000
FXUS61 KLWX 100955
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
455 AM EST WED FEB 10 2010
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF OF THE COAST OF THE CAROLINAS TODAY AND
THEN UP THE EASTERN SEABOARD OVERNIGHT AND THURSDAY. THIS LOW
PRESSURE SYSTEM WILL BRING ANOTHER ROUND OF WINTRY PRECIPITATION TO
THE AREA...ALONG WITH GUSTY WINDS. HIGH PRESSURE WILL BUILD OVER THE
AREA FOR THE LATTER HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
QUICK UPDATE TO THE ZONES TO BUMP DOWN THE TOTAL SNOWFALL AMOUNTS
ACROSS PORTIONS OF THE CWFA...ESPECIALLY THOSE AREAS THAT
EXPERIENCED A LONG BREAK IN THE SNOW AND THOSE AREAS THAT HAVE
RECEIVED A WINTRY MIX OVERNIGHT. PRODUCTS OUT SHORTLY.
THE BIGGEST CHANGE FOR THIS UPDATE IS AN UPGRADE TO BLIZZARD WARNING
FOR THE PORTIONS OF THE CWA...STARTING LATE MORNING THRU THE AFTN.
AREAS AFFECTED EXPECTED TO BE EXTREME NERN MD...ALONG THE
MASON-DIXON LINE /AND ESPECIALLY HIGHER TERRAIN ACROSS THE WRN ZONES
LIKE THE CATOCTINS AND POTOMAC HIGHLANDS/ AND ACROSS THE HIGHER
ELEVATIONS OF THE ALLEGHENY MTNS. THE TRUE DYNAMICS OF THIS SYSTEM
WILL GEAR-UP IN THE COMING HRS THIS MORNING...AS THE UPPER LOW
SHOOTS SEWD ACROSS THE CWA AND THE COASTAL LOW QUICKLY DEEPENS JUST
OFF THE DELMARVA COAST.
EARLY INDICATIONS OF WHAT/S IN STORE AS THESE ELEMENTS COME TOGETHER
OVER THE AREA CAN BE SEEN ON REGIONAL RADAR...W/ A SFC TROF THAT IS
QUICKLY SLIDING THRU WV...NOW CROSSING THE CNTRL APLCNS AND WILL
SHORTLY BE MOVING INTO THE I-81 CORRIDOR. WIND GUSTS OF 25-35KT
COMMON W/ THE PASSAGE...ALONG W/ ABOUT A 10-15 DEGREE TEMPERATURE
DROP AND A DECENT PRESSURE SURGE ASSOCIATED W/ THE FEATURE. AS THIS
FEATURE TRUDGES ACROSS THE FOOTHILLS AND PIEDMONT LATER INTO THE
PRE-DAWN HRS...THE LOW LEVEL WAA LAYER THAT GAVE PARTS OF THE REGION
A MIXED PRECIP REGIME OVERNIGHT WILL QUICKLY BE REPLACED W/ A COLD
AIRMASS AND DRIER AIR WILL ALSO MIX-DOWN...BUT MAINLY DOWN INTO
CNTRL-SRN VA.
CURRENTLY...SCATTERED AREAS OF LIGHT-MODERATE SNOW FILLING-IN OVER
MUCH OF THE CWA BEHIND THE HEAVIER ACTIVITY FROM LATE LAST
NIGHT...THAT HAS SINCE MOVED UP INTO NJ/SRN NY. BETWEEN THE
APPROACHING UPPER LOW AND THE DEEPENING COASTAL LOW WILL BE AN AXIS
OF HIGHER MOISTURE INFLUX AND LIFT...LEADING TO BANDING OF SNOW
ACROSS THE I-95 CORRIDOR OF NRN VA-ERN MD LATER THIS MORNING. ONCE
THIS FEATURE SETS-UP...PERIODS OF HEAVY SNOW AND NEAR WHITE-OUT
CONDITIONS WILL DEVELOP /ESPECIALLY ACROSS NERD MD/. HEAVIER
SNOWFALL RATES AND STRONGER WINDS WILL BEGIN TO OVERSPREAD THESE
AREAS...AND BLIZZARD CONDITIONS WILL BECOME MORE LIKELY FROM LATE
MORNING INTO THE EARLY AFTN HRS.
THE SNOW BAND WILL BEGIN TO MOVE EWD TOWARD DELMARVA INTO THE MID
AFTN HRS...AND MUCH OF THE SNOW WILL START TO TAPER OFF ACROSS THE
CWA THRU THE LATE AFTN AND EARLY EVENING HRS. A STRONG LOW LEVEL
JET WILL BE ORIENTED OVER THE AREA FOR MUCH OF THE DAY /50-60KT AT
850MB/...HELPING TO MIX-DOWN STRONGER GUSTS AND DISSIPATE PRECIP
FASTER BEHIND THE EXITING SYSTEM. WIND GUSTS OF 30-45 MPH WILL BE
COMMON ACROSS THE REGION...BLOWING AND DRIFTING NEWLY FALLEN SNOW.
THE BLIZZARD WARNING AREAS ARE MOST COINCIDENT W/ AREAS THAT ARE
EXPECTED TO EXPERIENCE THE NEAR WHITE-OUT CONDITIONS FROM THE
STRONGEST WINDS AND HEAVIEST SNOWFALL/BLOWING SNOW AT THE SAME TIME
/CENTERED MAINLY AROUND THE LATE MORNING-EARLY AFTN/.
ELSEWHERE...SNOW MAY TAPER OFF BEFORE THE HIGHEST WINDS MOVE ACROSS
THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
UPSLOPE SNOW WILL CONTINUE FOR THE CNTRL APLCNS WELL AFTER THE
COASTAL LOW HAS MOVED OFF THE MID ATLC COAST THRU THURSDAY AFTN.
MODERATE SNOW ACCUMULATION POSSIBLE FOR THE HIGHER ELEVATIONS DURING
THIS PERIOD. E OF THE MTNS...DRY-COLD AND WINDY WX WILL REPLACE THE
EXITING LOW PRESSURE SYSTEM.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES TO THE LONG TERM PORTION OF THE FORECAST WERE MADE.
UPSLOPE SNOW SHOWERS WILL BEGIN TO WANE ON THURSDAY AS HIGH PRESSURE
BUILDS IN FROM THE WEST. HAVE KEPT POPS PRETTY HIGH ACROSS THE
WESTERN RIDGES...BUT SNOW SHOULD COMPLETELY CUT OFF BY EARLY FRIDAY.
TEMPERATURES ARE EXPECTED TO REMAIN BLO FREEZING FOR MOST LOCALES
THURSDAY AND THURSDAY NIGHT...BUT ABOVE FREEZING MAX TEMPS ARE
EXPECTED FRIDAY AND SATURDAY. A COLD FRONT COMES THROUGH THE REGION
DURING THE WEEKEND...WITH HIGH PRESSURE BUILDING IN FOR THE FIRST
PART OF NEXT WEEK.
&&
.AVIATION /10Z WEDNESDAY THROUGH SUNDAY/...
A BRIEF LULL IN THE ACTIVITY OVERNIGHT FOR THE REGION /THO ONLY A
RELATIVE LULL...AS MOST AREAS REPORTING AT LEAST LIGHT FROZEN PRECIP
AND VERY LOW CIGS AND MODERATELY LOW VSBYS. A LARGE BAND OF MODERATE
TO HEAVY SNOW WILL SET-UP OVER THE DC-BALT METRO AREA /ESPECIALLY
THE BALT METRO AREA/ LATER THIS MORNING...AS WINDS ALSO INCREASE OUT
OF THE WNW. STRONG WINDS AT THE SFC AND ALOFT EXPECTED TOWARD THE
NOON HR...AND LASTING FOR THE NEXT 24-36 HRS. GUSTS NEAR 40KT WILL
BE COMMON THROUGHOUT THE AFTN/EVENING...SUBSIDING ONLY A BIT
OVERNIGHT AND LASTING INTO THU. IFR/LOWER EXPECTED ACROSS THE REGION
FOR THE NEXT SEVERAL HRS...AS SFC CONDITIONS REMAIN MOIST AND PRECIP
/MAINLY SNOW-SOME OF THE A MIX ALSO POSSIBLE/ LINGERS JUST AHEAD OF
THE STRONG WINDS. ONCE THE WINDS MIX-IN LATER THIS AFTN...DRIER
CONDITIONS WILL CLEAR-OUT MUCH OF THE SFC MOISTURE AND DENSE OVC BY
LATER THIS EVENING...BUT AS MENTIONED WINDS AT THE SFC AND THRU THE
LOWEST FEW THOU FT WILL BE FAIRLY STRONG.
CIGS/VSBYS ARE EXPECTED TO REMAIN VFR THROUGH THURSDAY AT MOST
LOCALES. HOWEVER...BLOWING SNOW MAY LOCALLY REDUCE SOME VSBYS BLO
VFR AT TIMES WHERE WINDS ARE THE MOST GUSTY. HIGH PRESSURE BUILDS IN
FOR THE REMAINDER OF THE WEEK AND NO CIGS/VSBY RESTRICTIONS ARE
ANTICIPATED.
&&
.MARINE...
LIGHT WINDS ON THE WATERS CURRENTLY...BUT THIS WILL QUICKLY BE
REPLACED W/ GALE CONDITIONS BY LATER THIS MORNING. A STRONG LOW
PRESSURE SYSTEM AFFECTING THE REGION WILL INCREASE WINDS OVER THE
WATERS TODAY...WELL INTO THE OVERNIGHT HRS AND INTO THU.
GALE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MOST OF THURSDAY AS
LOW PRESSURE MOVES UP THE EASTERN SEABOARD. THE GRADIENT IS EXPECTED
TO LESSEN THURSDAY EVENING AND OVERNIGHT AS HIGH PRESSURE BUILDS IN
FROM THE WEST. HOWEVER...SMALL CRAFT CONDITIONS ARE LIKELY THROUGH
THIS PERIOD. TO LESSEN CONFUSION...WILL NOT TACK ON THE SCA HEADLINE
ON THE END OF THE GALE. WILL MENTION IN THE SYNOPSIS AND HAVE 20
PLUS KT IN THE TEXT.
HIGH PRESSURE BUILDS IN FOR THE LATTER PART OF THE WEEK...AND
LIGHTER WINDS ARE EXPECTED.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ009-
013-016>018.
WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR
MDZ003>007-010-011-014-502.
BLIZZARD WARNING FROM 10 AM THIS MORNING TO 7 PM EST THIS
EVENING FOR MDZ003>007-010-011-014.
BLIZZARD WARNING FROM 10 AM THIS MORNING TO 4 PM EST THIS
AFTERNOON FOR MDZ502.
BLIZZARD WARNING UNTIL 7 AM EST THURSDAY FOR MDZ501.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ030-
031-040-042-050>057-501-502.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
VAZ025>029-036>039.
BLIZZARD WARNING UNTIL 7 AM EST THURSDAY FOR VAZ021.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ052-
053.
WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR WVZ050-
051-055-502-504.
BLIZZARD WARNING FROM 10 AM THIS MORNING TO 4 PM EST THIS
AFTERNOON FOR WVZ050-051-055-502-504.
BLIZZARD WARNING UNTIL 7 AM EST THURSDAY FOR WVZ054-501-503.
MARINE...GALE WARNING UNTIL 6 PM EST THURSDAY FOR ANZ530>543.
&&
$$
000
FXUS61 KLWX 100854
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
354 AM EST WED FEB 10 2010
.SYNOPSIS...
LOW PRESSURE WILL MOVE OFF OF THE COAST OF THE CAROLINAS TODAY AND
THEN UP THE EASTERN SEABOARD OVERNIGHT AND THURSDAY. THIS LOW
PRESSURE SYSTEM WILL BRING ANOTHER ROUND OF WINTRY PRECIPITATION TO
THE AREA...ALONG WITH GUSTY WINDS. HIGH PRESSURE WILL BUILD OVER THE
AREA FOR THE LATTER HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE BIGGEST CHANGE FOR THIS UPDATE IS AN UPGRADE TO BLIZZARD WARNING
FOR THE PORTIONS OF THE CWA...STARTING LATE MORNING THRU THE AFTN.
AREAS AFFECTED EXPECTED TO BE EXTREME NERN MD...ALONG THE
MASON-DIXON LINE /AND ESPECIALLY HIGHER TERRAIN ACROSS THE WRN ZONES
LIKE THE CATOCTINS AND POTOMAC HIGHLANDS/ AND ACROSS THE HIGHER
ELEVATIONS OF THE ALLEGHENY MTNS. THE TRUE DYNAMICS OF THIS SYSTEM
WILL GEAR-UP IN THE COMING HRS THIS MORNING...AS THE UPPER LOW
SHOOTS SEWD ACROSS THE CWA AND THE COASTAL LOW QUICKLY DEEPENS JUST
OFF THE DELMARVA COAST.
EARLY INDICATIONS OF WHAT/S IN STORE AS THESE ELEMENTS COME TOGETHER
OVER THE AREA CAN BE SEEN ON REGIONAL RADAR...W/ A SFC TROF THAT IS
QUICKLY SLIDING THRU WV...NOW CROSSING THE CNTRL APLCNS AND WILL
SHORTLY BE MOVING INTO THE I-81 CORRIDOR. WIND GUSTS OF 25-35KT
COMMON W/ THE PASSAGE...ALONG W/ ABOUT A 10-15 DEGREE TEMPERATURE
DROP AND A DECENT PRESSURE SURGE ASSOCIATED W/ THE FEATURE. AS THIS
FEATURE TRUDGES ACROSS THE FOOTHILLS AND PIEDMONT LATER INTO THE
PRE-DAWN HRS...THE LOW LEVEL WAA LAYER THAT GAVE PARTS OF THE REGION
A MIXED PRECIP REGIME OVERNIGHT WILL QUICKLY BE REPLACED W/ A COLD
AIRMASS AND DRIER AIR WILL ALSO MIX-DOWN...BUT MAINLY DOWN INTO
CNTRL-SRN VA.
CURRENTLY...SCATTERED AREAS OF LIGHT-MODERATE SNOW FILLING-IN OVER
MUCH OF THE CWA BEHIND THE HEAVIER ACTIVITY FROM LATE LAST
NIGHT...THAT HAS SINCE MOVED UP INTO NJ/SRN NY. BETWEEN THE
APPROACHING UPPER LOW AND THE DEEPENING COASTAL LOW WILL BE AN AXIS
OF HIGHER MOISTURE INFLUX AND LIFT...LEADING TO BANDING OF SNOW
ACROSS THE I-95 CORRIDOR OF NRN VA-ERN MD LATER THIS MORNING. ONCE
THIS FEATURE SETS-UP...PERIODS OF HEAVY SNOW AND NEAR WHITE-OUT
CONDITIONS WILL DEVELOP /ESPECIALLY ACROSS NERD MD/. HEAVIER
SNOWFALL RATES AND STRONGER WINDS WILL BEGIN TO OVERSPREAD THESE
AREAS...AND BLIZZARD CONDITIONS WILL BECOME MORE LIKELY FROM LATE
MORNING INTO THE EARLY AFTN HRS.
