CONTINUE TO FAVOR A DRY FORECAST FOR TUESDAY WITH ONLY
ISOLATED CONVECTION ACROSS THE NORTHWEST.
AIR MASS REMAINS THE SAME ON WEDNESDAY. MODELS HINT AT A BETTER
CHANCE OF DIURNAL CONVECTION SO HAVE INCLUDED CHANCE POPS IN THE
FORECAST FOR SCATTERED THUNDERSTORMS ACROSS THE CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SLIGHT HEIGHT FALLS ARE FORECAST TOWARD THE END OF THE WEEK AS AN
UPPER TROUGH APPROACHES...IN TANDEM WITH A COLD FRONT. THERE IS SOME
QUESTION REGARDING TIMING OF THE FROPA...LATEST GUIDANCE SUGGESTING
LATE THURSDAY INTO EARLY FRIDAY. DUE TO UNCERTAINTY HAVE CHANCE POPS
IN THE THURSDAY THROUGH FRIDAY TIME FRAME...AND WE CAN FINE TUNE THE
TIMING AS WE GET CLOSER.
THERE IS GOOD AGREEMENT THAT THE FRONT WILL HAVE MOVED THROUGH THE
AREA BY THE WEEKEND...FAVORING A COOLER/DRIER AIR MASS. FORECAST
REFLECTS MOSTLY CLEAR SKIES AND TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
IFR CONDS REMAIN ACROSS DCA/IAD/BWI. AT LEAST MVFR ELSW. MAY
INSOLATION WL ERODE LLVL MSTR...PERMITTING CONDITIONS TO IMPROVE
BY EARLY AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED...MAINLY THIS TAFTN AND EVENING. HWVR...LOW CONFIDENCE ON
DIRECT IMPACT FOR ANY AIRFIELD.
THERE IS THE POTENTIAL FOR SOME FOG/STRATUS EARLY TUESDAY...
PARTICULARLY IF SOME OVERNIGHT CLEARING TAKES PLACE AS LOW LEVEL
MOISTURE REMAINS. BUT CONFIDENCE REMAINS ONLY LOW-MODERATE ON
OCCURRENCE ATTM. VFR EXPECTED TO PREVAIL THE BALANCE OF TUESDAY.
CHANCE OF THUNDERSTORMS RETURNS FOR WEDNESDAY AFTERNOON...AND
SHRA/TSRA REMAIN POSSIBLE UNTIL A COLD FRONT MOVES THROUGH LATE
THURSDAY INTO EARLY FRIDAY.
&&
.MARINE...
SOUTHERLY WINDS ARE EXPECTED TODAY THROUGH TONIGHT AS A WMFNT MVS
NWD. HOWEVER...WIND SPEEDS WILL REMAIN BELOW SCA CRITERIA.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED...MAINLY THIS
AFTERNOON AND EVENING.
SOUTHERLY WINDS ARE EXPECTED DURING THE MID WEEK UNTIL A COLD FRONT
MOVES THROUGH TOWARD THE END OF THE WEEK SWITCHING WINDS TO THE
NORTHWEST. SOUTHERLY FLOW CHANNELLING UP THE BAY COULD BRING
MARGINAL SCA CONDITIONS UP THE BAY PARTICULARLY DURING THE LATE
AFTERNOON/EVENINGS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES REMAIN NEAR NORMAL EARLY THIS MORNING. SOUTHERLY
WINDS ARE WILL DEVELOP OVER THE WATERS TODAY AND ANOMALIES ARE
EXPECTED TO INCREASE. HOWEVER...THE HIGH TIDE THIS AFTERNOON WILL BE
THE LOWER OF THE TWO. WILL HAVE TO WATCH SOUTHERLY FLOW DURING THE
MID-WEEK AS IT MAY SUPPORT AN INCREASE IN DEPARTURES AGAIN. BUT
CBOFS KEEPS WATER LEVELS BELOW MINOR THRESHOLDS THROUGH HIGH TIDES
TUESDAY AFTERNOON.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BJL/BPP
NEAR TERM...HTS/BJL
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...HTS/BJL/BPP
MARINE...HTS/BJL/BPP
TIDES/COASTAL FLOODING...BJL/BPP
000
FXUS61 KLWX 200731
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
331 AM EDT MON MAY 20 2013
.SYNOPSIS...
