000
FXUS61 KLWX 230216 AAB
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
916 PM EST SUN NOV 22 2009
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO RETREAT TO THE NORTH TONIGHT WHILE AN
AREA OF LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST. THIS LOW WILL
TRACK UP THE MID-ATLANTIC COAST MONDAY AND TOWARDS NEW ENGLAND
MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS
SYSTEM LATER TUESDAY AND WEDNESDAY. A COLD FRONT WILL PASS THROUGH
THURSDAY BRINGING UNSETTLED CONDITIONS. AN UPPER-LEVEL LOW WILL
CONTINUE TO IMPACT THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
OVERALL SYNOPTIC EVOLUTION STILL ON TRACK FROM PREV FCST.
ISENTROPIC LIFT INCRS TNGT...WITH LOW-LVL CLD CVR XPCD TO SPREAD
ACRS FCST AREA LATE. RAIN WILL CONT TO SPREAD NWD AS MID-LVL
SHRTWV TROF APRCHS...BUT WILL ONLY ENCROACH UPON SRN ZONES THRU
TNGT. MODEL TRENDS HAVE BEEN TO SLOW ARRIVAL OF PCPN...AND THIS
TREND WAS FOLLOWED FOR THE EVE UPDATE. HAVE TRIMMED NRN EDGE OF
POPS DOWNWARD THRU TNGT. PREV DISCUSSION FOLLOWS...
CURRENT ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER NEW ENGLAND THIS
AFTERNOON. A SURFACE LOW CONTINUES TO TRACK ALONG THE GULF COAST
STATES. THE UPPER-LEVEL LOW ASSOCIATED WITH THE SURFACE LOW IS
TRACKING TOWARD THE TENNESSEE VALLEY.
SURFACE HIGH WILL CONTINUE TO RETREAT TO THE NORTHEAST TONIGHT WHILE
THE SURFACE LOW REDEVELOPS ALONG THE SOUTHEAST COAST. THE
UPPER-LEVEL LOW ASSOCIATED WITH THIS SYSTEM WILL TRACK THROUGH THE
TENNESSEE VALLEY TONIGHT AND TOWARD SOUTHWESTERN VIRGINIA BY MONDAY
MORNING.
A LOW-LEVEL EAST-SOUTHEAST FLOW AROUND THE DEPARTING HIGH AND THE
LOW PRESSURE SYSTEM WILL BRING INCREASING AMOUNTS OF MOISTURE OFF
THE ATLANTIC OCEAN. THE MOISTURE INCREASE COMBINED WITH ISENTROPIC
LIFT WILL RESULT IN INCREASING LOW CLOUDS LATER THIS EVENING INTO
THE OVERNIGHT HOURS. WITH THE ACTUAL STORM SYSTEM REMAINING WELL TO
THE SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH THIS EVENING.
HOWEVER...RAIN AHEAD OF THE STORM SYSTEM WILL BEGIN TO OVERSPREAD
THE REGION FROM SOUTH TO NORTH LATE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
RAIN WILL SPREAD NWD THRU FCST AREA DURG MID-LATE MRNG.
CATEGORICAL POPS LOOK REASONABLE STILL FOR TMW AFTN AND WERE
RETAINED...ALTHO IT APPEARS THAT ACCUMULATIONS WILL BE SLGTLY
HIGHER WITH EWD EXTENT CLOSER TO XPCD PATH OF SHRTWV TROF. PREV
DISCUSSION FOLLOWS...
THE SURFACE LOW WILL CONTINUE TO TRACK UP THE MID-
ATLANTIC COAST WHILE THE UPPER-LEVEL LOW SHEARS APART AS IT TRACKS
ACROSS OUR REGION. A LOW-LEVEL EASTERLY FLOW COMBINED WITH
ISENTROPIC LIFT WILL RESULT IN LOW CLOUDS ALONG WITH OCCASIONAL
RAIN. RAINFALL AMOUNTS SHOULD BE ON THE LIGHT SIDE DUE TO THE LACK
OF STRONG DYNAMICS WITH THIS SYSTEM. MAX TEMPS WILL BE SEVERAL
DEGREES COOLER THAN RECENT DAYS DUE TO THE RAINFALL...RANGING FROM
THE MID AND UPPER 40S ACROSS THE POTOMAC HIGHLANDS INTO THE
SHENANDOAH VALLEY...TO NEAR 50 IN WASHINGTON AND BALTIMORE...TO
THE LOWER AND MIDDLE 50S ACROSS LOWER SOUTHERN MARYLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ANY PCPN LINGERING MON NGT WUD BE AS A RSLT OF THE DEF AXIS ACRS
CWFA. HWVR...LOPRES RATHER WEAK...AND FAR OFFSHORE...SO DONT THINK
THAT PCPN WUD BE PLENTIFUL. WUD BE MORE CONCERNED ABT DZ...BUT SFC
WNDS NLY NOT NE/ELY.
HIPRES BRIEFLY BLDS TUE-TUE NGT. BUT IT SHUD BE A DIRTY RDG AS AMPLE
LLVL MSTR STILL LINGERS. SUNSHN SHUD BE LMTD...ASSUMING IT CAN BRK
THRU MARINE STRATUS. BASED ON TKNS OF MARINE DECK ON MDL
TIME-HGTS...THAT/LL BE A BIG ASSUMPTION. SUSPECT LLVL CLDS WL BE
SUFFICIENT FOR DZ TO DVLP TUE NGT...SPCLY SINCE SFC HIGH WEDGED A LA
CAD AND H9-8 FLOW BCMG SLY.
CMPLX SCENARIO SETTING UP FOR MID WK...AS S/WV ENERGY DROPS INTO
CNTRL PLAINS...CUTTING OFF H5 LOW BY TUE. ADDTL VORTS CARVE OUT A
2ND LOW...WHICH WL DEEPEN LOW OVR GRTLKS BY THU. LCLLY...CWFA WL
RECEIVE ISENT LIFT...THEN GLANCING BLOW OF PVA WED. THUS...CLDS
GOING NOWHERE...AND CHC SHRA RETURNS. SOME MIXING CUD PUNCH HOLES IN
THE CLD DECK BHD VORT LT WED-WED NGT.
TEMPS FAIRLY TEMPERATE THRU THE PD. NOT MUCH SPREAD IN MOS TEMPS
TMRW NGT-TUE...AND A SLGTLY LRGR SPREAD TUE NGT. CONSIDERING
CLDS...STAYED AWAY FM BIG DIURNAL SWINGS-- WARM SIDE OF MEAN FOR
MIN-T BUT COOLER SIDE FOR MAXT.
XTNDD...DP H5 TROF AXIS/CUTOFF LOW TO PIVOT ACRS CWFA THU-FRI. THIS
CYCLE...GDNC - SPCLY GFS - NOW TRANSFERRING ENERGY TO DVLPG CSTL
SYSTM LT THU NGT-ELY FRI MRNG. BUT EVEN THE MORE STBL ECMWF TRENDING
TWD GFS. EITHER WAY THE END RSLT WL BE SIMLR...FVRBL SUPPORT FOR
PCPN...AND SIGNALS THAT HIER ELEVS CUD RECEIVE SNW. WL INCR POPS
THU-THU NGT...AND STICK W/ MTN SNW/MIX ONCE CAA UPON US THU PM. NW
FLOW PTTN THRU SAT. WL ENHANCE UPSPL PCPN THRU THAT TIME.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
CIGS AOB 1.0 KFT XPCD TNGT AS ISENTROPIC LIFT INCRS ACRS RGN.
VSBYS ALSO XPCD TO DROP TO IFR-MVFR THRESHOLDS AS FOG DVLPS THIS
EVE. ONSET OF DRZL XPCD LATE TNGT...WITH RAIN MOVG NWD INTO SRN
PORTIONS OF FCST AREA BY 08-10 UTC. DRZL CONTS ACRS NRN TERMINALS
THRU MRNG UNTIL RAIN ARRIVES AT ALL TERMINALS DURG LATE MRNG.
RESTRICTIONS XPCD TO CONT THRU AT LEAST MON EVE.
FLGT RESTRICTIONS PSBL THRU MUCH OF WK AS UNSTTLD CONDS ABOUND. IF
THERE WERE A BRK IT WUD COME TUE AFTN/EVE...BUT LOW CLDS/DZ LKLY TO
RTN TUE NGT.
&&
.MARINE...
PRESSURE GRADIENT APPEARS TO BE SHARPENING SLGTLY EARLIER THAN
DEPICTED IN PREV GRIDS...MAINLY LWR PORTIONS OF MD CHSPK BAY AND
LWR TIDAL POTOMAC. HAVE ADJUSTED START TIME OF SMALL CRAFT ADZY TO
PRESENT TIME FOR THESE ZONES..WHERE 17-20 KT GUSTS COMMON AND XPCD
TO PERSIST. RMNDR OF ADZY WILL BGN AT MIDNIGHT AS PREVLY ISSUED.
PREV DISCUSSION FOLLOWS...
LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST TONIGHT. A
STRENGTHENING PRESSURE GRADIENT DUE TO THE LOW WILL BRING SCA WIND
GUSTS ACROSS THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC OVERNIGHT.
AS LOW PRESSURE TRACKS UP THE MID- ATLANTIC COAST MONDAY...MORE
SCA CONDITIONS ARE EXPECTED ACROSS THE LOWER TIDAL POTOMAC AND
CHESAPEAKE BAY. HAVE CAPPED WIND GUSTS MONDAY AROUND 15 KNOTS
ACROSS THE UPPER TIDAL POTOMAC...BUT WITH FASTER WINDS LESS THAN A
THOUSAND FEET FROM THE SURFACE...ANY MIXING WOULD BRING STRONGER
WIND GUSTS LATER MONDAY MORNING/AFTERNOON. THIS WILL HAVE TO BE
MONITORED BY LATER SHIFTS.
G20KT LKLY TO CONT INTO TMRW NGT DUE TO NLY FLOW...SPCLY FOR MAIN
CHANNEL BAY BLO POOLES ISL AND FOR LWR PTMC. WL INCL BIG INLETS BUT
NOT BALT HARBOR/PAX RIVER. HIPRES RDG SHUD DECR WNDS TUE-WED...ALTHO
LOW CLDS SHUD BE PLENTIFUL AND RA A PSBLTY BY WED.
&&
.TIDES/COASTAL FLOODING...
WITH HIGH PRESSURE WELL TO OUR NORTH...AN ONSHORE FLOW HAS DEVELOPED
THIS AFTERNOON. THE FLOW IS WEAK AND TIDAL ANOMALIES RANGE FROM NEAR
NORMAL TO ABOUT ONE HALF FOOT ABOVE NORMAL. LOW PRESSURE IS EXPECTED
TO DEVELOP OFF THE SOUTHEAST COAST TONIGHT AND THE GRADIENT IS
EXPECTED TO TIGHTEN BETWEEN THESE TWO SYSTEMS OVERNIGHT AND MONDAY.
AS THE LOW TRACKS UP THE MID-ATLANTIC COAST MONDAY INTO MONDAY
NIGHT...THIS WILL CAUSE TIDAL ANOMALIES TO INCREASE DURING THIS
TIME. LATEST CBOFS AND EXTRATROPICAL MODELS CONTINUE TO INDICATE
THAT WATER LEVELS WILL REMAIN BELOW THRESHOLDS FOR MINOR COASTAL
FLOODING. THE ASTRONOMICAL NORMS FOR WATER LEVELS ARE ALSO ON THE
LOWER SIDE DUE TO THE LUNAR CYCLE APPROACHING THE FIRST QUARTER
PHASE. HAVE NOT ISSUED AN ADVISORY FOR THESE TWO REASONS...BUT THIS
WILL HAVE TO BE MONITORED BY LATER SHIFTS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EST TUESDAY
FOR ANZ531>533-539>541.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 PM EST MONDAY
FOR ANZ530-538-542.
SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ534-537-543.
&&
$$
UPDATE...KRAMAR
PREV DISCUSSION...KRAMAR/LASORSA/HTS
000
FXUS61 KLWX 222216 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
516 PM EST SUN NOV 22 2009
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO RETREAT TO THE NORTH TONIGHT WHILE AN
AREA OF LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST. THIS LOW WILL
TRACK UP THE MID-ATLANTIC COAST MONDAY AND TOWARDS NEW ENGLAND
MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS
SYSTEM LATER TUESDAY AND WEDNESDAY. A COLD FRONT WILL PASS THROUGH
THURSDAY BRINGING UNSETTLED CONDITIONS. AN UPPER-LEVEL LOW WILL
CONTINUE TO IMPACT THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CURRENT ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER NEW ENGLAND THIS
AFTERNOON. A SURFACE LOW CONTINUES TO TRACK ALONG THE GULF COAST
STATES. THE UPPER-LEVEL LOW ASSOCIATED WITH THE SURFACE LOW IS
TRACKING TOWARD THE TENNESSEE VALLEY.
SURFACE HIGH WILL CONTINUE TO RETREAT TO THE NORTHEAST TONIGHT WHILE
THE SURFACE LOW REDEVELOPS ALONG THE SOUTHEAST COAST. THE
UPPER-LEVEL LOW ASSOCIATED WITH THIS SYSTEM WILL TRACK THROUGH THE
TENNESSEE VALLEY TONIGHT AND TOWARD SOUTHWESTERN VIRGINIA BY MONDAY
MORNING.
A LOW-LEVEL EAST-SOUTHEAST FLOW AROUND THE DEPARTING HIGH AND THE
LOW PRESSURE SYSTEM WILL BRING INCREASING AMOUNTS OF MOISTURE OFF
THE ATLANTIC OCEAN. THE MOISTURE INCREASE COMBINED WITH ISENTROPIC
LIFT WILL RESULT IN INCREASING LOW CLOUDS LATER THIS EVENING INTO
THE OVERNIGHT HOURS. WITH THE ACTUAL STORM SYSTEM REMAINING WELL TO
THE SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH THIS EVENING.
