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000
FXUS61 KLWX 060850
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
350 AM EST FRI MAR 6 2015

.SYNOPSIS...
HIGH PRESSURE BUILDS OVERHEAD TODAY...THEN SETTLES OVER THE
SOUTHEASTERN STATES THROUGH THIS WEEKEND. A WEAK COLD FRONT CROSSES
THE MID-ATLANTIC SATURDAY NIGHT WITH HIGH PRESSURE THEN BUILDING
OVERHEAD THROUGH SUNDAY NIGHT. LOW PRESSURE MOVES ALONG THE CAROLINA
COAST TUESDAY WITH A COLD FRONT CROSSING THE MID-ATLANTIC TUESDAY
NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CENTER OF SFC HIGH PRESSURE IS OVER THE LOWER MS VALLEY THIS
MORNING. STILL A PRESSURE GRADIENT OVER THE REGION...ALTHOUGH A FEW
SHELTERED OBS ARE 3 KT OR LESS. THESE TWO FACTORS ARE COMBATING EACH
OTHER IN THE RESULTING WIND CHILLS...AS TEMPS ARE FALLING A LITTLE
MORE SLOWLY THAN FORECAST. WILL KEEP THE ADVISORY GOING UNTIL 10
AM AS CRITERIA STILL REMAINS POSSIBLE.

THE HIGH WILL SLIDE EAST TODAY...RESULTING IN QUIET BUT VERY COLD
CONDITIONS WITH LOW LEVEL THERMAL TROUGH OVERHEAD. HIGHS WILL LIKELY
FALL SHORT OF THE FREEZING MARK EXCEPT IN CENTRAL VA...SOME 20-25
DEGREES BELOW NORMAL. MOISTURE FIELDS INDICATE POSSIBLE
STRATOCU...MAINLY W OF THE BLUE RIDGE...AND ADVANCING MID/HIGH
CLOUDS LATE AHEAD OF A SHORT WAVE TROUGH.

TEMPS WILL FALL AGAIN TONIGHT...AND WITH A WEAKER GRADIENT AND SNOW
PACK...EXPECT ANOTHER NIGHT OF TEENS AND SINGLE DIGITS. BLENDED IN
ECMWF DATA WITH CURRENT FORECAST WHICH CAPTURES AREAL DISTRIBUTION
WELL. SLIGHTLY HIGHER DEWPOINTS AND PERHAPS SOME CLOUD COVER
ASSOCIATED WITH THE UPPER TROUGH MAY LIMIT THE FALL.

WITH THE CENTER OF THE HIGH TO THE SE BY SATURDAY...RETURN FLOW WILL
HELP TEMPERATURES REBOUND NICELY FROM THE COLD MORNING. HOWEVER
HIGHS WILL STILL BE BELOW NORMAL. CLOUDS WILL INCREASE LATE IN THE
DAY AHEAD OF ANOTHER WEAK NORTHERN STREAM TROUGH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
NO LONGER A SIMPLE WARMING TREND THIS WEEKEND THROUGH MIDWEEK
AS PREVIOUSLY THOUGHT. THE SFC HIGH DOES REMAIN ANCHORED OVER THE
SERN CONUS. HOWEVER...A WEAK COLD FRONT FROM A LOW OVER THE ST.
LAWRENCE VALLEY SHIFTS EAST ACROSS THE MID-ATLANTIC SATURDAY NIGHT.
EXPECT AN INCH OF UPSLOPE SNOW WEST FROM THE ALLEGHENY FRONT...WITH
JUST CLOUDS EAST ACROSS THE CWA. WEST FLOW SUNDAY WILL DOWNSLOPE AND
WARM FOR MID TO UPR 40S N AND LOW TO MID 50S S.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
SFC HIGH SETTLES OVER THE AREA SUNDAY NIGHT. THIS IS DOWNSTREAM OF A
SRN JET STREAM TROUGH OVER THE SRN PLAINS. THIS TROUGH WILL PRODUCE
A LOW OFF THE CAROLINA COAST MONDAY NIGHT/TUESDAY. RAIN FROM THE
PRECIP SHIELD COULD SKIRT THE SRN PORTIONS OF THE CWA. WENT A LITTLE
ABOVE WPC GUIDANCE WITH 40 POPS TUESDAY FOR SRN MD AND CHANCES FOR
SRN HALF OF CWA AND EAST FROM I-95. SO FAR THIS LOOKS TO BE RAIN.
THOUGH SHOULD PRECIP COME IN EARLIER AND BE FARTHER NORTH...SOME MIX
OF SLEET OR FREEZING RAIN WOULD BE POSSIBLE.

UPR TROUGH SETS UP OVER NERN CONUS WEDNESDAY...PROGRESSING EAST
THURSDAY. THIS WILL INCREASE WEST WINDS OVER THE AREA...BUT EXPECT
DRY AND NEAR NORMAL TEMPERATURES.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE LIKELY THROUGH THE TAF PERIOD UNDER HIGH
PRESSURE. THE ONLY EXCEPTION WOULD BE POSSIBLE STRATOCU AT MRB TODAY
WHICH MAY FALL INTO THE MVFR CATEGORY IF THEY BECOME BKN. THINK THIS
IS A SMALL PROB. ALSO A SMALL SUBSET OF GUIDANCE SHOWING POSSIBLE
VSBY REDUCTIONS LATE TONIGHT AS SLIGHTLY HIGHER DEWPOINTS WORK
IN...BUT AM NOT SOLD ON THESE SOLUTIONS YET WITH THE DRY ARCTIC
AIRMASS IN PLACE. NORTHERLY WINDS AROUND 10 KT TODAY BECOME
LIGHT/VRB BY EVENING...THEN SOUTHERLY SATURDAY AROUND 10 KT.

VFR CONDS SATURDAY NIGHT THROUGH MONDAY NIGHT. LIGHT SW FLOW
SATURDAY NIGHT BECOMES WLY BEHIND A WEAK COLD FRONT. LIGHT W/NW FLOW
THEN THROUGH MONDAY. LIGHT RAIN POSSIBLE TUESDAY AS LOW PASSES
THE CAROLINA COAST.

&&

.MARINE...
OCCASIONAL SCA LEVEL GUSTS CONTINUE ON THE WATERS EARLY THIS
MORNING. WILL MONITOR THE NEED FOR POSSIBLE EXTENSION FOR THE
SEGMENTS WHICH EXPIRE AT 6 AM. HOWEVER...ALL GUSTINESS SHOULD
SUBSIDE BY MIDDAY AS HIGH PRESSURE BUILDS IN. BY SATURDAY AFTERNOON
SOUTHERLY WINDS DEVELOP BUT APPEAR TO STAY BELOW SCA LEVELS.

LIGHT SWLY FLOW SATURDAY NIGHT...THEN LIGHT WLY/NWLY FLOW SUNDAY
THROUGH MONDAY. LIGHT RAIN POSSIBLE TUESDAY AS A LOW PASSES THE
CAROLINA COAST.

&&

.HYDROLOGY...
ICE JAM APPEARS TO NOT BE BROKEN YET ON CACAPON RIVER NEAR GREAT
CACAPON. WILL CONTINUE TO MONITOR RISES THERE AND ANY OTHER RISES.
ICE JAMS APPEAR TO HAVE BROKEN ON GOOSE CREEK IN LEESBURG.

&&

.CLIMATE...
SNOWFALL DURING METEOROLOGICAL WINTER (DECEMBER 1ST
THROUGH FEBRUARY 28TH...OR 29TH IF IT IS A LEAP YEAR) WAS NEAR
NORMAL AT OUR THREE MAIN CLIMATE SITES. HOWEVER...ADDING EARLY
SEASON SNOWFALL FROM NOVEMBER AND THE RECENT SNOWFALL SO FAR IN
MARCH PUSHES THE ANNUAL SNOWFALL TOTALS ABOVE NORMAL.

BELOW IS A TABLE OF NORMAL ANNUAL SNOWFALL (RECORDED FROM JULY 1ST
OF A GIVEN YEAR TO JUNE 30TH OF THE FOLLOWING YEAR TO ENCOMPASS THE
ENTIRE COOL SEASON)...COMPARED TO OBSERVED 2014-15 VALUES THROUGH
MARCH 5TH.

.................NORMAL ANNUAL SNOWFALL (INCHES)....................
................NOV...DEC...JAN...FEB...MAR*..APR...TOTAL...........
WASHINGTON DC...0.5...2.3...5.6...5.7...1.3...0.0...15.4............
BALTIMORE MD....0.4...3.0...6.8...8.0...1.9...0.0...20.1............
DULLES AIRPORT..0.5...3.5...7.3...7.6...2.8...0.3...22.0............
*NORMAL VALUES FOR THE ENTIRE MONTH OF MARCH

...........OBSERVED 2014-15 SNOWFALL (INCHES, THROUGH MARCH 5TH)....
................NOV...DEC...JAN...FEB...MAR*..TOTAL..(DEPARTURE)....
WASHINGTON DC....T.....T....3.6...9.8...4.9...18.3...(+2.9).........
BALTIMORE MD....0.3...0.2...5.9..14.6...6.5...27.5...(+7.4).........
DULLES AIRPORT..1.6....T....8.7..16.1...9.6...36.0...(+14.0)........
*VALUES LISTED ARE TOTALS THROUGH MARCH 5TH...AND ARE ALREADY WELL
ABOVE NORMAL FOR THE MONTH.

MEANWHILE...AS HAS BEEN THE CASE MANY TIMES IN RECENT MONTHS...
RECORD COLD TEMPERATURES ARE IN JEOPARDY AS ANOTHER COLD AIRMASS
PIVOTS ACROSS THE REGION DURING THE NEXT 24 HOURS. BELOW IS A LIST
OF RECORD DAILY LOW TEMPERATURES FOR MARCH 6TH AND 7TH...AND
RECORD DAILY LOW MAXIMUM TEMPERATURES FOR MARCH 6TH.

SITE...RECORD MIN 03/06...RECORD LOW MAX 03/06...RECORD MIN 03/07...
DCA.....10 F (1988).........21 F (1901)...........13 F (1890).......
BWI.....13 F (1901/1873)....21 F (1901)...........10 F (1960).......
IAD.....15 F (1978).........32 F (2007)...........14 F (1985).......

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     MDZ003>006-011-501>508.
VA...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     VAZ025>031-040-501-503>508.
WV...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530-531-536-538-539-542.

&&

$$
SYNOPSIS...BAJ
NEAR TERM...ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...BAJ
CLIMATE...DFH




000
FXUS61 KLWX 060850
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
350 AM EST FRI MAR 6 2015

.SYNOPSIS...
HIGH PRESSURE BUILDS OVERHEAD TODAY...THEN SETTLES OVER THE
SOUTHEASTERN STATES THROUGH THIS WEEKEND. A WEAK COLD FRONT CROSSES
THE MID-ATLANTIC SATURDAY NIGHT WITH HIGH PRESSURE THEN BUILDING
OVERHEAD THROUGH SUNDAY NIGHT. LOW PRESSURE MOVES ALONG THE CAROLINA
COAST TUESDAY WITH A COLD FRONT CROSSING THE MID-ATLANTIC TUESDAY
NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CENTER OF SFC HIGH PRESSURE IS OVER THE LOWER MS VALLEY THIS
MORNING. STILL A PRESSURE GRADIENT OVER THE REGION...ALTHOUGH A FEW
SHELTERED OBS ARE 3 KT OR LESS. THESE TWO FACTORS ARE COMBATING EACH
OTHER IN THE RESULTING WIND CHILLS...AS TEMPS ARE FALLING A LITTLE
MORE SLOWLY THAN FORECAST. WILL KEEP THE ADVISORY GOING UNTIL 10
AM AS CRITERIA STILL REMAINS POSSIBLE.

THE HIGH WILL SLIDE EAST TODAY...RESULTING IN QUIET BUT VERY COLD
CONDITIONS WITH LOW LEVEL THERMAL TROUGH OVERHEAD. HIGHS WILL LIKELY
FALL SHORT OF THE FREEZING MARK EXCEPT IN CENTRAL VA...SOME 20-25
DEGREES BELOW NORMAL. MOISTURE FIELDS INDICATE POSSIBLE
STRATOCU...MAINLY W OF THE BLUE RIDGE...AND ADVANCING MID/HIGH
CLOUDS LATE AHEAD OF A SHORT WAVE TROUGH.

TEMPS WILL FALL AGAIN TONIGHT...AND WITH A WEAKER GRADIENT AND SNOW
PACK...EXPECT ANOTHER NIGHT OF TEENS AND SINGLE DIGITS. BLENDED IN
ECMWF DATA WITH CURRENT FORECAST WHICH CAPTURES AREAL DISTRIBUTION
WELL. SLIGHTLY HIGHER DEWPOINTS AND PERHAPS SOME CLOUD COVER
ASSOCIATED WITH THE UPPER TROUGH MAY LIMIT THE FALL.

WITH THE CENTER OF THE HIGH TO THE SE BY SATURDAY...RETURN FLOW WILL
HELP TEMPERATURES REBOUND NICELY FROM THE COLD MORNING. HOWEVER
HIGHS WILL STILL BE BELOW NORMAL. CLOUDS WILL INCREASE LATE IN THE
DAY AHEAD OF ANOTHER WEAK NORTHERN STREAM TROUGH.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
NO LONGER A SIMPLE WARMING TREND THIS WEEKEND THROUGH MIDWEEK
AS PREVIOUSLY THOUGHT. THE SFC HIGH DOES REMAIN ANCHORED OVER THE
SERN CONUS. HOWEVER...A WEAK COLD FRONT FROM A LOW OVER THE ST.
LAWRENCE VALLEY SHIFTS EAST ACROSS THE MID-ATLANTIC SATURDAY NIGHT.
EXPECT AN INCH OF UPSLOPE SNOW WEST FROM THE ALLEGHENY FRONT...WITH
JUST CLOUDS EAST ACROSS THE CWA. WEST FLOW SUNDAY WILL DOWNSLOPE AND
WARM FOR MID TO UPR 40S N AND LOW TO MID 50S S.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
SFC HIGH SETTLES OVER THE AREA SUNDAY NIGHT. THIS IS DOWNSTREAM OF A
SRN JET STREAM TROUGH OVER THE SRN PLAINS. THIS TROUGH WILL PRODUCE
A LOW OFF THE CAROLINA COAST MONDAY NIGHT/TUESDAY. RAIN FROM THE
PRECIP SHIELD COULD SKIRT THE SRN PORTIONS OF THE CWA. WENT A LITTLE
ABOVE WPC GUIDANCE WITH 40 POPS TUESDAY FOR SRN MD AND CHANCES FOR
SRN HALF OF CWA AND EAST FROM I-95. SO FAR THIS LOOKS TO BE RAIN.
THOUGH SHOULD PRECIP COME IN EARLIER AND BE FARTHER NORTH...SOME MIX
OF SLEET OR FREEZING RAIN WOULD BE POSSIBLE.