A WARM FRONT WILL PASS THROUGH THE AREA TODAY WHILE AN UPPER-LEVEL
DISTURBANCE MOVES THROUGH THE AREA. HIGH PRESSURE OVER THE ATLANTIC
WILL PROVIDE A SOUTHERLY FLOW FOR TUESDAY THROUGH
THURSDAY...BRINGING WARM AND HUMID CONDITIONS. A COLD FRONT WILL
PASS THROUGH THE AREA LATE IN THE WEEK AND COOLER CONDITIONS WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT ANALYSIS SHOWS A STATIONARY BOUNDARY OVER THE REGION EARLY
THIS MORNING WHILE UPPER-LEVEL LOW PRESSURE SLOWLY MOVES INTO THE
AREA FROM WEST VIRGINIA.
THE STATIONARY BOUNDARY SEPARATES WARM AND MOIST AIR TO THE SOUTH
AND WEST FROM COOLER MARINE AIR TO THE NORTH AND EAST. WIDESPREAD
LOW CLOUDS ALONG WITH FOG/DRIZZLE ARE EXPECTED TO THE NORTH AND
EAST OF THE BOUNDARY ACROSS NORTHEASTERN MARYLAND. HOWEVER...PLENTY
OF MOISTURE IS TRAPPED UNDERNEATH THE NOCTURNAL INVERSION SO AREAS
OF LOW CLOUDS AND FOG/DRIZZLE ARE ALSO EXPECTED SOUTH AND WEST OF
THE BOUNDARY. A FEW SHOWERS ARE POSSIBLE EARLY THIS
MORNING...ESPECIALLY CLOSER TO THE UPPER-LEVEL LOW ACROSS CENTRAL
VIRGINIA.
THE STATIONARY BOUNDARY WILL MOVE NORTH AS A WARM FRONT LATER THIS
MORNING AND AFTERNOON. SOUTHERLY WINDS BEHIND THE BOUNDARY WILL
USHER IN WARM AND HUMID CONDITIONS. THE UPPER-LEVEL LOW WILL SLOWLY
MOVE INTO THE REGION DURING THIS TIME. THE COMBINATION OF WARM AND
HUMID CONDITIONS ALONG WITH COOLER AIR ALOFT WILL CAUSE AN UNSTABLE
ATMOSPHERE THIS AFTERNOON. SHOWERS AND T-STORMS ARE EXPECTED TO
DEVELOP DURING THIS TIME. A LIGHT WIND FIELD AND INSTABILITY
REMAINING SOMEWHAT LIMITED DUE TO CLOUD COVER SHOULD KEEP THE SEVERE
THREAT LOW. SCATTERED SHOWERS/T-STORMS MAY CONTINUE INTO THIS
EVENING...BUT DRY CONDITIONS ARE EXPECTED OVERNIGHT DUE TO THE LOSS
OF DAYTIME HEATING.
WARM AND HUMID CONDITIONS WILL PERSIST OVERNIGHT WITH MIN TEMPS
HOLDING IN THE 60S FOR MOST AREAS. PLENTY OF MOISTURE UNDERNEATH THE
NOCTURNAL INVERSION WILL RESULT IN AREAS OF LOW CLOUDS/FOG.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
MID-ATLANTIC WILL RESIDE IN A WARM SECTOR DURING THE MID-WEEK. THIS
WILL ALLOW FOR A WARM UP TUESDAY THROUGH WEDNESDAY...WITH MAXIMA IN
THE MID 80S. IF THERE IS MORE SUNSHINE...THEN MAXIMA COULD EVEN
REACH UPPER 80S IN SOME LOCATIONS.