THE SNOW BAND WILL BEGIN TO MOVE EWD TOWARD DELMARVA INTO THE MID
AFTN HRS...AND MUCH OF THE SNOW WILL START TO TAPER OFF ACROSS THE
CWA THRU THE LATE AFTN AND EARLY EVENING HRS. A STRONG LOW LEVEL
JET WILL BE ORIENTED OVER THE AREA FOR MUCH OF THE DAY /50-60KT AT
850MB/...HELPING TO MIX-DOWN STRONGER GUSTS AND DISSIPATE PRECIP
FASTER BEHIND THE EXITING SYSTEM. WIND GUSTS OF 30-45 MPH WILL BE
COMMON ACROSS THE REGION...BLOWING AND DRIFTING NEWLY FALLEN SNOW.
THE BLIZZARD WARNING AREAS ARE MOST COINCIDENT W/ AREAS THAT ARE
EXPECTED TO EXPERIENCE THE NEAR WHITE-OUT CONDITIONS FROM THE
STRONGEST WINDS AND HEAVIEST SNOWFALL/BLOWING SNOW AT THE SAME TIME
/CENTERED MAINLY AROUND THE LATE MORNING-EARLY AFTN/.
ELSEWHERE...SNOW MAY TAPER OFF BEFORE THE HIGHEST WINDS MOVE ACROSS
THE AREA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
UPSLOPE SNOW WILL CONTINUE FOR THE CNTRL APLCNS WELL AFTER THE
COASTAL LOW HAS MOVED OFF THE MID ATLC COAST THRU THURSDAY AFTN.
MODERATE SNOW ACCUMULATION POSSIBLE FOR THE HIGHER ELEVATIONS DURING
THIS PERIOD. E OF THE MTNS...DRY-COLD AND WINDY WX WILL REPLACE THE
EXITING LOW PRESSURE SYSTEM.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
NO MAJOR CHANGES TO THE LONG TERM PORTION OF THE FORECAST WERE MADE.
UPSLOPE SNOW SHOWERS WILL BEGIN TO WANE ON THURSDAY AS HIGH PRESSURE
BUILDS IN FROM THE WEST. HAVE KEPT POPS PRETTY HIGH ACROSS THE
WESTERN RIDGES...BUT SNOW SHOULD COMPLETELY CUT OFF BY EARLY FRIDAY.
TEMPERATURES ARE EXPECTED TO REMAIN BLO FREEZING FOR MOST LOCALES
THURSDAY AND THURSDAY NIGHT...BUT ABOVE FREEZING MAX TEMPS ARE
EXPECTED FRIDAY AND SATURDAY. A COLD FRONT COMES THROUGH THE REGION
DURING THE WEEKEND...WITH HIGH PRESSURE BUILDING IN FOR THE FIRST
PART OF NEXT WEEK.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
A BRIEF LULL IN THE ACTIVITY OVERNIGHT FOR THE REGION /THO ONLY A
RELATIVE LULL...AS MOST AREAS REPORTING AT LEAST LIGHT FROZEN PRECIP
AND VERY LOW CIGS AND MODERATELY LOW VSBYS. A LARGE BAND OF MODERATE
TO HEAVY SNOW WILL SET-UP OVER THE DC-BALT METRO AREA /ESPECIALLY
THE BALT METRO AREA/ LATER THIS MORNING...AS WINDS ALSO INCREASE OUT
OF THE WNW. STRONG WINDS AT THE SFC AND ALOFT EXPECTED TOWARD THE
NOON HR...AND LASTING FOR THE NEXT 24-36 HRS. GUSTS NEAR 40KT WILL
BE COMMON THROUGHOUT THE AFTN/EVENING...SUBSIDING ONLY A BIT
OVERNIGHT AND LASTING INTO THU. IFR/LOWER EXPECTED ACROSS THE REGION
FOR THE NEXT SEVERAL HRS...AS SFC CONDITIONS REMAIN MOIST AND PRECIP
/MAINLY SNOW-SOME OF THE A MIX ALSO POSSIBLE/ LINGERS JUST AHEAD OF
THE STRONG WINDS. ONCE THE WINDS MIX-IN LATER THIS AFTN...DRIER
CONDITIONS WILL CLEAR-OUT MUCH OF THE SFC MOISTURE AND DENSE OVC BY
LATER THIS EVENING...BUT AS MENTIONED WINDS AT THE SFC AND THRU THE
LOWEST FEW THOU FT WILL BE FAIRLY STRONG.
CIGS/VSBYS ARE EXPECTED TO REMAIN VFR THROUGH THURSDAY AT MOST
LOCALES. HOWEVER...BLOWING SNOW MAY LOCALLY REDUCE SOME VSBYS BLO
VFR AT TIMES WHERE WINDS ARE THE MOST GUSTY. HIGH PRESSURE BUILDS IN
FOR THE REMAINDER OF THE WEEK AND NO CIGS/VSBY RESTRICTIONS ARE
ANTICIPATED.
&&
.MARINE...
LIGHT WINDS ON THE WATERS CURRENTLY...BUT THIS WILL QUICKLY BE
REPLACED W/ GALE CONDITIONS BY LATER THIS MORNING. A STRONG LOW
PRESSURE SYSTEM AFFECTING THE REGION WILL INCREASE WINDS OVER THE
WATERS TODAY...WELL INTO THE OVERNIGHT HRS AND INTO THU.
GALE CONDITIONS ARE EXPECTED TO CONTINUE THROUGH MOST OF THURSDAY AS
LOW PRESSURE MOVES UP THE EASTERN SEABOARD. THE GRADIENT IS EXPECTED
TO LESSEN THURSDAY EVENING AND OVERNIGHT AS HIGH PRESSURE BUILDS IN
FROM THE WEST. HOWEVER...SMALL CRAFT CONDITIONS ARE LIKELY THROUGH
THIS PERIOD. TO LESSEN CONFUSION...WILL NOT TACK ON THE SCA HEADLINE
ON THE END OF THE GALE. WILL MENTION IN THE SYNOPSIS AND HAVE 20
PLUS KT IN THE TEXT.
HIGH PRESSURE BUILDS IN FOR THE LATTER PART OF THE WEEK...AND
LIGHTER WINDS ARE EXPECTED.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR MDZ009-
013-016>018.
WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR
MDZ003>007-010-011-014-502.
BLIZZARD WARNING FROM 10 AM THIS MORNING TO 7 PM EST THIS
EVENING FOR MDZ003>007-010-011-014.
BLIZZARD WARNING FROM 10 AM THIS MORNING TO 4 PM EST THIS
AFTERNOON FOR MDZ502.
BLIZZARD WARNING UNTIL 7 AM EST THURSDAY FOR MDZ501.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR VAZ030-
031-040-042-050>057-501-502.
WINTER STORM WARNING UNTIL 4 PM EST THIS AFTERNOON FOR
VAZ025>029-036>039.
BLIZZARD WARNING UNTIL 7 AM EST THURSDAY FOR VAZ021.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR WVZ052-
053.
WINTER STORM WARNING UNTIL 10 AM EST THIS MORNING FOR WVZ050-
051-055-502-504.
BLIZZARD WARNING FROM 10 AM THIS MORNING TO 4 PM EST THIS
AFTERNOON FOR WVZ050-051-055-502-504.
BLIZZARD WARNING UNTIL 7 AM EST THURSDAY FOR WVZ054-501-503.
MARINE...GALE WARNING UNTIL 6 PM EST THURSDAY FOR ANZ530>543.
&&
$$
GMS/LISTEMAA/WOODY!
000
FXUS61 KLWX 100314
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1014 PM EST TUE FEB 9 2010
.SYNOPSIS...
LOW PRESSURE OFF THE CAROLINA COAST WILL INTENSIFY OFF THE
DELMARVA LATE TONIGHT INTO WEDNESDAY. THIS WILL PROVIDE ANOTHER
ROUND OF WINTRY PRECIPITATION TO THE MID ATLANTIC REGION THROUGH
WEDNESDAY ALONG WITH STRONG GUSTY WINDS ON WEDNESDAY. HIGH
PRESSURE RETURNS LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
NO CHANGES WERE MADE TO HEADLINES THIS EVENING. WINTER STORM
WARNINGS WILL REMAIN AS IS FOR NOW. PRECIPITATION OVERSPREAD THE
AREA LATE THIS AFTERNOON AND EVENING...AND NORTHERN MARYLAND SEEMS
TO HAVE BEEN THE SWEET SPOT SO FAR FOR SNOW. PLEASE REFER TO
WBCPNSLWX FOR THE LATEST SNOWFALL REPORTS. MEANWHILE...MIXING WITH
SLEET OR EVEN RAIN HAS CUT DOWN ON TOTALS SO FAR ACROSS SOUTHERN
MARYLAND.
SOMEWHAT OF A DRY SLOT WAS WORKING INTO THE SHENANDOAH VALLEY LATE
THIS EVENING...BUT FIGURE PRECIP WILL FILL BACK IN OVERNIGHT AS
UPPER LEVEL ENERGY MOVES THROUGH FROM THE WEST. DRY SLOT MAY NOT
BE ABLE TO PENETRATE A WHOLE LOT FURTHER NORTHEAST...AND
PRECIPITATION IS EXPECTED TO CONTINUE THROUGH NIGHT ACROSS THE
REST OF THE CWA...ESPECIALLY AS LOW PRESSURE BECOMES BETTER
DEVELOPED OFF THE EASTERN SEABOARD.
HEAVIEST IS LIKELY TO OCCUR ALONG THE WASHINGTON-BALTIMORE
CORRIDOR...MAINLY FROM WEDNESDAY MORNING INTO EARLY AFTERNOON.
HIGHEST GRAND TOTALS ARE PROGGED FOR NORTHERN MARYLAND AND THE
BALTIMORE AREA.
AS STORM CRANKS UP OFF THE COAST...WINDS WILL QUICKLY INCREASE.
GUSTS TO 45 MPH MAY AFFECT THE ENTIRE CWA ON WEDNESDAY. THESE
WINDS WILL PROMOTE BLOWING AND DRIFTING SNOW...AND WILL REDUCE
VISIBILITIES NEAR ONE QUARTER MILE AT TIMES WEDNESDAY. THE RESULT
WILL BE NEAR BLIZZARD CONDITIONS AND AN UPGRADE OF HEADLINES AT
LEAST ALONG THE WASHINGTON-BALTIMORE CORRIDOR MAY BECOME
NECESSARY ON WEDNESDAY TO ADDRESS THESE CONDITIONS.
TEMPERATURES WILL DROP TONIGHT AND WILL LIKELY CONTINUE TO DROP OR
BECOME STEADY ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
DP SFC LOW WL BE PULLING AWAY FM CWFA WED NGT...BUT THE WNDS WL BE
SLOW TO SUBSIDE AS THE P-GRAD REMAINS TIGHT. /GFS 00Z PROG 975 MB!/
THERE/S EASILY 35 KT W/IN MIXED LYR. GDNC SUGGESTS CLSR TO 40 KT...
BUT ALSO HINTS AT SFC BASED INVSN DVLPG. THAT REMAINS TO BE SEEN.
FCST WL ADVERTISE 20G35KT.
THERE MAY BE A FEW LINGERING SHSN WED NGT AS WELL...BUT THE BULK OF
THE ACCUM SNW WL BE DONE FOR MOST OF THE CWFA. THE XCPTN WL BE FOR
THE WRN UPSLP AREAS...WHERE CAA AND SNW GROWTH FVRBL...SPCLY WED
NGT. INVSN HGTS START TO DROP THU...BUT WONT BE TRULY LIMITED TIL
THU NGT-ELY FRI.
IT/LL STILL BE BRZY AND COLD E OF THE APPLCHNS THU-THU NGT...BUT
EFFECTS OF HIPRES SLOWLY WL BE REALIZED. COLD POOL ALOFT WL IMPEDE
NW FLOW IN SCOURING OUT CLDS...BUT THAT SHUD TAKE PLACE BY LT THU.
TEMPS WL BE WELL BLO AVG...MAXT IN THE MID 30S/MIN-T IN THE TEENS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
WKND STILL DOMINATED BY A STRONG SRN JET STREAM. ANY DISTURBANCES
SHUD BE SURPRESSED SUFFICIENTLY TO MISS CWFA. INSTEAD...WE WL BE
INFLUENCED BY SFC HIPRES. THAT SHUD PROVIDE WELCOMED DRY CONDS THRU
THE WKND. W/ NW FLOW AND A DEEP SNWPACK...DONT XPCT A SGFNT WARMUP
THO. TEMPS THRUT THE PD WL STRUGGLE TO REACH 40F...PRBLY TOPPING OUT
IN THE 30S.
CLIPPER SYSTEM PROGGED EITHER LT SUN OR ELY MON. ITS LOOKING WEAK
RIGHT NOW. IT REMAINS TO BE SEEN IF THOSE TRENDS WL CONT.
NONETHELESS...HV LEANED ON THE ELY SIDE /SUN/ IN PROGRESSIVE PTTN.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
IFR CONDITIONS EXPECTED TO PREVAIL ACROSS TERMINALS OVERNIGHT.
SOME IMPROVEMENT MAY OCCUR AT KCHO FOR A TIME IN A DRY SLOT WHEN
IT WONT BE PRECIPITATING. HEAVIEST SNOW AT THE HUBS WITH POSSIBLE
VLIFR CONDITIONS EXPECTED 12Z-18Z WED. SNOW ENDS WITHIN A FEW
HOURS OF 00Z THU. ALSO...NORTHWEST WINDS RAPIDLY INCREASE
WEDNESDAY MORNING BETWEEN 12Z-15Z WED...AND GUSTS TO 40 KT WILL BE
POSSIBLE.
ASIDE FM WNDS...THU WL BE VFR AS WELL. DO XPCT BKN CIGS...BUT
BASES SHUD BE ABV 3K FT. CLDS SHUD SCT OUT FRI-SAT. A CLIPPER WL
COME BY SUN. WL NEED TO WATCH IT...RIGHT NOW THINK MVFR
RESTRICTIONS PSBL.
&&
.MARINE...