HOWEVER...RAIN AHEAD OF THE STORM SYSTEM WILL BEGIN TO OVERSPREAD
THE REGION FROM SOUTH TO NORTH LATE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE SURFACE LOW WILL CONTINUE TO TRACK UP THE MID-ATLANTIC COAST
WHILE THE UPPER-LEVEL LOW SHEARS APART AS IT TRACKS ACROSS OUR
REGION. A LOW-LEVEL EASTERLY FLOW COMBINED WITH ISENTROPIC LIFT WILL
RESULT IN LOW CLOUDS ALONG WITH OCCASIONAL RAIN. RAINFALL AMOUNTS
SHOULD BE ON THE LIGHT SIDE DUE TO THE LACK OF STRONG DYNAMICS WITH
THIS SYSTEM. MAX TEMPS WILL BE SEVERAL DEGREES COOLER THAN RECENT
DAYS DUE TO THE RAINFALL...RANGING FROM THE MID AND UPPER 40S ACROSS
THE POTOMAC HIGHLANDS INTO THE SHENANDOAH VALLEY...TO NEAR 50 IN
WASHINGTON AND BALTIMORE...TO THE LOWER AND MIDDLE 50S ACROSS LOWER
SOUTHERN MARYLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ANY PCPN LINGERING MON NGT WUD BE AS A RSLT OF THE DEF AXIS ACRS
CWFA. HWVR...LOPRES RATHER WEAK...AND FAR OFFSHORE...SO DONT THINK
THAT PCPN WUD BE PLENTIFUL. WUD BE MORE CONCERNED ABT DZ...BUT SFC
WNDS NLY NOT NE/ELY.
HIPRES BRIEFLY BLDS TUE-TUE NGT. BUT IT SHUD BE A DIRTY RDG AS AMPLE
LLVL MSTR STILL LINGERS. SUNSHN SHUD BE LMTD...ASSUMING IT CAN BRK
THRU MARINE STRATUS. BASED ON TKNS OF MARINE DECK ON MDL
TIME-HGTS...THAT/LL BE A BIG ASSUMPTION. SUSPECT LLVL CLDS WL BE
SUFFICIENT FOR DZ TO DVLP TUE NGT...SPCLY SINCE SFC HIGH WEDGED A LA
CAD AND H9-8 FLOW BCMG SLY.
CMPLX SCENARIO SETTING UP FOR MID WK...AS S/WV ENERGY DROPS INTO
CNTRL PLAINS...CUTTING OFF H5 LOW BY TUE. ADDTL VORTS CARVE OUT A
2ND LOW...WHICH WL DEEPEN LOW OVR GRTLKS BY THU. LCLLY...CWFA WL
RECEIVE ISENT LIFT...THEN GLANCING BLOW OF PVA WED. THUS...CLDS
GOING NOWHERE...AND CHC SHRA RETURNS. SOME MIXING CUD PUNCH HOLES IN
THE CLD DECK BHD VORT LT WED-WED NGT.
TEMPS FAIRLY TEMPERATE THRU THE PD. NOT MUCH SPREAD IN MOS TEMPS
TMRW NGT-TUE...AND A SLGTLY LRGR SPREAD TUE NGT. CONSIDERING
CLDS...STAYED AWAY FM BIG DIURNAL SWINGS-- WARM SIDE OF MEAN FOR
MIN-T BUT COOLER SIDE FOR MAXT.
XTNDD...DP H5 TROF AXIS/CUTOFF LOW TO PIVOT ACRS CWFA THU-FRI. THIS
CYCLE...GDNC - SPCLY GFS - NOW TRANSFERRING ENERGY TO DVLPG CSTL
SYSTM LT THU NGT-ELY FRI MRNG. BUT EVEN THE MORE STBL ECMWF TRENDING
TWD GFS. EITHER WAY THE END RSLT WL BE SIMLR...FVRBL SUPPORT FOR
PCPN...AND SIGNALS THAT HIER ELEVS CUD RECEIVE SNW. WL INCR POPS
THU-THU NGT...AND STICK W/ MTN SNW/MIX ONCE CAA UPON US THU PM. NW
FLOW PTTN THRU SAT. WL ENHANCE UPSPL PCPN THRU THAT TIME.
&&
.AVIATION /22Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH EARLY THIS EVENING WITH
INCREASING HIGH CLOUDS. AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST
COAST...AN ONSHORE FLOW WILL RESULT IN LOW CLOUDS LATE THIS EVENING
AND OVERNIGHT. RAIN AND DRIZZLE WILL OVERSPREAD THE TERMINALS MONDAY
MORNING WHILE A NORTHEAST FLOW CONTINUES TO USHER IN PLENTY OF
LOW-LEVEL MOISTURE FROM THE ATLANTIC. CIGS WILL LIKELY DROP TO IFR
LEVELS LATE TONIGHT AND LAST THROUGH MONDAY. VSBYS WILL DROP
MAINLY TO MVFR LEVELS LATE TONIGHT...BUT IFR VSBYS ARE POSSIBLE ONCE
THE RAIN BEGINS.
FLGT RESTRICTIONS PSBL THRU MUCH OF WK AS UNSTTLD CONDS ABOUND. IF
THERE WERE A BRK IT WUD COME TUE AFTN/EVE...BUT LOW CLDS/DZ LKLY TO
RTN TUE NGT.
&&
.MARINE...
PRESSURE GRADIENT APPEARS TO BE SHARPENING SLGTLY EARLIER THAN
DEPICTED IN PREV GRIDS...MAINLY LWR PORTIONS OF MD CHSPK BAY AND
LWR TIDAL POTOMAC. HAVE ADJUSTED START TIME OF SMALL CRAFT ADZY TO
PRESENT TIME FOR THESE ZONES..WHERE 17-20 KT GUSTS COMMON AND XPCD
TO PERSIST. RMNDR OF ADZY WILL BGN AT MIDNIGHT AS PREVLY ISSUED.
PREV DISCUSSION FOLLOWS...
LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST TONIGHT. A
STRENGTHENING PRESSURE GRADIENT DUE TO THE LOW WILL BRING SCA WIND
GUSTS ACROSS THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC OVERNIGHT.
AS LOW PRESSURE TRACKS UP THE MID- ATLANTIC COAST MONDAY...MORE
SCA CONDITIONS ARE EXPECTED ACROSS THE LOWER TIDAL POTOMAC AND
CHESAPEAKE BAY. HAVE CAPPED WIND GUSTS MONDAY AROUND 15 KNOTS
ACROSS THE UPPER TIDAL POTOMAC...BUT WITH FASTER WINDS LESS THAN A
THOUSAND FEET FROM THE SURFACE...ANY MIXING WOULD BRING STRONGER
WIND GUSTS LATER MONDAY MORNING/AFTERNOON. THIS WILL HAVE TO BE
MONITORED BY LATER SHIFTS.
G20KT LKLY TO CONT INTO TMRW NGT DUE TO NLY FLOW...SPCLY FOR MAIN
CHANNEL BAY BLO POOLES ISL AND FOR LWR PTMC. WL INCL BIG INLETS BUT
NOT BALT HARBOR/PAX RIVER. HIPRES RDG SHUD DECR WNDS TUE-WED...ALTHO
LOW CLDS SHUD BE PLENTIFUL AND RA A PSBLTY BY WED.
&&
.TIDES/COASTAL FLOODING...
WITH HIGH PRESSURE WELL TO OUR NORTH...AN ONSHORE FLOW HAS DEVELOPED
THIS AFTERNOON. THE FLOW IS WEAK AND TIDAL ANOMALIES RANGE FROM NEAR
NORMAL TO ABOUT ONE HALF FOOT ABOVE NORMAL. LOW PRESSURE IS EXPECTED
TO DEVELOP OFF THE SOUTHEAST COAST TONIGHT AND THE GRADIENT IS
EXPECTED TO TIGHTEN BETWEEN THESE TWO SYSTEMS OVERNIGHT AND MONDAY.
AS THE LOW TRACKS UP THE MID-ATLANTIC COAST MONDAY INTO MONDAY
NIGHT...THIS WILL CAUSE TIDAL ANOMALIES TO INCREASE DURING THIS
TIME. LATEST CBOFS AND EXTRATROPICAL MODELS CONTINUE TO INDICATE
THAT WATER LEVELS WILL REMAIN BELOW THRESHOLDS FOR MINOR COASTAL
FLOODING. THE ASTRONOMICAL NORMS FOR WATER LEVELS ARE ALSO ON THE
LOWER SIDE DUE TO THE LUNAR CYCLE APPROACHING THE FIRST QUARTER
PHASE. HAVE NOT ISSUED AN ADVISORY FOR THESE TWO REASONS...BUT THIS
WILL HAVE TO BE MONITORED BY LATER SHIFTS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EST TUESDAY
FOR ANZ531>533-539>541.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 PM EST MONDAY
FOR ANZ530-538-542.
SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ534-537-543.
&&
$$
UPDATE...KRAMAR
PREV DISCUSSION...LASORSA/HTS
000
FXUS61 KLWX 222000
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
300 PM EST SUN NOV 22 2009
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO RETREAT TO THE NORTH TONIGHT WHILE AN
AREA OF LOW PRESSURE DEVELOPS OFF THE SOUTHEAST COAST. THIS LOW WILL
TRACK UP THE MID-ATLANTIC COAST MONDAY AND TOWARDS NEW ENGLAND
MONDAY NIGHT INTO TUESDAY. HIGH PRESSURE WILL BUILD IN BEHIND THIS
SYSTEM LATER TUESDAY AND WEDNESDAY. A COLD FRONT WILL PASS THROUGH
THURSDAY BRINGING UNSETTLED CONDITIONS. AN UPPER-LEVEL LOW WILL
CONTINUE TO IMPACT THE REGION LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
CURRENT ANALYSIS SHOWS HIGH PRESSURE CENTERED OVER NEW ENGLAND THIS
AFTERNOON. A SURFACE LOW CONTINUES TO TRACK ALONG THE GULF COAST
STATES. THE UPPER-LEVEL LOW ASSOCIATED WITH THE SURFACE LOW IS
TRACKING TOWARD THE TENNESSEE VALLEY.
SURFACE HIGH WILL CONTINUE TO RETREAT TO THE NORTHEAST TONIGHT WHILE
THE SURFACE LOW REDEVELOPS ALONG THE SOUTHEAST COAST. THE
UPPER-LEVEL LOW ASSOCIATED WITH THIS SYSTEM WILL TRACK THROUGH THE
TENNESSEE VALLEY TONIGHT AND TOWARD SOUTHWESTERN VIRGINIA BY MONDAY
MORNING.
A LOW-LEVEL EAST-SOUTHEAST FLOW AROUND THE DEPARTING HIGH AND THE
LOW PRESSURE SYSTEM WILL BRING INCREASING AMOUNTS OF MOISTURE OFF
THE ATLANTIC OCEAN. THE MOISTURE INCREASE COMBINED WITH ISENTROPIC
LIFT WILL RESULT IN INCREASING LOW CLOUDS LATER THIS EVENING INTO
THE OVERNIGHT HOURS. WITH THE ACTUAL STORM SYSTEM REMAINING WELL TO
THE SOUTH...DRY CONDITIONS ARE EXPECTED THROUGH THIS EVENING.
HOWEVER...RAIN AHEAD OF THE STORM SYSTEM WILL BEGIN TO OVERSPREAD
THE REGION FROM SOUTH TO NORTH LATE.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
THE SURFACE LOW WILL CONTINUE TO TRACK UP THE MID-ATLANTIC COAST
WHILE THE UPPER-LEVEL LOW SHEARS APART AS IT TRACKS ACROSS OUR
REGION. A LOW-LEVEL EASTERLY FLOW COMBINED WITH ISENTROPIC LIFT WILL
RESULT IN LOW CLOUDS ALONG WITH OCCASIONAL RAIN. RAINFALL AMOUNTS
SHOULD BE ON THE LIGHT SIDE DUE TO THE LACK OF STRONG DYNAMICS WITH
THIS SYSTEM. MAX TEMPS WILL BE SEVERAL DEGREES COOLER THAN RECENT
DAYS DUE TO THE RAINFALL...RANGING FROM THE MID AND UPPER 40S ACROSS
THE POTOMAC HIGHLANDS INTO THE SHENANDOAH VALLEY...TO NEAR 50 IN
WASHINGTON AND BALTIMORE...TO THE LOWER AND MIDDLE 50S ACROSS LOWER
SOUTHERN MARYLAND.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ANY PCPN LINGERING MON NGT WUD BE AS A RSLT OF THE DEF AXIS ACRS
CWFA. HWVR...LOPRES RATHER WEAK...AND FAR OFFSHORE...SO DONT THINK
THAT PCPN WUD BE PLENTIFUL. WUD BE MORE CONCERNED ABT DZ...BUT SFC
WNDS NLY NOT NE/ELY.
HIPRES BRIEFLY BLDS TUE-TUE NGT. BUT IT SHUD BE A DIRTY RDG AS AMPLE
LLVL MSTR STILL LINGERS. SUNSHN SHUD BE LMTD...ASSUMING IT CAN BRK
THRU MARINE STRATUS. BASED ON TKNS OF MARINE DECK ON MDL
TIME-HGTS...THAT/LL BE A BIG ASSUMPTION. SUSPECT LLVL CLDS WL BE
SUFFICIENT FOR DZ TO DVLP TUE NGT...SPCLY SINCE SFC HIGH WEDGED A LA
CAD AND H9-8 FLOW BCMG SLY.
CMPLX SCENARIO SETTING UP FOR MID WK...AS S/WV ENERGY DROPS INTO
CNTRL PLAINS...CUTTING OFF H5 LOW BY TUE. ADDTL VORTS CARVE OUT A
2ND LOW...WHICH WL DEEPEN LOW OVR GRTLKS BY THU. LCLLY...CWFA WL
RECEIVE ISENT LIFT...THEN GLANCING BLOW OF PVA WED. THUS...CLDS
GOING NOWHERE...AND CHC SHRA RETURNS. SOME MIXING CUD PUNCH HOLES IN
THE CLD DECK BHD VORT LT WED-WED NGT.
TEMPS FAIRLY TEMPERATE THRU THE PD. NOT MUCH SPREAD IN MOS TEMPS
TMRW NGT-TUE...AND A SLGTLY LRGR SPREAD TUE NGT. CONSIDERING
CLDS...STAYED AWAY FM BIG DIURNAL SWINGS-- WARM SIDE OF MEAN FOR
MIN-T BUT COOLER SIDE FOR MAXT.