TUESDAY MORNING MAY START OFF WITH SOME FOG/STRATUS...BUT CLOUDS
SHOULD BREAK FOR SOME SUNSHINE DURING THE AFTERNOON. MODELS SHOW
MOISTURE IN PLACE...AND SOME INSTABILITY AS WELL HOWEVER AM HAVING
TROUBLE FINDING ANY GOOD FORCING/FOCUSING MECHANISMS FOR CONVECTION
THEREFORE CONTINUE TO FAVOR A DRY FORECAST FOR TUESDAY WITH ONLY
ISOLATED CONVECTION ACROSS THE NORTHWEST.
AIR MASS REMAINS THE SAME ON WEDNESDAY. MODELS HINT AT A BETTER
CHANCE OF DIURNAL CONVECTION SO HAVE INCLUDED CHANCE POPS IN THE
FORECAST FOR SCATTERED THUNDERSTORMS ACROSS THE CWA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SLIGHT HEIGHT FALLS ARE FORECAST TOWARD THE END OF THE WEEK AS AN
UPPER TROUGH APPROACHES...IN TANDEM WITH A COLD FRONT. THERE IS SOME
QUESTION REGARDING TIMING OF THE FROPA...LATEST GUIDANCE SUGGESTING
LATE THURSDAY INTO EARLY FRIDAY. DUE TO UNCERTAINTY HAVE CHANCE POPS
IN THE THURSDAY THROUGH FRIDAY TIME FRAME...AND WE CAN FINE TUNE THE
TIMING AS WE GET CLOSER.
THERE IS GOOD AGREEMENT THAT THE FRONT WILL HAVE MOVED THROUGH THE
AREA BY THE WEEKEND...FAVORING A COOLER/DRIER AIR MASS. FORECAST
REFLECTS MOSTLY CLEAR SKIES AND TEMPERATURES NEAR CLIMATOLOGY.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
PLENTY OF MOISTURE REMAINS TRAPPED UNDERNEATH THE NOCTURNAL
INVERSION. LOW CLOUDS AND AREAS OF FOG WILL CAUSE IFR/SUB IFR
CIGS/VSBYS EARLY THIS MORNING. A WARM FRONT WILL PASS THROUGH THE
TERMINALS LATER THIS MORNING AND CONDITIONS WILL IMPROVE BY LATE
MORNING/EARLY AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED...MAINLY THIS AFTERNOON AND EVENING. AREAS OF LOW
CLOUDS/FOG ARE POSSIBLE AGAIN TONIGHT.
THERE IS THE POTENTIAL FOR SOME FOG/STRATUS EARLY
TUESDAY...PARTICULARLY IF SOME OVERNIGHT CLEARING TAKES PLACE AS
LOW LEVEL MOISTURE REMAINS. BUT CONFIDENCE REMAINS ONLY LOW-MODERATE
ON OCCURRENCE ATTM. VFR EXPECTED TO PREVAIL THE BALANCE OF TUESDAY.
CHANCE OF THUNDERSTORMS RETURNS FOR WEDNESDAY AFTERNOON...AND
SHRA/TSRA REMAIN POSSIBLE UNTIL A COLD FRONT MOVES THROUGH LATE
THURSDAY INTO EARLY FRIDAY.
&&
.MARINE...
A STATIONARY BOUNDARY OVER THE WATERS WILL MOVE TO THE NORTH AS A
WARM FRONT TODAY. SOUTHERLY WINDS ARE EXPECTED TODAY THROUGH TONIGHT
BEHIND THIS BOUNDARY. HOWEVER...WIND SPEEDS WILL REMAIN BELOW SCA
CRITERIA. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED...MAINLY
THIS AFTERNOON AND EVENING.