LOW PRESSURE WILL DEVELOP ALONG THE MID-ATLANTIC COAST OVERNIGHT
INTO WEDNESDAY. LOW PRESSURE WILL RAPIDLY INTENSIFY
WEDNESDAY...BRINGING WIND GUSTS OVER 40 KNOTS AT TIMES. A GALE
WARNING REMAINS IN EFFECT WEDNESDAY. SNOW TONIGHT AND WEDNESDAY
WILL REDUCE VISIBILITY BELOW ONE HALF MILE AT TIMES.
GLW XTNDD THRU THU AS 35 KT WELL W/IN REACH IN MIXED LYR. HIPRES
BLDS FRI...BUT SCA FLAGS MAY STILL LINGER. MORE TRANQUIL FOR THE
WKND.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR MDZ003>007-
009>011-013-014-016>018-501.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR MDZ502.
VA...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR VAZ021-030-
031-040-042-050>057-501-502.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR VAZ025>029-
036>039.
WV...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR WVZ052>054-
501-503.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR WVZ050-051-
055-502-504.
MARINE...GALE WARNING FROM 6 AM WEDNESDAY TO 6 PM EST THURSDAY FOR
ANZ530>543.
&&
$$
SYNOPSIS...PELOQUIN
NEAR TERM...PELOQUIN
SHORT TERM...HTS
LONG TERM...HTS
AVIATION...PELOQUIN/HTS
MARINE...PELOQUIN/BJL/HTS
000
FXUS61 KLWX 092016
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
316 PM EST TUE FEB 9 2010
.SYNOPSIS...
LOW PRESSURE OVER THE GULF STATES WILL MOVE OFF THE CAROLINA COAST
TONIGHT AND INTENSIFY OFF THE DELMARVA OVERNIGHT. THIS WILL PROVIDE
ANOTHER ROUND OF WINTRY PRECIPITATION TO THE MID ATLANTIC REGION
TODAY THROUGH WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
STRONG UPPER-LEVEL LOW IN THE NORTHERN BRANCH OF THE JET IS ROTATING
THROUGH THE MIDWEST LATE THIS AFTERNOON WHILE LOW PRESSURE DEVELOPS
OFF THE MID-ATLANTIC COAST IN THE SOUTHERN BRANCH OF THE JET. AS THE
UPPER-LEVEL LOW MOVES INTO THE REGION TONIGHT...LOW PRESSURE WILL
RAPIDLY INTENSIFY ALONG THE MID-ATLANTIC COAST AS IT SLOWLY MOVES
NORTHWARD. THIS WILL SPREAD PRECIPITATION OVER THE REGION
TONIGHT...MAINLY IN THE FORM OF SNOW. THERE WILL BE ENOUGH WARM AIR
DRAWN INTO THE SYSTEM FOR A MIXTURE OF RAIN/SLEET AND SNOW...MAINLY
ACROSS LOWER SOUTHERN MARYLAND.
THE DRY SLOT WILL WORK ITS WAY INTO THE SOUTHERN PORTION OF THE CWA
TOWARD WEDNESDAY MORNING CAUSING ANY PRECIPITATION TO BE LIGHT.
HOWEVER...AS THE LOW CONTINUES TO RAPIDLY INTENSIFY WEDNESDAY
MORNING...THE DEFORMATION ZONE WILL SET UP OVER THE NORTHEASTERN
HALF OF THE CWA...BRINGING HEAVY SNOW TO THIS AREA. SNOW WILL SLOWLY
TAPER OFF WEDNESDAY AFTERNOON AS THE LOW PULLS AWAY. WILL CONTINUE
WITH THE WINTER STORM WARNING ACROSS OUR CWA WITH THE HIGHEST
AMOUNTS AROUND NORTH-CENTRAL MARYLAND INTO THE BALTIMORE
METROPOLITAN AREA. STRONG WINDS WILL ALSO DEVELOP WEDNESDAY AS THE
LOW INTENSIFIES. A WIND ADVISORY MAY BE WARRANTED ACROSS THE ENTIRE
CWA FOR WIND GUSTS UP TO 50 MPH. STRONG WINDS WILL COMBINE WITH SNOW
AND BLOWING SNOW TO PRODUCE NEAR BLIZZARD CONDITIONS...ESPECIALLY
FOR LOCATIONS NORTH AND EAST OF WASHINGTON DC.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
DP SFC LOW WL BE PULLING AWAY FM CWFA WED NGT...BUT THE WNDS WL BE
SLOW TO SUBSIDE AS THE P-GRAD REMAINS TIGHT. /GFS 00Z PROG 975 MB!/
THERE/S EASILY 35 KT W/IN MIXED LYR. GDNC SUGGESTS CLSR TO 40 KT...
BUT ALSO HINTS AT SFC BASED INVSN DVLPG. THAT REMAINS TO BE SEEN.
FCST WL ADVERTISE 20G35KT.
THERE MAY BE A FEW LINGERING SHSN WED NGT AS WELL...BUT THE BULK OF
THE ACCUM SNW WL BE DONE FOR MOST OF THE CWFA. THE XCPTN WL BE FOR
THE WRN UPSLP AREAS...WHERE CAA AND SNW GROWTH FVRBL...SPCLY WED
NGT. INVSN HGTS START TO DROP THU...BUT WONT BE TRULY LIMITED TIL
THU NGT-ELY FRI.
IT/LL STILL BE BRZY AND COLD E OF THE APPLCHNS THU-THU NGT...BUT
EFFECTS OF HIPRES SLOWLY WL BE REALIZED. COLD POOL ALOFT WL IMPEDE
NW FLOW IN SCOURING OUT CLDS...BUT THAT SHUD TAKE PLACE BY LT THU.
TEMPS WL BE WELL BLO AVG...MAXT IN THE MID 30S/MIN-T IN THE TEENS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
WKND STILL DOMINATED BY A STRONG SRN JET STREAM. ANY DISTURBANCES
SHUD BE SURPRESSED SUFFICIENTLY TO MISS CWFA. INSTEAD...WE WL BE
INFLUENCED BY SFC HIPRES. THAT SHUD PROVIDE WELCOMED DRY CONDS THRU
THE WKND. W/ NW FLOW AND A DEEP SNWPACK...DONT XPCT A SGFNT WARMUP
THO. TEMPS THRUT THE PD WL STRUGGLE TO REACH 40F...PRBLY TOPPING OUT
IN THE 30S.
CLIPPER SYSTEM PROGGED EITHER LT SUN OR ELY MON. ITS LOOKING WEAK
RIGHT NOW. IT REMAINS TO BE SEEN IF THOSE TRENDS WL CONT.
NONETHELESS...HV LEANED ON THE ELY SIDE /SUN/ IN PROGRESSIVE PTTN.
&&
.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SNOW WILL OVERSPREAD THE TERMINALS LATE THIS AFTERNOON INTO EARLY
THIS EVENING. IFR/SUBIFR CIGS AND VSBYS ARE EXPECTED. SNOW WILL
CONTINUE THROUGH MOST OF THE DAY WEDNESDAY WITH CONTINUED IFR/SUBIFR
CIGS AND VSBYS. THE HEAVIEST SNOW WILL BE WEDNESDAY MORNING NEAR
KBWI AND KMTN.
NORTHWEST WINDS WILL BE SUSTAINED AROUND 15 TO 25 KNOTS WEDNESDAY
WITH GUSTS OVER 40 KNOTS.
ASIDE FM WNDS...THU WL BE VFR AS WELL. DO XPCT BKN CIGS...BUT
BASES SHUD BE ABV 3K FT. CLDS SHUD SCT OUT FRI-SAT. A CLIPPER WL
COME BY SUN. WL NEED TO WATCH IT...RIGHT NOW THINK MVFR
RESTRICTIONS PSBL.
&&
.MARINE...
LOW PRESSURE WILL DEVELOP ALONG THE MID-ATLANTIC COAST TONIGHT. LOW
PRESSURE WILL RAPIDLY INTENSIFY WEDNESDAY...BRINGING WIND GUSTS OVER
40 KNOTS AT TIMES. A GALE WARNING REMAINS IN EFFECT WEDNESDAY. SNOW
TONIGHT AND WEDNESDAY WILL REDUCE VISIBILITY BELOW ONE HALF MILE AT
TIMES.
GLW XTNDD THRU THU AS 35 KT WELL W/IN REACH IN MIXED LYR. HIPRES
BLDS FRI...BUT SCA FLAGS MAY STILL LINGER. MORE TRANQUIL FOR THE
WKND.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR MDZ003>007-
009>011-013-014-016>018-501.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR MDZ502.
VA...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR VAZ021-030-
031-040-042-050>057-501-502.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR VAZ025>029-
036>039.
WV...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR WVZ052>054-
501-503.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR WVZ050-051-
055-502-504.
MARINE...GALE WARNING FROM 8 AM WEDNESDAY TO 6 PM EST THURSDAY FOR
ANZ530>543.
&&
$$
SYNOPSIS...BJL
NEAR TERM...BJL
SHORT TERM...HTS
LONG TERM...HTS
AVIATION...BJL/HTS
MARINE...BJL/HTS
000
FXUS61 KLWX 091426
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
926 AM EST TUE FEB 9 2010
.SYNOPSIS...
LOW PRESSURE OVER THE GULF STATES WILL MOVE OFF THE CAROLINA COAST
TONIGHT AND INTENSIFY OFF THE DELMARVA OVERNIGHT. THIS WILL PROVIDE
ANOTHER ROUND OF WINTRY PRECIPITATION TO THE MID ATLANTIC REGION
TODAY THROUGH WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SNOW HAS ALREADY BEGUN ACROSS MANY LOCATIONS WEST OF THE BLUE
RIDGE MOUNTAINS THIS MORNING. WILL CONTINUE WITH SIDE WITH THE GFS
FOR START TIMES OF SNOWFALL...BY NOON FOR MOST LOCATIONS WEST OF
THE BLUE RIDGE AND BY EARLY AFTERNOON ACROSS WASHINGTON AND
BALTIMORE.
STRONG UPPER-LEVEL LOW IN THE NORTHERN BRANCH OF THE JET CONTINUES
TO PUSH THROUGH THE MIDWEST WHILE THE SOUTHERN BRANCH FEATURE
TRACKS THROUGH THE SOUTHEAST STATES AND TOWARD THE MID-ATLANTIC
COAST THIS AFTERNOON. OVERRUNNING OUT AHEAD OF THESE TWO SYSTEMS
WILL BE THE MAIN FORCING MECHANISM FOR SNOW THIS AFTERNOON. THERE
WILL BE ENOUGH WARM AIR ADVECTION FOR SNOW TO MIX WITH SLEET
ACROSS PORTIONS OF THE CENTRAL VIRGINIA INTO THE VIRGINIA PIEDMONT
AND LOWER SOUTHERN MARYLAND THIS AFTERNOON. SNOW ACCUMULATIONS
THROUGH THIS AFTERNOON WILL RANGE FROM A FEW INCHES NEAR THE
POTOMAC HIGHLANDS TO AN INCH OR TWO ACROSS EASTERN MARYLAND. THE
HEAVIEST SNOW IS STILL EXPECTED TONIGHT INTO WEDNESDAY AS LOW
PRESSURE RAPIDLY INTENSIFIES OFF THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TNGT THAT LOW WL MOVE E OF ORF AND BEGIN TO INTENSIFY. SNOWFALL
RATES WL BEGIN TO INCRS AS WELL ACRS THE MAJORITY OF THE CWA. BY
WED MRNG TOTALS RANGING FM ARND 6 INCHES IN THE HIGHLANDS TO 8-9
INCHES IN THE DC-BALT CORRIDOR ARE LKLY. THE COUNTIES THAT WERE
PRVSLY IN A WTCH - ST. MARY`S TO SPOTSY...HV BEEN UPGRADED TO A
WRNG. ST. MARY`S WAS TOUGH TO FCST FOR - BLV ARND PAX RVR BY WED
MRNG 2-3" PSBL WHILE IN THE NW PART OF THE COUNTY 7" IN LKLY.
LOW TEMPS IN THE HIGHLANDS U TEENS. RMNDR OF CWA IN THE 20S.
WED-WED NGT...
LITTLE CHANGE TO WED IN THE GRIDS OTHER THAN MAKING SOME TIMING
ADJUSTMENTS TO THE EXIT OF THE LOW PRESSURE SYSTEM AND SFC WINDS.
PERIODS OF HEAVY SNOW AND GUSTY WINDS EXPECTED AS THE COASTAL LOW
DEEPENS AND MOVES PARALLEL TO THE DELMARVA COAST ON WED AFTN. AS
THEY HAVE FOR THE PAST SEVERAL DAYS...MOST OF THE AVAILABLE GUIDANCE
CONTINUES TO PAINT A REGIONAL AREA OF PRECIP THAT QUICKLY DEVELOPS
OVER THE ERN HALF OF THE CWA ON WED MORNING...REACHING ITS PEAK
INTENSITY BY EARLY AFTN /CENTERED OVER THE MD CHESAPEAKE/ AND
EVENTUALLY ROTATING OFF THE COAST BY LATE AFTN-EARLY EVENING.
MAKING THE SITUATION MORE COMPLEX AND THE SYSTEM EVEN STRONGER IS A
SCENARIO WELL-DEPICTED ON THE LATEST NAM WITH TWO VERY DEEP SFC LOWS
ROTATING OFF THE MID ATLC COAST. THE DEEPER ONE SLIDES ABOUT THE
SERN SIDE OF THE ONE CLOSER TO THE COAST. BY MIDDAY WED...BOTH ARE
NEARING 985 MB...BY EARLY EVENING ALMOST ANOTHER 10MB DROP IN EACH
/AN EVEN BIGGER DROP FOR THE ONE JUST OFF THE SRN COAST OF CAPE
COD/. BOTH WILL EVENTUALLY BE WRAPPED BECOME VERTICALLY STACKED AS
THE UPPER LOW SWINGS OFF THE COAST BY LATE AFTN WED. THIS WILL
INCREASE THE INTENSITY OF PRECIP BANDS STREWN ACROSS THE ERN
SEABOARD OF THE MID ATLC /PARTICULARLY THE I-95 CORRIDOR OF NRN VA
AND ERN MD...THRU NJ AND LONG ISLAND.
IN THE ZONES...GUSTS OF 35-40 MPH APPEAR FOR THE WED-WED NIGHT
PERIOD WHICH IS COINCIDENT W/ HIGH SNOW CHANCES...BUT IN TERMS OF
TIMING AND PROGRESSION...THE STRONGEST WINDS WILL BE WRAPPED AROUND
THE BACKSIDE OF THE PRECIP W/ THE DRIER AIR THAT CUT-OFF THE PRECIP
ON THE WRN EDGE OF THE SNOW BANDS. SO EVEN THOUGH BREEZY CONDITIONS
/GUSTS 15-30 MPH/ WILL BE COMMON AS THE LAST FEW SNOW BANDS SET-UP
ACROSS THE REGION WED MORNING-AFTN...THE +35MPH GUSTS /ON LAND
AREAS/ EXPECTED TO MOSTLY APPEAR AFTER A BULK OF THE SNOW BANDS
HAVE DISSIPATED AND MOVED EAST.