XTNDD...DP H5 TROF AXIS/CUTOFF LOW TO PIVOT ACRS CWFA THU-FRI. THIS
CYCLE...GDNC - SPCLY GFS - NOW TRANSFERRING ENERGY TO DVLPG CSTL
SYSTM LT THU NGT-ELY FRI MRNG. BUT EVEN THE MORE STBL ECMWF TRENDING
TWD GFS. EITHER WAY THE END RSLT WL BE SIMLR...FVRBL SUPPORT FOR
PCPN...AND SIGNALS THAT HIER ELEVS CUD RECEIVE SNW. WL INCR POPS
THU-THU NGT...AND STICK W/ MTN SNW/MIX ONCE CAA UPON US THU PM. NW
FLOW PTTN THRU SAT. WL ENHANCE UPSPL PCPN THRU THAT TIME.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH EARLY THIS EVENING WITH
INCREASING HIGH CLOUDS. AS LOW PRESSURE DEVELOPS OFF THE SOUTHEAST
COAST...AN ONSHORE FLOW WILL RESULT IN LOW CLOUDS LATE THIS EVENING
AND OVERNIGHT. RAIN AND DRIZZLE WILL OVERSPREAD THE TERMINALS MONDAY
MORNING WHILE A NORTHEAST FLOW CONTINUES TO USHER IN PLENTY OF
LOW-LEVEL MOISTURE FROM THE ATLANTIC. CIGS WILL LIKELY DROP TO IFR
LEVELS LATE TONIGHT AND LAST THROUGH MONDAY. VSBYS WILL DROP
MAINLY TO MVFR LEVELS LATE TONIGHT...BUT IFR VSBYS ARE POSSIBLE ONCE
THE RAIN BEGINS.
FLGT RESTRICTIONS PSBL THRU MUCH OF WK AS UNSTTLD CONDS ABOUND. IF
THERE WERE A BRK IT WUD COME TUE AFTN/EVE...BUT LOW CLDS/DZ LKLY TO
RTN TUE NGT.
&&
.MARINE...
LOW PRESSURE WILL DEVELOP OFF THE SOUTHEAST COAST TONIGHT. A
STRENGTHENING PRESSURE GRADIENT DUE TO THE LOW WILL BRING SCA WIND
GUSTS ACROSS THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC OVERNIGHT.
AS LOW PRESSURE TRACKS UP THE MID-ATLANTIC COAST MONDAY...MORE SCA
CONDITIONS ARE EXPECTED ACROSS THE LOWER TIDAL POTOMAC AND
CHESAPEAKE BAY. HAVE CAPPED WIND GUSTS MONDAY AROUND 15 KNOTS ACROSS
THE UPPER TIDAL POTOMAC...BUT WITH FASTER WINDS LESS THAN A THOUSAND
FEET FROM THE SURFACE...ANY MIXING WOULD BRING STRONGER WIND GUSTS
LATER MONDAY MORNING/AFTERNOON. THIS WILL HAVE TO BE MONITORED BY
LATER SHIFTS.
G20KT LKLY TO CONT INTO TMRW NGT DUE TO NLY FLOW...SPCLY FOR MAIN
CHANNEL BAY BLO POOLES ISL AND FOR LWR PTMC. WL INCL BIG INLETS BUT
NOT BALT HARBOR/PAX RIVER. HIPRES RDG SHUD DECR WNDS TUE-WED...ALTHO
LOW CLDS SHUD BE PLENTIFUL AND RA A PSBLTY BY WED.
&&
.TIDES/COASTAL FLOODING...
WITH HIGH PRESSURE WELL TO OUR NORTH...AN ONSHORE FLOW HAS DEVELOPED
THIS AFTERNOON. THE FLOW IS WEAK AND TIDAL ANOMALIES RANGE FROM NEAR
NORMAL TO ABOUT ONE HALF FOOT ABOVE NORMAL. LOW PRESSURE IS EXPECTED
TO DEVELOP OFF THE SOUTHEAST COAST TONIGHT AND THE GRADIENT IS
EXPECTED TO TIGHTEN BETWEEN THESE TWO SYSTEMS OVERNIGHT AND MONDAY.
AS THE LOW TRACKS UP THE MID-ATLANTIC COAST MONDAY INTO MONDAY
NIGHT...THIS WILL CAUSE TIDAL ANOMALIES TO INCREASE DURING THIS
TIME. LATEST CBOFS AND EXTRATROPICAL MODELS CONTINUE TO INDICATE
THAT WATER LEVELS WILL REMAIN BELOW THRESHOLDS FOR MINOR COASTAL
FLOODING. THE ASTRONOMICAL NORMS FOR WATER LEVELS ARE ALSO ON THE
LOWER SIDE DUE TO THE LUNAR CYCLE APPROACHING THE FIRST QUARTER
PHASE. HAVE NOT ISSUED AN ADVISORY FOR THESE TWO REASONS...BUT THIS
WILL HAVE TO BE MONITORED BY LATER SHIFTS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EST TUESDAY
FOR ANZ531>534-537-539>541-543.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 8 PM EST MONDAY
FOR ANZ530-538-542.
&&
$$
SYNOPSIS...LASORSA
NEAR TERM...LASORSA
SHORT TERM...LASORSA
LONG TERM...HTS
AVIATION...LASORSA/HTS
MARINE...LASORSA/HTS
TIDES/COASTAL FLOODING...LASORSA
000
FXUS61 KLWX 221501
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1001 AM EST SUN NOV 22 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER NEW ENGLAND THIS AFTERNOON. WEAK
LOW PRESSURE WILL DEVELOP OFF THE CAROLINA COAST MONDAY BEFORE
MOVING SLOWLY NORTHEAST PAST THE MID ATLANTIC MONDAY NIGHT INTO
TUESDAY...BRINGING RAIN. HIGH PRESSURE WILL BRIEFLY BUILD LATE
TUESDAY INTO WEDNESDAY...WITH AN UPPER DISTURBANCE BRINGING
UNSETTLED WEATHER FOR LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENT ANALYSIS SHOWS SURFACE HIGH CENTERED OVER UPSTATE NEW YORK
WITH A SURFACE RIDGE AXIS WEDGING INTO THE MID-ATLANTIC. AN
UPPER-LEVEL LOW IS CENTERED OVER PENNSYLVANIA WHILE ANOTHER
UPPER-LEVEL LOW TRACKS THROUGH THE MISSISSIPPI VALLEY.
SURFACE HIGH WILL CONTINUE TO RETREAT TO THE NORTHEAST OVER NEW
ENGLAND THIS AFTERNOON. THE SURFACE RIDGE AXIS WILL REMAIN OVER THE
MID-ATLANTIC BRINGING DRY CONDITIONS ALONG WITH SOME SUNSHINE. THE
LOW-LEVEL FLOW WILL VEER MORE TOWARD THE EAST-NORTHEAST AND MOISTURE
OFF THE OCEAN WILL RESULT IN A SCATTERED TO BROKEN CU DECK THIS
AFTERNOON. MAX TEMPS WILL BE IN THE MID TO UPPER 50S FOR MOST
LOCATIONS...BUT 40S IN THE MOUNTAINS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
BOTH THE GFS AND THE NAM HAVE THE SURFACE RIDGE AXIS HOLDING OVER
THE CENTRAL CWFA WHILE A SURFACE LOW EMERGES OFF THE SE COAST LATE
TONIGHT/EARLY MONDAY. BOTH MODELS HAVE SLOWED THE ONSET OF ANY
PRECIPITATION ASSOCIATED WITH THE LOW PRESSURE SYSTEM UNTIL LATER IN
THE NIGHTTIME. HAVE MADE SOME SLIGHT ADJUSTMENTS TO THE POP GRIDS
OVERNIGHT...MAINLY TO DELAY THE ONSET OF PRECIP. TEMP
PROFILES...EVEN IN THE HIGHER ELEVATIONS OF NELSON/ALBEMARLE...SHOW
ALL RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
MONDAY AND MONDAY NIGHT...STRONG HIGH PUSHES EAST OFF NEW ENGLAND
AND THE CAROLINA COASTAL LOW PUSHES NORTHEAST OFF THE MID
ATLANTIC...CONTINUING ELY FLOW/CAD FOR THE AREA. EXPECT MARINE
MOISTURE/RAIN/DRIZZLE TO SPREAD NORTH ACROSS THE AREA WITH EAST
FACING SLOPES HAVING THE GREATEST PRECIP POTENTIAL DUE TO
TOPOGRAPHY. DUE TO OPAQUE LOW CLOUD COVER WITH SOME RAIN...EXPECT
LOW DIURNAL RANGE...MAX-T LOW TO MID 50S...MIN-T LOW TO MID 40S
/AROUND 50F NEAR SHORE/.
TUESDAY...COASTAL LOW DEVELOPS OFF THE NEW ENGLAND COAST WITH MOIST
NELY/NLY FLOW CONTINUING LIGHT RAIN/DRIZZLE EAST OF THE BLUE RIDGE
WELL INTO IF NOT THROUGH TUESDAY. A CLOSED LOW OVER THE CENTRAL
PLAINS/MID WEST TO SPREAD SWLY FLOW ACROSS THE WESTERN RIDGES BY
TUESDAY AFTERNOON. SLIGHT INCREASE IN TEMPERATURES TUESDAY...MID 50S.
TUESDAY NIGHT AND WEDNESDAY...UPPER LOW PUSHES EAST FROM THE
CENTRAL CONUS BREAKING CAD WEDGE AND ADVECTING IN MOIST SWLY FLOW.
MORE MILD TEMPERATURES...MIN-T MID TO UPPER 40S...MAX-T MID TO UPPER
50S...PERHAPS 60F IN THE MIDDLE SHENANDOAH VALLEY WITH SOME SUNSHINE.
WEDNESDAY NIGHT AND THANKSGIVING...S/W ENERGY DIGS UPPER TROUGH INTO
THE SERN CONUS BY THURSDAY. ONE OR MORE COLD FRONT PASSAGES ACROSS
THE MID ATLANTIC BRINGING PRECIP CHANCES. AMOUNT OF MOISTURE
AVAILABLE FOR THE CWA IS UNCERTAIN. COLD AIR DOES LOOK TO FOLLOW THE
FRONT...BRINGING A COOL DOWN /TO AROUND FIVE DEGREES BELOW NORMAL
MAX TEMPS/ FOR THE LATE PART OF THE WEEK INTO THE WEEKEND.
THURSDAY NIGHT THRU SATURDAY...UPPER TROUGH AXIS PUSHES ACROSS THE
CWA...WITH COASTAL CYCLOGENESIS IN THE MID ATLANTIC A POSSIBILITY IN
THE FRIDAY TIMEFRAME. CONTINUED CHANCES OF PRECIP ACROSS THE CWA FOR
THURSDAY NIGHT/FRIDAY MORNING...ADDED RAIN/SNOW MIX FOR HIGHER
ELEVATIONS /I.E. OVER 500 FT/ EAST OF THE BLUE RIDGE WITH COOLEST
AIR OF THE MONTH. BOTH THE EURO AND GFS HAVE A LOW OVER THE NERN
CONUS BY THE WEEKEND...INDICATING UPSLOPE SNOW IN NWLY FLOW FOR THE
ALLEGHENY FRONT AND POSSIBLY RIDGES FURTHER EAST. WILL HAVE TO
MONITOR FUTURE MODELS FOR CONSISTENCY ON UPPER TROUGH.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH THIS AFTERNOON. A SCATTERED TO
BROKEN CU DECK WILL DEVELOP THIS AFTERNOON...BUT CIGS SHOULD REMAIN
ABOVE 3KFT. CLOUDS WILL INCREASE THIS EVENING...BUT CIGS SHOULD
REMAIN ABOVE 3 KFT BEFORE MIDNIGHT. MVFR CIGS ARE EXPECTED AFTER
MIDNIGHT AT ALL TERMINAL SITES...WITH PATCHY MVFR FOG. SCT SHOWERS
ARE POSSIBLE AT KCHO TOWARDS 12Z MON.
ONSHORE NELY/ELY FLOW /AROUND 15 KT/ MONDAY WITH PRECIP BEGINNING BY
LATE MONDAY MORNING ACROSS THE TERMINALS. IFR CIGS/VSBYS IN
RAIN/DRIZZLE WELL INTO TUESDAY. SWLY FLOW AHEAD OF THE NEXT COLD
FRONT WEDNESDAY WITH IMPROVED AVIATION CONDITIONS. COLD FRONT/S/
WITH AN UNCERTAIN AMOUNT OF MOISTURE TO CROSS WEDNESDAY
NIGHT/THURSDAY AS AN UPPER TROUGH ENTERS THE AREA...BEGINNING A
PERIOD OF UNSETTLED WEATHER INTO THE WEEKEND. CERTAINLY PAY
ATTENTION TO SUBSEQUENT FORECASTS.
&&
.MARINE...
NORTH-NORTHEAST WINDS ARE EXPECTED THIS AFTERNOON...BUT WIND SPEEDS
SHOULD REMAIN BELOW SCA CRITERIA. THE PRESSURE GRADIENT IS EXPECTED
TO BEGIN TIGHTENING TONIGHT AS LOW PRESSURE DEVELOPS OFF THE SE
COAST. NE WINDS WILL BE SUSTAINED AT 10 TO 15 KT...WITH GUSTS TO
AROUND 20 KT.
HIGH PRESSURE OVER NEW ENGLAND AND A COASTAL LOW MOVING OFF CAPE
HATTERAS MONDAY BRINGS NELY FLOW. A SMALL CRAFT ADVISORY IN EFFECT
FOR MONDAY /WINDS AROUND 20 KT/ FOR ALL WATERS EXCEPT UPPER TIDAL
POTOMAC /WILL HAVE TO MONITOR INLAND EXTENT OF STRONGER WINDS/.
WINDS BECOME MORE NLY MONDAY NIGHT WITH THE SMALL CRAFT ADVISORY
POSSIBLY NEEDING EXTENSION. SWLY FLOW AHEAD OF THE NEXT FRONT
WEDNESDAY. ONE OR MORE FROPAS LATER WEDNESDAY THROUGH FRIDAY TO
BRING WLY FLOW...SOME PRECIP AND COLDER AIR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY
FOR ANZ530>534-537>543.
&&
$$
LASORSA/LISTEMAA/BAJ
000
FXUS61 KLWX 220829
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
329 AM EST SUN NOV 22 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVER NEW ENGLAND TODAY. WEAK LOW PRESSURE
WILL DEVELOP OFF THE CAROLINA COAST MONDAY BEFORE MOVING SLOWLY
NORTHEAST PAST THE MID ATLANTIC MONDAY NIGHT INTO TUESDAY...BRINGING
RAIN. HIGH PRESSURE WILL BRIEFLY BUILD LATE TUESDAY INTO
WEDNESDAY...WITH AN UPPER DISTURBANCE BRINGING UNSETTLED WEATHER FOR
LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TWO UPPER LOWS NOTED ON THE WATER VAPOR LOOP THIS MORNING...ONE OVER
NORTHEAST PA AND THE SECOND OVER SOUTH CENTRAL MISSISSIPPI. UPPER
LOW OVER PA WILL DROP SLIGHTLY SOUTH TODAY...ALONG THE MASON DIXON
LINE. THE MISSISSIPPI LOW WILL BEGIN TO MOVE NORTHEAST AND FILL.