SOUTHERLY WINDS ARE EXPECTED DURING THE MID WEEK UNTIL A COLD FRONT
MOVES THROUGH TOWARD THE END OF THE WEEK SWITCHING WINDS TO THE
NORTHWEST. SOUTHERLY FLOW CHANNELLING UP THE BAY COULD BRING
MARGINAL SCA CONDITIONS UP THE BAY PARTICULARLY DURING THE LATE
AFTERNOON/EVENINGS.
&&
.TIDES/COASTAL FLOODING...
TIDAL ANOMALIES REMAIN NEAR NORMAL EARLY THIS MORNING. SOUTHERLY
WINDS ARE WILL DEVELOP OVER THE WATERS TODAY AND ANOMALIES ARE
EXPECTED TO INCREASE. HOWEVER...THE HIGH TIDE THIS AFTERNOON WILL BE
THE LOWER OF THE TWO. WILL HAVE TO WATCH SOUTHERLY FLOW DURING THE
MID-WEEK AS IT MAY SUPPORT AN INCREASE IN DEPARTURES AGAIN. BUT
CBOFS KEEPS WATER LEVELS BELOW MINOR THRESHOLDS THROUGH HIGH TIDES
TUESDAY AFTERNOON.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BJL/BPP
NEAR TERM...BJL
SHORT TERM...BPP
LONG TERM...BPP
AVIATION...BJL/BPP
MARINE...BJL/BPP
TIDES/COASTAL FLOODING...BJL/BPP
000
FXUS61 KLWX 200110
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
910 PM EDT SUN MAY 19 2013
.SYNOPSIS...
A WARM FRONT WILL SLOWLY LIFT NORTH OF THE AREA TONIGHT INTO
MONDAY MORNING. A WEAK MID-LEVEL TROUGH WILL MOVE THROUGH MONDAY.
HIGH PRESSURE BUILDS OVER THE WESTERN ATLANTIC TUESDAY AND
WEDNESDAY...WITH SOUTHERLY RETURN FLOW PROVIDING WARM TEMPERATURES
TO THE REGION. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES
LATE THIS WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
HIGH PRESSURE LOCATED OVER THE NORTHERN ATLANTIC HAS LED TO
SOUTHERLY FLOW ACROSS THE MID ATLANTIC. A STATIONARY FRONT IS
CURRENTLY DRAPED ACROSS VA STATE AND WILL MOVE NORTHWARD AS A WARM
FRONT BY MONDAY AFTERNOON. THE WARM FRONT NOSED NORTHWARD LATE THIS
AFTERNOON AND MIXING OCCURRED TO BREAK UP SOME OF THE LOW CEILINGS.
AS SFC HEATING CEASED CLOUDS INCREASED AGAIN THIS EVENING. SFC
ANALYSIS DOES NOT SHOW A DISTINCT STATIONARY FRONT BUT BELIEVE IT IS
SITUATED NORTH OF THE BAY AND ACROSS CENTRAL VIRGINIA. OVERNIGHT...
LITTLE MOVEMENT OF WARM FRONT AND THEREFORE LITTLE CHANGE TO
CURRENT AIRMASS AND SCATTERED SHOWERS WILL CONTINUE ACROSS CENTRAL
VIRGINIA. HEAVIER SHOWERS TO THE SOUTH HAVE WANED THIS EVENING AND
DO EXPECT THAT TO CONTINUE OVERNIGHT. SATURATED LOW LEVELS
ELSEWHERE WILL LEAD TO DRIZZLE AND PATCHY FOG OVERNIGHT AND MONDAY
MORNING.
AN UPPER LEVEL LOW WILL MOVE ACROSS THE REGION MONDAY AND HELP MIX
THE LOW CEILINGS. SHOWERS AND THUNDERSTORMS ARE POSSIBLE ACROSS THE
CWA IN THE AFTERNOON AND EVENING. SOUTHERLY FLOW WILL CONTINUE TO
USHER IN HIGH PWAT AIR AND FCST SOUNDINGS SHOW CAPE VALUES AROUND
500 J/KG WITH A SLOW STORM MOTION. HEAVY RAIN WILL BE POSSIBLE IN
THUNDERSTORM ACTIVITY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
LOW CLDS AND FOG WL CONT TO BE A FACTOR INTO THE MRNG HRS.