THE STRONG NW FLOW WILL CONTINUE INTO THE LATE NIGHT HRS...W/ A FEW
BANDS OF LIGHT SNOW CONTINUING TO STREAM DOWN THE NERN PORTIONS OF
MD AND ADJACENT NRN VA BUT LITTLE ACCUMULATION EXPECTED FROM THIS
ACTIVITY. UPSLOPE SNOW FOR THE MTNS WILL CONTINUE INTO MIDDAY THU
AND MORE BREEZY NW FLOW FOR THE REST OF THE AREA.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
AFTER THE TUE-WED SNOW STORM...LITTLE ON THE HORIZON IN TERMS OF
WX-MAKERS...JUST A DAILY ROUTINE OF NW WINDS...TEMPS BARELY PEAKING
OUT OF FREEZING DURING THE DAYTIME HRS...DROPPING BACK WELL-BELOW
FREEZING OVERNIGHT. THIS REGIME IS FROM REINFORCING UPPER WAVES OF
CANADIAN AIR THAT SLIDE DOWN THE GREAT LAKES FROM S CNTRL
CANADA...AND ROTATE AROUND A RESIDENT UPPER LOW STATIONED OVER NEW
FOUNDLAND. ONE OF THESE UPPER VORT WILL PUSH DOWN THE NRN PLAINS
EARLY NEXT WEEK /LIKE THIS INCOMING STORM SYSTEM/ BUT WON/T HAVE THE
SUPPORT OF GULF MOISTURE AND THEREFORE LOOKS TO BE LITTLE MORE THAN
A DISORGANIZED BATCH OF PRECIP AS IT MOVES THRU SUN NIGHT INTO MON.
THO IT DOES MEAN MORE UPSLOPE SNOW FOR THE CNTRL APLCNS FOR
CONSECUTIVE DAYS.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
IFR/SUBIFR CONDITIONS ARE EXPECTED THIS AFTERNOON AS SNOW
OVERSPREADS THE TERMINALS. FIRST KCHO BY NOON...AND ACROSS THE
REST OF THE TERMINALS BY EARLY AFTERNOON. IFR/SUBIFR CONDITIONS
ARE EXPECTED TONIGHT THROUGH WEDNESDAY MORNING. THE HEAVIEST SNOW
WILL BE TONIGHT THROUGH WEDNESDAY MORNING. BANDS OF HEAVY SNOW
WILL PERSIST INTO THE AFTERNOON ACROSS THE EASTERN TERMINALS.
THIS SYSTEM WILL MOVE OFF THE COAST LATE WED AND NW FLOW WILL
PUSH OVER THE REGION INTO NEXT WEEKEND. GUSTY WINDS WILL BE A
CONCERN W/ THE LOW PRESSURE SYSTEM...AS WELL AS AFTER THE SYSTEM
EXITS AND COLD-DRY NW FLOW SETTLES IN OVER THE AREA.
&&
.MARINE...
WINDS WL BE UNDER SCA VALUES THROUGH TNGT. LGT SNOW WL BEGIN TO
FALL THIS AFTN...BECMG HVR AFTR MDNGT AND DCSRG VSBY TO 1/2 MILE
BY MRNG.
WINDS WILL APPROACH SCA CRIT AFT SUNRISE WED...BUT GALE CONDITIONS
WILL QUICKLY BE REALIZED INTO THE MID-LATE MORNING...AS A COASTAL
LOW STRENGTHENS OFF THE MID ATLC...PICKING UP WINDS OVER THE MID
ATLC AND ESPECIALLY OVER THE BAY/TP. THE LOW WILL REACH PEAK
STRENGTH AND PROXIMITY JUST OFF THE COAST FROM WED AFTN INTO EARLY
THU...KEEPING GALE CONDITIONS OVER THE WATERS WELL INTO THE LATE
NIGHT HRS...SOLID SCA AFTER THAT /INTO MUCH OF THU/. NW FLOW WILL
THEN BE COMMON FOR THE REGION INTO THE WEEKEND...W/ INTERMITTENT
PERIODS OF SCA CONDITIONS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR MDZ003>007-
009>011-013-014-016>018.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR MDZ502.
WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR MDZ501.
VA...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR VAZ030-031-
040-042-050>057-501-502.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR VAZ025>029-
036>039.
WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR VAZ021.
WV...WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR WVZ052-053.
WINTER STORM WARNING UNTIL 4 PM EST WEDNESDAY FOR WVZ050-051-
055-502-504.
WINTER STORM WARNING UNTIL 7 PM EST WEDNESDAY FOR WVZ054-501-
503.
MARINE...GALE WARNING FROM 8 AM WEDNESDAY TO 6 AM EST THURSDAY FOR
ANZ530>543.
&&
$$
PRODUCTS...LASORSA/WOODY!/GMS
000
FXUS61 KLWX 090854
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
354 AM EST TUE FEB 9 2010
.SYNOPSIS...
LOW PRESSURE OVER THE GULF STATES WILL MOVE OFF THE CAROLINA COAST
TONIGHT AND INTENSIFY OFF THE DELMARVA OVERNIGHT. THIS WILL PROVIDE
ANOTHER ROUND OF WINTRY PRECIPITATION TO THE MID ATLANTIC REGION
TODAY THROUGH WEDNESDAY. HIGH PRESSURE RETURNS LATE IN THE WEEK.
&&
.NEAR TERM /TODAY/...
IT`S BEEN AN INTENSE NGT...IN ADDITION TO THE WX WE`VE HAD TO DEAL
W/ A SHUTDOWN OF THE COOLING SYSTEM WHERE OUR COMPUTERS ARE HOUSED.
GNRL GIST OF THE FCST RMNS UNCHGD - ANOTHER ROUND OF WINTER WX AS
LOW PRES DVLPG OVR THE LOWER GULF STATES INTENSIFIES E OF ORF
TNGT. LGT SNOW ALREADY ON RDR ABT 50 MILES S OF NELSON/AUGUSTA
COUNTIES WL BE MOVG INTO THE SRN SXN OF OUR CWA AFTR 4
AM...REACHING THE DC BELTWAY ARND 9 AM. SNOWFALL SHOULD BE ON LGT
SIDE TDA. TENMPS THIS AFTN SHOULD BE AT OR STLY BLO FRZG ACROSS
THE CWA.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NGT/...
TNGT THAT LOW WL MOVE E OF ORF AND BEGIN TO INTENSIFY. SNOWFALL
RATES WL BEGIN TO INCRS AS WELL ACRS THE MAJORITY OF THE CWA. BY
WED MRNG TOTALS RANGING FM ARND 6 INCHES IN THE HIGHLANDS TO 8-9
INCHES IN THE DC-BALT CORRIDOR ARE LKLY. THE COUNTIES THAT WERE
PRVSLY IN A WTCH - ST. MARY`S TO SPOTSY...HV BEEN UPGRADED TO A
WRNG. ST. MARY`S WAS TOUGH TO FCST FOR - BLV ARND PAX RVR BY WED
MRNG 2-3" PSBL WHILE IN THE NW PART OF THE COUNTY 7" IN LKLY.
LOW TEMPS IN THE HIGHLANDS U TEENS. RMNDR OF CWA IN THE 20S.
WED-WED NGT...
LITTLE CHANGE TO WED IN THE GRIDS OTHER THAN MAKING SOME TIMING
ADJUSTMENTS TO THE EXIT OF THE LOW PRESSURE SYSTEM AND SFC WINDS.
PERIODS OF HEAVY SNOW AND GUSTY WINDS EXPECTED AS THE COASTAL LOW
DEEPENS AND MOVES PARALLEL TO THE DELMARVA COAST ON WED AFTN. AS
THEY HAVE FOR THE PAST SEVERAL DAYS...MOST OF THE AVAILABLE GUIDANCE
CONTINUES TO PAINT A REGIONAL AREA OF PRECIP THAT QUICKLY DEVELOPS
OVER THE ERN HALF OF THE CWA ON WED MORNING...REACHING ITS PEAK
INTENSITY BY EARLY AFTN /CENTERED OVER THE MD CHESAPEAKE/ AND
EVENTUALLY ROTATING OFF THE COAST BY LATE AFTN-EARLY EVENING.
MAKING THE SITUATION MORE COMPLEX AND THE SYSTEM EVEN STRONGER IS A
SCENARIO WELL-DEPICTED ON THE LATEST NAM WITH TWO VERY DEEP SFC LOWS
ROTATING OFF THE MID ATLC COAST. THE DEEPER ONE SLIDES ABOUT THE
SERN SIDE OF THE ONE CLOSER TO THE COAST. BY MIDDAY WED...BOTH ARE
NEARING 985 MB...BY EARLY EVENING ALMOST ANOTHER 10MB DROP IN EACH
/AN EVEN BIGGER DROP FOR THE ONE JUST OFF THE SRN COAST OF CAPE
COD/. BOTH WILL EVENTUALLY BE WRAPPED BECOME VERTICALLY STACKED AS
THE UPPER LOW SWINGS OFF THE COAST BY LATE AFTN WED. THIS WILL
INCREASE THE INTENSITY OF PRECIP BANDS STREWN ACROSS THE ERN
SEABOARD OF THE MID ATLC /PARTICULARLY THE I-95 CORRIDOR OF NRN VA
AND ERN MD...THRU NJ AND LONG ISLAND.
IN THE ZONES...GUSTS OF 35-40 MPH APPEAR FOR THE WED-WED NIGHT
PERIOD WHICH IS COINCIDENT W/ HIGH SNOW CHANCES...BUT IN TERMS OF
TIMING AND PROGRESSION...THE STRONGEST WINDS WILL BE WRAPPED AROUND
THE BACKSIDE OF THE PRECIP W/ THE DRIER AIR THAT CUT-OFF THE PRECIP
ON THE WRN EDGE OF THE SNOW BANDS. SO EVEN THOUGH BREEZY CONDITIONS
/GUSTS 15-30 MPH/ WILL BE COMMON AS THE LAST FEW SNOW BANDS SET-UP
ACROSS THE REGION WED MORNING-AFTN...THE +35MPH GUSTS /ON LAND
AREAS/ EXPECTED TO MOSTLY APPEAR AFTER A BULK OF THE SNOW BANDS
HAVE DISSIPATED AND MOVED EAST.
THE STRONG NW FLOW WILL CONTINUE INTO THE LATE NIGHT HRS...W/ A FEW
BANDS OF LIGHT SNOW CONTINUING TO STREAM DOWN THE NERN PORTIONS OF
MD AND ADJACENT NRN VA BUT LITTLE ACCUMULATION EXPECTED FROM THIS
ACTIVITY. UPSLOPE SNOW FOR THE MTNS WILL CONTINUE INTO MIDDAY THU
AND MORE BREEZY NW FLOW FOR THE REST OF THE AREA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AFTER THE TUE-WED SNOW STORM...LITTLE ON THE HORIZON IN TERMS OF
WX-MAKERS...JUST A DAILY ROUTINE OF NW WINDS...TEMPS BARELY PEAKING
OUT OF FREEZING DURING THE DAYTIME HRS...DROPPING BACK WELL-BELOW
FREEZING OVERNIGHT. THIS REGIME IS FROM REINFORCING UPPER WAVES OF
CANADIAN AIR THAT SLIDE DOWN THE GREAT LAKES FROM S CNTRL
CANADA...AND ROTATE AROUND A RESIDENT UPPER LOW STATIONED OVER NEW
FOUNDLAND. ONE OF THESE UPPER VORT WILL PUSH DOWN THE NRN PLAINS
EARLY NEXT WEEK /LIKE THIS INCOMING STORM SYSTEM/ BUT WON/T HAVE THE
SUPPORT OF GULF MOISTURE AND THEREFORE LOOKS TO BE LITTLE MORE THAN
A DISORGANIZED BATCH OF PRECIP AS IT MOVES THRU SUN NIGHT INTO MON.
THO IT DOES MEAN MORE UPSLOPE SNOW FOR THE CNTRL APLCNS FOR
CONSECUTIVE DAYS.
&&
.AVIATION /TODAY THROUGH SATURDAY/...
VFR CONDS THIS MRNG WL BEGIN TO DEGRADE 1ST AT CHO. THE MAJOR
AIRPORTS WL MOVE INTO IFR REALM ATER NOON...AND DEGRADE TO LIFR
TONGT IN MDT SNOW...BCMG HVY TOWARDS WED MRNG.
BANDS OF HEAVY SNOW POSSIBLE WED MORNING AND MID AFTN. THIS SYSTEM
WILL MOVE OFF THE COAST LATE WED AND NW FLOW WILL PUSH OVER THE
REGION INTO NEXT WEEKEND. GUSTY WINDS WILL BE A CONCERN W/ THE LOW
PRESSURE SYSTEM...AS WELL AS AFTER THE SYSTEM EXITS AND COLD-DRY NW
FLOW SETTLES IN OVER THE AREA.
&&
.MARINE...
WINDS WL BE UNDER SCA VALUES TDA AND TNGT. LGT SNOW WL BEGIN TO
FALL THIS AFTN...BECMG HVR AFTR MDNGT AND DCSRG VSBY TO 1/2 MILE
BY MRNG.
WINDS WILL APPROACH SCA CRIT AFT SUNRISE WED...BUT GALE CONDITIONS
WILL QUICKLY BE REALIZED INTO THE MID-LATE MORNING...AS A COASTAL
LOW STRENGTHENS OFF THE MID ATLC...PICKING UP WINDS OVER THE MID
ATLC AND ESPECIALLY OVER THE BAY/TP. THE LOW WILL REACH PEAK
STRENGTH AND PROXIMITY JUST OFF THE COAST FROM WED AFTN INTO EARLY
THU...KEEPING GALE CONDITIONS OVER THE WATERS WELL INTO THE LATE
NIGHT HRS...SOLID SCA AFTER THAT /INTO MUCH OF THU/. NW FLOW WILL
THEN BE COMMON FOR THE REGION INTO THE WEEKEND...W/ INTERMITTENT
PERIODS OF SCA CONDITIONS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM NOON TODAY TO 7 PM EST WEDNESDAY FOR
DCZ001.