AT THE SURFACE...HIGH PRESSURE CENTER ACROSS THE EASTERN GREAT LAKES
WILL SHIFT INTO NEW ENGLAND. THE RIDGE AXIS SHOULD CONTINUE TO HOLD
STRONG ACROSS THE MID ATLANTIC TODAY AS LOW PRESSURE FORMS ALONG THE
GULF COAST.
NO PRECIP IS EXPECTED TODAY...BUT CLOUDS WILL BE ON THE INCREASE AS
MOISTURE GETS TRANSPORTED NORTHWARD FROM THE DEEP SOUTH. AREAS ALONG
THE MASON DIXON LINE SHOULD SEE THE MOST SUNSHINE TODAY...WITH THE
PIEDMONT AND CENTRAL SHENANDOAH VALLEY CLOUDING OVER THE EARLIEST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
BOTH THE GFS AND THE NAM HAVE THE SURFACE RIDGE AXIS HOLDING OVER
THE CENTRAL CWFA WHILE A SURFACE LOW EMERGES OFF THE SE COAST LATE
TONIGHT/EARLY MONDAY. BOTH MODELS HAVE SLOWED THE ONSET OF ANY
PRECIPITATION ASSOCIATED WITH THE LOW PRESSURE SYSTEM UNTIL LATER IN
THE NIGHTTIME. HAVE MADE SOME SLIGHT ADJUSTMENTS TO THE POP GRIDS
OVERNIGHT...MAINLY TO DELAY THE ONSET OF PRECIP. TEMP
PROFILES...EVEN IN THE HIGHER ELEVATIONS OF NELSON/ALBEMARLE...SHOW
ALL RAIN.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
MONDAY AND MONDAY NIGHT...STRONG HIGH PUSHES EAST OFF NEW ENGLAND
AND THE CAROLINA COASTAL LOW PUSHES NORTHEAST OFF THE MID
ATLANTIC...CONTINUING ELY FLOW/CAD FOR THE AREA. EXPECT MARINE
MOISTURE/RAIN/DRIZZLE TO SPREAD NORTH ACROSS THE AREA WITH EAST
FACING SLOPES HAVING THE GREATEST PRECIP POTENTIAL DUE TO
TOPOGRAPHY. DUE TO OPAQUE LOW CLOUD COVER WITH SOME RAIN...EXPECT
LOW DIURNAL RANGE...MAX-T LOW TO MID 50S...MIN-T LOW TO MID 40S
/AROUND 50F NEAR SHORE/.
TUESDAY...COASTAL LOW DEVELOPS OFF THE NEW ENGLAND COAST WITH MOIST
NELY/NLY FLOW CONTINUING LIGHT RAIN/DRIZZLE EAST OF THE BLUE RIDGE
WELL INTO IF NOT THROUGH TUESDAY. A CLOSED LOW OVER THE CENTRAL
PLAINS/MID WEST TO SPREAD SWLY FLOW ACROSS THE WESTERN RIDGES BY
TUESDAY AFTERNOON. SLIGHT INCREASE IN TEMPERATURES TUESDAY...MID 50S.
TUESDAY NIGHT AND WEDNESDAY...UPPER LOW PUSHES EAST FROM THE
CENTRAL CONUS BREAKING CAD WEDGE AND ADVECTING IN MOIST SWLY FLOW.
MORE MILD TEMPERATURES...MIN-T MID TO UPPER 40S...MAX-T MID TO UPPER
50S...PERHAPS 60F IN THE MIDDLE SHENANDOAH VALLEY WITH SOME SUNSHINE.
WEDNESDAY NIGHT AND THANKSGIVING...S/W ENERGY DIGS UPPER TROUGH INTO
THE SERN CONUS BY THURSDAY. ONE OR MORE COLD FRONT PASSAGES ACROSS
THE MID ATLANTIC BRINGING PRECIP CHANCES. AMOUNT OF MOISTURE
AVAILABLE FOR THE CWA IS UNCERTAIN. COLD AIR DOES LOOK TO FOLLOW THE
FRONT...BRINGING A COOL DOWN /TO AROUND FIVE DEGREES BELOW NORMAL
MAX TEMPS/ FOR THE LATE PART OF THE WEEK INTO THE WEEKEND.
THURSDAY NIGHT THRU SATURDAY...UPPER TROUGH AXIS PUSHES ACROSS THE
CWA...WITH COASTAL CYCLOGENESIS IN THE MID ATLANTIC A POSSIBILITY IN
THE FRIDAY TIMEFRAME. CONTINUED CHANCES OF PRECIP ACROSS THE CWA FOR
THURSDAY NIGHT/FRIDAY MORNING...ADDED RAIN/SNOW MIX FOR HIGHER
ELEVATIONS /I.E. OVER 500 FT/ EAST OF THE BLUE RIDGE WITH COOLEST
AIR OF THE MONTH. BOTH THE EURO AND GFS HAVE A LOW OVER THE NERN
CONUS BY THE WEEKEND...INDICATING UPSLOPE SNOW IN NWLY FLOW FOR THE
ALLEGHENY FRONT AND POSSIBLY RIDGES FURTHER EAST. WILL HAVE TO
MONITOR FUTURE MODELS FOR CONSISTENCY ON UPPER TROUGH.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
PATCHY MVFR FOG IS LIKELY JUST BEFORE AND RIGHT AROUND SUNRISE THIS
MORNING. ANY FOG SHOULD QUICKLY BURN OFF AFTER SUNRISE. CIGS/VSBYS
EXPECTED TO BE VFR THROUGH THE AFTERNOON. CLOUDS WILL BEGIN TO
INCREASE EARLY THIS EVENING...BUT CIGS SHOULD REMAIN ABOVE 3 KFT
BEFORE MIDNIGHT. MVFR CIGS ARE EXPECTED AFTER MIDNIGHT AT ALL
TERMINAL SITES...WITH PATCHY MVFR FOG. SCT SHOWERS ARE POSSIBLE AT
KCHO TOWARDS 12Z MON.
ONSHORE NELY/ELY FLOW /AROUND 15 KT/ MONDAY WITH PRECIP BEGINNING BY
LATE MONDAY MORNING ACROSS THE TERMINALS. IFR CIGS/VSBYS IN
RAIN/DRIZZLE WELL INTO TUESDAY. SWLY FLOW AHEAD OF THE NEXT COLD
FRONT WEDNESDAY WITH IMPROVED AVIATION CONDITIONS. COLD FRONT/S/
WITH AN UNCERTAIN AMOUNT OF MOISTURE TO CROSS WEDNESDAY
NIGHT/THURSDAY AS AN UPPER TROUGH ENTERS THE AREA...BEGINNING A
PERIOD OF UNSETTLED WEATHER INTO THE WEEKEND. CERTAINLY PAY
ATTENTION TO SUBSEQUENT FORECASTS.
&&
.MARINE...
NORTHERLY FLOW OF 15 KT OR LESS IS EXPECTED ON THE WATERS TODAY. THE
PRESSURE GRADIENT IS EXPECTED TO BEGIN TIGHTENING TONIGHT AS LOW
PRESSURE OFF THE SE COAST. WINDS WILL SHIFT TO THE NE WITH SUSTAINED
SPEEDS OF 10 TO 15 KT...AND GUSTS TO AROUND 20 KT.
HIGH PRESSURE OVER NEW ENGLAND AND A COASTAL LOW MOVING OFF CAPE
HATTERAS MONDAY BRINGS NELY FLOW. A SMALL CRAFT ADVISORY IN EFFECT
FOR MONDAY /WINDS AROUND 20 KT/ FOR ALL WATERS EXCEPT UPPER TIDAL
POTOMAC /WILL HAVE TO MONITOR INLAND EXTENT OF STRONGER WINDS/.
WINDS BECOME MORE NLY MONDAY NIGHT WITH THE SMALL CRAFT ADVISORY
POSSIBLY NEEDING EXTENSION. SWLY FLOW AHEAD OF THE NEXT FRONT
WEDNESDAY. ONE OR MORE FROPAS LATER WEDNESDAY THROUGH FRIDAY TO
BRING WLY FLOW...SOME PRECIP AND COLDER AIR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY
FOR ANZ530>534-537>543.
&&
$$
LISTEMAA/BAJ
000
FXUS61 KLWX 220015 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
715 PM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT BEFORE SETTLING
OVER NEW ENGLAND SUNDAY. LOW PRESSURE WILL DEVELOP OFF THE MID-
ATLANTIC COAST MONDAY BEFORE MOVING SLOWLY UP THE EAST COAST MONDAY
NIGHT INTO TUESDAY...BRINGING RAIN. HIGH PRESSURE WILL BUILD
BRIEFLY LATE TUESDAY INTO WEDNESDAY...BUT A COLD FRONT WILL PASS
THROUGH LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
BKN-OVC CLD CVRG RMNS SLOW TO ERODE OVER CNTRL PORTIONS OF FCST
AREA. HAVE RESTRUCTURED CLD GRIDS TNGT AND INTRODUCED FOG INTO WX
GRIDS. OTHERWISE...FCST GENLY IN GOOD SHAPE. TEXT PRODUCTS HAVE
BEEN UPDATED. PREV DISCUSSION FOLLOWS...
CURRENT ANALYSIS SHOWS AN AREA OF HIGH PRESSURE OVER THE OHIO VALLEY
THAT EXTENDS INTO THE MID-ATLANTIC. A SPLIT JET CONTINUES ACROSS THE
CENTRAL AND EASTERN CONUS. AN UPPER-LEVEL LOW IN THE NORTHERN BRANCH
IS MOVING INTO PENNSYLVANIA THIS AFTERNOON WHILE AN UPPER-LEVEL LOW
IN THE SOUTHERN BRANCH TRACKS INTO THE GULF COAST STATES.
SURFACE HIGH PRESSURE WILL CONTINUE TO BRING DRY AND SEASONABLE
CONDITIONS TONIGHT. THE STRATO CU DECK ASSOCIATED WITH THE
UPPER-LEVEL LOW OVER PA SHOULD DISSIPATE ACROSS MOST AREAS THIS
EVENING WITH THE LOSS OF DAYTIME HEATING. HOWEVER...CLOUDS MAY HANG
ON ACROSS THE NORTHWESTERN CWA INTO THE POTOMAC HIGHLANDS WHERE
THERE IS A LITTLE MORE LOW-LEVEL MOISTURE. MIN TEMPS WILL RANGE FROM
THE LOWER AND MID 30S IN PORTIONS OF THE POTOMAC HIGHLANDS INTO THE
SHENANDOAH VALLEY...TO THE MID 40S IN DOWNTOWN WASHINGTON/BALTIMORE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
THE UPPER-LEVEL LOW CURRENTLY LOCATED OVER PENNSYLVANIA WILL SLOWLY
TRACK SOUTH INTO OUR REGION WHILE THE SURFACE HIGH BUILDS TOWARD NEW
ENGLAND SUNDAY. THE SOUTHERN BRANCH SYSTEM WILL TRACK INTO THE
SOUTHEASTERN CONUS...BUT IT SHOULD REMAIN FAR ENOUGH TO OUR SOUTH
NOT TO HAVE ANY IMPACT ON OUR WEATHER THROUGH SUNDAY.
A LOW-LEVEL NORTH-NORTHEAST FLOW AROUND HIGH PRESSURE TO OUR NORTH
WILL KEEP DRY CONDITIONS IN PLACE ALONG WITH SUNSHINE. MAX TEMPS
WILL TOP OFF IN THE MID TO UPPER 50S ACROSS MOST LOCATIONS...BUT
UPPER 40S IN THE HIGHER ELEVATIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
GDNC TRENDING MUCH SLOER...HOLDING OFF PCPN SUN NGT AS STRONG HIPRES
OVR NEW ENGLND RDGS DWN ATLC CST. EMPHASIS OF RAFL NOW MON-MON
NGT...AS A WK WV IN THE SRN STREAM SPILLS MSTR NWD...AND EVENTUALLY
SPAWNS CSTL LOW. WAA ON SRN DOORSTEP SUNSET SUN...AND CLDS WL
THICKEN/LWR THRU EVE. WL BRING POPS INTO GRIDS LT SUN EVE/SUN
OVNGT...SPCLY SRN CNTYS WHICH IS NEARER TRIGGERING MECHANISM.
BY MON-MON NGT...ENERGY WL TRANSFER OFF CST. PCPN WL BE IN RESPONSE
TO DVLPG LOW...MOSTLY IN DEFORMATION ZN. HV LINGERED A CHC INTO
TUE...SPCLY NRN CNTYS. HWVR...CAA SHUD BE ABLE TO MIX OUT THE DEEP
MSTR. BUT...FLOW WONT GO WLY...AND AS SUCH AM AFRAID WL HOLD ONTO A
PRTL MARINE DECK INTO MIDWK. PER XTNDD DSCN 2 PARAGRAPHS DWN...FCST
AT THIS PT BECOMES A BIT MORE UNCERTAIN...AND GRIDDED DETAILS BECOME
BROADER IN SCOPE.
PER TEMPS...HV LMTD DIURNAL SWINGS IN RESPONSE TO CLDCVR NXT CPL
DAYS...GOING ON HIGH SIDE FOR MIN-T...AND LOW END FOR MAXT. DID
SHADE DWNWD MON NGT SINCE CWFA WL BE AFFECTED BY CAA BY THEN.
WE/VE ENTERED THE TIME OF YEAR WHEN SPLIT FLOW WRECKS HAVOC ON MDL
SOLNS. IT APPEARS WE/RE ENTERING SUCH A PD. THE MAIN FCST CHALLENGES
REVOLVE ARND S/WV ENERGY DIGGING INTO TROF ACRS THE PLAINS...LKLY
CUTTING OFF AN UPR LOW...AND THEN TRAVERSING THE CONUS AS ADDTL
PIECES OF S/WV ENERGY DIVE INTO THE TROF AXIS. GFS AND GGEM DEEPER
AND QUICKER W/ H5 LOW...WHICH IS ALMOST CONTRADICTORY. WL TAKE A
HIGHLY ENSEMBLED APPROACH...LEANING ON STEADIER ECMWF. REGARDLESS...