HWVR...THE MAY SUN ANGLE WL GRDLY ERODE THE SATD LYR...PERMITTING
THE FNT TO JUMP N OF AREA BY THE AFTN. SOUTH OF THIS FRONT...A
WARM AND A MODESTLY HUMID AIRMASS WILL BE IN PLACE. MAX TEMPS IN
THE 80S EACH DAY ALTHOUGH CLOUDS MAY INHIBIT TEMPS FROM REACHING
80F IN SOME LOCATIONS ON MON.
NAM/GFS/ECMWF PROG A MID-LVL SHORTWAVE TROUGH TO MV THRU THE MID-
ATLC REGION ON MON. LIFT/MOISTURE AHEAD OF THE TROUGH IN CONJUNCTION
WITH DAYTIME HEATING WILL SUPPORT DIURNAL CONVECTION OVER THE CWA.
POPS HIGHEST TOWARD CENTRAL VA/SRN MD BUT STILL IN CHANCE RANGE.
MID-LVL RIDGE BUILDS OVERHEAD TUE AND WED AFTER THE SHORTWAVE
TROUGH EXITS THE AREA. COVERAGE OF SHOWERS AND STORMS WILL BE LOW
TUE AND WED DUE TO AN ABSENCE OF ORGANIZED LIFT AND A STRENGTHENING
SUBSIDENCE INVERSION. MAV/MET DIVERGE HERE. KEPT FCST DRY FOR MOST
OF THE I-95 CORRIDOR AND CHSPK BAY AS WEAK STEERING FLOW WILL
LIMIT HOW FAR EAST CONVECTION PROPAGATES ONCE INITIATED OVER THE
MTS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL APPROACH FROM THE
GREAT LAKES/MIDWEST REGIONS WED NGT AND THU BEFORE PASSING THRU
THE AREA ON FRI. CHANCES FOR SHOWERS AND STORMS WILL ACCORDINGLY
INCREASE LATE IN THE WEEK AND WILL BE HIGHEST WITH FROPA. ABOVE
NORMAL TEMPS AHEAD OF THE COLD FRONT WILL TREND MUCH COOLER IN
WAKE OF FROPA FRI INTO THE WEEKEND.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
IFR CONDITIONS EXPECTED THIS EVENING AND INTO MONDAY MORNING. SOUTHERLY
FLOW WILL CONTINUE THROUGH THIS PERIOD AND LOW CEILINGS AND VSBYS
EXPECTED.
IFR CONDITIONS LIKELY TO START THE DAY MON BEFORE MRNG STRATUS/
FOG MIX OUT FROM W TO E. PREDOMINATELY VFR CONDITIONS EXPECTED MON
AFTN ALTHOUGH BRIEF RESTRICTIONS IN SHRA/TSRA ARE POSSIBLE.
DIURNAL FOG/LOW CLOUDS POSSIBLE AT NGT AND ERY IN THE MRNG EACH
DAY IN THE MIDWEEK. CHANCES FOR SHRA/TSRA WILL BE LOW DURING THIS
TIME.
&&
.MARINE...
SCA ADVISORY CANCELED FOR THIS EVENING.
SOUTHERLY FLOW WILL CONTINUE OVER THE WATERS BUT SHOULD STAY UNDER
SCA CRITERIA. SHOWERS AND DRIZZLE EXPECTED WITH LOW CEILINGS
OVERNIGHT. AN UPPER LEVEL DISTURBANCE WILL CROSS THE REGION MONDAY
AND SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE. SLOW STORM MOTION
AND HIGH MOISTURE WILL LEAD TO HEAVY RAIN IN ACTIVITY.
LGT SLY FLOW ELY IN THE WEEK WILL STRENGTHEN LATER IN THE WEEK.