UPR TROUGH SETS UP OVER NERN CONUS WEDNESDAY...PROGRESSING EAST
THURSDAY. THIS WILL INCREASE WEST WINDS OVER THE AREA...BUT EXPECT
DRY AND NEAR NORMAL TEMPERATURES.

&&

.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE LIKELY THROUGH THE TAF PERIOD UNDER HIGH
PRESSURE. THE ONLY EXCEPTION WOULD BE POSSIBLE STRATOCU AT MRB TODAY
WHICH MAY FALL INTO THE MVFR CATEGORY IF THEY BECOME BKN. THINK THIS
IS A SMALL PROB. ALSO A SMALL SUBSET OF GUIDANCE SHOWING POSSIBLE
VSBY REDUCTIONS LATE TONIGHT AS SLIGHTLY HIGHER DEWPOINTS WORK
IN...BUT AM NOT SOLD ON THESE SOLUTIONS YET WITH THE DRY ARCTIC
AIRMASS IN PLACE. NORTHERLY WINDS AROUND 10 KT TODAY BECOME
LIGHT/VRB BY EVENING...THEN SOUTHERLY SATURDAY AROUND 10 KT.

VFR CONDS SATURDAY NIGHT THROUGH MONDAY NIGHT. LIGHT SW FLOW
SATURDAY NIGHT BECOMES WLY BEHIND A WEAK COLD FRONT. LIGHT W/NW FLOW
THEN THROUGH MONDAY. LIGHT RAIN POSSIBLE TUESDAY AS LOW PASSES
THE CAROLINA COAST.

&&

.MARINE...
OCCASIONAL SCA LEVEL GUSTS CONTINUE ON THE WATERS EARLY THIS
MORNING. WILL MONITOR THE NEED FOR POSSIBLE EXTENSION FOR THE
SEGMENTS WHICH EXPIRE AT 6 AM. HOWEVER...ALL GUSTINESS SHOULD
SUBSIDE BY MIDDAY AS HIGH PRESSURE BUILDS IN. BY SATURDAY AFTERNOON
SOUTHERLY WINDS DEVELOP BUT APPEAR TO STAY BELOW SCA LEVELS.

LIGHT SWLY FLOW SATURDAY NIGHT...THEN LIGHT WLY/NWLY FLOW SUNDAY
THROUGH MONDAY. LIGHT RAIN POSSIBLE TUESDAY AS A LOW PASSES THE
CAROLINA COAST.

&&

.HYDROLOGY...
ICE JAM APPEARS TO NOT BE BROKEN YET ON CACAPON RIVER NEAR GREAT
CACAPON. WILL CONTINUE TO MONITOR RISES THERE AND ANY OTHER RISES.
ICE JAMS APPEAR TO HAVE BROKEN ON GOOSE CREEK IN LEESBURG.

&&

.CLIMATE...
SNOWFALL DURING METEOROLOGICAL WINTER (DECEMBER 1ST
THROUGH FEBRUARY 28TH...OR 29TH IF IT IS A LEAP YEAR) WAS NEAR
NORMAL AT OUR THREE MAIN CLIMATE SITES. HOWEVER...ADDING EARLY
SEASON SNOWFALL FROM NOVEMBER AND THE RECENT SNOWFALL SO FAR IN
MARCH PUSHES THE ANNUAL SNOWFALL TOTALS ABOVE NORMAL.

BELOW IS A TABLE OF NORMAL ANNUAL SNOWFALL (RECORDED FROM JULY 1ST
OF A GIVEN YEAR TO JUNE 30TH OF THE FOLLOWING YEAR TO ENCOMPASS THE
ENTIRE COOL SEASON)...COMPARED TO OBSERVED 2014-15 VALUES THROUGH
MARCH 5TH.

.................NORMAL ANNUAL SNOWFALL (INCHES)....................
................NOV...DEC...JAN...FEB...MAR*..APR...TOTAL...........
WASHINGTON DC...0.5...2.3...5.6...5.7...1.3...0.0...15.4............
BALTIMORE MD....0.4...3.0...6.8...8.0...1.9...0.0...20.1............
DULLES AIRPORT..0.5...3.5...7.3...7.6...2.8...0.3...22.0............
*NORMAL VALUES FOR THE ENTIRE MONTH OF MARCH

...........OBSERVED 2014-15 SNOWFALL (INCHES, THROUGH MARCH 5TH)....
................NOV...DEC...JAN...FEB...MAR*..TOTAL..(DEPARTURE)....
WASHINGTON DC....T.....T....3.6...9.8...4.9...18.3...(+2.9).........
BALTIMORE MD....0.3...0.2...5.9..14.6...6.5...27.5...(+7.4).........
DULLES AIRPORT..1.6....T....8.7..16.1...9.6...36.0...(+14.0)........
*VALUES LISTED ARE TOTALS THROUGH MARCH 5TH...AND ARE ALREADY WELL
ABOVE NORMAL FOR THE MONTH.

MEANWHILE...AS HAS BEEN THE CASE MANY TIMES IN RECENT MONTHS...
RECORD COLD TEMPERATURES ARE IN JEOPARDY AS ANOTHER COLD AIRMASS
PIVOTS ACROSS THE REGION DURING THE NEXT 24 HOURS. BELOW IS A LIST
OF RECORD DAILY LOW TEMPERATURES FOR MARCH 6TH AND 7TH...AND
RECORD DAILY LOW MAXIMUM TEMPERATURES FOR MARCH 6TH.

SITE...RECORD MIN 03/06...RECORD LOW MAX 03/06...RECORD MIN 03/07...
DCA.....10 F (1988).........21 F (1901)...........13 F (1890).......
BWI.....13 F (1901/1873)....21 F (1901)...........10 F (1960).......
IAD.....15 F (1978).........32 F (2007)...........14 F (1985).......

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     MDZ003>006-011-501>508.
VA...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     VAZ025>031-040-501-503>508.
WV...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530-531-536-538-539-542.

&&

$$
SYNOPSIS...BAJ
NEAR TERM...ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...BAJ
CLIMATE...DFH





000
FXUS61 KLWX 060311
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1011 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
SOME LIGHT RETURNS REMAINING ON RADAR LATE THIS EVENING. SOME
LIGHT SNOW POSSIBLE ALONG AND EAST OF THE I-95 CORRIDOR...BUT NO
ADDITIONAL ACCUMULATION IS EXPECTED.

HIGH PRESSURE WILL BUILD INTO THE AREA OVERNIGHT...WITH CLEARING
SKIES FROM WEST TO EAST. PRESSURE GRADIENT WILL REMAIN IN PLACE
MUCH OF THE NIGHT BETWEEN THE HIGH TO THE WEST AND THE OFFSHORE
LOW. THIS SHOULD PROMOTE AT LEAST A LIGHT NW WIND. LOW TEMPS STILL
EXPECTED TO DROP INTO THE SINGLE DIGITS OVER MOST OF THE
CWA...WITH SOME ZERO OR SLIGHTLY BELOW ZERO LOWS OVER THE
HIGHLANDS. WIND CHILL ADVISORY REMAINS IN EFFECT FROM THE
BALTIMORE/WASHINGTON NWRN SUBURBS TO THE BLUE RIDGE AND POINTS
WESTWARD.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS TONIGHT AS HIGH PRESSURE BUILDS TOWARD THE
TERMINALS. NORTH-NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH-NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY. WINDS
MAY DROP BELOW SCA CRITERIA FOR A WHILE LATE TONIGHT. SCA REMAINS
IN EFFECT FRIDAY MORNING OVER THE SOUTHERN MARINE ZONES...WHERE
GUSTS SHOULD REDEVELOP FOR AT LEAST A WHILE IN THE MORNING BEFORE
SUBSIDING AS HIGH PRESSURE BUILDS IN.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS EXPECTED FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL
BE MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR MDZ003>006-
     501>507.
VA...WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR VAZ025>031-040-
     501-503>508.
WV...WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR WVZ050>053-055-
     501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/KCS/MSE
MARINE...MSE/HTS
HYDROLOGY...




000
FXUS61 KLWX 060311
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1011 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
SOME LIGHT RETURNS REMAINING ON RADAR LATE THIS EVENING. SOME
LIGHT SNOW POSSIBLE ALONG AND EAST OF THE I-95 CORRIDOR...BUT NO
ADDITIONAL ACCUMULATION IS EXPECTED.

HIGH PRESSURE WILL BUILD INTO THE AREA OVERNIGHT...WITH CLEARING
SKIES FROM WEST TO EAST. PRESSURE GRADIENT WILL REMAIN IN PLACE
MUCH OF THE NIGHT BETWEEN THE HIGH TO THE WEST AND THE OFFSHORE
LOW. THIS SHOULD PROMOTE AT LEAST A LIGHT NW WIND. LOW TEMPS STILL
EXPECTED TO DROP INTO THE SINGLE DIGITS OVER MOST OF THE
CWA...WITH SOME ZERO OR SLIGHTLY BELOW ZERO LOWS OVER THE
HIGHLANDS. WIND CHILL ADVISORY REMAINS IN EFFECT FROM THE
BALTIMORE/WASHINGTON NWRN SUBURBS TO THE BLUE RIDGE AND POINTS
WESTWARD.

&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS TONIGHT AS HIGH PRESSURE BUILDS TOWARD THE
TERMINALS. NORTH-NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH-NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY. WINDS
MAY DROP BELOW SCA CRITERIA FOR A WHILE LATE TONIGHT. SCA REMAINS
IN EFFECT FRIDAY MORNING OVER THE SOUTHERN MARINE ZONES...WHERE
GUSTS SHOULD REDEVELOP FOR AT LEAST A WHILE IN THE MORNING BEFORE
SUBSIDING AS HIGH PRESSURE BUILDS IN.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS EXPECTED FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL
BE MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR MDZ003>006-
     501>507.
VA...WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR VAZ025>031-040-
     501-503>508.
WV...WIND CHILL ADVISORY UNTIL 10 AM EST FRIDAY FOR WVZ050>053-055-
     501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/KCS/MSE
MARINE...MSE/HTS
HYDROLOGY...




000
FXUS61 KLWX 060109
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
809 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
WINTER STORM WARNING HAS BEEN CANCELLED. THE FINAL BAND OF HEAVY
SNOW HAS MOVED OUT OF ST. MARYS COUNTY AND INTO THE DELMARVA AND
SERN VA. SOME LINGERING LIGHT SNOW REMAINS ACROSS THE CWA...AND
WILL CONTINUE FOR A FEW MORE HOURS...BUT ANY ACCUMULATION WILL BE
MINIMAL.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.

&&

.SHORT TERM /FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
HEAVIEST SNOW HAS MOVED TO THE EAST AND SOUTH OF THE TERMINALS.
ONE FINAL AREA OF SNOW WILL MOVE ACROSS THE TERMINALS THIS
EVENING...WITH POTENTIAL LOWERED CIGS/VSBYS. CONDITIONS WILL
QUICKLY IMPROVE MID-LATE EVENING AS HIGH PRESSURE BUILDS TOWARD
THE TERMINALS. NORTH- NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH- NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
NEAR TERM UPDATE...KCS





000
FXUS61 KLWX 060109
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
809 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
WINTER STORM WARNING HAS BEEN CANCELLED. THE FINAL BAND OF HEAVY
SNOW HAS MOVED OUT OF ST. MARYS COUNTY AND INTO THE DELMARVA AND
SERN VA. SOME LINGERING LIGHT SNOW REMAINS ACROSS THE CWA...AND
WILL CONTINUE FOR A FEW MORE HOURS...BUT ANY ACCUMULATION WILL BE
MINIMAL.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.

&&

.SHORT TERM /FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
HEAVIEST SNOW HAS MOVED TO THE EAST AND SOUTH OF THE TERMINALS.
ONE FINAL AREA OF SNOW WILL MOVE ACROSS THE TERMINALS THIS
EVENING...WITH POTENTIAL LOWERED CIGS/VSBYS. CONDITIONS WILL
QUICKLY IMPROVE MID-LATE EVENING AS HIGH PRESSURE BUILDS TOWARD
THE TERMINALS. NORTH- NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH- NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
NEAR TERM UPDATE...KCS





000
FXUS61 KLWX 060109
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
809 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
WINTER STORM WARNING HAS BEEN CANCELLED. THE FINAL BAND OF HEAVY
SNOW HAS MOVED OUT OF ST. MARYS COUNTY AND INTO THE DELMARVA AND
SERN VA. SOME LINGERING LIGHT SNOW REMAINS ACROSS THE CWA...AND
WILL CONTINUE FOR A FEW MORE HOURS...BUT ANY ACCUMULATION WILL BE
MINIMAL.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.

&&

.SHORT TERM /FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
HEAVIEST SNOW HAS MOVED TO THE EAST AND SOUTH OF THE TERMINALS.
ONE FINAL AREA OF SNOW WILL MOVE ACROSS THE TERMINALS THIS
EVENING...WITH POTENTIAL LOWERED CIGS/VSBYS. CONDITIONS WILL
QUICKLY IMPROVE MID-LATE EVENING AS HIGH PRESSURE BUILDS TOWARD
THE TERMINALS. NORTH- NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH- NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
NEAR TERM UPDATE...KCS




000
FXUS61 KLWX 060013
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
713 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
STRONGEST BAND OF SNOW IS EXPECTED TO EXIT ST. MARYS COUNTY SOON.
ADDITIONAL LIGHT SNOW CONTINUES ACROSS NORTH CENTRAL MD...EASTERN
WV AND WRN VA. THIS ACTIVITY IS EXPECTED TO MOVE THROUGH THE AREA
OVER THE NEXT FEW HOURS THIS EVENING. MINOR ADDITIONAL SNOW
ACCUMULATION IS POSSIBLE...UP TO AN INCH IN SOME LOCATIONS.
ALLOWED WINTER STORM WARNING TO EXPIRE ON SCHEDULE AT 7PM FOR ALL
AREAS ALONG AND WEST OF THE BLUE RIDGE...AND ACROSS NRN MD. REST
OF THE WARNING REMAINS IN PLACE...BUT LOOKS ON TRACK TO EXPIRE ON
TIME OR POSSIBLY EARLY OVER THE REST OF THE CWA. WILL CONTINUE TO
EVALUATE.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.

&&

.SHORT TERM /FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HEAVIEST SNOW HAS MOVED TO THE EAST AND SOUTH OF THE TERMINALS.
ONE FINAL AREA OF SNOW WILL MOVE ACROSS THE TERMINALS THIS
EVENING...WITH POTENTIAL LOWERED CIGS/VSBYS. CONDITIONS WILL
QUICKLY IMPROVE MID-LATE EVENING AS HIGH PRESSURE BUILDS TOWARD
THE TERMINALS. NORTH- NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH- NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/KCS/MSE
MARINE...MSE/HTS/KCS
HYDROLOGY...