MD...WINTER STORM WARNING FROM NOON TODAY TO 7 PM EST WEDNESDAY FOR
MDZ003>007-009>011-013-014-016>018.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 4 PM EST
WEDNESDAY FOR MDZ502.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 7 PM EST
WEDNESDAY FOR MDZ501.
VA...WINTER STORM WARNING FROM NOON TODAY TO 7 PM EST WEDNESDAY FOR
VAZ030-031-040-042-050>057-501-502.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 4 PM EST
WEDNESDAY FOR VAZ025>029-036>039.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 7 PM EST
WEDNESDAY FOR VAZ021.
WV...WINTER STORM WARNING FROM NOON TODAY TO 7 PM EST WEDNESDAY FOR
WVZ052-053.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 4 PM EST
WEDNESDAY FOR WVZ050-051-055-502-504.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO 7 PM EST
WEDNESDAY FOR WVZ054-501-503.
MARINE...GALE WARNING FROM 8 AM WEDNESDAY TO 6 AM EST THURSDAY FOR
ANZ530>543.
&&
$$
PRODUCTS...WOODY!/GMS
000
FXUS61 KLWX 090220
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
920 PM EST MON FEB 8 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH TONIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY...PROVIDING ANOTHER ROUND OF WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
IN LIGHT OF THE 18Z NAM/GFS GUIDANCE...WE UPGRADED THE WINTER
STORM WATCH TO A WARNING IN THE CHARLOTTESVILLE AREA...BUT KEPT
THE WATCH UP FOR THE REST OF CENTRAL VA EAST TO LOWER SOUTHERN
MARYLAND. THE REASON FOR THE LATTER IS THAT THERE WILL BE A
SLOWER ONSET OF PRECIPITATION ACROSS THIS AREA /MID TO LATE
AFTERNOON TUESDAY/ AND THAT THERE IS EXPECTED TO BE SOME
SLEET/RAIN PERHAPS MIXED THROUGH TUESDAY NIGHT THAT REDUCES
CONFIDENCE IN WARNING SNOW AMOUNTS INITIALLY. HOWEVER...IT SHOULD
BE NOTED THAT GUIDANCE INDICATES THAT ALL SNOW WILL OCCUR ON
WEDNESDAY...AND AMOUNTS MAY BE SIGNIFICANT SO THE WATCH WILL
LIKELY NEED TO BE UPGRADED TO A WARNING EVENTUALLY.
IN THE MEANTIME...TONIGHT WILL GENERALLY BE DRY WITH INCREASING
AND THICKENING CLOUDS. DESPITE CLOUDS...IT WILL BE ANOTHER COLD
NIGHT WITH LOW TEMPERATURES BELOW NORMAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
MADE VERY MINOR ADJUSTMENTS TO PRECIPITATION ONSET...OTHERWISE NO
CHANGES MADE FOR TUESDAY. SNOW IS FORECAST TO BEGIN ACROSS THE
SOUTHWEST AND WILL SPREAD EAST THROUGH THE DAY TUESDAY.
PREV...
DP CLOSED UPR LOW MOVES ACRS OHVLY TUE MRNG...ENTRAINING DRY AIR
INTO CIRCULATION AS IT DPNS AND DISLODGING ARCTIC ORIGIN AMS INTO
OHVLY. MEANWHILE...COASTAL LOPRES STRENGTHENS OFF CAROLINA COAST
AND MOVES NWD TWD DELMARVA. DPNG SFC FEATURE WILL PROMOTE SWD
REINFORCEMENT OF COLD AIR TUE AFTN.
PCPN WILL SPREAD NEWD ACRS FCST AREA THRU TUE. THERMAL PROFILES
SUPPORT AN INITIAL PCPN TYPE OF SNOW. AS COASTAL LOPRES NEARS...
WARM AIR WILL BE DRAWN WWD VCTY H85 LVL...AND WILL CREATE THERMAL
STRUCTURE SUPPORTIVE OF SLEET ACRS SRN MD AND NRN PIEDMONT RGN TUE
AFTN. GRIDS DEPICT MIX OF SLEET AND SNOW THRU TUE AFTN IN THIS
PORTION OF FCST AREA.
DIFFLUENT RGN AHEAD OF DPNG CLOSED UPR LOW XPCD TO MOVE DIRECTLY
ACRS FCST AREA...WITH INDUCED UPWARD MOTION ENHANCING PCPN RATES
IN NRN TWO-THIRDS OF CWA TUE NGT.
SFC LOW MOVES NEWD TUE EVE...WRAPPING WARM AIR INTO SRN MD THRU
TUE EVE AND REINFORCING SWD SURGE OF COLD AIR ACRS RMNDR OF FCST
AREA. PCPN MAY CHG TO SLEET AND RAIN IN SRN MD TUE EVE...BUT
STRONG COLD AIR ADVCTN IN WAKE OF NEWD-MOVG SFC LOW WILL PROMOTE
CHG TO SNOW ALL ZONES BY LATE TUE NGT.
HEADLINES HAVE BEEN ISSUED. WATCH RMNS IN EFFECT SRN ZONES WHERE
LWR CONFIDENCE IN CRITERION SNOW BEING MET EXISTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BY 12Z WED...CSTL LOW BEGINS TO BOMB OUT E OF THE DELMARVA WHILE
DEEP UPR LOW ATTAINS NEG TILT AS IT SWEEPS ACRS CWFA. THE COMBO OF
THESE TWO PROCESSES INITIATES STRONG CAA. THE ADDED EFFECTS OF THE
DYNAMIC AND ADVECTIVE COOLING WUD SUPPORT STEEPENED LAPSE RATES...
WHICH WL ENHANCE ACCUM AMTS AND WIPE OUT ANY DRY SLOT. MDL SNDGS
DEPICT A DEEP SATD LYR W/ AMPLE LIFT W/IN SNOW GROWTH RGN WED. TO
THAT END FEEL POPS/ACCUMS NEED TO BE INCREASED. IN PARTICULAR...
PROFILES IN BALT-WASH METRO SUPPORT PDS OF HVY SNW WED MRNG...W/
BANDED STRUCTURES XPCTD. SNWFL RATES OF 1-2 INCHES/HR REALISTIC.
HV ADDED THESE FEATURES INTO THE DATABASE.
ANTHR CONCERN ARE WNDS...SINCE SFC P-GRAD TIGHT AND STRONG H8 WNDS
SHUD EFFECTIVELY MIX TO SFC. THAT WL MAKE BLOWING/DRIFTING SNW AN
ADDED CONCERN. TOO FAR OUT TO ADDRESS HEADLINE-WISE...THERE/S THE
POTL IT MAY HV TO BE.
IN THE WRN UPSLP AREAS...STRONG CAA ALREADY ONGOING BY START OF DAY
WED...AND WL CONT THRU THU. THIS WL ADD ADDTL ACCUMS-- CAT POPS
WED...LKLY POPS WED NGT. POSTED WRNGS DO NOT CONSIDER THIS ASPECT
DUE TO HOW FAR IN ADVC IT IS. LATER FCSTS WL PROVIDE THESE VALUES AS
THE TIME NEARS.
MAXT WED DECR BY A SIZEABLE AMT DUE TO ONGOING SNWFL/CAA. CORE OF
COLD AIR PASSES OHD WED AFTN...AND WL STRUGGLE TO RISE THU. CHGS WED
NGT-THU MINIMAL.
XTNDD PD DOMINATED BY A STRONG SRN JET STREAM. MEANWHILE...SFC
HIPRES WL BE IN PLACE E OF THE MISSISSIPPI...CNTRD ACRS THE GRTLKS.
THAT SHUD PROVIDE WELCOMED DRY CONDS THRU THE WKND. W/ NLY FLOW AND
A DEEP SNWPACK...DONT XPCT A SGFNT WARMUP THO. TEMPS THRUT THE PD WL
STRUGGLE TO REACH 40F...PRBLY TOPPING OUT IN THE 30S. CLIMO WUD BE
IN THE LWR-MID 40S.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
HIGH/MID CLOUDS WILL BE ON THE INCREASE TONIGHT IN ADVANCE OF
ANOTHER STORM APPROACHING THE AREA. SNOW DEVELOPS TUESDAY MORNING
TO MIDDAY...WITH A QUICK DETERIORATION TO IFR CONDITIONS. VLIFR
CONDITIONS EXPECTED AT NIGHT.
POOR CONDS WED IN SNW. WNDS PICK UP DURING DAY AS SNW ENDS...
LEADING TO BLOWING/DRIFTING CONCERNS INTO THU. OTRW...VFR REST OF
PD.
&&
.MARINE...
WINDS HAVE DIMINISHED ACROSS THE WATERS EARLY THIS EVENING AND
SMALL CRAFT WAS ALLOWED TO EXPIRE. A PERIOD OF RELATIVELY LIGHT
WINDS ARE EXPECTED THROUGH TUESDAY. GRADIENT INCREASES TUESDAY
NIGHT...PAVING THE WAY FOR GUSTY WINDS WEDNESDAY.
STRONG CAA ACRS WATERS WED. COMBINED W/ STEEP LAPSE RATES AND
FVRBL MIXING...THE SFC P-GRAD TIGHTENS. THUS...SCA CONDS
SOLID...AND GLW ON THE BAY/LWR PTMC SEEMS LKLY. HIPRES BLDS
THRAFTR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR DCZ001.
MD...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR MDZ003>007-009>011-013-014-016-018.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR MDZ502.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR MDZ501.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR MDZ017.
VA...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR VAZ030-031-040-042-051>054-501-502.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR VAZ025>029-036>039.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR VAZ021.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR VAZ050-055>057.
WV...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR WVZ052-053.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR WVZ050-051-055-502-504.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR WVZ054-501-503.
MARINE...NONE.
&&
$$
SYNOPSIS...PELOQUIN
NEAR TERM...PELOQUIN
SHORT TERM...PELOQUIN/MRK
LONG TERM...HTS
AVIATION...PELOQUIN/HTS
MARINE...PELOQUIN/HTS
000
FXUS61 KLWX 082306
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
606 PM EST MON FEB 8 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH TONIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY...PROVIDING ANOTHER ROUND OF WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
18Z NAM AND GFS HAVE PROVIDED INCREASED CONFIDENCE IN WARNING
SNOWFALL AMOUNTS ACROSS THE CHARLOTTESVILLE AREA.
THEREFORE...WATCH HAS BEEN UPGRADED. WILL KEEP WATCH OUT FOR
ORANGE COUNTY VIRGINIA EAST TO ST MARYS COUNTY MARYLAND GIVEN
LOWER CONFIDENCE IN INITIAL SNOWFALL AMOUNTS DUE TO POSSIBLE
MIXING. HOWEVER...AT LEAST TOWARD THE END OF THE STORM...5 OR MORE
INCHES WILL BE POSSIBLE IN THE REMAINING WATCH AREA.
PREV...
STRONG UPR LOW ACRS NRN PLNS CONTS TO MOVE SSEWD THIS AFTN. SRN
STREAM WAVE OVER TX PNHDL WILL MOVE EWD THIS AFTN AND IS XPCD TO
PHASE WITH DIGGING NRN PLNS LOW THIS EVE. SHRTWV RDGG AHEAD OF
DIGGING LOW WILL SUPPRESS PCPN THRU LATE TNGT. SWLY FLOW WILL BGN
TO SPREAD MSTR NEWD THRU TNGT...WITH PCPN IMPINGING ON SWRN
PERIPHERY OF FCST AREA TWD SUNRISE.
INCRG UPR-LVL CLDS WILL LIMIT RADIATIONAL COOLING A BIT TNGT BUT
WHAT THE ATMOSPHERE LACKS IN RADIATIONAL COOLING MAY BE MADE UP
FOR BY RMNG SNOW PACK. KW99 AND KSHD BOTH SAW OVERNIGHT MINIMA
LAST NIGHT OF 9 BLW ZERO. WILL NOT FCST MINIMA TNGT QUITE THAT
AGGRESSIVELY BUT HAVE UNDERCUT MOS NUMBERS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
DP CLOSED UPR LOW MOVES ACRS OHVLY TUE MRNG...ENTRAINING DRY AIR
INTO CIRCULATION AS IT DPNS AND DISLODGING ARCTIC ORIGIN AMS INTO
OHVLY. MEANWHILE...COASTAL LOPRES STRENGTHENS OFF CAROLINA COAST
AND MOVES NWD TWD DELMARVA. DPNG SFC FEATURE WILL PROMOTE SWD
REINFORCEMENT OF COLD AIR TUE AFTN.
PCPN WILL SPREAD NEWD ACRS FCST AREA THRU TUE. THERMAL PROFILES
SUPPORT AN INITIAL PCPN TYPE OF SNOW. AS COASTAL LOPRES NEARS...
WARM AIR WILL BE DRAWN WWD VCTY H85 LVL...AND WILL CREATE THERMAL
STRUCTURE SUPPORTIVE OF SLEET ACRS SRN MD AND NRN PIEDMONT RGN TUE
AFTN. GRIDS DEPICT MIX OF SLEET AND SNOW THRU TUE AFTN IN THIS
PORTION OF FCST AREA.
DIFFLUENT RGN AHEAD OF DPNG CLOSED UPR LOW XPCD TO MOVE DIRECTLY
ACRS FCST AREA...WITH INDUCED UPWARD MOTION ENHANCING PCPN RATES
IN NRN TWO-THIRDS OF CWA TUE NGT.
SFC LOW MOVES NEWD TUE EVE...WRAPPING WARM AIR INTO SRN MD THRU
TUE EVE AND REINFORCING SWD SURGE OF COLD AIR ACRS RMNDR OF FCST
AREA. PCPN MAY CHG TO SLEET AND RAIN IN SRN MD TUE EVE...BUT
STRONG COLD AIR ADVCTN IN WAKE OF NEWD-MOVG SFC LOW WILL PROMOTE
CHG TO SNOW ALL ZONES BY LATE TUE NGT.
HEADLINES HAVE BEEN ISSUED. WATCH RMNS IN EFFECT SRN ZONES WHERE
LWR CONFIDENCE IN CRITERION SNOW BEING MET EXISTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BY 12Z WED...CSTL LOW BEGINS TO BOMB OUT E OF THE DELMARVA WHILE
DEEP UPR LOW ATTAINS NEG TILT AS IT SWEEPS ACRS CWFA. THE COMBO OF
THESE TWO PROCESSES INITIATES STRONG CAA. THE ADDED EFFECTS OF THE
DYNAMIC AND ADVECTIVE COOLING WUD SUPPORT STEEPENED LAPSE RATES...