SCA CONDITIONS POSSIBLE BY THU...WHEN A COLD FRONT APPROACHES FROM
THE NW.
&&
.TIDES/COASTAL FLOODING...
NO TIDAL FLOOD ISSUES EXPECTED IN THE NEAR FUTURE /TNGT OR EVEN
TOMORROW/.
WATER LEVELS SHOULD TICK UPWARD ELY NEXT WEEK WITH SLY FLOW
PERSISTING AND A WAXING GIBBOUS MOON. THIS FAR OUT...STILL SOME
UNCERTAINTY IF POSITIVE ANOMALIES INCREASE ENOUGH TO REACH MINOR
THRESHOLD.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...SHEFFIELD
000
FXUS61 KLWX 191858
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
258 PM EDT SUN MAY 19 2013
.SYNOPSIS...
A WARM FRONT WILL SLOWLY LIFT NORTH OF THE AREA TONIGHT INTO
MONDAY MORNING. A WEAK MID-LEVEL TROUGH WILL MOVE THROUGH MONDAY.
HIGH PRESSURE BUILDS OVER THE WESTERN ATLANTIC TUESDAY AND
WEDNESDAY...WITH SOUTHERLY RETURN FLOW PROVIDING WARM TEMPERATURES
TO THE REGION. A COLD FRONT WILL APPROACH FROM THE GREAT LAKES
LATE THIS WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE QSTNRY FNT ALNG THE VA/NC BRDR HAS BEGUN TO CREEP BACK NWD AGN
AS A WMFNT...SPCLY INVOF THE DELMARVA. STILL WEDGING IN THE SHEN
VLY TO I-95. AMS N OF BNDRY STILL STBL...AS EVIDENCED BY THE LACK OF
RADR RTNS AS WELL AS THE LOW CLDS/CIGS. MEANWHILE...NMRS TSRA ACRS
NC/SRN WVA SHUD ADVECT NWD AND OVERRIDE THE STBL LLVLS. THEREFORE...
AM KEEPING LOW LKLY POPS FOR THE LT AFTN-ELY EVNG...AND SCALE BACK
FM THERE.
MDL SNDGS DEPICT A SATD LYR SFC-H9...SPCLY DURING THE OVNGT HRS.
THEREFORE THINK THAT DZFG WL ONCE AGN BE AN ISSUE TNGT. THE WMFNT
WL LKLY CONT TO INCH NWD...BUT W/ LTL WND AND NO BLYR ROOTING...
IT/LL BE HARD TO TELL.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
LOW CLDS AND FOG WL CONT TO BE A FACTOR INTO THE MRNG HRS.
HWVR...THE MAY SUN ANGLE WL GRDLY ERODE THE SATD LYR...PERMITTING
THE FNT TO JUMP N OF AREA BY THE AFTN. SOUTH OF THIS FRONT...A
WARM AND A MODESTLY HUMID AIRMASS WILL BE IN PLACE. MAX TEMPS IN
THE 80S EACH DAY ALTHOUGH CLOUDS MAY INHIBIT TEMPS FROM REACHING
80F IN SOME LOCATIONS ON MON.
NAM/GFS/ECMWF PROG A MID-LVL SHORTWAVE TROUGH TO MV THRU THE MID-
ATLC REGION ON MON. LIFT/MOISTURE AHEAD OF THE TROUGH IN CONJUNCTION
WITH DAYTIME HEATING WILL SUPPORT DIURNAL CONVECTION OVER THE CWA.
POPS HIGHEST TOWARD CENTRAL VA/SRN MD BUT STILL IN CHANCE RANGE.