000
FXUS61 KLWX 060013
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
713 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
STRONGEST BAND OF SNOW IS EXPECTED TO EXIT ST. MARYS COUNTY SOON.
ADDITIONAL LIGHT SNOW CONTINUES ACROSS NORTH CENTRAL MD...EASTERN
WV AND WRN VA. THIS ACTIVITY IS EXPECTED TO MOVE THROUGH THE AREA
OVER THE NEXT FEW HOURS THIS EVENING. MINOR ADDITIONAL SNOW
ACCUMULATION IS POSSIBLE...UP TO AN INCH IN SOME LOCATIONS.
ALLOWED WINTER STORM WARNING TO EXPIRE ON SCHEDULE AT 7PM FOR ALL
AREAS ALONG AND WEST OF THE BLUE RIDGE...AND ACROSS NRN MD. REST
OF THE WARNING REMAINS IN PLACE...BUT LOOKS ON TRACK TO EXPIRE ON
TIME OR POSSIBLY EARLY OVER THE REST OF THE CWA. WILL CONTINUE TO
EVALUATE.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.

&&

.SHORT TERM /FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HEAVIEST SNOW HAS MOVED TO THE EAST AND SOUTH OF THE TERMINALS.
ONE FINAL AREA OF SNOW WILL MOVE ACROSS THE TERMINALS THIS
EVENING...WITH POTENTIAL LOWERED CIGS/VSBYS. CONDITIONS WILL
QUICKLY IMPROVE MID-LATE EVENING AS HIGH PRESSURE BUILDS TOWARD
THE TERMINALS. NORTH- NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH- NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/KCS/MSE
MARINE...MSE/HTS/KCS
HYDROLOGY...





000
FXUS61 KLWX 060013
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
713 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
STRONGEST BAND OF SNOW IS EXPECTED TO EXIT ST. MARYS COUNTY SOON.
ADDITIONAL LIGHT SNOW CONTINUES ACROSS NORTH CENTRAL MD...EASTERN
WV AND WRN VA. THIS ACTIVITY IS EXPECTED TO MOVE THROUGH THE AREA
OVER THE NEXT FEW HOURS THIS EVENING. MINOR ADDITIONAL SNOW
ACCUMULATION IS POSSIBLE...UP TO AN INCH IN SOME LOCATIONS.
ALLOWED WINTER STORM WARNING TO EXPIRE ON SCHEDULE AT 7PM FOR ALL
AREAS ALONG AND WEST OF THE BLUE RIDGE...AND ACROSS NRN MD. REST
OF THE WARNING REMAINS IN PLACE...BUT LOOKS ON TRACK TO EXPIRE ON
TIME OR POSSIBLY EARLY OVER THE REST OF THE CWA. WILL CONTINUE TO
EVALUATE.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.

&&

.SHORT TERM /FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HEAVIEST SNOW HAS MOVED TO THE EAST AND SOUTH OF THE TERMINALS.
ONE FINAL AREA OF SNOW WILL MOVE ACROSS THE TERMINALS THIS
EVENING...WITH POTENTIAL LOWERED CIGS/VSBYS. CONDITIONS WILL
QUICKLY IMPROVE MID-LATE EVENING AS HIGH PRESSURE BUILDS TOWARD
THE TERMINALS. NORTH- NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH- NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/KCS/MSE
MARINE...MSE/HTS/KCS
HYDROLOGY...




000
FXUS61 KLWX 060013
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
713 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /THROUGH FRIDAY/...
STRONGEST BAND OF SNOW IS EXPECTED TO EXIT ST. MARYS COUNTY SOON.
ADDITIONAL LIGHT SNOW CONTINUES ACROSS NORTH CENTRAL MD...EASTERN
WV AND WRN VA. THIS ACTIVITY IS EXPECTED TO MOVE THROUGH THE AREA
OVER THE NEXT FEW HOURS THIS EVENING. MINOR ADDITIONAL SNOW
ACCUMULATION IS POSSIBLE...UP TO AN INCH IN SOME LOCATIONS.
ALLOWED WINTER STORM WARNING TO EXPIRE ON SCHEDULE AT 7PM FOR ALL
AREAS ALONG AND WEST OF THE BLUE RIDGE...AND ACROSS NRN MD. REST
OF THE WARNING REMAINS IN PLACE...BUT LOOKS ON TRACK TO EXPIRE ON
TIME OR POSSIBLY EARLY OVER THE REST OF THE CWA. WILL CONTINUE TO
EVALUATE.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.

&&

.SHORT TERM /FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.

&&

.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HEAVIEST SNOW HAS MOVED TO THE EAST AND SOUTH OF THE TERMINALS.
ONE FINAL AREA OF SNOW WILL MOVE ACROSS THE TERMINALS THIS
EVENING...WITH POTENTIAL LOWERED CIGS/VSBYS. CONDITIONS WILL
QUICKLY IMPROVE MID-LATE EVENING AS HIGH PRESSURE BUILDS TOWARD
THE TERMINALS. NORTH- NORTHWEST WINDS AROUND 5 TO 10 KNOTS ARE
EXPECTED. THE NORTH- NORTHWEST FLOW WILL CONTINUE THROUGH FRIDAY
WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.

&&

.MARINE...
SCA CONDITIONS HAVE DEVELOPED OVER THE WATERS WITH GUSTS MAINLY
20-25KTS UNDER NORTHERLY FLOW. HV SCA CONDS FOR ALL WATERS
TNGT...AND ADJUSTED CONTINUATION INTO FRI MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/KCS/MSE
MARINE...MSE/HTS/KCS
HYDROLOGY...





000
FXUS61 KLWX 051950
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
250 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS PRVSLY PROGGED...BAND OF HVY SNW HAS DROPPED ACRS CENTRL VA
AND SRN MD. THIS IS THE AREA WHERE MID-LVL FGEN FORCING RESIDES.
WHEN THE FORCING AND LIFT COMBINED OVER CENTRAL MD/ERN WVA/NRN VA
SNOWFALL RATES OF 1-2 INCHES/HR WERE OBSRVD. BASED ON OBS SINCE
18Z...BELIEVE THE SAME OCCURRING OVER CENTRL VA ATTM. THAT WL
QUICKLY MAKE UP FOR THE LACK OF SNOW DURING THE MRNG. MINOR
ADJUSTMENTS MADE TO SNOW TTL MAP. END RESULT A WIDESPREAD 4-8
INCHES...W/ A CPL BANDS UP TO 10 INCHES PSBL.

ACCUMULATING SNOW WILL WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS AS CNVGNC SLIDES SE OF THE AREA. HWVR...RRQ OF UPR JET WL
ARRIVE AS MID- LVL FORCING DEPARTS. THAT SUGGESTS THAT FLURRIES
MAY LINGER INTO THE EVNG. STILL HV ACCUM SNOW /FRACTION OF AN
INCH/ INTO ELY EVNG ACRS SRN MD. NO ADDTL SNOWFALL XPCTD ELSW.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.
&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.
&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SNOW WILL GRADUALLY SLIDE SOUTH AND EAST LATE THIS AFTERNOON ACROSS
THE TERMINALS. IFR CIGS/VSBYS ARE EXPECTED IN SNOWFALL THROUGH LATE
THIS AFTERNOON. CONDITIONS WILL QUICKLY IMPROVE THIS EVENING AS HIGH
PRESSURE BUILDS TOWARD THE TERMINALS. NORTH-NORTHWEST WINDS AROUND 5
TO 10 KNOTS ARE EXPECTED. THE NORTH-NORTHWEST FLOW WILL CONTINUE
THROUGH FRIDAY WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.
&&

.MARINE...
SCA CONDITIONS HV YET TO REALLY DVLP TDA...ASIDE FM AN OCNL GUST.
STILL BELIEVE POTL EXISTS AS COLDER AIR MOVES IN AND PCPN MOVES
OUT. IN FACT...THE LACK OF PCPN MAY FACILITATE FULL MIXING. HV SCA
CONDS FOR ALL WATERS TNGT...AND ADJUSTED CONTINUATION INTO FRI
MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.
&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
SYNOPSIS...BJL/HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/MSE
MARINE...HTS/MSE
HYDROLOGY...JE




000
FXUS61 KLWX 051950
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
250 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS PRVSLY PROGGED...BAND OF HVY SNW HAS DROPPED ACRS CENTRL VA
AND SRN MD. THIS IS THE AREA WHERE MID-LVL FGEN FORCING RESIDES.
WHEN THE FORCING AND LIFT COMBINED OVER CENTRAL MD/ERN WVA/NRN VA
SNOWFALL RATES OF 1-2 INCHES/HR WERE OBSRVD. BASED ON OBS SINCE
18Z...BELIEVE THE SAME OCCURRING OVER CENTRL VA ATTM. THAT WL
QUICKLY MAKE UP FOR THE LACK OF SNOW DURING THE MRNG. MINOR
ADJUSTMENTS MADE TO SNOW TTL MAP. END RESULT A WIDESPREAD 4-8
INCHES...W/ A CPL BANDS UP TO 10 INCHES PSBL.

ACCUMULATING SNOW WILL WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS AS CNVGNC SLIDES SE OF THE AREA. HWVR...RRQ OF UPR JET WL
ARRIVE AS MID- LVL FORCING DEPARTS. THAT SUGGESTS THAT FLURRIES
MAY LINGER INTO THE EVNG. STILL HV ACCUM SNOW /FRACTION OF AN
INCH/ INTO ELY EVNG ACRS SRN MD. NO ADDTL SNOWFALL XPCTD ELSW.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.
&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.
&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SNOW WILL GRADUALLY SLIDE SOUTH AND EAST LATE THIS AFTERNOON ACROSS
THE TERMINALS. IFR CIGS/VSBYS ARE EXPECTED IN SNOWFALL THROUGH LATE
THIS AFTERNOON. CONDITIONS WILL QUICKLY IMPROVE THIS EVENING AS HIGH
PRESSURE BUILDS TOWARD THE TERMINALS. NORTH-NORTHWEST WINDS AROUND 5
TO 10 KNOTS ARE EXPECTED. THE NORTH-NORTHWEST FLOW WILL CONTINUE
THROUGH FRIDAY WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.
&&

.MARINE...
SCA CONDITIONS HV YET TO REALLY DVLP TDA...ASIDE FM AN OCNL GUST.
STILL BELIEVE POTL EXISTS AS COLDER AIR MOVES IN AND PCPN MOVES
OUT. IN FACT...THE LACK OF PCPN MAY FACILITATE FULL MIXING. HV SCA
CONDS FOR ALL WATERS TNGT...AND ADJUSTED CONTINUATION INTO FRI
MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.
&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
SYNOPSIS...BJL/HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/MSE
MARINE...HTS/MSE
HYDROLOGY...JE





000
FXUS61 KLWX 051950
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
250 PM EST THU MAR 5 2015

.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO PUSH WELL SOUTH AND EAST OF THE
AREA LATE THIS AFTERNOON. HIGH PRESSURE WILL BUILD OVERHEAD
TONIGHT THROUGH FRIDAY BEFORE DRIFTING TO THE SOUTH THIS WEEKEND
INTO EARLY NEXT WEEK.
&&

.NEAR TERM /THROUGH TONIGHT/...
AS PRVSLY PROGGED...BAND OF HVY SNW HAS DROPPED ACRS CENTRL VA
AND SRN MD. THIS IS THE AREA WHERE MID-LVL FGEN FORCING RESIDES.
WHEN THE FORCING AND LIFT COMBINED OVER CENTRAL MD/ERN WVA/NRN VA
SNOWFALL RATES OF 1-2 INCHES/HR WERE OBSRVD. BASED ON OBS SINCE
18Z...BELIEVE THE SAME OCCURRING OVER CENTRL VA ATTM. THAT WL
QUICKLY MAKE UP FOR THE LACK OF SNOW DURING THE MRNG. MINOR
ADJUSTMENTS MADE TO SNOW TTL MAP. END RESULT A WIDESPREAD 4-8
INCHES...W/ A CPL BANDS UP TO 10 INCHES PSBL.

ACCUMULATING SNOW WILL WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS AS CNVGNC SLIDES SE OF THE AREA. HWVR...RRQ OF UPR JET WL
ARRIVE AS MID- LVL FORCING DEPARTS. THAT SUGGESTS THAT FLURRIES
MAY LINGER INTO THE EVNG. STILL HV ACCUM SNOW /FRACTION OF AN
INCH/ INTO ELY EVNG ACRS SRN MD. NO ADDTL SNOWFALL XPCTD ELSW.

MEAN LYR RH DROPS RAPIDLY OVNGT...WHICH SHUD ALLOW CLDS TO SCATTER
OUT. MEANWHILE THE DRY ARCTIC AMS WL CONT TO STREAM IN. KEPT A
MIN-T FCST THAT FOCUSED ON A MOS MEAN...LWRG BY A DEGF OR TWO FOR
THE FRESH SNOW AND CLRG SKIES. WHILE WINDS SHUD DIMINISH OVNGT...
DONT BELIEVE THEY WL OUTRIGHT DCPL. THAT COMBO PLACES OUTLYING
AREA OF CWFA...FM DC/BALT NWRN BURBS TO BLURDG WWD...AT THE
THRESHOLD FOR WIND CHILL ADVY. OPTED IN TO ALERT SNOW STORM
RECOVERY EFFORTS.
&&

.SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
HIPRES BLDS INTO CWFA FRIDAY. NRN STREAM S/WV ENERGY WL OVERRIDE
RDG...WHICH WL ERASE THE SUNNY START TO THE DAY. XPCT MOCLDY TO
PREVAIL DURING THE AFTN-EVE HRS.

THE THERMAL TROF WL BE CROSSING THE AREA DURING THE DAY. AS A
RESULT...FRI WL BE A COOLER DAY W/ MAXT IN THE MID-UPR 20S AND
MIN-T 10-15F.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS WAS THE CASE YESTERDAY...NOT MUCH HAS CHANGED FROM PREVIOUS
FORECASTS FOR THE EXTENDED PERIOD. WHILE SOME WARMING BEGINS
SATURDAY...SNOW COVER WILL LIKELY TEMPER THIS TREND INITIALLY. HIGHS
SATURDAY WILL REMAIN BELOW NORMAL...WITH HIGHS IN THE 40S NORTH AND
50S SOUTH.