WHICH WL ENHANCE ACCUM AMTS AND WIPE OUT ANY DRY SLOT. MDL SNDGS
DEPICT A DEEP SATD LYR W/ AMPLE LIFT W/IN SNOW GROWTH RGN WED. TO
THAT END FEEL POPS/ACCUMS NEED TO BE INCREASED. IN PARTICULAR...
PROFILES IN BALT-WASH METRO SUPPORT PDS OF HVY SNW WED MRNG...W/
BANDED STRUCTURES XPCTD. SNWFL RATES OF 1-2 INCHES/HR REALISTIC.
HV ADDED THESE FEATURES INTO THE DATABASE.
ANTHR CONCERN ARE WNDS...SINCE SFC P-GRAD TIGHT AND STRONG H8 WNDS
SHUD EFFECTIVELY MIX TO SFC. THAT WL MAKE BLOWING/DRIFTING SNW AN
ADDED CONCERN. TOO FAR OUT TO ADDRESS HEADLINE-WISE...THERE/S THE
POTL IT MAY HV TO BE.
IN THE WRN UPSLP AREAS...STRONG CAA ALREADY ONGOING BY START OF DAY
WED...AND WL CONT THRU THU. THIS WL ADD ADDTL ACCUMS-- CAT POPS
WED...LKLY POPS WED NGT. POSTED WRNGS DO NOT CONSIDER THIS ASPECT
DUE TO HOW FAR IN ADVC IT IS. LATER FCSTS WL PROVIDE THESE VALUES AS
THE TIME NEARS.
MAXT WED DECR BY A SIZEABLE AMT DUE TO ONGOING SNWFL/CAA. CORE OF
COLD AIR PASSES OHD WED AFTN...AND WL STRUGGLE TO RISE THU. CHGS WED
NGT-THU MINIMAL.
XTNDD PD DOMINATED BY A STRONG SRN JET STREAM. MEANWHILE...SFC
HIPRES WL BE IN PLACE E OF THE MISSISSIPPI...CNTRD ACRS THE GRTLKS.
THAT SHUD PROVIDE WELCOMED DRY CONDS THRU THE WKND. W/ NLY FLOW AND
A DEEP SNWPACK...DONT XPCT A SGFNT WARMUP THO. TEMPS THRUT THE PD WL
STRUGGLE TO REACH 40F...PRBLY TOPPING OUT IN THE 30S. CLIMO WUD BE
IN THE LWR-MID 40S.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
NO AVIATION HAZARDS THRU TNGT. SNOW XPCD TO DVLP TUE MRNG-TUE AFTN
AT ALL TERMINALS...WITH INCRG SNOW RATES AND VLIFR CONDITIONS
DVLPG TUE NGT.
POOR CONDS WED IN SNW. WNDS PICK UP DURING DAY AS SNW ENDS...
LEADING TO BLOWING/DRIFTING CONCERNS INTO THU. OTRW...VFR REST OF
PD.
&&
.MARINE...
EXTENDED SMALL CRAFT ADZY THRU RMNDR OF THIS AFTN. WINDS WILL
SUBSIDE THIS EVE AS PRESSURE GRADIENT RELAXES AMID BUILDING
HIPRES. WINTRY PCPN XPCD TUE AFTN THRU TUE NGT ACRS WATERS.
STRONG CAA ACRS WATERS WED. COMBINED W/ STEEP LAPSE RATES AND
FVRBL MIXING...THE SFC P-GRAD TIGHTENS. THUS...SCA CONDS
SOLID...AND GLW ON THE BAY/LWR PTMC SEEMS LKLY. HIPRES BLDS
THRAFTR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR DCZ001.
MD...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR MDZ003>007-009>011-013-014-016-018.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR MDZ502.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR MDZ501.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR MDZ017.
VA...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR VAZ030-031-040-042-051>054-501-502.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR VAZ025>029-036>039.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR VAZ021.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR VAZ050-055>057.
WV...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR WVZ052-053.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR WVZ050-051-055-502-504.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR WVZ054-501-503.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
ANZ530>543.
&&
$$
SYNOPSIS...BPP
NEAR TERM...BPP
SHORT TERM...MRK
LONG TERM...HTS
AVIATION...MRK/HTS
MARINE...MRK/HTS
000
FXUS61 KLWX 082031
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
331 PM EST MON FEB 8 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH TONIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY AND IS LIKELY TO PRODUCE WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
STRONG UPR LOW ACRS NRN PLNS CONTS TO MOVE SSEWD THIS AFTN. SRN
STREAM WAVE OVER TX PNHDL WILL MOVE EWD THIS AFTN AND IS XPCD TO
PHASE WITH DIGGING NRN PLNS LOW THIS EVE. SHRTWV RDGG AHEAD OF
DIGGING LOW WILL SUPPRESS PCPN THRU LATE TNGT. SWLY FLOW WILL BGN
TO SPREAD MSTR NEWD THRU TNGT...WITH PCPN IMPINGING ON SWRN
PERIPHERY OF FCST AREA TWD SUNRISE.
INCRG UPR-LVL CLDS WILL LIMIT RADIATIONAL COOLING A BIT TNGT BUT
WHAT THE ATMOSPHERE LACKS IN RADIATIONAL COOLING MAY BE MADE UP
FOR BY RMNG SNOW PACK. KW99 AND KSHD BOTH SAW OVERNIGHT MINIMA
LAST NIGHT OF 9 BLW ZERO. WILL NOT FCST MINIMA TNGT QUITE THAT
AGGRESSIVELY BUT HAVE UNDERCUT MOS NUMBERS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 AM WEDNESDAY/...
DP CLOSED UPR LOW MOVES ACRS OHVLY TUE MRNG...ENTRAINING DRY AIR
INTO CIRCULATION AS IT DPNS AND DISLODGING ARCTIC ORIGIN AMS INTO
OHVLY. MEANWHILE...COASTAL LOPRES STRENGTHENS OFF CAROLINA COAST
AND MOVES NWD TWD DELMARVA. DPNG SFC FEATURE WILL PROMOTE SWD
REINFORCEMENT OF COLD AIR TUE AFTN.
PCPN WILL SPREAD NEWD ACRS FCST AREA THRU TUE. THERMAL PROFILES
SUPPORT AN INITIAL PCPN TYPE OF SNOW. AS COASTAL LOPRES NEARS...
WARM AIR WILL BE DRAWN WWD VCTY H85 LVL...AND WILL CREATE THERMAL
STRUCTURE SUPPORTIVE OF SLEET ACRS SRN MD AND NRN PIEDMONT RGN TUE
AFTN. GRIDS DEPICT MIX OF SLEET AND SNOW THRU TUE AFTN IN THIS
PORTION OF FCST AREA.
DIFFLUENT RGN AHEAD OF DPNG CLOSED UPR LOW XPCD TO MOVE DIRECTLY
ACRS FCST AREA...WITH INDUCED UPWARD MOTION ENHANCING PCPN RATES
IN NRN TWO-THIRDS OF CWA TUE NGT.
SFC LOW MOVES NEWD TUE EVE...WRAPPING WARM AIR INTO SRN MD THRU
TUE EVE AND REINFORCING SWD SURGE OF COLD AIR ACRS RMNDR OF FCST
AREA. PCPN MAY CHG TO SLEET AND RAIN IN SRN MD TUE EVE...BUT
STRONG COLD AIR ADVCTN IN WAKE OF NEWD-MOVG SFC LOW WILL PROMOTE
CHG TO SNOW ALL ZONES BY LATE TUE NGT.
HEADLINES HAVE BEEN ISSUED. WATCH RMNS IN EFFECT SRN ZONES WHERE
LWR CONFIDENCE IN CRITERION SNOW BEING MET EXISTS.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
BY 12Z WED...CSTL LOW BEGINS TO BOMB OUT E OF THE DELMARVA WHILE
DEEP UPR LOW ATTAINS NEG TILT AS IT SWEEPS ACRS CWFA. THE COMBO OF
THESE TWO PROCESSES INITIATES STRONG CAA. THE ADDED EFFECTS OF THE
DYNAMIC AND ADVECTIVE COOLING WUD SUPPORT STEEPENED LAPSE RATES...
WHICH WL ENHANCE ACCUM AMTS AND WIPE OUT ANY DRY SLOT. MDL SNDGS
DEPICT A DEEP SATD LYR W/ AMPLE LIFT W/IN SNOW GROWTH RGN WED. TO
THAT END FEEL POPS/ACCUMS NEED TO BE INCREASED. IN PARTICULAR...
PROFILES IN BALT-WASH METRO SUPPORT PDS OF HVY SNW WED MRNG...W/
BANDED STRUCTURES XPCTD. SNWFL RATES OF 1-2 INCHES/HR REALISTIC.
HV ADDED THESE FEATURES INTO THE DATABASE.
ANTHR CONCERN ARE WNDS...SINCE SFC P-GRAD TIGHT AND STRONG H8 WNDS
SHUD EFFECTIVELY MIX TO SFC. THAT WL MAKE BLOWING/DRIFTING SNW AN
ADDED CONCERN. TOO FAR OUT TO ADDRESS HEADLINE-WISE...THERE/S THE
POTL IT MAY HV TO BE.
IN THE WRN UPSLP AREAS...STRONG CAA ALREADY ONGOING BY START OF DAY
WED...AND WL CONT THRU THU. THIS WL ADD ADDTL ACCUMS-- CAT POPS
WED...LKLY POPS WED NGT. POSTED WRNGS DO NOT CONSIDER THIS ASPECT
DUE TO HOW FAR IN ADVC IT IS. LATER FCSTS WL PROVIDE THESE VALUES AS
THE TIME NEARS.
MAXT WED DECR BY A SIZEABLE AMT DUE TO ONGOING SNWFL/CAA. CORE OF
COLD AIR PASSES OHD WED AFTN...AND WL STRUGGLE TO RISE THU. CHGS WED
NGT-THU MINIMAL.
XTNDD PD DOMINATED BY A STRONG SRN JET STREAM. MEANWHILE...SFC
HIPRES WL BE IN PLACE E OF THE MISSISSIPPI...CNTRD ACRS THE GRTLKS.
THAT SHUD PROVIDE WELCOMED DRY CONDS THRU THE WKND. W/ NLY FLOW AND
A DEEP SNWPACK...DONT XPCT A SGFNT WARMUP THO. TEMPS THRUT THE PD WL
STRUGGLE TO REACH 40F...PRBLY TOPPING OUT IN THE 30S. CLIMO WUD BE
IN THE LWR-MID 40S.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
NO AVIATION HAZARDS THRU TNGT. SNOW XPCD TO DVLP TUE MRNG-TUE AFTN
AT ALL TERMINALS...WITH INCRG SNOW RATES AND VLIFR CONDITIONS
DVLPG TUE NGT.
POOR CONDS WED IN SNW. WNDS PICK UP DURING DAY AS SNW ENDS...
LEADING TO BLOWING/DRIFTING CONCERNS INTO THU. OTRW...VFR REST OF
PD.
&&
.MARINE...
EXTENDED SMALL CRAFT ADZY THRU RMNDR OF THIS AFTN. WINDS WILL
SUBSIDE THIS EVE AS PRESSURE GRADIENT RELAXES AMID BUILDING
HIPRES. WINTRY PCPN XPCD TUE AFTN THRU TUE NGT ACRS WATERS.
STRONG CAA ACRS WATERS WED. COMBINED W/ STEEP LAPSE RATES AND
FVRBL MIXING...THE SFC P-GRAD TIGHTENS. THUS...SCA CONDS
SOLID...AND GLW ON THE BAY/LWR PTMC SEEMS LKLY. HIPRES BLDS
THRAFTR.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR DCZ001.
MD...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR MDZ003>007-009>011-013-014-016-018.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR MDZ502.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR MDZ501.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR MDZ017.
VA...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR VAZ030-031-040-042-051>054-501-502.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR VAZ026>029-038-039.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR VAZ025-036-037.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR VAZ021.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR VAZ050-055>057.
WV...WINTER STORM WARNING FROM NOON TUESDAY TO 7 PM EST WEDNESDAY
FOR WVZ052-053.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 4 PM EST WEDNESDAY
FOR WVZ050-051-055-502-504.
WINTER STORM WARNING FROM 9 AM TUESDAY TO 7 PM EST WEDNESDAY
FOR WVZ054-501-503.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ530>543.
&&
$$
KRAMAR/HTS
000
FXUS61 KLWX 081542
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1042 AM EST MON FEB 8 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH MONDAY NIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY AND IS LIKELY TO PRODUCE WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIPRES BUILDS ACRS RGN TDA. PRESSURE GRADIENT RMNS SUFFICIENTLY
TIGHT TDA TO PROMOTE GUSTY WINDS ACRS ERN PORTIONS OF FCST AREA.
H9-H8 TEMPS...IN COMBINATION WITH RMNG SNOW PACK...WILL LIMIT
HEATING. MAXIMA LWR 30S MOST AREAS...PSBLY MID 30S IN SRN MD.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
SHRTWV RDGG PASSES THRU ALOFT TNGT. FARTHER TO THE W...SRN STREAM
TROF OVER TX PNHDL WILL PHASE WITH DIGGING UPR TROF OVER CNTRL PLNS.
THIS SYSTEM XPCD TO DPN OVER MS RVR VLY LATE TNGT INTO TUE. LOPRES
ALSO WILL MOVE NWD ALONG SERN COASTLINE THRU TUE.
PCPN XPCD TO DVLP IN WARM AIR ADVCTN PATTERN AMID SWLY FLOW ALOFT
TUE MRNG...AND WILL AFFECT PRIMARILY WRN ZONES THRU MID-MRNG. AS THE
UPPER AND COASTAL SYSTEMS DRAW CLOSER TUE AFTN...PCPN WILL DVLP ACRS
RMNDR OF FCST AREA. HAVE INCRD POPS TUE AFTN ACRS ENTIRE FCST AREA.
CAVEAT WILL BE ARRIVAL OF WARM AIR NEAR H85. APPEARS PROBABLE THAT
SLEET WILL MIX IN TUE AFTN ACRS FAR SRN SECTIONS OF FCST AREA. WX
GRIDS WERE ADJUSTED ACCORDINGLY.
CSTL LOW SHUD BE TAKING OVR TUE NGT...BACKING WNDS NE. SUCH A
FLOW...W/ DROPPING H8 TEMPS AND A S/WV ABT TO KICK THRU...WUD
ENHANCE LLVL COLD AIR...CHGG PTYPE BACK TO SN. SNW WL CONT INTO
WED...BEFORE DRY SLOT WORKS IN. STRONG CAA KICKS IN THEREAFTR. FOR
NOW...HV REVISED WND DIR/PTYPE TUE NGT...AND ADDED UPSLP SNW POTL
WED-THU. TUE NGT-WED MAY BE WINDIER THAN CRRNTLY FCST...AND WL
REVISIT THAT LATER TDA AFTR REVIEWING 12Z GDNC.