WL HV AN UPR TROF IN THE NEIGHBORHOOD /PRBLY CNTRD OVR THE GRTLKS/
THIS THXGVG...WHICH MEANS THE XTNDD FCST WL START OUT WARM...THEN HV
A CFP COOL CWFA OFF. THERE ALSO WL BE THE SUPPORT FOR PCPN-- RA AT
1ST...BUT HGTS/TKNSS/H8 TEMPS WUD SUPPORT AT LEAST SOME SNW...SPCLY
FOR THE MTNS BY THU NGT..WHICH MAY CONT INTO FRI ACRS WRN UPSLP
AREAS. POP FCST LOW CONFIDENCE ATTM...BUT WL CONT TO BE MONITORED
DUE TO POTL TRVL IMPACTS. THE WRN UPSLP ASPECT TO THE FCST THE MOST
SOLID.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
LIGHT VRB-NLY WINDS XPCD TNGT. CIGS AROUND 5 KFT MAKING SLOW WWD
PROGRESS. THESE CLDS XPCD TO LINGER THRU THIS EVE AT KMRB/KIAD BUT
WILL ERODE LATE THIS EVE. CLDS MAY BE REPLACED BY PATCHY MVFR FOG
AS RGN WILL BE FOUND IN SWRN QUADRANT OF BROAD SFC HIPRES CNTRD IN
NEW ENGLAND. INCRG CLDS SUN AFTN AS ENELY FETCH BGNS TO TRANSPORT
ATLC MSTR WWD.
VFR SUN EVE...AS CLDS THICKEN/LWR FM S-N. FLGT RESTRICTIONS PSBL
OVNGT AS RA SPREADS IN. RESTRICTIONS PREVALENT MON-MON NGT AS LOPRES
PASSES E OF TERMINALS.
SHUD BE A BREAK TUE-WED...THO MARINE LYR CUD POTENTIALLY HOLD ON.
THEN...ANTHR STORM SYSTEM MVS IN WED NGT-THU...FLLWD BY COLD AIR BY
END OF WK.
&&
.MARINE...
SFC HIPRES BUILDS ACRS NEW ENGLAND TNGT. NO HAZARDS XPCD THRU SUN
AS WINDS VEER SLGTLY FROM NLY TO NELY. SUSTAINED WINDS AOA 10 KT
XPCD SUN AMID MOSTLY SUNNY SKIES.
WK WV OF LOPRES TRACKS ACRS SERN CONUS SUN NGT...AND
TRANSFERS/DEEPENS OFF DELMARVA MON-MON NGT. WNDS INCR DURING THIS
PD...W/ SCA CONDS PSBL.
IN WAKE OF THIS LOW AND IN ADVC OF NXT STORM SYSTM...N WNDS VEER
ELY. MORE PCPN WL SPREAD IN MIDWK...BUT SCA NOT XPCTD ATTM.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...KRAMAR
PREV DISCUSSION...LASORSA/HTS
000
FXUS61 KLWX 211943
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
243 PM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT BEFORE SETTLING
OVER NEW ENGLAND SUNDAY. AN AREA OF LOW PRESSURE WILL DEVELOP OFF
THE MID-ATLANTIC COAST MONDAY BEFORE SLOWLY MOVING UP THE
EASTERN SEABOARD MONDAY NIGHT INTO TUESDAY...BRINGING RAIN. HIGH
PRESSURE WILL BRIEFLY BUILD IN LATE TUESDAY INTO WEDNESDAY...BUT
ANOTHER COLD FRONT WILL PASS THROUGH LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT ANALYSIS SHOWS AN AREA OF HIGH PRESSURE OVER THE OHIO VALLEY
THAT EXTENDS INTO THE MID-ATLANTIC. A SPLIT JET CONTINUES ACROSS THE
CENTRAL AND EASTERN CONUS. AN UPPER-LEVEL LOW IN THE NORTHERN BRANCH
IS MOVING INTO PENNSYLVANIA THIS AFTERNOON WHILE AN UPPER-LEVEL LOW
IN THE SOUTHERN BRANCH TRACKS INTO THE GULF COAST STATES.
SURFACE HIGH PRESSURE WILL CONTINUE TO BRING DRY AND SEASONABLE
CONDITIONS TONIGHT. THE STRATO CU DECK ASSOCIATED WITH THE
UPPER-LEVEL LOW OVER PA SHOULD DISSIPATE ACROSS MOST AREAS THIS
EVENING WITH THE LOSS OF DAYTIME HEATING. HOWEVER...CLOUDS MAY HANG
ON ACROSS THE NORTHWESTERN CWA INTO THE POTOMAC HIGHLANDS WHERE
THERE IS A LITTLE MORE LOW-LEVEL MOISTURE. MIN TEMPS WILL RANGE FROM
THE LOWER AND MID 30S IN PORTIONS OF THE POTOMAC HIGHLANDS INTO THE
SHENANDOAH VALLEY...TO THE MID 40S IN DOWNTOWN WASHINGTON/BALTIMORE.
&&
.SHORT TERM /SUNDAY/...
THE UPPER-LEVEL LOW CURRENTLY LOCATED OVER PENNSYLVANIA WILL SLOWLY
TRACK SOUTH INTO OUR REGION WHILE THE SURFACE HIGH BUILDS TOWARD NEW
ENGLAND SUNDAY. THE SOUTHERN BRANCH SYSTEM WILL TRACK INTO THE
SOUTHEASTERN CONUS...BUT IT SHOULD REMAIN FAR ENOUGH TO OUR SOUTH
NOT TO HAVE ANY IMPACT ON OUR WEATHER THROUGH SUNDAY.
A LOW-LEVEL NORTH-NORTHEAST FLOW AROUND HIGH PRESSURE TO OUR NORTH
WILL KEEP DRY CONDITIONS IN PLACE ALONG WITH SUNSHINE. MAX TEMPS
WILL TOP OFF IN THE MID TO UPPER 50S ACROSS MOST LOCATIONS...BUT
UPPER 40S IN THE HIGHER ELEVATIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
GDNC TRENDING MUCH SLOER...HOLDING OFF PCPN SUN NGT AS STRONG HIPRES
OVR NEW ENGLND RDGS DWN ATLC CST. EMPHASIS OF RAFL NOW MON-MON
NGT...AS A WK WV IN THE SRN STREAM SPILLS MSTR NWD...AND EVENTUALLY
SPAWNS CSTL LOW. WAA ON SRN DOORSTEP SUNSET SUN...AND CLDS WL
THICKEN/LWR THRU EVE. WL BRING POPS INTO GRIDS LT SUN EVE/SUN
OVNGT...SPCLY SRN CNTYS WHICH IS NEARER TRIGGERING MECHANISM.
BY MON-MON NGT...ENERGY WL TRANSFER OFF CST. PCPN WL BE IN RESPONSE
TO DVLPG LOW...MOSTLY IN DEFORMATION ZN. HV LINGERED A CHC INTO
TUE...SPCLY NRN CNTYS. HWVR...CAA SHUD BE ABLE TO MIX OUT THE DEEP
MSTR. BUT...FLOW WONT GO WLY...AND AS SUCH AM AFRAID WL HOLD ONTO A
PRTL MARINE DECK INTO MIDWK. PER XTNDD DSCN 2 PARAGRAPHS DWN...FCST
AT THIS PT BECOMES A BIT MORE UNCERTAIN...AND GRIDDED DETAILS BECOME
BROADER IN SCOPE.
PER TEMPS...HV LMTD DIURNAL SWINGS IN RESPONSE TO CLDCVR NXT CPL
DAYS...GOING ON HIGH SIDE FOR MIN-T...AND LOW END FOR MAXT. DID
SHADE DWNWD MON NGT SINCE CWFA WL BE AFFECTED BY CAA BY THEN.
WE/VE ENTERED THE TIME OF YEAR WHEN SPLIT FLOW WRECKS HAVOC ON MDL
SOLNS. IT APPEARS WE/RE ENTERING SUCH A PD. THE MAIN FCST CHALLENGES
REVOLVE ARND S/WV ENERGY DIGGING INTO TROF ACRS THE PLAINS...LKLY
CUTTING OFF AN UPR LOW...AND THEN TRAVERSING THE CONUS AS ADDTL
PIECES OF S/WV ENERGY DIVE INTO THE TROF AXIS. GFS AND GGEM DEEPER
AND QUICKER W/ H5 LOW...WHICH IS ALMOST CONTRADICTORY. WL TAKE A
HIGHLY ENSEMBLED APPROACH...LEANING ON STEADIER ECMWF. REGARDLESS...
WL HV AN UPR TROF IN THE NEIGHBORHOOD /PRBLY CNTRD OVR THE GRTLKS/
THIS THXGVG...WHICH MEANS THE XTNDD FCST WL START OUT WARM...THEN HV
A CFP COOL CWFA OFF. THERE ALSO WL BE THE SUPPORT FOR PCPN-- RA AT
1ST...BUT HGTS/TKNSS/H8 TEMPS WUD SUPPORT AT LEAST SOME SNW...SPCLY
FOR THE MTNS BY THU NGT..WHICH MAY CONT INTO FRI ACRS WRN UPSLP
AREAS. POP FCST LOW CONFIDENCE ATTM...BUT WL CONT TO BE MONITORED
DUE TO POTL TRVL IMPACTS. THE WRN UPSLP ASPECT TO THE FCST THE MOST
SOLID.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
PATCHY BR MAY BRING A BRIEF PERIOD OF MVFR VSBYS EARLY SUNDAY
MORNING...OTHERWISE VFR CONDITIONS ARE EXPECTED TONIGHT THROUGH
SUNDAY. LIGHT NORTHERLY WINDS ARE EXPECTED TONIGHT...WINDS SHOULD
REMAIN BELOW 10 KNOTS SUNDAY WITH THE DIRECTIONS VEERING TOWARD THE
NORTHEAST.
VFR SUN EVE...AS CLDS THICKEN/LWR FM S-N. FLGT RESTRICTIONS PSBL
OVNGT AS RA SPREADS IN. RESTRICTIONS PREVALENT MON-MON NGT AS LOPRES
PASSES E OF TERMINALS.
SHUD BE A BREAK TUE-WED...THO MARINE LYR CUD POTENTIALLY HOLD ON.
THEN...ANTHR STORM SYSTEM MVS IN WED NGT-THU...FLLWD BY COLD AIR BY
END OF WK.
&&
.MARINE...
HIGH PRESSURE OVER THE WATERS TONIGHT WILL BUILD TOWARD THE NORTH
SUNDAY. NORTHERLY WINDS TONIGHT WILL VEER TOWARD THE NORTHEAST
DURING THE DAY SUNDAY. WIND SPEEDS WILL REMAIN BELOW SCA CRITERIA.
WK WV OF LOPRES TRACKS ACRS SERN CONUS SUN NGT...AND
TRANSFERS/DEEPENS OFF DELMARVA MON-MON NGT. WNDS INCR DURING THIS
PD...W/ SCA CONDS PSBL.
IN WAKE OF THIS LOW AND IN ADVC OF NXT STORM SYSTM...N WNDS VEER
ELY. MORE PCPN WL SPREAD IN MIDWK...BUT SCA NOT XPCTD ATTM.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BJL
LONG TERM...HTS
AVIATION...BJL/HTS
MARINE...BJL/HTS
000
FXUS61 KLWX 211450
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
950 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL CROSS THE REGION AND SETTLE OVER NEW ENGLAND
THROUGH THE WEEKEND. A LOW PRESSURE AREA WILL MOVE UP COASTAL
CAROLINA SUNDAY NIGHT INTO TUESDAY...BRINGING RAIN. HIGH PRESSURE
WILL RETURN LATE TUESDAY...THOUGH A COLD FRONTAL PASSAGE IS
EXPECTED IN THE MIDDLE TO LATE PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENT ANALYSIS SHOWS A SURFACE HIGH THAT IS DRAPED ACROSS THE OHIO
VALLEY INTO THE MID-ATLANTIC. THE JETSTREAM REMAINS SPLIT ACROSS THE
CENTRAL AND EASTERN CONUS. AN UPPER-LEVEL LOW IN THE NORTHERN BRANCH
IS LOCATED OVER THE OHIO VALLEY WHILE ANOTHER UPPER-LEVEL LOW IS
LOCATED OVER TEXAS IN THE SOUTHERN BRANCH.
A SOUTHWEST FLOW BETWEEN THESE TWO SYSTEMS HAS ALLOWED FOR HIGH
CLOUDS TO OVERSPREAD THE AREA THIS MORNING. A STRATO CU DECK HAS
ALSO SPREAD INTO THE AREA FROM THE NORTHWEST. HIGH CLOUDS SHOULD
DISSIPATE FROM NORTHWEST TO SOUTHEAST DURING THE AFTERNOON HOURS AS
THE DRY SLOT WRAPS AROUND THE UPPER-LEVEL LOW THAT IS LOCATED OVER
THE OHIO VALLEY. THE STRATO CU DECK WILL HANG ON THROUGHOUT THE
DAY...ESPECIALLY ACROSS THE NORTHERN AND WESTERN CWA. WILL CONTINUE
MOSTLY CLOUDY/PARTLY SUNNY SKIES.
SURFACE HIGH PRESSURE WILL KEEP DRY CONDITIONS IN PLACE. MAX TEMPS
SHOULD BE NEAR CLIMO...IN THE 50S ACROSS MOST LOCATIONS...BUT 40S IN
THE HIGHER ELEVATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
CIRRUS AND LOWER STRATUS DECK IN THE NW ARE EXPECTED TO THIN OUT A
BIT BY THE EVENING...HOWEVER MOISTURE FROM THE GULF STATES SYSTEM IS
EXPECTED TO STREAM NORTHWARD OVERNIGHT. PARTLY CLOUDY/MOSTLY CLOUDY
SKIES ARE EXPECTED MAINLY AFTER MIDNIGHT. MAV NUMBERS CONTINUE TO
VERIFY SLIGHTLY BETTER THAN THE OTHER GUIDANCE...AND HAVE USED FOR
THE OVERNIGHT MINS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SUNDAY...FLOW BECOMES NELY WITH HIGH PRESSURE OVER NEW ENGLAND AND
AN APPROACHING COASTAL LOW OFF THE CAROLINAS. CLOUDS IN THE REGION
DUE TO COASTAL SYSTEM...SO EXPECT MOSTLY SUNNY SKIES UNTIL CLOUD
BANK ROLLS N-WARD IN ADVANCE OF THE LOW. WITH MORE SUN NRN
ZONES...MAX TEMPS SUNDAY COULD BE THE INVERSE OF NORMAL WITH WARMEST
/AROUND 60F/ LOCALES IN HARFORD/BALTIMORE AND COOLER /MID 50S/
NELSON/ALBEMARLE.
SUNDAY NIGHT THROUGH MONDAY NIGHT...HIGH PUSHES OFF NEW ENGLAND AND
LOW PUSHES EAST OF HATTERAS...BRINGING ELY FLOW/CAD TO THE AREA.