LIGHT LOW-LEVEL WESTERLY FLOW DEVELOPS OVERNIGHT SATURDAY AND
CONTINUES THROUGH THE DAY SUNDAY. RAISED MAX TEMPS A FEW DEGREES
ABOVE GUIDANCE TO ACCOUNT FOR SOME DOWNSLOPE WARMING. OVERNIGHT LOWS
SUNDAY WILL FINALLY BE ABOVE FREEZING...EXCEPT IN HIGHER ELEVATIONS
WHERE UPPER 20S WILL BE MORE COMMON. EXPECT THIS TREND TO CONTINUE
WITH NIGHTTIME LOWS REMAINING AOA FREEZING THROUGH THE EXTENDED.
DAYTIME HIGHS WILL ALSO RETURN TO NEAR NORMAL. KEPT TUESDAY A LITTLE
COOLER THAN THE REST OF THE WEEK DUE TO POTENTIAL CLOUD COVER FROM
APPROACHING SYSTEM. STILL UNCLEAR IF THIS SYSTEM WILL AFFECT OUR
AREA OR SKIRT TO OUR SOUTH...FOR NOW LEFT SCHC POPS IN OUR FAR
SOUTHERN ZONES TO ACCOUNT FOR THIS.
&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
SNOW WILL GRADUALLY SLIDE SOUTH AND EAST LATE THIS AFTERNOON ACROSS
THE TERMINALS. IFR CIGS/VSBYS ARE EXPECTED IN SNOWFALL THROUGH LATE
THIS AFTERNOON. CONDITIONS WILL QUICKLY IMPROVE THIS EVENING AS HIGH
PRESSURE BUILDS TOWARD THE TERMINALS. NORTH-NORTHWEST WINDS AROUND 5
TO 10 KNOTS ARE EXPECTED. THE NORTH-NORTHWEST FLOW WILL CONTINUE
THROUGH FRIDAY WITH VFR CONDITIONS.

EXPECT VFR CONDITIONS THROUGH THE WEEKEND.
&&

.MARINE...
SCA CONDITIONS HV YET TO REALLY DVLP TDA...ASIDE FM AN OCNL GUST.
STILL BELIEVE POTL EXISTS AS COLDER AIR MOVES IN AND PCPN MOVES
OUT. IN FACT...THE LACK OF PCPN MAY FACILITATE FULL MIXING. HV SCA
CONDS FOR ALL WATERS TNGT...AND ADJUSTED CONTINUATION INTO FRI
MRNG FOR THE BAY.

WINDS WILL BE LIGHT OVER THE WEEKEND...SO NOT EXPECTING
ANY MARINE CONCERNS THROUGH THIS PERIOD.
&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. MANY OF THE STREAMS HAVE NOW CRESTED AND
ARE FALLING. IT IS VERY LIKELY THAT THERE IS AN ICE JAM ON THE
LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA ABOVE GREAT CACAPON THAT
HAS NOT YET BROKEN...BUT WITH COLD AIR NOW BACK IN PLACE...IT MAY
NOT UNTIL TEMPERATURES WARM AGAIN...KEEPING RISES GRADUAL FOR NOW.

ALSO APPEARS THERE MAY BE SOME SORT OF ICE EFFECT ON GOOSE CREEK
BETWEEN EVERGREEN MILLS AND LANSDOWNE. THE CURRENT STAGE/FLOW AT THE
EVERGREEN MILLS GAUGE IS HIGHER THAN WOULD BE EXPECTED BASED ON
UPSTREAM SITES...AND STILL RISING. STILL A FEW FEET BELOW FLOOD
STAGE AT THIS TIME.

SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER TODAY FOR
AT LEAST A WEEK...THE MELT OF THE NEWLY-FALLEN SNOW SHOULD BE
GRADUAL. SO THE FLOOD THREAT FROM THAT SHOULD BE MINIMAL BUT WILL BE
MONITORED NEXT WEEK.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR MDZ003>006-501>507.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 10 AM EST FRIDAY
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530-531-535-
     536-538-539-542.

&&

$$
SYNOPSIS...BJL/HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...BJL/MSE
MARINE...HTS/MSE
HYDROLOGY...JE





000
FXUS61 KLWX 051618
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1118 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 16Z...TRANSITION ZONE TO SNW NOW SITTING NEAR CHO-EZF-NHK.
REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH HV BEEN
ENHANCING SNOWFALL RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC
SNOW GROWTH WITHIN APPROX THE SAME CORRIDOR. WE/RE RECEIVING
REPORTS W/ SNOWFALL RATES OF 1-2 INCHES/HR UNDER THIS BAND. AREA
AFFECTED INCL NWRN BURBS OF DC UP TO BALT CITY. HV ADDED HEAVY AT
TIMES WORDING TO GRIDS AND BUMPED UP SNOW TTLS BY AN INCH OR TWO
W/IN THIS CORRIDOR.

AS 12Z GDNC ARRIVES...FOCUSING PROGRESS OF BAND OF FGEN FORCING.
ALL SIGNALS STILL SUGGESTING THAT THE BAND WILL BE SINKING INTO
CENTRAL VA AND SRN MD TAFTN. HV ADJUSTED GRIDS ACCRDGLY.

ACCUMULATING SNOW WILL WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. HWVR...RRQ OF UPR JET WL ARRIVE AS MID-LVL FORCING DEPARTS.
THAT SUGGESTS THAT FLURRIES MAY LINGER INTO THE EVNG. STILL HV
ACCUM SNOW /FRACTION OF AN INCH/ INTO ELY EVNG ACRS SRN MD. NO
ADDTL SNOWFALL XPCTD ELSW.

SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE





000
FXUS61 KLWX 051618
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1118 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 16Z...TRANSITION ZONE TO SNW NOW SITTING NEAR CHO-EZF-NHK.
REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH HV BEEN
ENHANCING SNOWFALL RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC
SNOW GROWTH WITHIN APPROX THE SAME CORRIDOR. WE/RE RECEIVING
REPORTS W/ SNOWFALL RATES OF 1-2 INCHES/HR UNDER THIS BAND. AREA
AFFECTED INCL NWRN BURBS OF DC UP TO BALT CITY. HV ADDED HEAVY AT
TIMES WORDING TO GRIDS AND BUMPED UP SNOW TTLS BY AN INCH OR TWO
W/IN THIS CORRIDOR.

AS 12Z GDNC ARRIVES...FOCUSING PROGRESS OF BAND OF FGEN FORCING.
ALL SIGNALS STILL SUGGESTING THAT THE BAND WILL BE SINKING INTO
CENTRAL VA AND SRN MD TAFTN. HV ADJUSTED GRIDS ACCRDGLY.

ACCUMULATING SNOW WILL WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. HWVR...RRQ OF UPR JET WL ARRIVE AS MID-LVL FORCING DEPARTS.
THAT SUGGESTS THAT FLURRIES MAY LINGER INTO THE EVNG. STILL HV
ACCUM SNOW /FRACTION OF AN INCH/ INTO ELY EVNG ACRS SRN MD. NO
ADDTL SNOWFALL XPCTD ELSW.

SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE




000
FXUS61 KLWX 051618
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1118 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 16Z...TRANSITION ZONE TO SNW NOW SITTING NEAR CHO-EZF-NHK.
REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH HV BEEN
ENHANCING SNOWFALL RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC
SNOW GROWTH WITHIN APPROX THE SAME CORRIDOR. WE/RE RECEIVING
REPORTS W/ SNOWFALL RATES OF 1-2 INCHES/HR UNDER THIS BAND. AREA
AFFECTED INCL NWRN BURBS OF DC UP TO BALT CITY. HV ADDED HEAVY AT
TIMES WORDING TO GRIDS AND BUMPED UP SNOW TTLS BY AN INCH OR TWO
W/IN THIS CORRIDOR.

AS 12Z GDNC ARRIVES...FOCUSING PROGRESS OF BAND OF FGEN FORCING.
ALL SIGNALS STILL SUGGESTING THAT THE BAND WILL BE SINKING INTO
CENTRAL VA AND SRN MD TAFTN. HV ADJUSTED GRIDS ACCRDGLY.

ACCUMULATING SNOW WILL WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. HWVR...RRQ OF UPR JET WL ARRIVE AS MID-LVL FORCING DEPARTS.
THAT SUGGESTS THAT FLURRIES MAY LINGER INTO THE EVNG. STILL HV
ACCUM SNOW /FRACTION OF AN INCH/ INTO ELY EVNG ACRS SRN MD. NO
ADDTL SNOWFALL XPCTD ELSW.

SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE





000
FXUS61 KLWX 051618
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1118 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 16Z...TRANSITION ZONE TO SNW NOW SITTING NEAR CHO-EZF-NHK.
REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH HV BEEN
ENHANCING SNOWFALL RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC
SNOW GROWTH WITHIN APPROX THE SAME CORRIDOR. WE/RE RECEIVING
REPORTS W/ SNOWFALL RATES OF 1-2 INCHES/HR UNDER THIS BAND. AREA
AFFECTED INCL NWRN BURBS OF DC UP TO BALT CITY. HV ADDED HEAVY AT
TIMES WORDING TO GRIDS AND BUMPED UP SNOW TTLS BY AN INCH OR TWO
W/IN THIS CORRIDOR.

AS 12Z GDNC ARRIVES...FOCUSING PROGRESS OF BAND OF FGEN FORCING.
ALL SIGNALS STILL SUGGESTING THAT THE BAND WILL BE SINKING INTO
CENTRAL VA AND SRN MD TAFTN. HV ADJUSTED GRIDS ACCRDGLY.

ACCUMULATING SNOW WILL WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. HWVR...RRQ OF UPR JET WL ARRIVE AS MID-LVL FORCING DEPARTS.
THAT SUGGESTS THAT FLURRIES MAY LINGER INTO THE EVNG. STILL HV
ACCUM SNOW /FRACTION OF AN INCH/ INTO ELY EVNG ACRS SRN MD. NO
ADDTL SNOWFALL XPCTD ELSW.

SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE




000
FXUS61 KLWX 051413
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
913 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 14Z...TRANSITION ZONE TO SNW RESIDES JUST N OF NAK...INVOF
DCA...JUST S OF SHD. WHILE DURATION OF RAIN HAS BEEN LONGER THAN
PRVSLY FCST...TRANSITION FM RA TO SNW ALSO TAKING PLACE MORE
QUICKLY /IE...THERE HAS BEEN VERY LTL SLEET OBSVD/. OVER THE NEXT
HOUR OR TWO...THINK THAT THE TRANSITION SHUD PROGRESS SOUTH OVER
THE REST OF THE CWFA AS CAA CONTS SFC-H8. FOR SITES THAT HV SEEN
SNOW...A QUICK INCH OR TWO HAS BEEN COMMON.

REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH WUD ENHANCE
SNOW RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC SNOW GROWTH
WITHIN APPROX THE SAME CORRIDOR. BTTM LINE...ONCE SNOW STARTS...
WL HV A PD OF MDT-LCLLY HEAVY SNOWFALL W/ RATES UP TO AN INCH/HR
FOR SVRL HRS. FOCUS PERIOD WL BE THE MIDDLE OF THE DAY-- A PINCH
ERLR TO THE NW AND LATER SE.

SNOWFALL TTLS HV BEEN REFINED SLGTLY...LWR FOR PTMC HIGHLANDS AND
HIER W/IN ZONE WHERE BEST INGREDIENTS RESIDE. ALSO TOUCHED UP TEMP
GRIDS. TEMPS WL BE DROPPING THRUT THE DAY...BUT THE SHARPER DROP
WL TAKE PLACE JUST AFTER TRANSITION TO SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD.
SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE




000
FXUS61 KLWX 051413
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
913 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 14Z...TRANSITION ZONE TO SNW RESIDES JUST N OF NAK...INVOF
DCA...JUST S OF SHD. WHILE DURATION OF RAIN HAS BEEN LONGER THAN
PRVSLY FCST...TRANSITION FM RA TO SNW ALSO TAKING PLACE MORE
QUICKLY /IE...THERE HAS BEEN VERY LTL SLEET OBSVD/. OVER THE NEXT
HOUR OR TWO...THINK THAT THE TRANSITION SHUD PROGRESS SOUTH OVER
THE REST OF THE CWFA AS CAA CONTS SFC-H8. FOR SITES THAT HV SEEN
SNOW...A QUICK INCH OR TWO HAS BEEN COMMON.

REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH WUD ENHANCE
SNOW RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC SNOW GROWTH
WITHIN APPROX THE SAME CORRIDOR. BTTM LINE...ONCE SNOW STARTS...
WL HV A PD OF MDT-LCLLY HEAVY SNOWFALL W/ RATES UP TO AN INCH/HR
FOR SVRL HRS. FOCUS PERIOD WL BE THE MIDDLE OF THE DAY-- A PINCH
ERLR TO THE NW AND LATER SE.

SNOWFALL TTLS HV BEEN REFINED SLGTLY...LWR FOR PTMC HIGHLANDS AND
HIER W/IN ZONE WHERE BEST INGREDIENTS RESIDE. ALSO TOUCHED UP TEMP
GRIDS. TEMPS WL BE DROPPING THRUT THE DAY...BUT THE SHARPER DROP
WL TAKE PLACE JUST AFTER TRANSITION TO SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD.
SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE





000
FXUS61 KLWX 051413
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
913 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 14Z...TRANSITION ZONE TO SNW RESIDES JUST N OF NAK...INVOF
DCA...JUST S OF SHD. WHILE DURATION OF RAIN HAS BEEN LONGER THAN
PRVSLY FCST...TRANSITION FM RA TO SNW ALSO TAKING PLACE MORE
QUICKLY /IE...THERE HAS BEEN VERY LTL SLEET OBSVD/. OVER THE NEXT
HOUR OR TWO...THINK THAT THE TRANSITION SHUD PROGRESS SOUTH OVER
THE REST OF THE CWFA AS CAA CONTS SFC-H8. FOR SITES THAT HV SEEN
SNOW...A QUICK INCH OR TWO HAS BEEN COMMON.

REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH WUD ENHANCE
SNOW RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC SNOW GROWTH
WITHIN APPROX THE SAME CORRIDOR. BTTM LINE...ONCE SNOW STARTS...
WL HV A PD OF MDT-LCLLY HEAVY SNOWFALL W/ RATES UP TO AN INCH/HR
FOR SVRL HRS. FOCUS PERIOD WL BE THE MIDDLE OF THE DAY-- A PINCH
ERLR TO THE NW AND LATER SE.