WATCH WL HOLD AS IS FOR NOW. WL LOOK AT ITS AREAL CVRG AND THE ACCUM
POTL FM THIS SYSTM NXT CPL UPDATES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
ANOTHER GULF COAST LOW PRESSURE SYSTEM DEVELOPS OFF THE TX GULF
COAST LATER IN THE WEEK...BUT ENOUGH COLD-AIR REINFORCING UPPER VORT
EXIST TO THE NORTH OF THE SYSTEM AND KEEP IT SUPPRESSED DOWN ACROSS
THE I-10 CORRIDOR OF THE GULF COAST REGION...WHILE SEVERAL DAYS OF
DRY NW FLOW ARE IN-STORE FOR THE MID ATLC WELL INTO NEXT WEEK.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
NO HAZARDS TDA. WIND GUSTS 15-20KT XPCD THRU MID-AFTN AT MOST
TERMINALS.
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH THE AREA...BUT FROM THE
OHIO VLY. STILL...SOME GULF AND ATLANTIC MOISTURE WILL LIKELY
COMBINE OVER THE I-95 CORRIDOR AND MUCH OF THE MID ATLC TO BRING
MORE LIGHT-MODERATE SNOW FROM TUE AFTN INTO WED AFTN. THIS SYSTEM
WILL MOVE OFF THE COAST LATE WED AND NW FLOW WILL PUSH OVER THE
REGION INTO NEXT WEEKEND. GUSTY WINDS WILL BE A CONCERN W/ THE LOW
PRESSURE SYSTEM...AS WELL AS AFTER THE SYSTEM EXITS AND COLD-DRY NW
FLOW SETTLES IN OVER THE AREA.
&&
.MARINE...
HAVE EXPANDED SMALL CRAFT ADZY TO ENCOMPASS ALL OF MD CHSPK BAY AND
TIDAL POTOMAC RVR GIVEN OBS OF GUSTS AOA 20 KT. WINDS XPCD TO
SUBSIDE THIS AFTN AS PRESSURE GRADIENT RELAXES.
WINDS WILL APPROACH SCA CRIT CLOSER TO SUNRISE WED...AS A COASTAL
LOW MOVES UP THE CAROLINA COAST OVERNIGHT AND INTO EARLY WED. THE
LOW WILL BE PARALLEL TO THE DELMARVA COAST ON WED...PICKING UP WINDS
OVER THE MID ATLC AND ESPECIALLY OVER THE BAY/TP. GALE CONDITIONS
WILL BE POSSIBLE AS THE LOW REACHES ITS PEAK STRENGTH AND PROXIMITY
JUST OFF THE COAST FROM WED EVENING INTO THU MORNING. NW FLOW WILL
THEN BE COMMON FOR THE REGION INTO THE WEEKEND...W/ INTERMITTENT
PERIODS OF SCA CONDITIONS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR DCZ001.
MD...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR MDZ004>007-009>011-013-014.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR MDZ003-501-502.
VA...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR VAZ040-042-052>054-501.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR VAZ027>031.
WV...WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR WVZ050>053-055-501>504.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
ANZ530>543.
&&
$$
SYNOPSIS...
NEAR TERM...KRAMAR
SHORT TERM...KRAMAR/HTS
LONG TERM...GMS
AVIATION...KRAMAR/GMS
MARINE...KRAMAR/GMS
000
FXUS61 KLWX 080845
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
345 AM EST MON FEB 8 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH MONDAY NIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY AND IS LIKELY TO PRODUCE WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /TODAY/...
HIGH PRES REMAINS OVER THE AREA TODAY. LIKE YDA ABUNDANT SUNSHINE.
AFTN TEMPS WL REACH LM30S.
&&
.SHORT TERM /TONIGHT/...
AND TNGT WL BE THE LAST W/ AREA UNDER THE INFLUENCE OF HIGH PRES.
HIGH CLDS MAY BEGIN TO SLIDE IN FM THE W LATE...BUT OVERALL ANOTHER
CLR COLD NGT W/ LOWS RANGING FM THE L20S ALONG THE BAY TO SINGLE
DIGITS FAR W. E OF MTNS TO THE BAY IN THE TEENS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
SOME MINOR ADJUSTMENTS TO THE UPCOMING LOW PRESSURE SYSTEM FOR ONSET
THRU EXIT. 00Z GFS CAME IN A BIT FASTER W/ ONSET...WHICH THE LATEST
NAM IS NEARLY IN AGREEMENT ON AND FROM THERE...THEY ARE NEARLY
IN-SYNC W/ STRENGTH....TIMING AND TRACK OF THE UPPER CLOSED LOW AS
IT MOVES DUE EAST FROM THE UPPER MIDWEST OVER TO THE MID ATLANTIC.
INCREASED POPS FOR THE AREA LATE TUE NIGHT...AS WELL AS A SLIGHTLY
FASTER ONSET OF PRECIP ON TUE AFTN ACROSS THE REGION. ON TUE
MORNING...AS THE SYSTEM APPROACHES FROM THE WEST...IT WILL BE IN
EARLY STAGES OF ORGANIZATION SINCE IT WAS INITIALLY TWO SEPARATE
UPPER LEVEL FEATURES THAT BASICALLY INTERSECTED OVER THE MID MS VLY
OVERNIGHT MON.
THE UPPER LOW THAT MOVED DOWN ACROSS THE NRN PLAINS WILL DEEPEN AS
IT MOVES INTO THE UPPER MIDWEST...TURNING THE UPPER LOW THAT WAS
OVER THE DESERT SW INTO AN ACCOMPANYING UPPER TROF AXIS THAT HELPS
TO DRAW A FETCH OF GULF MOISTURE UP THRU THE DEEP SOUTH. THIS
ADDITION TO THE SYSTEM HOWEVER WILL BE FAIRLY SHORT-LIVED AS THE
UPPER MIDWEST LOW DIGS DOWN TOO FAR INTO THE OHIO VLY AND PUSHES
THE GULF MOISTURE MORE EASTWARD...TOWARD THE SOUTHERN ATLC COAST.
CLOSER TO THE UPPER LOW...MORE SCATTERED PRECIP WILL BE COMING IN
ACROSS THE CNTRL APLCNS /ALL-SNOW TO START ACROSS MUCH OF THE AREA/.
BY TUE AFTN...A WEAK SFC LOW WILL MOVING UP THE SC/NC COAST TOWARD
THE CAPE HATTERAS COAST. THE BEST ORGANIZATION OF THIS STORM SYSTEM
WILL THEN BE REALIZED AS THE LOW DEEPENS AS IT MOVES OFFSHORE AND
BEGINS TO WRAP SOME GULF MOISTURE INTO IT. THE UPPER LEVEL DYNAMICS
WILL STILL BE BACK ACROSS THE OHIO VLY. OVER THE PAST FEW
DAYS...LONG RANGE GUIDANCE HAS SHOWN A DEFINITE PERIOD OF HIGHER QPF
FOR THE ERN HALF OF THE CWA /E OF THE BLUE RIDGE AND ESPECIALLY FROM
I-95 TO THE ERN DELMARVA COAST/ LATE TUE INTO EARLY WED. BY SUNRISE
WED...THE COASTAL LOW WILL BE ROTATING JUST OFF THE DE COAST...AND
MAKE A BRIEF NWD TREK TOWARD LONG ISL BEFORE SHIFTING BACK TOWARD THE
SE. THE REASON FOR THE DIRECTIONAL CHANGE WILL BE THE SHIFTING OF
THE UPPER LOW MAKING A OCCLUSION PATTERN BY BECOMING A NEARLY-
VERTICALLY STAKED SYSTEM AS IT MOVES OFF THE COAST. DURING THIS
TRANSITION PERIOD...POSSIBLY ANOTHER ROUND OF TIGHT SNOW BANDS AND
GUSTY WINDS FOR THE ERN HALF OF THE CWA.
THE RAIN-SNOW-SLEET LINE WILL AGAIN BE ACROSS THE SRN-MOST PORTIONS
OF THE CWA LATE TUE INTO WED...AS THE UPPER LOW BASICALLY BISECTS
THE MIDDLE PORTION OF THE CWA AND DRAWS RELATIVELY WARMER AIR FROM
THE SE AND REINFORCES COOLER AIR FROM THE NW.
ANOTHER GULF COAST LOW PRESSURE SYSTEM DEVELOPS OFF THE TX GULF
COAST LATER IN THE WEEK...BUT ENOUGH COLD-AIR REINFORCING UPPER VORT
EXIST TO THE NORTH OF THE SYSTEM AND KEEP IT SUPPRESSED DOWN ACROSS
THE I-10 CORRIDOR OF THE GULF COAST REGION...WHILE SEVERAL DAYS OF
DRY NW FLOW ARE IN-STORE FOR THE MID ATLC WELL INTO NEXT WEEK.
&&
.AVIATION /TODAY THROUGH FRIDAY/...
VFR CONDS TDA AND TNGT.
ANOTHER LOW PRESSURE SYSTEM WILL APPROACH THE AREA...BUT FROM THE
OHIO VLY. STILL...SOME GULF AND ATLANTIC MOISTURE WILL LIKELY
COMBINE OVER THE I-95 CORRIDOR AND MUCH OF THE MID ATLC TO BRING
MORE LIGHT-MODERATE SNOW FROM TUE AFTN INTO WED AFTN. THIS SYSTEM
WILL MOVE OFF THE COAST LATE WED AND NW FLOW WILL PUSH OVER THE
REGION INTO NEXT WEEKEND. GUSTY WINDS WILL BE A CONCERN W/ THE LOW
PRESSURE SYSTEM...AS WELL AS AFTER THE SYSTEM EXITS AND COLD-DRY NW
FLOW SETTLES IN OVER THE AREA.
&&
.MARINE...
WINDS GUSTING INTO M TEENS AT MOMENT WL BE DCSRG AS MRNG WEARS ON
AS HIGH PRES SETTLES OVR THE WATERS THIS AFTN. LGT WINDS TNGT.
WINDS WILL APPROACH SCA CRIT CLOSER TO SUNRISE WED...AS A COASTAL
LOW MOVES UP THE CAROLINA COAST OVERNIGHT AND INTO EARLY WED. THE
LOW WILL BE PARALLEL TO THE DELMARVA COAST ON WED...PICKING UP WINDS
OVER THE MID ATLC AND ESPECIALLY OVER THE BAY/TP. GALE CONDITIONS
WILL BE POSSIBLE AS THE LOW REACHES ITS PEAK STRENGTH AND PROXIMITY
JUST OFF THE COAST FROM WED EVENING INTO THU MORNING. NW FLOW WILL
THEN BE COMMON FOR THE REGION INTO THE WEEKEND...W/ INTERMITTENT
PERIODS OF SCA CONDITIONS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR DCZ001.
MD...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR MDZ004>007-009>011-013-014.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR MDZ003-501-502.
VA...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR VAZ040-042-052>054-501.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR VAZ027>031.
WV...WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR WVZ050>053-055-501>504.
MARINE...NONE.
&&
$$
PRODUCTS...WOODY!/GMS
000
FXUS61 KLWX 080145
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
845 PM EST SUN FEB 7 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH MONDAY NIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY AND IS LIKELY TO PRODUCE WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HIGH PRESSURE WILL CONTINUE TO BUILD IN FROM THE WEST OVERNIGHT.
SKIES HAVE CLEARED ACROSS MOST AREAS...WITH JUST SOME LINGERING SCT
CU ACROSS THE POTOMAC HIGHLANDS. CONTINUED TO UNDERCUT GUIDANCE FOR
OVERNIGHT MINS DUE TO THE SNOWPACK. LATEST WINDS/DEWPOINTS INGESTED
INTO THE GRIDS. OTHERWISE...NO MAJOR CHANGES NEEDED.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SFC HIPRES BUILDS INTO THE RGN THRU MON AS UPR RDG MOVES ACRS NERN
CONUS. WINDS WILL BCM LIGHT LATE MON AFTN. MAXIMA WILL BE TEMPERED
BY DEEP SNOW PACK. FCST MAXIMA ARE SVRL DEG BLW MOS NUMBERS...ALTHO
MODERATED SLGTLY OWING TO INCRG H9-H8 TEMPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ANOTHER ROUND OF SNOW EXPECTED TO IMPACT THE AREA LATER TUE INTO
WED. HAVE ISSUED A WINTER STORM WATCH FOR THE NRN HALF OF THE CWFA
/SEE WSWLWX FOR EXACT COUNTIES/ FOR TUE AFTN THRU WED AFTN WITH THE
POTENTIAL OF 5 INCHES OR MORE OF SNOWFALL. DECIDED TO ISSUE A
WATCH THIS FAR OUT /LATE FOURTH PD/ WITH THE CONSIDERATION OF A
HEIGHTENED IMPACT ACROSS THE AREA DUE TO LINGERING EFFECTS OF
YESTERDAY/S STORM. STILL TOO FAR OUT TO PINPOINT SPECIFIC SNOWFALL
ACCUMULATIONS.
A STRONG UPPER LOW DIGGING ACROSS THE UPPER MIDWEST WILL PHASE WITH
A DECAYING SRN STREAM WAVE...INDUCING COASTAL CYCLOGENESIS ALONG
THE CAROLINA COAST. 15Z SREF AND 12Z ECMWF/GFS/NAM/GGEM GUIDANCE
HAVE TRENDED COLDER AND FARTHER S WITH THE TRACK OF THE NRN STREAM
UPPER LOW AND DEVELOPMENT OF THE COASTAL LOW AS IT MOVES UP THE MID-
ATLANTIC COAST. THIS TRANSLATES TO A LARGER IMPACT ACROSS THE AREA
THAN PREVIOUS GUIDANCE HAD INDICATED...ESPECIALLY OVER NORTHEASTERN
MD...WHERE SNOWFALL MAY BE THE HIGHEST.
WILL NOT ISSUE A WATCH FOR SRN AREAS AS THE UPPER LOW TRACKS JUST TO
THE N OF THE CWA...ALLOWING FOR A DRY SLOT TO MOVE ACROSS SRN PORTIONS
OF THE CWFA AND CUTTING DOWN PRECIP AMOUNTS THERE. IF THE TRACK OF
THE UPPER LOW/COASTAL LOW CONTINUES TO SHIFTS FARTHER S...THEN A
MUCH LARGER IMPACT WOULD BE POSSIBLE S OF THE WATCH...THOUGH THERE
IS CURRENTLY NO EVIDENCE SUPPORTING THAT. EXPECT PTYPE ISSUES
ACROSS THE SAME AREAS THAT EXPERIENCED MIXED PRECIP FROM THIS PAST
WEEKEND/S STORM IN NRN PIEDMONT AND SRN MD.