MID-LVL RIDGE BUILDS OVERHEAD TUE AND WED AFTER THE SHORTWAVE
TROUGH EXITS THE AREA. COVERAGE OF SHOWERS AND STORMS WILL BE LOW
TUE AND WED DUE TO AN ABSENCE OF ORGANIZED LIFT AND A STRENGTHENING
SUBSIDENCE INVERSION. MAV/MET DIVERGE HERE. KEPT FCST DRY FOR MOST
OF THE I-95 CORRIDOR AND CHSPK BAY AS WEAK STEERING FLOW WILL
LIMIT HOW FAR EAST CONVECTION PROPAGATES ONCE INITIATED OVER THE
MTS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT WILL APPROACH FROM THE
GREAT LAKES/MIDWEST REGIONS WED NGT AND THU BEFORE PASSING THRU
THE AREA ON FRI. CHANCES FOR SHOWERS AND STORMS WILL ACCORDINGLY
INCREASE LATE IN THE WEEK AND WILL BE HIGHEST WITH FROPA. ABOVE
NORMAL TEMPS AHEAD OF THE COLD FRONT WILL TREND MUCH COOLER IN
WAKE OF FROPA FRI INTO THE WEEKEND.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
FLGT RESTRICTIONS REMAIN...BUT IMPVMNT BGNG. IFR HANGING ON METRO
BALT AS WELL AS CHO AND MRB. CIGS AT IAD/DCA HV RISEN TO MVFR. HV
FLLWD LAMP GDNC WHICH HAS GOOD PERFORMANCE TDA. WHILE FLGT CATS
SHUD REACH MVFR ELSW TAFTN...DONT FORSEE VFR ANYWHERE. SCH SHRA
PSBL...BUT CVRG LMTD/BRIEF.
AFDK...THE TREND SHUD REVERSE...ONCE AGN PER LAMP. LLVLS SATURATE
AND WNDS LGT. AOB IFR XPCTD OVNGT.
IFR CONDITIONS LIKELY TO START THE DAY MON BEFORE MRNG STRATUS/
FOG MIX OUT FROM W TO E. PREDOMINATELY VFR CONDITIONS EXPECTED MON
AFTN ALTHOUGH BRIEF RESTRICTIONS IN SHRA/TSRA ARE POSSIBLE.
DIURNAL FOG/LOW CLOUDS POSSIBLE AT NGT AND ERY IN THE MRNG EACH
DAY IN THE MIDWEEK. CHANCES FOR SHRA/TSRA WILL BE LOW DURING THIS
TIME.
&&
.MARINE...
MD BAY/TIDAL PTMC ON THE STBL SIDE OF A WMFNT ATTM. MIXING POOR
AND WNDS AOB 10 KT. HWVR THIS FNT SLOWLY WORKING NWD AGN. SCA GOES
INTO EFFECT FOR MID BAY AND LWR PTMC AT 3PM...AND FOR BAY POOLES
ISL-NBEACH AT 6PM. SUSPECT THIS IS A BIT FAST...AND DONT HV A
GOOD FEEL WHETHER SPDS WL REACH SCA CRITERIA AT ALL OR BE TRAPPED
ABV AN INVSN. WL MAINTAIN STATUS QUO FOR NOW.
LGT SLY FLOW ELY IN THE WEEK WILL STRENGTHEN LATER IN THE WEEK.
SCA CONDITIONS POSSIBLE BY THU...WHEN A COLD FRONT APPROACHES FROM
THE NW.
&&
.TIDES/COASTAL FLOODING...
DEPARTURES CONT TO DECREASE TODAY...NOW ALL LESS THAN A HALF-FOOT.
NO TIDAL FLOOD ISSUES EXPECTED IN THE NEAR FUTURE /TNGT OR EVEN
TOMORROW/.
WATER LEVELS SHOULD TICK UPWARD ELY NEXT WEEK WITH SLY FLOW
PERSISTING AND A WAXING GIBBOUS MOON. THIS FAR OUT...STILL SOME
UNCERTAINTY IF POSITIVE ANOMALIES INCREASE ENOUGH TO REACH MINOR
THRESHOLD.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO MIDNIGHT EDT
TONIGHT FOR ANZ531-532-539-540.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR ANZ533-534-
537-541-543.
&&
$$
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