SNOWFALL TTLS HV BEEN REFINED SLGTLY...LWR FOR PTMC HIGHLANDS AND
HIER W/IN ZONE WHERE BEST INGREDIENTS RESIDE. ALSO TOUCHED UP TEMP
GRIDS. TEMPS WL BE DROPPING THRUT THE DAY...BUT THE SHARPER DROP
WL TAKE PLACE JUST AFTER TRANSITION TO SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD.
SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE





000
FXUS61 KLWX 051413
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
913 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 14Z...TRANSITION ZONE TO SNW RESIDES JUST N OF NAK...INVOF
DCA...JUST S OF SHD. WHILE DURATION OF RAIN HAS BEEN LONGER THAN
PRVSLY FCST...TRANSITION FM RA TO SNW ALSO TAKING PLACE MORE
QUICKLY /IE...THERE HAS BEEN VERY LTL SLEET OBSVD/. OVER THE NEXT
HOUR OR TWO...THINK THAT THE TRANSITION SHUD PROGRESS SOUTH OVER
THE REST OF THE CWFA AS CAA CONTS SFC-H8. FOR SITES THAT HV SEEN
SNOW...A QUICK INCH OR TWO HAS BEEN COMMON.

REGIONAL RADAR SHOWS A SWATH OF PCPN ACRS THE CWFA FM SW TO NE.
THIS ZONE CONNECTED TO A LONG STREAM OF MSTR...XTNDG BACK TO LA.
STRONG F-GEN CNVGNC RESIDES W/IN THIS ZONE...WHICH WUD ENHANCE
SNOW RATES. THERES ALSO A PERIOD OF GOOD DENDRITIC SNOW GROWTH
WITHIN APPROX THE SAME CORRIDOR. BTTM LINE...ONCE SNOW STARTS...
WL HV A PD OF MDT-LCLLY HEAVY SNOWFALL W/ RATES UP TO AN INCH/HR
FOR SVRL HRS. FOCUS PERIOD WL BE THE MIDDLE OF THE DAY-- A PINCH
ERLR TO THE NW AND LATER SE.

SNOWFALL TTLS HV BEEN REFINED SLGTLY...LWR FOR PTMC HIGHLANDS AND
HIER W/IN ZONE WHERE BEST INGREDIENTS RESIDE. ALSO TOUCHED UP TEMP
GRIDS. TEMPS WL BE DROPPING THRUT THE DAY...BUT THE SHARPER DROP
WL TAKE PLACE JUST AFTER TRANSITION TO SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON
HOURS. BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD.
SKIES MAY ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY
ARCTIC AIRMASS PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON
TONIGHT...WITH TEENS EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE
MOUNTAINS. WIND CHILL ADVISORIES MAY BE NEEDED IN THE POTOMAC
HIGHLANDS FOR READINGS BELOW -10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
IFR CONDITIONS OR LOWER HAS COMMENCED AT ALL TERMINALS DUE TO A
BAND OF HEAVY SNOW. SN WILL LIGHTEN DURING THE AFTERNOON...WITH
CONDITIONS IMPROVING DURING THE EVENING. VFR IS EXPECTED LATER
OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO 20 KT
POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN AND ICE-INDUCED STREAM RISES HAVE OCCURRED ACROSS MUCH OF THE
HYDROLOGIC SERVICE AREA. GUNPOWDER FALLS AT GLENCOE ROSE ABOVE FLOOD
STAGE OVERNIGHT DUE TO ICE EFFECTS AND REMAINS ABOVE FLOOD AT THIS
TIME. IT ALSO APPEARS EXTREMELY LIKELY THAT THERE IS AN ICE JAM ON
THE LOST/CACAPON RIVER IN EASTERN WEST VIRGINIA SINCE THE GAUGE AT
GREAT CACAPON HAS MOVED VERY LITTLE DESPITE THE RAIN.

WITH THE RAIN NOW CHANGING TO SNOW...THESE ARE THE TWO MOST LIKELY
AREAS FOR MINOR FLOODING TODAY...WITH THE THREAT RAPIDLY DECREASING
ELSEWHERE. SINCE THERE ARE NO ADDITIONAL PRECIPITATION EVENTS AFTER
TODAY FOR AT LEAST A WEEK...THE MELT OF THE CURRENTLY-FALLING SNOW
SHOULD BE GRADUAL AND IS UNLIKELY TO POSE A FLOOD THREAT IN THE
COMING DAYS.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...HTS/ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ/ADS
MARINE...ADS/BAJ
HYDROLOGY...JE




000
FXUS61 KLWX 050842
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
342 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM...SFC BOUNDARY HAS SLIPPED TO NEAR THE NC/VA BORDER.
HOWEVER...COLDER AIR IS ONLY TRICKLING INTO THE AREA. THERE HAVE
BEEN A SOME OBS OF SN IN THE HIGHER ELEVATIONS TO THE
NORTHWEST...BUT THERE IS A TEMPORARY LULL IN RADAR THAT MAY TAKE
UNTIL CLOSER TO DAYBREAK TO FILL BACK IN AND HAVE BETTER SNOW RATES
SPREAD EAST.

WX GRIDS WERE ADJUSTED TO SLOW DOWN THE CHANGEOVER...WHICH WILL PUSH
SE REACHING THE SE EXTENT OF THE FORECAST AREA BY MID/LATE MORNING.
SO JUST BECAUSE CONDITIONS MAY BE JUST WET AT DAYBREAK...CONDITIONS
ARE STILL EXPECTED TO DETERIORATE DURING THE MORNING. THERE STILL
LOOKS LIKE A GOOD PROB OF A FEW HOURS OF SLEET MIXTURE...ESPECIALLY
AS THE TRANSITION ZONE TRAVERSES FARTHER SE. FOR THESE REASONS...IN
ADDITION TO A LARGE CHUNK OF SNOW FALLING DURING THE DAYLIGHT HOURS
(MARCH SUN ANGLE)...SNOW TOTALS HAVE BEEN TRIMMED BACK BY A FEW
INCHES ACROSS A GOOD PART OF THE AREA.

NEVERTHELESS...THERE WILL STILL BE GOOD BANDING POTENTIAL. HAVE
HEARD REPORTS OF NEARLY A FOOT OF SNOW IN N-CNTL KY (NOT TO DRAW A
DIRECT CORRELATION TO THE LOCAL AREA...JUST THE POTENCY OF THE
SYSTEM AND THE DEEP MOISTURE TAP). THERE WILL PROBABLY BE A WINDOW
OF A FEW HOURS WHERE RATES COULD BE AN INCH PER HOUR OR MORE. THIS
WOULD BE EARLY MORNING FOR NW SECTIONS...MIDDAY FOR THE METROS TO
CNTL SHEN VALLEY...AFTERNOON FOR CNTL VA TO SRN MD. PINPOINTING
BANDING LOCATION AND DURATION WILL ULTIMATELY INFLUENCE SNOW TOTALS
SINCE IT WILL REPRESENT THE BEST CHANCE AT ACCUMULATIONS.

TEMPERATURES WILL GRADUALLY FALL THROUGH THE DAY. BLENDING IN
CURRENT GUIDANCE SUGGESTS THIS FALL WILL BE SLOWER THAN PREVIOUS
FORECAST...ANOTHER LIMITING FACTOR TO THE SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON HOURS.
BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD. SKIES MAY
ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY ARCTIC AIRMASS
PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON TONIGHT...WITH TEENS
EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE MOUNTAINS. WIND CHILL
ADVISORIES MAY BE NEEDED IN THE POTOMAC HIGHLANDS FOR READINGS BELOW
-10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
MVFR...POSSIBLY VFR AT TIMES...WITH LIGHT RAIN CAN BE EXPECTED
THROUGH AT LEAST DAYBREAK AT THE TERMINALS. A CHANGEOVER FROM NW TO
SE THROUGH THE MORNING. THERE WILL LIKELY BE A FEW-HOUR PERIOD OF
RA/SN/PL BEFORE CHANGING TO ALL SN. CONDITIONS WILL DETERIORATE TO
IFR OR LOWER...AND A BAND OF HEAVY SNOW IS POSSIBLE. WILL CONTINUE
TO MONITOR AND ADJUST TIMING IN THE TAFS. SN WILL LIGHTEN DURING THE
AFTERNOON...WITH CONDITIONS IMPROVING DURING THE EVENING. VFR IS
EXPECTED LATER OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO
20 KT POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN IS CHANGING OVER TO WINTRY PRECIPITATION FROM NW TO SE.
ADDITIONAL RAIN WILL BE BETWEEN AROUND 1/4 INCH.

STREAMS IN NORTH-CENTRAL MARYLAND HAVE RISEN TO NEAR BANKFULL DUE
TO RAIN AND ICE EFFECTS. ANY SIGNIFICANT FLOODED WILL BE
ADDRESSED.

OTHERWISE...TEMPERATURES WILL DROP BELOW FREEZING TODAY AND SNOW
WILL OVERSPREAD THE AREA.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...BAJ




000
FXUS61 KLWX 050842
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
342 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM...SFC BOUNDARY HAS SLIPPED TO NEAR THE NC/VA BORDER.
HOWEVER...COLDER AIR IS ONLY TRICKLING INTO THE AREA. THERE HAVE
BEEN A SOME OBS OF SN IN THE HIGHER ELEVATIONS TO THE
NORTHWEST...BUT THERE IS A TEMPORARY LULL IN RADAR THAT MAY TAKE
UNTIL CLOSER TO DAYBREAK TO FILL BACK IN AND HAVE BETTER SNOW RATES
SPREAD EAST.

WX GRIDS WERE ADJUSTED TO SLOW DOWN THE CHANGEOVER...WHICH WILL PUSH
SE REACHING THE SE EXTENT OF THE FORECAST AREA BY MID/LATE MORNING.
SO JUST BECAUSE CONDITIONS MAY BE JUST WET AT DAYBREAK...CONDITIONS
ARE STILL EXPECTED TO DETERIORATE DURING THE MORNING. THERE STILL
LOOKS LIKE A GOOD PROB OF A FEW HOURS OF SLEET MIXTURE...ESPECIALLY
AS THE TRANSITION ZONE TRAVERSES FARTHER SE. FOR THESE REASONS...IN
ADDITION TO A LARGE CHUNK OF SNOW FALLING DURING THE DAYLIGHT HOURS
(MARCH SUN ANGLE)...SNOW TOTALS HAVE BEEN TRIMMED BACK BY A FEW
INCHES ACROSS A GOOD PART OF THE AREA.

NEVERTHELESS...THERE WILL STILL BE GOOD BANDING POTENTIAL. HAVE
HEARD REPORTS OF NEARLY A FOOT OF SNOW IN N-CNTL KY (NOT TO DRAW A
DIRECT CORRELATION TO THE LOCAL AREA...JUST THE POTENCY OF THE
SYSTEM AND THE DEEP MOISTURE TAP). THERE WILL PROBABLY BE A WINDOW
OF A FEW HOURS WHERE RATES COULD BE AN INCH PER HOUR OR MORE. THIS
WOULD BE EARLY MORNING FOR NW SECTIONS...MIDDAY FOR THE METROS TO
CNTL SHEN VALLEY...AFTERNOON FOR CNTL VA TO SRN MD. PINPOINTING
BANDING LOCATION AND DURATION WILL ULTIMATELY INFLUENCE SNOW TOTALS
SINCE IT WILL REPRESENT THE BEST CHANCE AT ACCUMULATIONS.

TEMPERATURES WILL GRADUALLY FALL THROUGH THE DAY. BLENDING IN
CURRENT GUIDANCE SUGGESTS THIS FALL WILL BE SLOWER THAN PREVIOUS
FORECAST...ANOTHER LIMITING FACTOR TO THE SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON HOURS.
BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD. SKIES MAY
ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY ARCTIC AIRMASS
PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON TONIGHT...WITH TEENS
EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE MOUNTAINS. WIND CHILL
ADVISORIES MAY BE NEEDED IN THE POTOMAC HIGHLANDS FOR READINGS BELOW
-10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
MVFR...POSSIBLY VFR AT TIMES...WITH LIGHT RAIN CAN BE EXPECTED
THROUGH AT LEAST DAYBREAK AT THE TERMINALS. A CHANGEOVER FROM NW TO
SE THROUGH THE MORNING. THERE WILL LIKELY BE A FEW-HOUR PERIOD OF
RA/SN/PL BEFORE CHANGING TO ALL SN. CONDITIONS WILL DETERIORATE TO
IFR OR LOWER...AND A BAND OF HEAVY SNOW IS POSSIBLE. WILL CONTINUE
TO MONITOR AND ADJUST TIMING IN THE TAFS. SN WILL LIGHTEN DURING THE
AFTERNOON...WITH CONDITIONS IMPROVING DURING THE EVENING. VFR IS
EXPECTED LATER OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO
20 KT POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN IS CHANGING OVER TO WINTRY PRECIPITATION FROM NW TO SE.
ADDITIONAL RAIN WILL BE BETWEEN AROUND 1/4 INCH.

STREAMS IN NORTH-CENTRAL MARYLAND HAVE RISEN TO NEAR BANKFULL DUE
TO RAIN AND ICE EFFECTS. ANY SIGNIFICANT FLOODED WILL BE
ADDRESSED.

OTHERWISE...TEMPERATURES WILL DROP BELOW FREEZING TODAY AND SNOW
WILL OVERSPREAD THE AREA.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...BAJ





000
FXUS61 KLWX 050842
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
342 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM...SFC BOUNDARY HAS SLIPPED TO NEAR THE NC/VA BORDER.
HOWEVER...COLDER AIR IS ONLY TRICKLING INTO THE AREA. THERE HAVE
BEEN A SOME OBS OF SN IN THE HIGHER ELEVATIONS TO THE
NORTHWEST...BUT THERE IS A TEMPORARY LULL IN RADAR THAT MAY TAKE
UNTIL CLOSER TO DAYBREAK TO FILL BACK IN AND HAVE BETTER SNOW RATES
SPREAD EAST.

WX GRIDS WERE ADJUSTED TO SLOW DOWN THE CHANGEOVER...WHICH WILL PUSH
SE REACHING THE SE EXTENT OF THE FORECAST AREA BY MID/LATE MORNING.
SO JUST BECAUSE CONDITIONS MAY BE JUST WET AT DAYBREAK...CONDITIONS
ARE STILL EXPECTED TO DETERIORATE DURING THE MORNING. THERE STILL
LOOKS LIKE A GOOD PROB OF A FEW HOURS OF SLEET MIXTURE...ESPECIALLY
AS THE TRANSITION ZONE TRAVERSES FARTHER SE. FOR THESE REASONS...IN
ADDITION TO A LARGE CHUNK OF SNOW FALLING DURING THE DAYLIGHT HOURS
(MARCH SUN ANGLE)...SNOW TOTALS HAVE BEEN TRIMMED BACK BY A FEW
INCHES ACROSS A GOOD PART OF THE AREA.