HAVING ALREADY MOISTENED...EXPECT LIGHT RAIN SPREADING EAST ACROSS
THE AREA WITH EAST FACING SLOPES HAVING THE GREATEST PRECIP
POTENTIAL DUE TO TOPOGRAPHY. SHOULD BE QUITE CLOUDY WITH SOME
RAIN...EXPECT LOW DIURNAL RANGE...MINS MID 40S...MAXES MID 50S.
TUESDAY AND WEDNESDAY...A CLOSED LOW OVER THE CENTRAL PLAINS/MID
WEST TO BREAK CAD WITH SWLY FLOW BY TUESDAY AFTERNOON /DID INCREASE
POPS FOR TUESDAY MORNING ACROSS EASTERN HALF OF CWA DUE TO EXTENDED
CAD/. WARMING TREND TUE /UPPER 50S/ TO WED /AROUND 60F/ AHEAD OF
FROPA.
WEDNESDAY NIGHT/THANKSGIVING...S/W LOBE/S/ FROM THE LOW TO BRING ONE
OR MORE COLD FRONTS PASSAGES IN MID TO LATE WEEK TIMEFRAME BRINGING
PRECIP CHANCES ACROSS THE CWA. HOWEVER...MOISTURE AVAILABILITY FOR
THE MID ATLANTIC IS UNCERTAIN. COLD AIR DOES LOOK TO FOLLOW THE
FRONT...BRINGING A COOL DOWN AND MOUNTAIN WINTRY PRECIP.
THURSDAY NIGHT/FRIDAY...MODELS UNCERTAIN OF LOW INTENSITY AND
TRACK...BUT THE POTENTIAL IS THERE FOR AN EARLY UPSLOPE SNOW EVENT
IN NWLY FLOW AROUND THE BACKSIDE OF THE LOW FEEDING GREAT LAKE
MOISTURE TO THE ALLEGHENY FRONT AND POSSIBLY RIDGES FURTHER EAST.
WILL HAVE TO MONITOR FUTURE MODELS FOR CONSISTENCY/GREATER
DISCERNMENT. IF ANYTHING...COOLING TREND LATE NEXT WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS THIS AFTERNOON. HIGH CLOUDS WILL DISSIPATE FROM
NORTHWEST TO SOUTHEAST THIS AFTERNOON...BUT A BKN STRATO CU DECK
WILL PERSIST THROUGH THE AFTERNOON. CIGS WILL REMAIN ABOVE 3KFT. THE
STRATO CU DECK WILL DISSIPATE THIS EVENING. VFR CONDITIONS ALONG
WITH LIGHT WINDS ARE EXPECTED MOST OF TONIGHT. MVFR VSBYS ARE
POSSIBLE TOWARDS MORNING WITH PATCHY BR.
ONSHORE NELY FLOW SETS UP SUNDAY...WITH MOISTENING/PRECIP BEGINNING
BY LATE SUNDAY NIGHT AS ELY FLOW SETS UP ACROSS THE TERMINALS. LOW
CIGS AND REDUCED VSBYS IN RAIN/DRIZZLE INTO TUESDAY MORNING. SWLY
FLOW AHEAD OF THE NEXT COLD FRONT LATER TUESDAY/WEDNESDAY WITH
IMPROVED AVIATION CONDITIONS. QUANTITY OF PRECIP ASSOCD WITH FRONT
LOOKS TO BE LOW AT THIS TIME THOUGH WITH TIMING LATER
WEDNESDAY/EARLY THURSDAY CERTAINLY PAY ATTENTION TO SUBSEQUENT
FORECASTS.
&&
.MARINE...
NORTH-NORTHWEST WINDS ARE EXPECTED ACROSS THE MARINE AREA THROUGH
TONIGHT. NO FLAGS ARE EXPECTED.
HIGH PRESSURE BUILDING OVER NEW ENGLAND AND A COASTAL LOW MOVING UP
THE CAROLINAS SUNDAY/NIGHT BRINGS ABOUT NELY FLOW. SMALL CRAFT
ADVISORY WINDS POSSIBLE SUNDAY NIGHT THROUGH MONDAY NIGHT. SWLY FLOW
AHEAD OF THE NEXT FRONT LATER TUESDAY AND WEDNESDAY. ONE OR MORE
FROPAS LATER WEDNESDAY THROUGH FRIDAY TO BRING SOME PRECIP AND
COLDER AIR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
LISTEMAA/LASORSA/BAJ
000
FXUS61 KLWX 211051
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
551 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL CROSS THE REGION AND SETTLE OVER NEW ENGLAND
THROUGH THE WEEKEND. A LOW PRESSURE AREA WILL MOVE UP COASTAL
CAROLINA SUNDAY NIGHT INTO TUESDAY...BRINGING RAIN. HIGH PRESSURE
WILL RETURN LATE TUESDAY...THOUGH A COLD FRONTAL PASSAGE IS
EXPECTED IN THE MIDDLE TO LATE PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE FOR SKY COVER EARLY THIS MORNING. STRATUS DECK
AROUND 4 KFT HAS MADE IT EAST OF THE BLUE RIDGE MOUNTAINS. WILL GO
AHEAD AND BUMP UP THE SKY COVER BETWEEN THE WASHINGTON METRO AREA
AND THE MASON DIXON LINE. OTHERWISE...NO CHANGES.
PREVIOUS DISCUSSION BELOW.
HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN OHIO VALLEY TODAY.
LIGHT NORTHERLY SURFACE FLOW WILL CONTINUE...WITH HIGHS RANGING FROM
THE MIDDLE 40S IN THE HIGHER TERRAIN TO UPPER 50S ACROSS THE
PIEDMONT. NO PRECIP IS ANTICIPATED.
WATER VAPOR LOOP AND 500MB ANALYSIS SHOWS A TROUGH ACROSS THE
CENTRAL GREAT LAKES...WITH STRONG SHORTWAVE ENERGY ROTATING THROUGH
THE BASE. THE TROUGH WILL CONTINUE TO MOVE EASTWARD TODAY...AND SET
UP ALONG THE MASON DIXON LINE THROUGH TONIGHT. THE GFS AND NAM ARE
SLIGHTLY DIFFERENT WITH THEIR SOLUTIONS FOR THE TROUGH
EVOLUTION...AND BOTH INITIALIZED RATHER WELL. THE NAM DEVELOPS A CUT
OFF LOW ACROSS THE NORTHERN CWFA OVERNIGHT...WHILE THE GFS MAINTAINS
A SHEAR AXIS. NEITHER MODEL IS PRODUCING PRECIP...JUST INCREASED
CLOUDINESS.
250MB JET STREAK CONTINUES TO HELP SPREAD CIRRUS ACROSS THE CWFA
EARLY THIS MORNING. EXPECT THE CIRRUS TO HANG AROUND MOST OF
TODAY...AT TIMES BECOMING OPAQUE. HAVE OPTED TO GO PARTLY SUNNY FOR
TODAY...RATHER THAN MOSTLY SUNNY FOR MOST OF THE CWFA. THE NW CWFA
SHOULD REMAIN CLOUDY/MOSTLY CLOUDY IN THE BKN/OVC STRATUS DECK.
THICKER CIRRUS COULD LEND TO TEMPS BEING A DEGREE OR SO COOLER THAN
GUIDANCE. SINCE THE MAV MOS HAS BEEN PERFORMING RATHER WELL...HAVE
USED THOSE NUMBERS AND BUMPED TEMPS DOWN A DEGREE OR TWO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
CIRRUS AND LOWER STRATUS DECK IN THE NW ARE EXPECTED TO THIN OUT A
BIT BY THE EVENING...HOWEVER MOISTURE FROM THE GULF STATES SYSTEM IS
EXPECTED TO STREAM NORTHWARD OVERNIGHT. PARTLY CLOUDY/MOSTLY CLOUDY
SKIES ARE EXPECTED MAINLY AFTER MIDNIGHT. MAV NUMBERS CONTINUE TO
VERIFY SLIGHTLY BETTER THAN THE OTHER GUIDANCE...AND HAVE USED FOR
THE OVERNIGHT MINS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SUNDAY...FLOW BECOMES NELY WITH HIGH PRESSURE OVER NEW ENGLAND AND
AN APPROACHING COASTAL LOW OFF THE CAROLINAS. CLOUDS IN THE REGION
DUE TO COASTAL SYSTEM...SO EXPECT MOSTLY SUNNY SKIES UNTIL CLOUD
BANK ROLLS N-WARD IN ADVANCE OF THE LOW. WITH MORE SUN NRN
ZONES...MAX TEMPS SUNDAY COULD BE THE INVERSE OF NORMAL WITH WARMEST
/AROUND 60F/ LOCALES IN HARFORD/BALTIMORE AND COOLER /MID 50S/
NELSON/ALBEMARLE.
SUNDAY NIGHT THROUGH MONDAY NIGHT...HIGH PUSHES OFF NEW ENGLAND AND
LOW PUSHES EAST OF HATTERAS...BRINGING ELY FLOW/CAD TO THE AREA.
HAVING ALREADY MOISTENED...EXPECT LIGHT RAIN SPREADING EAST ACROSS
THE AREA WITH EAST FACING SLOPES HAVING THE GREATEST PRECIP
POTENTIAL DUE TO TOPOGRAPHY. SHOULD BE QUITE CLOUDY WITH SOME
RAIN...EXPECT LOW DIURNAL RANGE...MINS MID 40S...MAXES MID 50S.
TUESDAY AND WEDNESDAY...A CLOSED LOW OVER THE CENTRAL PLAINS/MID
WEST TO BREAK CAD WITH SWLY FLOW BY TUESDAY AFTERNOON /DID INCREASE
POPS FOR TUESDAY MORNING ACROSS EASTERN HALF OF CWA DUE TO EXTENDED
CAD/. WARMING TREND TUE /UPPER 50S/ TO WED /AROUND 60F/ AHEAD OF
FROPA.
WEDNESDAY NIGHT/THANKSGIVING...S/W LOBE/S/ FROM THE LOW TO BRING ONE
OR MORE COLD FRONTS PASSAGES IN MID TO LATE WEEK TIMEFRAME BRINGING
PRECIP CHANCES ACROSS THE CWA. HOWEVER...MOISTURE AVAILABILITY FOR
THE MID ATLANTIC IS UNCERTAIN. COLD AIR DOES LOOK TO FOLLOW THE
FRONT...BRINGING A COOL DOWN AND MOUNTAIN WINTRY PRECIP.
THURSDAY NIGHT/FRIDAY...MODELS UNCERTAIN OF LOW INTENSITY AND
TRACK...BUT THE POTENTIAL IS THERE FOR AN EARLY UPSLOPE SNOW EVENT
IN NWLY FLOW AROUND THE BACKSIDE OF THE LOW FEEDING GREAT LAKE
MOISTURE TO THE ALLEGHENY FRONT AND POSSIBLY RIDGES FURTHER EAST.
WILL HAVE TO MONITOR FUTURE MODELS FOR CONSISTENCY/GREATER
DISCERNMENT. IF ANYTHING...COOLING TREND LATE NEXT WEEK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS CONTINUE ACROSS THE CWFA AS HIGH PRESSURE REMAINS
ACROSS THE EASTERN OHIO VALLEY. UPPER JET STREAK CONTINUES TO HELP
SPREAD CIRRUS ACROSS THE AREA TONIGHT...WITH CIGS WELL ABOVE 3 KFT.
SOME LOWER STRATUS HAS SETTLED ACROSS KMRB...IN THE NORTHERLY
SURFACE FLOW...BUT CIGS ARE AROUND 4 KFT. EXPECT THE CIRRUS CIGS TO
CONTINUE THROUGH THE AFTERNOON...AT TIMES BKN. THE LOWER STRATUS
SHOULD CONTINUE TO SLOWLY SPREAD ALONG THE MASON DIXON LINE...BUT
CIGS BLO 3 KFT ARE NOT EXPECTED.
ONSHORE NELY FLOW SETS UP SUNDAY...WITH MOISTENING/PRECIP BEGINNING
BY LATE SUNDAY NIGHT AS ELY FLOW SETS UP ACROSS THE TERMINALS. LOW
CIGS AND REDUCED VSBYS IN RAIN/DRIZZLE INTO TUESDAY MORNING. SWLY
FLOW AHEAD OF THE NEXT COLD FRONT LATER TUESDAY/WEDNESDAY WITH
IMPROVED AVIATION CONDITIONS. QUANTITY OF PRECIP ASSOCD WITH FRONT
LOOKS TO BE LOW AT THIS TIME THOUGH WITH TIMING LATER
WEDNESDAY/EARLY THURSDAY CERTAINLY PAY ATTENTION TO SUBSEQUENT
FORECASTS.
&&
.MARINE...
NORTHERLY FLOW IS EXPECTED TO CONTINUE ACROSS THE MARINE AREA
THOUGHT TONIGHT...WITH WIND SPEEDS 15 KT OR LESS.
HIGH PRESSURE BUILDING OVER NEW ENGLAND AND A COASTAL LOW MOVING UP
THE CAROLINAS SUNDAY/NIGHT BRINGS ABOUT NELY FLOW. SMALL CRAFT
ADVISORY WINDS POSSIBLE SUNDAY NIGHT THROUGH MONDAY NIGHT. SWLY FLOW
AHEAD OF THE NEXT FRONT LATER TUESDAY AND WEDNESDAY. ONE OR MORE
FROPAS LATER WEDNESDAY THROUGH FRIDAY TO BRING SOME PRECIP AND
COLDER AIR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...LISTEMAA
000
FXUS61 KLWX 210842
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
342 AM EST SAT NOV 21 2009
.SYNOPSIS...
HIGH PRESSURE WILL CROSS THE REGION AND SETTLE OVER NEW ENGLAND
THROUGH THE WEEKEND. A LOW PRESSURE AREA WILL MOVE UP COASTAL
CAROLINA SUNDAY NIGHT INTO TUESDAY...BRINGING RAIN. HIGH PRESSURE
WILL RETURN LATE TUESDAY...THOUGH A COLD FRONTAL PASSAGE IS
EXPECTED IN THE MIDDLE TO LATE PORTIONS OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN OHIO VALLEY TODAY.
LIGHT NORTHERLY SURFACE FLOW WILL CONTINUE...WITH HIGHS RANGING FROM
THE MIDDLE 40S IN THE HIGHER TERRAIN TO UPPER 50S ACROSS THE
PIEDMONT. NO PRECIP IS ANTICIPATED.