SYNOPTIC CLIMATOLOGICALLY SPEAKING...THE DC-BALTIMORE REGION DOES NOT
OFTEN SEE MAJOR SNOWSTORMS WHEN THE NRN STREAM SYSTEM TRACKS N OF
THE AREA AND IS MUCH STRONGER THAN THE SRN STREAM WAVE. THE BIG DEC
AND FEB SNOWSTORMS THIS WINTER HAVE BEEN ASSOCIATED WITH PHASING
BETWEEN A STRONGER SUB-TROPICAL SYSTEM COMMONLY SEEN IN THIS
EL-NINO PATTERN AND A WEAKER UPPER SHORTWAVE FEATURE EMBEDDED IN THE
POLAR JET STREAM.
BEHIND THE STORM...HIPRES WILL BUILD INTO THE AREA FOR THE END OF
THE WEEK. NW FLOW WILL KEEP THE MID ATLANTIC REGION COLDER THAN
NORMAL FOR THE SECOND HALF OF THE WEEK.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH TOMORROW. N/NW WINDS AROUND 5
KT WILL CONTINUE TONIGHT...WHILE SUSTAINED SPEEDS OF AROUND 10 KT
WILL BE LIKELY TOMORROW.
A STORM SYSTEM IS EXPECTED TO BRING ANOTHER ROUND OF SNOW TUE AFTN
THRU THE FIRST HALF OF WED. IFR VSBYS/CIGS AND BELOW WILL ACCOMPANY
THE SNOW. CURRENTLY THE HIGHEST IMPACTS ON AVIATION ARE EXPECTED
ACROSS BWI/MTN.
BEHIND THE STORM...VFR CONDITIONS RETURN AS HIPRES BUILDS OVER THE
AREA WED NGT THRU THE REST OF THE WEEK.
&&
.MARINE...
N/NW FLOW CONTINUES ACROSS THE CWFA OVERNIGHT. SUSTAINED SPEEDS OF
10 TO 15 KT ARE LIKELY ACROSS THE BAY...WHILE ACROSS THE TIDAL
POTOMAC WIND SPEEDS OF 5 TO 10 KT WILL BE THE RULE.
LOPRES WILL DEVELOP OFF THE CAROLINA COAST LATE TUE AND STRENGTHEN
RAPIDLY WED. SMALL CRAFT CONDITIONS ARE LIKELY WED INTO THU AS THE
LOW TRACKS TOWARD NEW ENGLAND. IF THE LOW DEEPENS OFF THE MID-
ATLANTIC COAST EARLIER AND FASTER THAN FORECASTED...THAN GALE
CONDITIONS WOULD BE POSSIBLE WED AFTN AND NIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR DCZ001.
MD...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR MDZ004>007-009>011-013-014.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR MDZ003-501-502.
VA...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR VAZ040-042-052>054-501.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR VAZ027>031.
WV...WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR WVZ050>053-055-501>504.
MARINE...NONE.
&&
$$
UPDATE...LISTEMAA
000
FXUS61 KLWX 072006
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
306 PM EST SUN FEB 7 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH MONDAY NIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY AND IS LIKELY TO PRODUCE WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
HIPRES DOMINATES TNGT WITH NO WX XPCD. TEMPS WILL FALL TO SINGLE
DIGITS TNGT OVER MAJORITY OF FCST AREA AS SNOW PACK...DRY AIR AND
LIGHT WINDS COMBINE. LWR TENS XPCD IN COASTAL AREAS WHERE MARINE
INFLUENCE WILL BE FELT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SFC HIPRES BUILDS INTO THE RGN THRU MON AS UPR RDG MOVES ACRS NERN
CONUS. WINDS WILL BCM LIGHT LATE MON AFTN. MAXIMA WILL BE TEMPERED
BY DEEP SNOW PACK. FCST MAXIMA ARE SVRL DEG BLW MOS NUMBERS...ALTHO
MODERATED SLGTLY OWING TO INCRG H9-H8 TEMPS.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
ANOTHER ROUND OF SNOW EXPECTED TO IMPACT THE AREA LATER TUE INTO
WED. HAVE ISSUED A WINTER STORM WATCH FOR THE NRN HALF OF THE CWFA
/SEE WSWLWX FOR EXACT COUNTIES/ FOR TUE AFTN THRU WED AFTN WITH THE
POTENTIAL OF 5 INCHES OR MORE OF SNOWFALL. DECIDED TO ISSUE A
WATCH THIS FAR OUT /LATE FOURTH PD/ WITH THE CONSIDERATION OF A
HEIGHTENED IMPACT ACROSS THE AREA DUE TO LINGERING EFFECTS OF
YESTERDAY/S STORM. STILL TOO FAR OUT TO PINPOINT SPECIFIC SNOWFALL
ACCUMULATIONS.
A STRONG UPPER LOW DIGGING ACROSS THE UPPER MIDWEST WILL PHASE WITH
A DECAYING SRN STREAM WAVE...INDUCING COASTAL CYCLOGENESIS ALONG
THE CAROLINA COAST. 15Z SREF AND 12Z ECMWF/GFS/NAM/GGEM GUIDANCE
HAVE TRENDED COLDER AND FARTHER S WITH THE TRACK OF THE NRN STREAM
UPPER LOW AND DEVELOPMENT OF THE COASTAL LOW AS IT MOVES UP THE MID-
ATLANTIC COAST. THIS TRANSLATES TO A LARGER IMPACT ACROSS THE AREA
THAN PREVIOUS GUIDANCE HAD INDICATED...ESPECIALLY OVER NORTHEASTERN
MD...WHERE SNOWFALL MAY BE THE HIGHEST.
WILL NOT ISSUE A WATCH FOR SRN AREAS AS THE UPPER LOW TRACKS JUST TO
THE N OF THE CWA...ALLOWING FOR A DRY SLOT TO MOVE ACROSS SRN PORTIONS
OF THE CWFA AND CUTTING DOWN PRECIP AMOUNTS THERE. IF THE TRACK OF
THE UPPER LOW/COASTAL LOW CONTINUES TO SHIFTS FARTHER S...THEN A
MUCH LARGER IMPACT WOULD BE POSSIBLE S OF THE WATCH...THOUGH THERE
IS CURRENTLY NO EVIDENCE SUPPORTING THAT. EXPECT PTYPE ISSUES
ACROSS THE SAME AREAS THAT EXPERIENCED MIXED PRECIP FROM THIS PAST
WEEKEND/S STORM IN NRN PIEDMONT AND SRN MD.
SYNOPTIC CLIMATOLOGICALLY SPEAKING...THE DC-BALTIMORE REGION DOES NOT
OFTEN SEE MAJOR SNOWSTORMS WHEN THE NRN STREAM SYSTEM TRACKS N OF
THE AREA AND IS MUCH STRONGER THAN THE SRN STREAM WAVE. THE BIG DEC
AND FEB SNOWSTORMS THIS WINTER HAVE BEEN ASSOCIATED WITH PHASING
BETWEEN A STRONGER SUB-TROPICAL SYSTEM COMMONLY SEEN IN THIS
EL-NINO PATTERN AND A WEAKER UPPER SHORTWAVE FEATURE EMBEDDED IN THE
POLAR JET STREAM.
BEHIND THE STORM...HIPRES WILL BUILD INTO THE AREA FOR THE END OF
THE WEEK. NW FLOW WILL KEEP THE MID ATLANTIC REGION COLDER THAN
NORMAL FOR THE SECOND HALF OF THE WEEK.
&&
.AVIATION /20Z SUNDAY THROUGH FRIDAY/...
VFR CONDITIONS AND GENLY LIGHT WINDS AOB 10 KT XPCD AT ALL
TERMINALS THRU FCST PD.
A STORM SYSTEM IS EXPECTED TO BRING ANOTHER ROUND OF SNOW TUE AFTN
THRU THE FIRST HALF OF WED. IFR VSBYS/CIGS AND BELOW WILL ACCOMPANY
THE SNOW. CURRENTLY THE HIGHEST IMPACTS ON AVIATION ARE EXPECTED
ACROSS BWI/MTN.
BEHIND THE STORM...VFR CONDITIONS RETURN AS HIPRES BUILDS OVER THE
AREA WED NGT THRU THE REST OF THE WEEK.
&&
.MARINE...
WINDS BCM LIGHT AOB 10 KT AS HIPRES BUILDS INTO THE AREA. NO
MARINE HAZARDS XPCD THRU MON AFTN.
LOPRES WILL DEVELOP OFF THE CAROLINA COAST LATE TUE AND STRENGTHEN
RAPIDLY WED. SMALL CRAFT CONDITIONS ARE LIKELY WED INTO THU AS THE
LOW TRACKS TOWARD NEW ENGLAND. IF THE LOW DEEPENS OFF THE MID-
ATLANTIC COAST EARLIER AND FASTER THAN FORECASTED...THAN GALE
CONDITIONS WOULD BE POSSIBLE WED AFTN AND NIGHT.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR DCZ001.
MD...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR MDZ004>007-009>011-013-014.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR MDZ003-501-502.
VA...WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR VAZ040-042-052>054-501.
WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR VAZ027>031.
WV...WINTER STORM WATCH FROM TUESDAY MORNING THROUGH WEDNESDAY
AFTERNOON FOR WVZ050>053-055-501>504.
MARINE...NONE.
&&
$$
KRAMAR/KLEIN
000
FXUS61 KLWX 071423 AAA
AFDLWX
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
923 AM EST SUN FEB 7 2010
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA THROUGH MONDAY NIGHT. LOW
PRESSURE WILL DEVELOP OFF THE MID-ATLANTIC COAST TUESDAY AND
WEDNESDAY AND IS LIKELY TO PRODUCE WINTRY PRECIPITATION. HIGH
PRESSURE RETURNS LATE THIS WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
NO CHGS TO SYNOPTIC REASONING OF PREV FCST. MADE ADJUSTMENTS TO
TEMP...DEWPT AND WIND GRIDS TO REFLECT CURRENT TRENDS. PREV
DISCUSSION FOLLOWS...
HIGH PRES OVR THE RGN WL GIVE AREA A CHC TO TAKE A BREATH...MOVE
SNOW...OR BOTH. WL GO UNDER FCST TEMP GDNC GIVEN DEEP SNOW PACK -
MOST PLACES ONLY GETTING INTO THE MU20S THIS AFTN.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
TEMPS WILL FALL TO SINGLE DIGITS TNGT OVER MAJORITY OF FCST AREA
AS SNOW PACK...DRY AIR AND LIGHT WINDS COMBINE. LWR TENS XPCD IN
COASTAL AREAS WHERE MARINE INFLUENCE WILL BE FELT.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL REMAIN OVER THE REGION MONDAY...BRINGING SUNSHINE
ALONG WITH CHILLY CONDITIONS. MAX TEMPS WILL BE IN THE 30S ACROSS
MOST LOCATIONS...BUT COLDER IN THE MOUNTAINS.
HIGH PRESSURE WILL MOVE OFF THE COAST MONDAY NIGHT WHILE ANOTHER
STORM SYSTEM MOVES THROUGH THE MIDWEST. A STRONG UPPER-LEVEL LOW IN
THE NORTHERN BRANCH OF THE JET WILL PHASE WITH THE SOUTHERN BRANCH
SYSTEM TO PRODUCE COASTAL LOW PRESSURE. THERE IS STILL SOME
UNCERTAINTY AS TO EXACTLY WHEN THESE SYSTEMS WOULD PHASE AND
CONSEQUENTLY HOW STRONG THE COASTAL LOW WILL GET BEFORE MOVING OFF
TO OUR NORTHEAST. EITHER WAY...THERE IS A GOOD CHANCE FOR WINTRY
PRECIPITATION LATER TUESDAY INTO WEDNESDAY AS THESE SYSTEMS PHASE
AND LOW PRESSURE DEVELOPS OFF THE MID-ATLANITC COAST. ACCUMULATING
SNOW IS LIKELY FROM NEAR THE CITIES OF WASHINGTON AND BALTIMORE TO
THE NORTH AND WEST...WITH MIXED PRECIPITATION LIKELY TO THE SOUTH
AND EAST. PLEASE CONTINUE TO MONITOR THE LATEST FORECASTS WITH THIS
SYSTEM BECAUSE A SLIGHT CHANGE IN THE TIMING OF THESE TWO SYSTEMS
PHASING TOGETHER WILL HAVE A SIGNIFICANT IMPACT ON THE AMOUNT OF
PRECIPITATION THAT WILL OCCUR.
HIGH PRESSURE WILL BUILD IN BEHIND THIS SYSTEM FOR LATE IN THE WEEK
INTO THE WEEKEND...BRINGING DRY AND COLD CONDITIONS.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
VFR CONDS TDA AND TNGT.
VFR CONDITIONS ARE EXPECTED THROUGH MONDAY NIGHT. HIGH AND MID-LEVEL
CLOUDS WILL INCREASE MONDAY NIGHT. LOW PRESSURE WILL DEVELOP OFF THE
MID-ATLANTIC COAST TUESDAY INTO WEDNESDAY BEFORE HEADING TOWARD NEW
ENGLAND. THIS SYSTEM WILL BRING A GOOD CHANCE FOR SNOW OR WINTRY
PRECIPITATION ALONG WITH IFR/SUBIFR CIGS AND VSBYS.
HIGH PRESSURE WILL RETURN FOR LATE IN THE WEEK.
&&
.MARINE...
HAVE TRIMMED NRN EXTENT OF SMALL CRAFT ADZY AS WINDS GUSTING TO 15
KT MAXIMALLY. ACRS SRN PORTIONS OF MD CHSPK BAY...GUSTS 15 TO 20
KT STILL NOTED...SO ATTM WILL RETAIN ADZY THRU EXPIRATION TIME.
PREV DISCUSSION FOLLOWS...
NO FLAGS EXPECTED MONDAY AND MONDAY NIGHT. LOW PRESSURE WILL DEVELOP
OFF THE MID-ATLANTIC COAST TUESDAY AND RAPIDLY INTENSIFY AS IT HEADS
TOWARD NEW ENGLAND WEDNESDAY. HIGH PRESSURE WILL SLOWLY BUILD TOWARD
THE WATERS THURSDAY BEFORE BUILDING OVERHEAD LATE IN THE WEEK. A
SMALL CRAFT ADVISORY MAY BE WARRANTED WEDNESDAY AND THURSDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ533-534-537-
541>543.
&&
$$
UPDATE...KRAMAR
PREV DISCUSSION...WOODY!/LASORSA
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