NEVERTHELESS...THERE WILL STILL BE GOOD BANDING POTENTIAL. HAVE
HEARD REPORTS OF NEARLY A FOOT OF SNOW IN N-CNTL KY (NOT TO DRAW A
DIRECT CORRELATION TO THE LOCAL AREA...JUST THE POTENCY OF THE
SYSTEM AND THE DEEP MOISTURE TAP). THERE WILL PROBABLY BE A WINDOW
OF A FEW HOURS WHERE RATES COULD BE AN INCH PER HOUR OR MORE. THIS
WOULD BE EARLY MORNING FOR NW SECTIONS...MIDDAY FOR THE METROS TO
CNTL SHEN VALLEY...AFTERNOON FOR CNTL VA TO SRN MD. PINPOINTING
BANDING LOCATION AND DURATION WILL ULTIMATELY INFLUENCE SNOW TOTALS
SINCE IT WILL REPRESENT THE BEST CHANCE AT ACCUMULATIONS.

TEMPERATURES WILL GRADUALLY FALL THROUGH THE DAY. BLENDING IN
CURRENT GUIDANCE SUGGESTS THIS FALL WILL BE SLOWER THAN PREVIOUS
FORECAST...ANOTHER LIMITING FACTOR TO THE SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON HOURS.
BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD. SKIES MAY
ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY ARCTIC AIRMASS
PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON TONIGHT...WITH TEENS
EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE MOUNTAINS. WIND CHILL
ADVISORIES MAY BE NEEDED IN THE POTOMAC HIGHLANDS FOR READINGS BELOW
-10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
MVFR...POSSIBLY VFR AT TIMES...WITH LIGHT RAIN CAN BE EXPECTED
THROUGH AT LEAST DAYBREAK AT THE TERMINALS. A CHANGEOVER FROM NW TO
SE THROUGH THE MORNING. THERE WILL LIKELY BE A FEW-HOUR PERIOD OF
RA/SN/PL BEFORE CHANGING TO ALL SN. CONDITIONS WILL DETERIORATE TO
IFR OR LOWER...AND A BAND OF HEAVY SNOW IS POSSIBLE. WILL CONTINUE
TO MONITOR AND ADJUST TIMING IN THE TAFS. SN WILL LIGHTEN DURING THE
AFTERNOON...WITH CONDITIONS IMPROVING DURING THE EVENING. VFR IS
EXPECTED LATER OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO
20 KT POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN IS CHANGING OVER TO WINTRY PRECIPITATION FROM NW TO SE.
ADDITIONAL RAIN WILL BE BETWEEN AROUND 1/4 INCH.

STREAMS IN NORTH-CENTRAL MARYLAND HAVE RISEN TO NEAR BANKFULL DUE
TO RAIN AND ICE EFFECTS. ANY SIGNIFICANT FLOODED WILL BE
ADDRESSED.

OTHERWISE...TEMPERATURES WILL DROP BELOW FREEZING TODAY AND SNOW
WILL OVERSPREAD THE AREA.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...BAJ





000
FXUS61 KLWX 050842
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
342 AM EST THU MAR 5 2015

.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO DRIFT SOUTH ACROSS THE REGION THROUGH
THIS MORNING WITH PRECIPITATION CONTINUING UNTIL THIS EVENING. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN SETTLES OVER THE SOUTHEASTERN
STATES THIS WEEKEND THROUGH THE MIDWEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 AM...SFC BOUNDARY HAS SLIPPED TO NEAR THE NC/VA BORDER.
HOWEVER...COLDER AIR IS ONLY TRICKLING INTO THE AREA. THERE HAVE
BEEN A SOME OBS OF SN IN THE HIGHER ELEVATIONS TO THE
NORTHWEST...BUT THERE IS A TEMPORARY LULL IN RADAR THAT MAY TAKE
UNTIL CLOSER TO DAYBREAK TO FILL BACK IN AND HAVE BETTER SNOW RATES
SPREAD EAST.

WX GRIDS WERE ADJUSTED TO SLOW DOWN THE CHANGEOVER...WHICH WILL PUSH
SE REACHING THE SE EXTENT OF THE FORECAST AREA BY MID/LATE MORNING.
SO JUST BECAUSE CONDITIONS MAY BE JUST WET AT DAYBREAK...CONDITIONS
ARE STILL EXPECTED TO DETERIORATE DURING THE MORNING. THERE STILL
LOOKS LIKE A GOOD PROB OF A FEW HOURS OF SLEET MIXTURE...ESPECIALLY
AS THE TRANSITION ZONE TRAVERSES FARTHER SE. FOR THESE REASONS...IN
ADDITION TO A LARGE CHUNK OF SNOW FALLING DURING THE DAYLIGHT HOURS
(MARCH SUN ANGLE)...SNOW TOTALS HAVE BEEN TRIMMED BACK BY A FEW
INCHES ACROSS A GOOD PART OF THE AREA.

NEVERTHELESS...THERE WILL STILL BE GOOD BANDING POTENTIAL. HAVE
HEARD REPORTS OF NEARLY A FOOT OF SNOW IN N-CNTL KY (NOT TO DRAW A
DIRECT CORRELATION TO THE LOCAL AREA...JUST THE POTENCY OF THE
SYSTEM AND THE DEEP MOISTURE TAP). THERE WILL PROBABLY BE A WINDOW
OF A FEW HOURS WHERE RATES COULD BE AN INCH PER HOUR OR MORE. THIS
WOULD BE EARLY MORNING FOR NW SECTIONS...MIDDAY FOR THE METROS TO
CNTL SHEN VALLEY...AFTERNOON FOR CNTL VA TO SRN MD. PINPOINTING
BANDING LOCATION AND DURATION WILL ULTIMATELY INFLUENCE SNOW TOTALS
SINCE IT WILL REPRESENT THE BEST CHANCE AT ACCUMULATIONS.

TEMPERATURES WILL GRADUALLY FALL THROUGH THE DAY. BLENDING IN
CURRENT GUIDANCE SUGGESTS THIS FALL WILL BE SLOWER THAN PREVIOUS
FORECAST...ANOTHER LIMITING FACTOR TO THE SNOW.

THE SNOW WILL QUICKLY WIND DOWN DURING THE MID-LATE AFTERNOON HOURS.
BY 6 PM THE SNOW MAY BE LIMITED TO PORTIONS OF SRN MD. SKIES MAY
ACTUALLY CLEAR FAIRLY QUICKLY OVERNIGHT AS THE DRY ARCTIC AIRMASS
PUSHES IN. SINGLE DIGIT LOWS WILL BE COMMON TONIGHT...WITH TEENS
EAST OF I-95 AND POSSIBLY BELOW ZERO IN THE MOUNTAINS. WIND CHILL
ADVISORIES MAY BE NEEDED IN THE POTOMAC HIGHLANDS FOR READINGS BELOW
-10F.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
HIGH PRESSURE CENTERS OVERHEAD FRIDAY WITH SUNNY AND TRANQUIL
CONDITIONS. MAX TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH
SNOW.

HIGH PRESSURE THEN SETTLES OVER THE SOUTHEASTERN STATES FRIDAY NIGHT
THROUGH SUNDAY. COLD AGAIN SATURDAY MORNING WITH MINIMA AROUND 10F
FOR MANY INTERIOR LOCATIONS...TEENS MORE LIKELY WHERE MIXING
PERSISTS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
BROAD TROUGH CROSSES THE UPR MIDWEST TO THE NRN MID-ATLANTIC
MONDAY...THOUGH IT APPEARS CLOUD COVER WOULD BE THE ONLY SENSIBLE
WEATHER. OTHERWISE...A WELCOME CALM WEATHER PATTERN WITH A WARMING
TREND. A FEW DEGREES WARMER ON MAX TEMPS EACH DAY IN SWLY FLOW...LOW
40S FOR SATURDAY...MID 40S N...MID 50S S MONDAY. 60S POSSIBLE SOUTH
OF DC TUESDAY THROUGH THURSDAY.

&&

.AVIATION /09Z THURSDAY THROUGH MONDAY/...
MVFR...POSSIBLY VFR AT TIMES...WITH LIGHT RAIN CAN BE EXPECTED
THROUGH AT LEAST DAYBREAK AT THE TERMINALS. A CHANGEOVER FROM NW TO
SE THROUGH THE MORNING. THERE WILL LIKELY BE A FEW-HOUR PERIOD OF
RA/SN/PL BEFORE CHANGING TO ALL SN. CONDITIONS WILL DETERIORATE TO
IFR OR LOWER...AND A BAND OF HEAVY SNOW IS POSSIBLE. WILL CONTINUE
TO MONITOR AND ADJUST TIMING IN THE TAFS. SN WILL LIGHTEN DURING THE
AFTERNOON...WITH CONDITIONS IMPROVING DURING THE EVENING. VFR IS
EXPECTED LATER OVERNIGHT. WINDS GENERALLY N OR NW...SOME GUSTS UP TO
20 KT POSSIBLE TODAY.

HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH VFR/TRANQUIL
CONDS. COLD AGAIN FRIDAY NIGHT WITH MIN TEMPS IN THE TEENS TO 10F.
SWLY FLOW AND MORE HIGH PRESSURE SATURDAY THROUGH THE FIRST HALF OF
NEXT WEEK.

&&

.MARINE...
SCA CONDITIONS EXPECTED TO DEVELOP TODAY AND PERSIST THROUGH
TONIGHT FOR ALL WATERS WITH N/NW WINDS GUSTING 20 TO 25 KT AS
COLDER AIR MOVES IN. RAIN WILL CHANGE TO SLEET AND SNOW FROM MID
MORNING THROUGH MIDDAY. PRECIP ENDS THIS EVENING BUT WINDS WILL
CONTINUE TO GUST TO SCA LEVELS THURSDAY MORNING...WHEN HIGH
PRESSURE WILL THEN TAKE CONTROL.

SCA CONTINUES FOR SRN MD WATERS FRIDAY MORNING FOR NLY
CHANNELING. HIGH PRESSURE BUILDS OVERHEAD FRIDAY AFTERNOON...THEN
SETTLES OVER THE SERN STATES THROUGH THE WEEKEND WITH LIGHT SWLY
FLOW EXPECTED.

&&

.HYDROLOGY...
RAIN IS CHANGING OVER TO WINTRY PRECIPITATION FROM NW TO SE.
ADDITIONAL RAIN WILL BE BETWEEN AROUND 1/4 INCH.

STREAMS IN NORTH-CENTRAL MARYLAND HAVE RISEN TO NEAR BANKFULL DUE
TO RAIN AND ICE EFFECTS. ANY SIGNIFICANT FLOODED WILL BE
ADDRESSED.

OTHERWISE...TEMPERATURES WILL DROP BELOW FREEZING TODAY AND SNOW
WILL OVERSPREAD THE AREA.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     MDZ003>006-011-501>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR MDZ013-
     014-016-018.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR MDZ017.
VA...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-040-501-503>508.
     WINTER STORM WARNING UNTIL 9 PM EST THIS EVENING FOR VAZ038-
     039-050>055-502.
     WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR VAZ036-
     037-056-057.
WV...WINTER STORM WARNING UNTIL 7 PM EST THIS EVENING FOR
     WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR ANZ530>532-535-
     536-538>542.
     SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR ANZ533-534-537-
     543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...ADS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...BAJ




000
FXUS61 KLWX 050239
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
939 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD FRONT HAS MOVED THROUGH MOST OF THE CWA...WITH LIGHT
NORTHERLY WINDS ESTABLISHED AS FAR EAST AS THE I-95 CORRIDOR. THE
FRONT WILL CONTINUE TO MOVE THROUGH THE REST OF THE CWA LATE THIS
EVENING. SURFACE TEMPS BEHIND THE FRONT ARE COOLING...ALBEIT
GRADUALLY AT THE START. MOST OF THE CWA REMAINS IN THE 40S...WITH
SOME UPPER 30S OVER MD. THE NOTABLY COLDER AIR IS JUST TO THE
NORTH AND WEST OF THE CWA...WITH TEMPS NEAR OR BELOW FREEZING
ACROSS SOUTHWESTERN PA AND CENTRAL WV. MAIN ISSUE FOR TONIGHT WILL
BE HOW QUICKLY THIS COLDER AIR IS ABLE TO MOVE INTO THE REGION AND
PROMOTE PRECIPITATION TO TURN FROM RAIN TO SNOW/SLEET OVERNIGHT.
HAVE NOT MADE CHANGES TO THE SNOW FORECAST WITH THE COLDER AIR SO
CLOSE AT HAND.

DENSE FOG HAS ALSO BEEN AN ISSUE THIS EVENING WITH ABUNDANT LOW
LEVEL MOISTURE AND LIGHT WINDS AHEAD OF THE FRONT. EARLIER
ADVISORY FOR BALTIMORE/WASHINGTON METROS HAS BEEN CANCELLED AS
SLIGHTLY DRIER AIR AND LIGHT NW FLOW HAS ALLOWED VSBYS TO IMPROVE
GRADUALLY. ADVISORY FOR ALBEMARLE/ORANGE COUNTIES IN EFFECT UNTIL
MIDNIGHT. FOG WILL ALSO BE PREVALENT OVER THE REST OF THE PIEDMONT
AND SRN MD LATE THIS EVENING UNTIL THE FRONTAL PASSAGE.

OVERNIGHT...AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA
TO SNW W/ A SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY
NEED TO BE ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY
SUNRISE XPCTG ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL
OR PLRA MIX TO THE S.

&&

.SHORT TERM /THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
MAINLY IFR CONDITIONS TONIGHT. RAIN WILL GRADUALLY CHANGE TO A MIX
SNOW AND SLEET AND EVENTUALLY ALL SNOW LATE TONIGHT INTO EARLY
MORNING. ADJUSTMENTS TO TIMING POSSIBLE WITH LATER UPDATES
TONIGHT. GENERALLY N WINDS TONIGHT AND GRADUALLY INCREASING TO
AROUND 10KT. WIND GUSTS UP TO AROUND 20KT EXPECTED THURSDAY.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.

&&

.MARINE...
WINDS HAVE SHIFTED TO THE NORTH OVER MOST OF THE WATERS. WIND
SPEED WILL GRADUALLY INCREASE TONIGHT. SCA GOES INTO EFFECT AT 1
AM AND CONTINUES UNTIL THURSDAY NIGHT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.

&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
 ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...KCS/MSE
MARINE...MSE/HTS/KCS
HYDROLOGY...




000
FXUS61 KLWX 050239
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
939 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD FRONT HAS MOVED THROUGH MOST OF THE CWA...WITH LIGHT
NORTHERLY WINDS ESTABLISHED AS FAR EAST AS THE I-95 CORRIDOR. THE
FRONT WILL CONTINUE TO MOVE THROUGH THE REST OF THE CWA LATE THIS
EVENING. SURFACE TEMPS BEHIND THE FRONT ARE COOLING...ALBEIT
GRADUALLY AT THE START. MOST OF THE CWA REMAINS IN THE 40S...WITH
SOME UPPER 30S OVER MD. THE NOTABLY COLDER AIR IS JUST TO THE
NORTH AND WEST OF THE CWA...WITH TEMPS NEAR OR BELOW FREEZING
ACROSS SOUTHWESTERN PA AND CENTRAL WV. MAIN ISSUE FOR TONIGHT WILL
BE HOW QUICKLY THIS COLDER AIR IS ABLE TO MOVE INTO THE REGION AND
PROMOTE PRECIPITATION TO TURN FROM RAIN TO SNOW/SLEET OVERNIGHT.
HAVE NOT MADE CHANGES TO THE SNOW FORECAST WITH THE COLDER AIR SO
CLOSE AT HAND.