WATER VAPOR LOOP AND 500MB ANALYSIS SHOWS A TROUGH ACROSS THE
CENTRAL GREAT LAKES...WITH STRONG SHORTWAVE ENERGY ROTATING THROUGH
THE BASE. THE TROUGH WILL CONTINUE TO MOVE EASTWARD TODAY...AND SET
UP ALONG THE MASON DIXON LINE THROUGH TONIGHT. THE GFS AND NAM ARE
SLIGHTLY DIFFERENT WITH THEIR SOLUTIONS FOR THE TROUGH
EVOLUTION...AND BOTH INITIALIZED RATHER WELL. THE NAM DEVELOPS A CUT
OFF LOW ACROSS THE NORTHERN CWFA OVERNIGHT...WHILE THE GFS MAINTAINS
A SHEAR AXIS. NEITHER MODEL IS PRODUCING PRECIP...JUST INCREASED
CLOUDINESS.
250MB JET STREAK CONTINUES TO HELP SPREAD CIRRUS ACROSS THE CWFA
EARLY THIS MORNING. EXPECT THE CIRRUS TO HANG AROUND MOST OF
TODAY...AT TIMES BECOMING OPAQUE. HAVE OPTED TO GO PARTLY SUNNY FOR
TODAY...RATHER THAN MOSTLY SUNNY FOR MOST OF THE CWFA. THE NW CWFA
SHOULD REMAIN CLOUDY/MOSTLY CLOUDY IN THE BKN/OVC STRATUS DECK.
THICKER CIRRUS COULD LEND TO TEMPS BEING A DEGREE OR SO COOLER THAN
GUIDANCE. SINCE THE MAV MOS HAS BEEN PERFORMING RATHER WELL...HAVE
USED THOSE NUMBERS AND BUMPED TEMPS DOWN A DEGREE OR TWO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
CIRRUS AND LOWER STRATUS DECK IN THE NW ARE EXPECTED TO THIN OUT A
BIT BY THE EVENING...HOWEVER MOISTURE FROM THE GULF STATES SYSTEM IS
EXPECTED TO STREAM NORTHWARD OVERNIGHT. PARTLY CLOUDY/MOSTLY CLOUDY
SKIES ARE EXPECTED MAINLY AFTER MIDNIGHT. MAV NUMBERS CONTINUE TO
VERIFY SLIGHTLY BETTER THAN THE OTHER GUIDANCE...AND HAVE USED FOR
THE OVERNIGHT MINS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
SUNDAY...FLOW BECOMES NELY WITH HIGH PRESSURE OVER NEW ENGLAND AND
AN APPROACHING COASTAL LOW OFF THE CAROLINAS. CLOUDS IN THE REGION
DUE TO COASTAL SYSTEM...SO EXPECT MOSTLY SUNNY SKIES UNTIL CLOUD
BANK ROLLS N-WARD IN ADVANCE OF THE LOW. WITH MORE SUN NRN
ZONES...MAX TEMPS SUNDAY COULD BE THE INVERSE OF NORMAL WITH WARMEST
/AROUND 60F/ LOCALES IN HARFORD/BALTIMORE AND COOLER /MID 50S/
NELSON/ALBEMARLE.
SUNDAY NIGHT THROUGH MONDAY NIGHT...HIGH PUSHES OFF NEW ENGLAND AND
LOW PUSHES EAST OF HATTERAS...BRINGING ELY FLOW/CAD TO THE AREA.
HAVING ALREADY MOISTENED...EXPECT LIGHT RAIN SPREADING EAST ACROSS
THE AREA WITH EAST FACING SLOPES HAVING THE GREATEST PRECIP
POTENTIAL DUE TO TOPOGRAPHY. SHOULD BE QUITE CLOUDY WITH SOME
RAIN...EXPECT LOW DIURNAL RANGE...MINS MID 40S...MAXES MID 50S.
TUESDAY AND WEDNESDAY...A CLOSED LOW OVER THE CENTRAL PLAINS/MID
WEST TO BREAK CAD WITH SWLY FLOW BY TUESDAY AFTERNOON /DID INCREASE
POPS FOR TUESDAY MORNING ACROSS EASTERN HALF OF CWA DUE TO EXTENDED
CAD/. WARMING TREND TUE /UPPER 50S/ TO WED /AROUND 60F/ AHEAD OF
FROPA.
WEDNESDAY NIGHT/THANKSGIVING...S/W LOBE/S/ FROM THE LOW TO BRING ONE
OR MORE COLD FRONTS PASSAGES IN MID TO LATE WEEK TIMEFRAME BRINGING
PRECIP CHANCES ACROSS THE CWA. HOWEVER...MOISTURE AVAILABILITY FOR
THE MID ATLANTIC IS UNCERTAIN. COLD AIR DOES LOOK TO FOLLOW THE
FRONT...BRINGING A COOL DOWN AND MOUNTAIN WINTRY PRECIP.
THURSDAY NIGHT/FRIDAY...MODELS UNCERTAIN OF LOW INTENSITY AND
TRACK...BUT THE POTENTIAL IS THERE FOR AN EARLY UPSLOPE SNOW EVENT
IN NWLY FLOW AROUND THE BACKSIDE OF THE LOW FEEDING GREAT LAKE
MOISTURE TO THE ALLEGHENY FRONT AND POSSIBLY RIDGES FURTHER EAST.
WILL HAVE TO MONITOR FUTURE MODELS FOR CONSISTENCY/GREATER
DISCERNMENT. IF ANYTHING...COOLING TREND LATE NEXT WEEK.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS CONTINUE ACROSS THE CWFA AS HIGH PRESSURE REMAINS
ACROSS THE EASTERN OHIO VALLEY. UPPER JET STREAK CONTINUES TO HELP
SPREAD CIRRUS ACROSS THE AREA TONIGHT...WITH CIGS WELL ABOVE 3 KFT.
SOME LOWER STRATUS HAS SETTLED ACROSS KMRB...IN THE NORTHERLY
SURFACE FLOW...BUT CIGS ARE AROUND 4 KFT. EXPECT THE CIRRUS CIGS TO
CONTINUE THROUGH THE AFTERNOON...AT TIMES BKN. THE LOWER STRATUS
SHOULD CONTINUE TO SLOWLY SPREAD ALONG THE MASON DIXON LINE...BUT
CIGS BLO 3 KFT ARE NOT EXPECTED.
ONSHORE NELY FLOW SETS UP SUNDAY...WITH MOISTENING/PRECIP BEGINNING
BY LATE SUNDAY NIGHT AS ELY FLOW SETS UP ACROSS THE TERMINALS. LOW
CIGS AND REDUCED VSBYS IN RAIN/DRIZZLE INTO TUESDAY MORNING. SWLY
FLOW AHEAD OF THE NEXT COLD FRONT LATER TUESDAY/WEDNESDAY WITH
IMPROVED AVIATION CONDITIONS. QUANTITY OF PRECIP ASSOCD WITH FRONT
LOOKS TO BE LOW AT THIS TIME THOUGH WITH TIMING LATER
WEDNESDAY/EARLY THURSDAY CERTAINLY PAY ATTENTION TO SUBSEQUENT
FORECASTS.
&&
.MARINE...
NORTHERLY FLOW IS EXPECTED TO CONTINUE ACROSS THE MARINE AREA
THOUGHT TONIGHT...WITH WIND SPEEDS 15 KT OR LESS.
HIGH PRESSURE BUILDING OVER NEW ENGLAND AND A COASTAL LOW MOVING UP
THE CAROLINAS SUNDAY/NIGHT BRINGS ABOUT NELY FLOW. SMALL CRAFT
ADVISORY WINDS POSSIBLE SUNDAY NIGHT THROUGH MONDAY NIGHT. SWLY FLOW
AHEAD OF THE NEXT FRONT LATER TUESDAY AND WEDNESDAY. ONE OR MORE
FROPAS LATER WEDNESDAY THROUGH FRIDAY TO BRING SOME PRECIP AND
COLDER AIR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
LISTEMAA/BAJ
000
FXUS61 KLWX 210213 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
913 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SATURDAY. HIGH
PRESSURE WILL RETREAT TO THE NORTH SUNDAY AND LOW PRESSURE WILL MOVE
UP THE EASTERN SEABOARD SUNDAY NIGHT THROUGH MONDAY NIGHT...BRINGING
ANOTHER ROUND OF RAIN. HIGH PRESSURE WILL RETURN TUESDAY...BUT A
COLD FRONT WILL PASS THROUGH DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM SATURDAY MORNING/...
A RESIDUAL UPPER WAVE REMAINS BACK TO THE NW...SLIDING DOWN THRU
THE UPPER MIDWEST TONIGHT W/ LITTLE-NO PRECIP BUT A LARGE MASS OF
LOW CLOUDS STREAMING FROM THE SHORES OF LAKE ERIE DOWN INTO THE
CNTRL APLCNS. THIS WILL BE ABOUT THE ONLY WX ACTIVITY FOR THE
REGION INTO THE EARLY PART OF THE WEEKEND. PORTIONS OF THIS CLOUD
BANK WILL BREAK-UP AND SLIDE DOWN ACROSS THE NRN SHENANDOAH VLY
AND POTOMAC HIGHLANDS THRU THE OVERNIGHT HRS. WINDS DECREASING
AND AFTER A LONG PERIOD OF NWLY WINDS THIS AFTN...CONDITIONS ARE
RELATIVELY DRY...SO WIDESPREAD FOG DEVELOPMENT NOT EXPECTED
/OUTSIDE OF SHELTERED VLYS AND OTHER TYPICAL FOG-PRONE AREAS
TOWARD THE PRE-DAWN HRS/. THE RELATIVELY DRY CONDITIONS WILL ALSO
ALLOW TEMPS TO SLIDE DOWN INTO M/U30S /L40S IN THE METRO AREAS AND
CLOSER TO THE BAY/.
&&
.SHORT TERM /7 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
SURFACE HIGH WILL REMAIN OVER THE REGION SATURDAY BRINGING DRY AND
SEASONABLE CONDITIONS. MAX TEMPS WILL BE IN THE MID TO UPPER 50S
ACROSS MOST LOCATIONS. MOSTLY/PARTLY SUNNY SKIES ARE EXPECTED WITH A
SCATTERED CU DECK DUE TO DIURNAL HEATING AND SOME HIGH CLOUDS DUE TO
A SOUTHWEST FLOW ALOFT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
LRG HIPRES HANGING OUT ACRS THE NE/GRTLKS RGN SAT NGT-SUN. DIFF THIS
CYCLE IS THE COMBO OF SFC HIGH AND H5 RDGG...MAKING IT HARDER TO
DISLODGE. THRFR..GDNC THIS CYCLE SLOER THAN PRVS CYCLES. GFS SEEMS
TO BE QUICKER...BUT IT ALSO SEEMS TO BE AFFECTED BY GRIDSCALE
FEEDBACK...OWING TO S/WV PHASING. GGEM/NAM IN CONCERT...SUGGESTING
PCPN WL BE CENTERED ON SUN NGT-MON. A WK LOW WL THEN EMERGE OFF MID
ATLC CST MON NGT. WL MAKE APPRO CHGS TO GRIDS. ONE THING OF NOTE IS
THAT THERE/S NO COLD AIR ARND. AFTR MAKING APPRO MOS TEMP
ADJUSTMENTS /NEGLECTING THE COOLER MAXT OF WET GFS AND SIDING WARMER
SUN NGT AS CLDS ADVECT NWD/...MAXT WL BE NEAR NRML BUT MIN-T WARMER
THAN NRML.
SHUD GET A RESPITE TUE BEFORE ANTHR STORM AFFECTS CWFA IN THE
WED-THU TIMEFRAME. WL NEED TO MONITOR DUE TO TRAVEL IMPACTS. ATTM...
THE WARM TREND CONTS AS A CUTOFF H5 LOW DVLPS W OF THE MISSISSIPPI.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BRING VFR CONDITIONS THROUGH SATURDAY. A
SCATTERED STRATUS DECK /3-4 KFT/ WILL CONTINUE TO DRIFT IN FROM
THE NW /BUT ONLY IN SMALLER PORTIONS FROM ITS LARGER MASS - BACK
ACROSS OH/WRN PA. THIS AREA OF CLOUDS WILL CONTINUE TO MOVE INTO
THE AREA TOWARD SATURDAY MORNING AND INTO THE AFTERNOON...DRIFTING
THRU AND DISSIPATING BY LATER IN THE EVNG. WIND SPEEDS WILL REMAIN
BELOW 10 KNOTS THRU THIS TIME.
VFR THRU SUN. FLGT RESTRICTION DUE TO LOPRES SUN NGT-MON NGT.
&&
.MARINE...
NLY WINDS WILL CONTINUE TO MOVE OVER THE WATERS OVERNIGHT...AND
HIGH PRESSURE BEGINS TO MOVE IN FROM THE WEST...THOUGH WINDS WILL
BE LIGHT W/ A MINIMAL PRES GRADIENT...SO NO WX CONCERNS INTO THE
WEEKEND.
NO FLAGS XPCTD THRU THE WKND. LOPRES AFFECTING WATERS MON. WNDS MAY
PICK UP IN ADVC OF LOW...W/ A ENELY FETCH.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
UPDATE...GMS
PREV DISCUSSION...BJL/HTS
000
FXUS61 KLWX 202000
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
300 PM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH SATURDAY. HIGH
PRESSURE WILL RETREAT TO THE NORTH SUNDAY AND LOW PRESSURE WILL MOVE
UP THE EASTERN SEABOARD SUNDAY NIGHT THROUGH MONDAY NIGHT...BRINGING
ANOTHER ROUND OF RAIN. HIGH PRESSURE WILL RETURN TUESDAY...BUT A
COLD FRONT WILL PASS THROUGH DURING THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
HIGH PRESSURE WILL REMAIN OVER THE REGION TONIGHT BRINGING DRY AND
SEASONABLE CONDITIONS. A MID-LEVEL TROUGH WILL MOVE INTO THE OHIO
VALLEY OVERNIGHT WHILE AN AREA OF LOW PRESSURE DEVELOPS OVER THE
SOUTH-CENTRAL CONUS. A FEW HIGH AND MID-LEVEL CLOUDS WILL MOVE IN
LATE TONIGHT AHEAD OF THESE SYSTEMS...ESPECIALLY ACROSS THE WESTERN
CWA. MIN TEMPS WILL RANGE FROM NEAR 30 IN THE POTOMAC HIGHLANDS TO
THE MIDDLE 40S IN DOWNTOWN WASHINGTON/BALTIMORE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH 6 PM SATURDAY/...
SURFACE HIGH WILL REMAIN OVER THE REGION SATURDAY BRINGING DRY AND
SEASONABLE CONDITIONS. MAX TEMPS WILL BE IN THE MID TO UPPER 50S
ACROSS MOST LOCATIONS. MOSTLY/PARTLY SUNNY SKIES ARE EXPECTED WITH A
SCATTERED CU DECK DUE TO DIURNAL HEATING AND SOME HIGH CLOUDS DUE TO
A SOUTHWEST FLOW ALOFT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
LRG HIPRES HANGING OUT ACRS THE NE/GRTLKS RGN SAT NGT-SUN. DIFF THIS
CYCLE IS THE COMBO OF SFC HIGH AND H5 RDGG...MAKING IT HARDER TO
DISLODGE. THRFR..GDNC THIS CYCLE SLOER THAN PRVS CYCLES. GFS SEEMS
TO BE QUICKER...BUT IT ALSO SEEMS TO BE AFFECTED BY GRIDSCALE
FEEDBACK...OWING TO S/WV PHASING. GGEM/NAM IN CONCERT...SUGGESTING
PCPN WL BE CENTERED ON SUN NGT-MON. A WK LOW WL THEN EMERGE OFF MID
ATLC CST MON NGT. WL MAKE APPRO CHGS TO GRIDS. ONE THING OF NOTE IS
THAT THERE/S NO COLD AIR ARND. AFTR MAKING APPRO MOS TEMP
ADJUSTMENTS /NEGLECTING THE COOLER MAXT OF WET GFS AND SIDING WARMER
SUN NGT AS CLDS ADVECT NWD/...MAXT WL BE NEAR NRML BUT MIN-T WARMER
THAN NRML.
SHUD GET A RESPITE TUE BEFORE ANTHR STORM AFFECTS CWFA IN THE
WED-THU TIMEFRAME. WL NEED TO MONITOR DUE TO TRAVEL IMPACTS. ATTM...
THE WARM TREND CONTS AS A CUTOFF H5 LOW DVLPS W OF THE MISSISSIPPI.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BRING VFR CONDITIONS THROUGH SATURDAY. A
SCATTERED CU DECK AROUND 3KFT IS EXPECTED TO DEVELOP LATER SATURDAY
MORNING INTO SATURDAY AFTERNOON. WIND SPEEDS WILL REMAIN BELOW 10
KNOTS.
VFR THRU SUN. FLGT RESTRICTION DUE TO LOPRES SUN NGT-MON NGT.
&&
.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 4 PM THIS AFTERNOON
FOR THE LOWER TIDAL POTOMAC AND CHESAPEAKE BAY. WINDS WILL DIMINISH
LATE THIS AFTERNOON AS HIGH PRESSURE BUILDS TOWARD THE WATERS.
NORTH-NORTHWEST WINDS WILL CHANNEL DOWN THE LOWER BAY A TONIGHT
WITH WIND SPEEDS UP TO 15 KNOTS EXPECTED.
HIGH PRESSURE WILL BUILD OVER THE WATERS SATURDAY BRINGING TRANQUIL
CONDITIONS.
NO FLAGS XPCTD THRU THE WKND. LOPRES AFFECTING WATERS MON. WNDS MAY
PICK UP IN ADVC OF LOW...W/ A ENELY FETCH.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ530>534-537>543.
&&
$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...BJL
LONG TERM...HTS
AVIATION...BJL/HTS
MARINE...BJL/HTS
000
FXUS61 KLWX 201439
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
939 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC THROUGH SATURDAY.
HIGH PRESSURE THEN RETREATS TO THE NORTH ON SUNDAY AS LOW PRESSURE
APPROACHES FROM THE SOUTH. LOW PRESSURE IS EXPECTED TO MOVE UP THE
EASTERN SEABOARD SUNDAY NIGHT INTO MONDAY...PRODUCING RAIN ACROSS
THE REGION. HIGH PRESSURE RETURNS TUESDAY...THEN A COLD FRONT MAY
AFFECT THE AREA ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE CURRENTLY LOCATED OVER THE OHIO VALLEY WILL BUILD OVER
THE REGION TODAY BRINGING DRY CONDITIONS ALONG WITH SUNSHINE. WITH
PLENTY OF SUNSHINE AND A DOWNSLOPING WEST-NORTHWEST FLOW...MAX TEMPS
WILL BE A FEW DEGREES ABOVE CLIMO...TOPPING OFF IN THE UPPER 50S TO
LOWER 60S ACROSS MOST LOCATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HIPRES DRIFTS CLOSER TNGT...WITH MOSTLY CLEAR SKIES AND LGT WINDS.
EVEN WITH AMPLE RADIATION COOLING...XPCT TEMPS SLIGHTLY ABOVE
SEASONAL MEANS...30S FOR MINIMA...XCPT 40S NEAR URBAN CENTERS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE AT THE SURFACE BUILDS OVER THE MID ATLANTIC SATURDAY
THEN RETREATS TO THE NORTHEAST ON SUNDAY AS LOW PRESSURE BEGINS TO
APPROACH FROM THE GULF STATES.
THIS WEEKEND WILL BE SEASONABLE...WITH HIGHS IN THE 50S ACROSS THE
CWA. PLENTY OF SUNSHINE IS EXPECTED ON SATURDAY...BUT CLOUDS WILL BE
BACK ON THE INCREASE SUNDAY WELL AHEAD OF GULF LOW PRESSURE...AND
THERE MAY BE SOME RAIN THAT BREAKS OUT LATE IN THE DAY.
MODELS ARE IN AGREEMENT WITH LOW PRESSURE MOVING NORTHEAST UP THE
EASTERN SEABOARD IN THE SUNDAY NIGHT/MONDAY TIME FRAME...BUT THERE
ARE TIMING DIFFERENCES. THERE ARE ALSO TRACK DIFFERENCES REGARDING
EXACTLY HOW NEAR THE COAST LOW PRESSURE WILL BE...BUT MODELS
GENERALLY CONVERGE ON A SOLUTION THAT LOW PRESSURE WILL BE IN A
POSITION TO LIKELY BRING RAIN TO THE CWA. AS FOR TIMING...HAVE
HIGHLIGHTED THE SUNDAY NIGHT/MONDAY TIME FRAME FOR LIKELY POPS...AND
MORE TIMING DETAIL AND QPF DETAIL CAN BE ADDED IN FUTURE FORECASTS.
LOW PRESSURE EXITS MONDAY NIGHT INTO TUESDAY...BUT A SHORTWAVE/FRONT
IS EXPECTED TO PASS THROUGH THE REGION TUESDAY NIGHT INTO WEDNESDAY.
THIS WILL BE RENEW CHANCES OF RAIN ESPECIALLY ACROSS WESTERN AREAS.
A SECONDARY SHORTWAVE ROTATES THROUGH THURSDAY...ENHANCING UPSLOPE
PRECIPITATION POTENTIAL.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE WILL BRING VFR CONDITIONS THROUGH TONIGHT. NORTHWEST
WINDS WILL GUST AROUND 15 TO 20 KNOTS THROUGH MID-AFTERNOON. WINDS
WILL DIMINISH TOWARD EVENING.
HIGH PRESSURE WILL BUILD ACROSS THE AIR SPACE ON SATURDAY...THEN
RETREATS ON SUNDAY AS LOW PRESSURE APPROACHES FROM THE SOUTH. RAIN
IS EXPECTED SUNDAY NIGHT INTO MONDAY...WITH A GOOD CHANCE OF IFR
CIGS AND MVFR-IFR VSBYS. HIGH PRESSURE RETURNS TUESDAY.
&&
.MARINE...
12Z KIAD SOUNDING SHOWS WIND SPEEDS AROUND 20 KNOTS JUST A COUPLE
THOUSAND FEET FROM THE SURFACE. STILL FEEL THAT SOME OF THESE WINDS
MAY MIX DOWN ACROSS THE CHESAPEAKE BAY AND LOWER TIDAL POTOMAC
TODAY. WILL CONTINUE WITH AN SCA UNTIL 4 PM THIS AFTERNOON. WINDS
WILL DIMINISH LATER THIS AFTERNOON INTO TONIGHT AS HIGH PRESSURE
APPROACHES FROM THE WEST.
HIGH PRESSURE OVER THE WATERS SATURDAY LIFTS NORTH OF THE AREA ON
SUNDAY AS LOW PRESSURE APPROACHES FROM THE SOUTH. LOW PRESSURE WILL
RIDE UP THE EAST COAST SUNDAY NIGHT INTO MONDAY. SMALL CRAFT
ADVISORY CONDITIONS MAY OCCUR DURING THAT TIME...ALONG WITH REDUCED
VISIBILITIES IN RAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ530>534-537>543.
&&
$$
SYNOPSIS...SBK
NEAR TERM...BJL
SHORT TERM...SBK
LONG TERM...BPP
AVIATION...SBK/BJL/BPP
MARINE...SBK/BJL/BPP
000
FXUS61 KLWX 200858
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
358 AM EST FRI NOV 20 2009
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE MID ATLANTIC THROUGH SATURDAY.
HIGH PRESSURE THEN RETREATS TO THE NORTH ON SUNDAY AS LOW PRESSURE
APPROACHES FROM THE SOUTH. LOW PRESSURE IS EXPECTED TO MOVE UP THE
EASTERN SEABOARD SUNDAY NIGHT INTO MONDAY...PRODUCING RAIN ACROSS
THE REGION. HIGH PRESSURE RETURNS TUESDAY...THEN A COLD FRONT MAY
AFFECT THE AREA ON WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CDFNT SLIDING OFF ERN SEABOARD ERY THIS MRNG...WITH HIPRES BUILDING
IN FROM OHIO VLY. PATCHY FOG OVR SHEN VALLEY...VA PIEDMONT AND
VALLEYS OVER VA FOOTHILLS E OF BLUE RIDGE WILL DIMINISH WITH
SUNRISE...LEAVING MOSTLY SUNNY SKIES FOR REMAINDER OF DAY.
DOWNSLOPING WINDS WILL AID DIURNAL EFFECTS IN OFFSETS CAA. WENT
CLOSE TO MET GUIDANCE FOR MAXIMA...U50S/L60S AREAWIDE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
HIPRES DRIFTS CLOSER TNGT...WITH MOSTLY CLEAR SKIES AND LGT WINDS.
EVEN WITH AMPLE RADIATION COOLING...XPCT TEMPS SLIGHTLY ABOVE
SEASONAL MEANS...30S FOR MINIMA...XCPT 40S NEAR URBAN CENTERS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
HIGH PRESSURE AT THE SURFACE BUILDS OVER THE MID ATLANTIC SATURDAY
THEN RETREATS TO THE NORTHEAST ON SUNDAY AS LOW PRESSURE BEGINS TO
APPROACH FROM THE GULF STATES.
THIS WEEKEND WILL BE SEASONABLE...WITH HIGHS IN THE 50S ACROSS THE
CWA. PLENTY OF SUNSHINE IS EXPECTED ON SATURDAY...BUT CLOUDS WILL BE
BACK ON THE INCREASE SUNDAY WELL AHEAD OF GULF LOW PRESSURE...AND
THERE MAY BE SOME RAIN THAT BREAKS OUT LATE IN THE DAY.
MODELS ARE IN AGREEMENT WITH LOW PRESSURE MOVING NORTHEAST UP THE
EASTERN SEABOARD IN THE SUNDAY NIGHT/MONDAY TIME FRAME...BUT THERE
ARE TIMING DIFFERENCES. THERE ARE ALSO TRACK DIFFERENCES REGARDING
EXACTLY HOW NEAR THE COAST LOW PRESSURE WILL BE...BUT MODELS
GENERALLY CONVERGE ON A SOLUTION THAT LOW PRESSURE WILL BE IN A
POSITION TO LIKELY BRING RAIN TO THE CWA. AS FOR TIMING...HAVE
HIGHLIGHTED THE SUNDAY NIGHT/MONDAY TIME FRAME FOR LIKELY POPS...AND
MORE TIMING DETAIL AND QPF DETAIL CAN BE ADDED IN FUTURE FORECASTS.
LOW PRESSURE EXITS MONDAY NIGHT INTO TUESDAY...BUT A SHORTWAVE/FRONT
IS EXPECTED TO PASS THROUGH THE REGION TUESDAY NIGHT INTO WEDNESDAY.
THIS WILL BE RENEW CHANCES OF RAIN ESPECIALLY ACROSS WESTERN AREAS.
A SECONDARY SHORTWAVE ROTATES THROUGH THURSDAY...ENHANCING UPSLOPE
PRECIPITATION POTENTIAL.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
SHELTERED VALLEY AT KCHO HAS ALLOWED FOR MOISTURE TO POOL NEAR SFC
OF DECOUPLED ATMOSPHERE...KEEPING MVFR/IFR CIGS. THIS SHUD IMPROVE
AT SUNRISE AS MIXING TAKES HOLD. VFR CONDS ELSEWHERE...WHICH WILL
PREVAIL THRU THE DAY. NW WINDS WILL INCR DRNG THE MRNG...BUT GUSTS
AOB 20 KT.
HIGH PRESSURE WILL BUILD ACROSS THE AIR SPACE ON SATURDAY...THEN
RETREATS ON SUNDAY AS LOW PRESSURE APPROACHES FROM THE SOUTH. RAIN
IS EXPECTED SUNDAY NIGHT INTO MONDAY...WITH A GOOD CHANCE OF IFR
CIGS AND MVFR-IFR VSBYS. HIGH PRESSURE RETURNS TUESDAY.
&&
.MARINE...
CDFNT PASSED OVR THE WATERS ERY THIS MRNG...NW WINDS GRADUALLY
INCRG...WITH GUSTS TO 20-25 KTS XPCD AFTN SUNRISE THRU AFTN ACRS MD
CHESAPEAKE AND LOWER TIDAL POTOMAC. MIDDLE/UPPER POTOMAC SHUD SEE
GUSTS RMN AROUND 15 KTS. HIPRES BUILDS ACRS APPALACHIANS FROM THE
WEST TOWARD THE WATERS THIS EVNG...ALLOWING WINDS TO SUBSIDE TO
BELOW SCA THRESHOLDS.
HIGH PRESSURE OVER THE WATERS SATURDAY LIFTS NORTH OF THE AREA ON
SUNDAY AS LOW PRESSURE APPROACHES FROM THE SOUTH. LOW PRESSURE WILL
RIDE UP THE EAST COAST SUNDAY NIGHT INTO MONDAY. SMALL CRAFT
ADVISORY CONDITIONS MAY OCCUR DURING THAT TIME...ALONG WITH REDUCED
VISIBILITIES IN RAIN.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
ANZ530>534-537>543.
&&
$$
SYNOPSIS...SBK/PELOQUIN
NEAR TERM...SBK
SHORT TERM...SBK
LONG TERM...PELOQUIN
AVIATION...SBK/PELOQUIN
MARINE...SBK/PELOQUIN
| 