DENSE FOG HAS ALSO BEEN AN ISSUE THIS EVENING WITH ABUNDANT LOW
LEVEL MOISTURE AND LIGHT WINDS AHEAD OF THE FRONT. EARLIER
ADVISORY FOR BALTIMORE/WASHINGTON METROS HAS BEEN CANCELLED AS
SLIGHTLY DRIER AIR AND LIGHT NW FLOW HAS ALLOWED VSBYS TO IMPROVE
GRADUALLY. ADVISORY FOR ALBEMARLE/ORANGE COUNTIES IN EFFECT UNTIL
MIDNIGHT. FOG WILL ALSO BE PREVALENT OVER THE REST OF THE PIEDMONT
AND SRN MD LATE THIS EVENING UNTIL THE FRONTAL PASSAGE.

OVERNIGHT...AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA
TO SNW W/ A SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY
NEED TO BE ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY
SUNRISE XPCTG ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL
OR PLRA MIX TO THE S.

&&

.SHORT TERM /THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
MAINLY IFR CONDITIONS TONIGHT. RAIN WILL GRADUALLY CHANGE TO A MIX
SNOW AND SLEET AND EVENTUALLY ALL SNOW LATE TONIGHT INTO EARLY
MORNING. ADJUSTMENTS TO TIMING POSSIBLE WITH LATER UPDATES
TONIGHT. GENERALLY N WINDS TONIGHT AND GRADUALLY INCREASING TO
AROUND 10KT. WIND GUSTS UP TO AROUND 20KT EXPECTED THURSDAY.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.

&&

.MARINE...
WINDS HAVE SHIFTED TO THE NORTH OVER MOST OF THE WATERS. WIND
SPEED WILL GRADUALLY INCREASE TONIGHT. SCA GOES INTO EFFECT AT 1
AM AND CONTINUES UNTIL THURSDAY NIGHT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.

&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
 ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...KCS/MSE
MARINE...MSE/HTS/KCS
HYDROLOGY...





000
FXUS61 KLWX 050239
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
939 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
COLD FRONT HAS MOVED THROUGH MOST OF THE CWA...WITH LIGHT
NORTHERLY WINDS ESTABLISHED AS FAR EAST AS THE I-95 CORRIDOR. THE
FRONT WILL CONTINUE TO MOVE THROUGH THE REST OF THE CWA LATE THIS
EVENING. SURFACE TEMPS BEHIND THE FRONT ARE COOLING...ALBEIT
GRADUALLY AT THE START. MOST OF THE CWA REMAINS IN THE 40S...WITH
SOME UPPER 30S OVER MD. THE NOTABLY COLDER AIR IS JUST TO THE
NORTH AND WEST OF THE CWA...WITH TEMPS NEAR OR BELOW FREEZING
ACROSS SOUTHWESTERN PA AND CENTRAL WV. MAIN ISSUE FOR TONIGHT WILL
BE HOW QUICKLY THIS COLDER AIR IS ABLE TO MOVE INTO THE REGION AND
PROMOTE PRECIPITATION TO TURN FROM RAIN TO SNOW/SLEET OVERNIGHT.
HAVE NOT MADE CHANGES TO THE SNOW FORECAST WITH THE COLDER AIR SO
CLOSE AT HAND.

DENSE FOG HAS ALSO BEEN AN ISSUE THIS EVENING WITH ABUNDANT LOW
LEVEL MOISTURE AND LIGHT WINDS AHEAD OF THE FRONT. EARLIER
ADVISORY FOR BALTIMORE/WASHINGTON METROS HAS BEEN CANCELLED AS
SLIGHTLY DRIER AIR AND LIGHT NW FLOW HAS ALLOWED VSBYS TO IMPROVE
GRADUALLY. ADVISORY FOR ALBEMARLE/ORANGE COUNTIES IN EFFECT UNTIL
MIDNIGHT. FOG WILL ALSO BE PREVALENT OVER THE REST OF THE PIEDMONT
AND SRN MD LATE THIS EVENING UNTIL THE FRONTAL PASSAGE.

OVERNIGHT...AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA
TO SNW W/ A SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY
NEED TO BE ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY
SUNRISE XPCTG ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL
OR PLRA MIX TO THE S.

&&

.SHORT TERM /THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.

&&

.AVIATION /03Z THURSDAY THROUGH MONDAY/...
MAINLY IFR CONDITIONS TONIGHT. RAIN WILL GRADUALLY CHANGE TO A MIX
SNOW AND SLEET AND EVENTUALLY ALL SNOW LATE TONIGHT INTO EARLY
MORNING. ADJUSTMENTS TO TIMING POSSIBLE WITH LATER UPDATES
TONIGHT. GENERALLY N WINDS TONIGHT AND GRADUALLY INCREASING TO
AROUND 10KT. WIND GUSTS UP TO AROUND 20KT EXPECTED THURSDAY.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.

&&

.MARINE...
WINDS HAVE SHIFTED TO THE NORTH OVER MOST OF THE WATERS. WIND
SPEED WILL GRADUALLY INCREASE TONIGHT. SCA GOES INTO EFFECT AT 1
AM AND CONTINUES UNTIL THURSDAY NIGHT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.

&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
 ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KCS/HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...KCS/MSE
MARINE...MSE/HTS/KCS
HYDROLOGY...




000
FXUS61 KLWX 042350
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
650 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
...UPDATE...
A DENSE FOG ADVISORY HAS BEEN ISSUED FOR PORTIONS OF
THE WASHINGTON DC METRO AREA...ALL OF THE BALTIMORE METRO AREA AND
WESTWARD TO FREDERICK COUNTY MD. VISIBILITIES HAVE DROPPED TO ONE
QUARTER MILE AT NUMEROUS LOCATIONS IN THIS AREA...AND WILL
PROBABLY PERSIST UNTIL A COLD FRONT MOVES THROUGH THIS EVENING AND
NW WINDS DEVELOP.

...PREVIOUS DISCUSSION...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO
HV COMBINED INTO ONE... STRETCHING FM INVOF MRB- BNA- SHV. GIVEN
THE LACK OF FORCING...PCPN HAS BEEN SLOW IN ADVCG EWD TDA.
HWVR...LTST RADAR COMPOSITE DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA.
ANTICIPATE PCPN TO OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.

&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.

&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MDZ003-501-
     502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR MDZ004>006-
     011-013-014-503>508.
VA...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR VAZ028-503-
     504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ053-054.
WV...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR WVZ050>052-
     055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS/KCS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...MSE/HTS
MARINE...MSE/HTS
HYDROLOGY...




000
FXUS61 KLWX 042350
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
650 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
...UPDATE...
A DENSE FOG ADVISORY HAS BEEN ISSUED FOR PORTIONS OF
THE WASHINGTON DC METRO AREA...ALL OF THE BALTIMORE METRO AREA AND
WESTWARD TO FREDERICK COUNTY MD. VISIBILITIES HAVE DROPPED TO ONE
QUARTER MILE AT NUMEROUS LOCATIONS IN THIS AREA...AND WILL
PROBABLY PERSIST UNTIL A COLD FRONT MOVES THROUGH THIS EVENING AND
NW WINDS DEVELOP.

...PREVIOUS DISCUSSION...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO
HV COMBINED INTO ONE... STRETCHING FM INVOF MRB- BNA- SHV. GIVEN
THE LACK OF FORCING...PCPN HAS BEEN SLOW IN ADVCG EWD TDA.
HWVR...LTST RADAR COMPOSITE DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA.
ANTICIPATE PCPN TO OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.

&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.

&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MDZ003-501-
     502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR MDZ004>006-
     011-013-014-503>508.
VA...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR VAZ028-503-
     504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ053-054.
WV...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR WVZ050>052-
     055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS/KCS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...MSE/HTS
MARINE...MSE/HTS
HYDROLOGY...




000
FXUS61 KLWX 042350
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
650 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
...UPDATE...
A DENSE FOG ADVISORY HAS BEEN ISSUED FOR PORTIONS OF
THE WASHINGTON DC METRO AREA...ALL OF THE BALTIMORE METRO AREA AND
WESTWARD TO FREDERICK COUNTY MD. VISIBILITIES HAVE DROPPED TO ONE
QUARTER MILE AT NUMEROUS LOCATIONS IN THIS AREA...AND WILL
PROBABLY PERSIST UNTIL A COLD FRONT MOVES THROUGH THIS EVENING AND
NW WINDS DEVELOP.

...PREVIOUS DISCUSSION...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO
HV COMBINED INTO ONE... STRETCHING FM INVOF MRB- BNA- SHV. GIVEN
THE LACK OF FORCING...PCPN HAS BEEN SLOW IN ADVCG EWD TDA.
HWVR...LTST RADAR COMPOSITE DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA.
ANTICIPATE PCPN TO OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.

&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.

&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MDZ003-501-
     502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR MDZ004>006-
     011-013-014-503>508.
VA...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR VAZ028-503-
     504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ053-054.
WV...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR WVZ050>052-
     055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS/KCS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...MSE/HTS
MARINE...MSE/HTS
HYDROLOGY...





000
FXUS61 KLWX 042350
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
650 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /THROUGH THURSDAY/...
...UPDATE...
A DENSE FOG ADVISORY HAS BEEN ISSUED FOR PORTIONS OF
THE WASHINGTON DC METRO AREA...ALL OF THE BALTIMORE METRO AREA AND
WESTWARD TO FREDERICK COUNTY MD. VISIBILITIES HAVE DROPPED TO ONE
QUARTER MILE AT NUMEROUS LOCATIONS IN THIS AREA...AND WILL
PROBABLY PERSIST UNTIL A COLD FRONT MOVES THROUGH THIS EVENING AND
NW WINDS DEVELOP.

...PREVIOUS DISCUSSION...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO
HV COMBINED INTO ONE... STRETCHING FM INVOF MRB- BNA- SHV. GIVEN
THE LACK OF FORCING...PCPN HAS BEEN SLOW IN ADVCG EWD TDA.
HWVR...LTST RADAR COMPOSITE DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA.
ANTICIPATE PCPN TO OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.

&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.

&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR DCZ001.
MD...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR MDZ003-501-
     502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR MDZ004>006-
     011-013-014-503>508.
VA...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR VAZ028-503-
     504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
     DENSE FOG ADVISORY UNTIL 10 PM EST THIS EVENING FOR VAZ053-054.
WV...WINTER STORM WARNING UNTIL 7 PM EST THURSDAY FOR WVZ050>052-
     055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS/KCS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...MSE/HTS
MARINE...MSE/HTS
HYDROLOGY...





000
FXUS61 KLWX 041958
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
258 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.
&&

.NEAR TERM /THROUGH TONIGHT/...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO HV COMBINED INTO ONE...
STRETCHING FM INVOF MRB-BNA-SHV. GIVEN THE LACK OF FORCING...PCPN
HAS BEEN SLOW IN ADVCG EWD TDA. HWVR...LTST RADAR COMPOSITE
DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA. ANTICIPATE PCPN TO
OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZEABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.
&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.
&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.
&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...HTS/MSE
MARINE...HTS/MSE
HYDROLOGY...JE




000
FXUS61 KLWX 041958
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
258 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.
&&

.NEAR TERM /THROUGH TONIGHT/...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO HV COMBINED INTO ONE...
STRETCHING FM INVOF MRB-BNA-SHV. GIVEN THE LACK OF FORCING...PCPN
HAS BEEN SLOW IN ADVCG EWD TDA. HWVR...LTST RADAR COMPOSITE
DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA. ANTICIPATE PCPN TO
OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZEABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.
&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.
&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.
&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...HTS/MSE
MARINE...HTS/MSE
HYDROLOGY...JE





000
FXUS61 KLWX 041958
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
258 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.
&&

.NEAR TERM /THROUGH TONIGHT/...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO HV COMBINED INTO ONE...
STRETCHING FM INVOF MRB-BNA-SHV. GIVEN THE LACK OF FORCING...PCPN
HAS BEEN SLOW IN ADVCG EWD TDA. HWVR...LTST RADAR COMPOSITE
DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA. ANTICIPATE PCPN TO
OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZEABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.
&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.
&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.
&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...HTS/MSE
MARINE...HTS/MSE
HYDROLOGY...JE





000
FXUS61 KLWX 041958
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
258 PM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. ASSOCIATED
PRECIPITATION WILL CONTINUE INTO THURSDAY AS SNOWFALL DUE TO THE
PASSAGE OF A CORE OF STRONGER WINDS IN THE JET STREAM. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.
&&

.NEAR TERM /THROUGH TONIGHT/...
THE TWO SFC BNDRYS OF THIS MRNG SEEM TO HV COMBINED INTO ONE...
STRETCHING FM INVOF MRB-BNA-SHV. GIVEN THE LACK OF FORCING...PCPN
HAS BEEN SLOW IN ADVCG EWD TDA. HWVR...LTST RADAR COMPOSITE
DEPICTS PCPN /ALL RAIN/ ACRS NRN CWFA. ANTICIPATE PCPN TO
OVERSPREAD THE REST OF THE AREA TAFTN.

DUE TO IN-SITU WEDGE...ITS BEEN TOUGH TO GET TEMPS OUT OF THE 40S
TDA. W99 HAS BEEN THE ONE EXCEPTION. THE ARRIVAL OF RAFL WL PUT AN
END TO ANY ADDTL TEMP RISE.

LTST GDNC CYCLE REVEALS A DECENT AMT OF CONSISTENCY SYNOPTICALLY.
HV SUBTLE THERMAL TIMING CHGS...WHICH IS XPCTD. BUT FROM AN
ENSEMBLE VIEWPOINT...GDNC CONFIRMING THAT GOING FCST ON TRACK...
AND HV NOT ADJUSTED MUCH. THE END RESULT IS TO COVERT THE SRN
FRINGE OF THE CWFA FROM A WATCH TO A LOW END WARNING. PTYPES IN
THIS AREA A BIT OF A CONCERN.

AS ALREADY MENTIONED...IT WL BE RAINING AT THE BGNG OF THE TNGT
PD. AS THE CDFNT WORKS SWD...COLDER AIR WL BE DRAINING SOUTH...
WHILE BAROCLINICITY AND THE UPR JET WL PROVIDE FORCING FOR CONTD
PCPN GENERATION. THE MSTR FEED WL COME FROM THE WRN GLFMEX AS
WELL AS THE PACIFIC. PWAT FM RNK 12Z RAOB WAS 250 PCT OF NORMAL.
CERTAINLY PLENTY OF MSTR IN PLAY.

AM KEEPING FCST CONSISTENT IN TRANSITIONING FROM RA TO SNW W/ A
SHORT PD OF PL IN BTWN. EXACT TIMING OF EACH STILL MAY NEED TO BE
ADJUSTED BY AN HR OR TWO EITHER WAY. BTTM LINE...BY SUNRISE XPCTG
ALL SNOW BY SUNRISE TMRW N OF SHD-DCA-NAK. HV A SNPL OR PLRA MIX
TO THE S.

&&

.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
WL TAKE THE TRANSITION TO SNW FM SHD-DCA-NAK AT THE START OF PD
SWD TO EDGE OF CWFA BY MID MRNG. UVV ALIGNS VERY WELL W/ SNOW
GROWTH REGION A CPL HRS BHD TRANSITION TO SNOW. SCREAMING MESSAGE
HERE...EVEN THOUGH IT MAY NOT LOOK BAD UPON WAKING UP...XPCT CONDS
TO GET WORSE DURING THE DAY. WL HV THE RRQ OF 160 KT UPR JET...
SNOW GROWTH REGION...AND FGEN FORCING ALL CROSSING CWFA DURING THE
MIDDAY HRS-- A LTL ERLR TO THE N AND LATER CENTRAL VA/SRN MD. THAT
IS WHEN THE BULK OF THE FCSTD SNOW WL ACCUMULATE. SMALL TWEAKS
HERE CUD HV BIG IMPACTS ON STORM TTLS. DID NOT MASSAGE FCST AS ANY
CHGS WUD BE MINOR WRT PSBL FCST ERRORS.

GDNC HOLDS ONTO PL A BIT LONGER IN SRN MD. ULTIMATELY THAT WL
IMPACT SNW TTLS...POTENTIALLY BY CUTTING THEM DOWN. CURRENT FCST
REPRESENTS BEST ASSESSMENT AT THIS TIME. RECOGNIZE THAT THIS
ASPECT OF THE FCST SUBJECT TO MORE SIZEABLE ERRORS THAN THE REST
OF THE CWFA.

BACK EDGE OF SNOW SHUD MV SE BY LATE DAY. ADDED A CHC SNW ELY
EVENING TO ACCNT FOR LINGERING ACTIVITY/TIMING DIFFS. AFTER THAT
ITLL ALL BE A TEMP FCST. TEMPS WL ALREADY BE DROPPING DUE TO CAA
DURING THE DAY THU...AND THAT DROP WL ONLY BE ENHANCED AT NGT W/
THE LOSS OF DAYLIGHT. USED MOS MEAN W/ A SMALL CONTRIBUTION FM
PRVS FCST FOR MIN-T. WL HV PLENTY OF LOWS INTHE SINGLE DIGITS AND
TEENS...AND WL NEED TO BE CONSIDERING SUBZERO WIND CHILL FACTOR
BY DAWN FRI MRNG.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
NOT MUCH HAS CHANGED FROM PREVIOUS FORECASTS FOR THE EXTENDED
PERIOD. AFTER AN EXTREMELY COLD START FRIDAY MORNING...TEMPERATURES
WILL BE VERY SLOW TO RISE THROUGH FRIDAY...WITH WEAK CAA AND
RESIDUAL SNOW PACK. VERY WEAK SOUTHERLY FLOW COMMENCES LATE FRIDAY
NIGHT...BUT THE SNOWPACK AND STRONG RADIATIONAL COOLING WILL KEEP
NIGHTTIME LOWS WELL BELOW NORMAL.

WARMING BEGINS SATURDAY...AND DESPITE THE PASSAGE OF A WEAK COLD
FRONT SATURDAY NIGHT...TEMPERATURES WILL SLOWLY WARM THROUGH THE
REST OF THE WEEKEND AND THROUGH THE EARLY/MIDDLE PART OF NEXT WEEK.
FOR NOW KEPT THE EXTENDED POP FREE DUE TO LARGE MODEL DIVERGENCE.
&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
STILL HV VFR CIGS ACRS THE TERMINALS ATTM. RESTRICTIONS COMING FM
VSBYS. THAT SHUD CHG AS RA OVERSPREADS TERMINALS BY DARK. HV CONDS
DROPPING TO IFR AFTR MIDNIGHT WHEN RA MIXES WITH PL AND THEN SNOW.
ALL TERMINALS WL HV JUST SNW BEFORE THE START OF THE MRNG PUSH
TMRW. THE LOWEST CONDS WL OCCUR DURING THE MIDDAY OF THE DAY WHEN
THE SNOW WL BE HEAVIEST.

CONDS WL BE IMPRVG MID-LT AFTN. VFR PSBL BY THU EVNG...AND LKLY BY
THU NGT.

EXPECT VFR CONDITIONS FRIDAY AS WINDS CALM AND CEILINGS RISE. VFR
CONDITIONS EXPECTED THROUGH THE REST OF THE WEEKEND.
&&

.MARINE...
ASIDE FM TPLM2...ALL WNDS AOB 10 KT ATTM. STILL HV SLY FLOW. THE
TRANSITION TO NNWLY FLOW WL OCCUR THIS EVNG AS CDFNT CROSSES
WATERS. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOR THE LATTER
PART OF THE NGT INTO THU NGT.

SCA LIKELY EXTENDS INTO FRIDAY BEFORE HIGH PRESSURE BUILDS OVERHEAD.
DO NOT ANTICIPATE MARINE CONCERNS THROUGH THE REMAINDER OF THE
WEEKEND.
&&

.HYDROLOGY...
RAIN IS ONGOING ACROSS THE NORTHERN HALF OF THE FORECAST AREA...AND
WILL SPREAD SOUTHWARD THIS EVENING. PRIOR TO THE CHANGEOVER TO
WINTRY PRECIPITATION...ADDITIONAL RAIN WILL BE BETWEEN 1/4 AND 1
INCH. WITH NO DIRECT SUNSHINE...SNOWMELT HAS BEEN SLOW BUT STEADY.

THE ONLY STREAM REACTIONS THROUGH MID AFTERNOON HAVE BEEN IN THE
NORTH BRANCH POTOMAC...NORTH FORK SOUTH BRANCH POTOMAC...AND WILLS
CREEK BASINS. THE NORTH BRANCH POTOMAC AT KITZMILLER HAS RISEN ABOVE
ACTION STAGE AND WILL BE MONITORED FOR POSSIBLE FLOODING ALL NIGHT.
OTHER STREAMS IN THOSE BASINS ARE SHOWING SOME ICE EFFECTS AND HAVE
RISEN QUITE A BIT...BUT ARE STILL WELL BELOW BANKFULL.

POOR DRAINAGE FLOODING AND PONDING ARE LIKELY WHERE NORMAL DRAINAGE
PATTERNS ARE DISTURBED BY SNOWPACK AND/OR ICE. HOWEVER...LOCALIZED
MINOR OUT-OF-BANK FLOODING OF STREAMS CANNOT BE RULED OUT...
ESPECIALLY IN NRN MD AND THE HIGHLANDS.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WARNING FROM 3 AM TO 10 PM EST THURSDAY FOR
     VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...HTS
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...HTS/MSE
MARINE...HTS/MSE
HYDROLOGY...JE




000
FXUS61 KLWX 041414
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
914 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY AND TONIGHT. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC ANALY DEPICTS A CPL OF BNDRYS IN THE PRES FIELDS THIS MRNG.
THE FIRST ONE RUNS FM BALT/DC TO CHO...THEN HEADS WSWWD ACRS TN TO
ARKANSAS. THIS BNDRY HAS LLVL THERMAL SUPPORT. THE LATTER
STRETCHES ACRS NW PA AND NRN OH. THE UPR JET DYNAMICS LIE HERE.

REGIONAL RADAR THIS MORNING ALREADY SHOWS THE DYNAMICAL...HIGH
MOISTURE CONTENT FRONTAL ZONE SAGGING OUR WAY. THERES PLENTY OF
MSTR W OF THE APLCNS ATTM...AND WL NEED TO MONITOR HOW MUCH OF
THIS CAN HOP THE MTNS.

IN SHORT...TODAY WILL FEATURE OCCASIONAL ROUNDS OF RAIN...MOST
PREVALENT ACROSS THE NORTHERN HALF OF THE CWA. WILL KEEP AN EYE ON
RAIN TOTALS...ESPECIALLY IN THE HIGHLANDS WHERE TEMPERATURES HAVE
WARMED AND THE HEAVIEST RAIN WILL FALL.

IN-SITU WEDGE WILL HOLD TEMPERATURES IN THE 40S ACROSS MUCH OF
AREA. GOING FCST HAS GOOD LAMP SUPPORT. NO TEMP CHGS ANTICIPATED
ATTM.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
SYNOPTIC PTTN FM LTST GDNC RUNS SEEM TO BE SIMLR TO THOSE YDA.
ONLY ADJUSTMENTS BASED ON SUBTLE THERMAL DIFFS. KEY FACTORS ARE A
SLGTLY SLOWER TIMING AND HIER QPF VALUE. BASED ON THAT...THE
MIDNIGHT SHIFT TRANSITIONED THE WINTER STORM WATCH TO A WARNING
FOR MOST OF THE CWFA. THE SRN FRINGE OF THE AREA IS THE EXCEPTION
DUE TO A LONGER PD OF TIME IN RAIN AND SLEET.

THE BNDRYS /MDL GDNC DOESNT DO A GOOD JOB DISTINCTLY RESOLVING
BOTH OF THEM/ WL CONT SLIDE SWD TNGT...ALLOWING THE ARCTIC AMS FM
THE GRTLKS TO OVERSPREAD THE AREA. MEANWHILE...A SATD MSTR STREAM
WL CONT SPREADING ENEWD...OVERRIDING THE COLDER AMS. DYNAMICS WL
BE FUELED BY THE RRQ OF THE UPR JETMAX AS WELL AS LLVL
BAROCLINICITY. ALL OF THIS SUPPORTS A TRANSITION FM RA TO PL AND
THEN TO SNW.

FCST BASED ON AN ENSEMBLE APPROACH...WHICH SUGGESTS A PD OF FVRBL
DENDRITIC GROWTH AS WELL AS FGEN FORCING IN A CORRIDOR BHD THE
SN/PL TRANSITION. THATS THE JUSTIFICATION FOR RAISING SNW TTLS
ACRS N-CENTRAL MD/ERN WVA/NRN SHEN VLY...AS THESE FEATURES WL
COINCIDE W/ SNWFL THE LONGEST. SUFFICIENT COLD AIR TO SUPPORT SNW
WL REACH THE SRN EDGE OF THE CWFA BY AFTN. WL BE MAKING THE
WRNG/ADVY DECISION FOR THE SRNMOST 5 CNTYS ONCE 12Z GDNC ARRIVES.

TAIL END OF SNOW THURSDAY EVENING IS A FEW MORE TENTHS INCH
FOR SRN MD BEFORE TAPERING OFF. SKIES CLEAR LATE IN THE NIGHT WITH
HIGH PRESSURE QUICKLY BUILDING OVERHEAD. GUSTY NW FLOW (AROUND 20
MPH) FOLLOWS THE COLD FRONT. WIND CHILLS REACH ZERO ACROSS THE CWA
WITH WIND CHILL ADVISORIES LIKELY OVER PORTIONS WEST OF INTERSTATE
95. AREAS WEST OF INTERSTATE 95 SHOULD DECOUPLE BEFORE SUNRISE WHICH
WILL ALLOW FOR SINGLE DIGIT MIN TEMPS...TEENS EAST.

SUNNY FRIDAY UNDER HIGH PRESSURE WITH TRANQUIL CONDITIONS AND MAX
TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH SNOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ONE OF THE LONGEST CONSISTENT WARMING PATTERNS IN AWHILE
SATURDAY THROUGH MIDDLE OF NEXT WEEK AS VERY BROAD EAST COAST TROUGH
SLOWLY DEAMPLIFIES. WELCOME CALM WEATHER PATTERN AS THE SUBTROPICAL
RIDGE BUILDS INTO THE SERN CONUS. A FEW DEGREES WARMER ON MAX TEMPS
EACH DAY IN SWLY FLOW...LOW 40S FOR SATURDAY...50S BY
MONDAY...60S...MAINLY SOUTH OF DC MONDAY THROUGH WEDNESDAY.
UNCERTAINTY DUE TO CLOUD COVER IN THE MIDDLE OF NEXT WEEK PREVENTED
A BOLDER FORECAST OF MID 60S SOUTH/MID 50S NORTH BY WEDNESDAY...AS
OF NOW IT IS AROUND 60F SOUTH AND AROUND 50 NORTH.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS PREVALENT ACRS THE TERMINALS ATTM...BUT W/ PATCHES OF
IFR. SOLID FLGT RESTRICTIONS WL ARRIVE FOR THE AFTN PUSH...W/
CONSISTENT AOB IFR COINCIENT W/ A TRANSITION TO SNW AFTR MIDNGT.
AOB IFR SHUD CONT THRU THE DAY THU.

CONDS QUICKLY IMPROVE TO VFR THURSDAY EVENING FROM NW TO SE
WITH NW GUSTS AROUND 20 KT. SINGLE DIGITS MIN TEMPS THAT NIGHT FOR
MOST OF THE AREA. HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH
VFR/TRANQUIL CONDS. SWLY FLOW AND MORE HIGH PRESSURE THEN THROUGH
THE WEEKEND.

&&

.MARINE...
ALL WNDS AOB 10 KT ATTM. A TRANSITION TO NNWLY FLOW WL OCCUR LATER
TDA OR TNGT. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOER THE
LATTER PART OF THE NGT INTO THU NGT.

SCA LIKELY TO EXTEND INTO FRIDAY BEFORE HIGH PRESSURE BUILDS
OVERHEAD. HIGH PRESSURE THEN THROUGH THE WEEKEND WITH SWLY FLOW
DEVELOPING FRIDAY NIGHT.

&&

.HYDROLOGY...
THERE HAS BEEN NOTEABLE SNOWMELT ACRS THE AREA THUS FAR. ADD IN
RAINFALL UP TO A HALF-INCH...AND RIVERS IN THE UPR PTMC BASIN HV
EXPERIENCED SGFNT W/IN BANK RISES. STILL DO NOT XPCT FLOODING...
BUT WL CONT TO MONITOR CLOSELY. AT THIS RATE...RAINFALL MAY REACH
1-2 INCHES.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP THIS EVENING OCCURS LATER THAN EXPECTED...
CONCERNS MAY BECOME HEIGHTENED. TRENDS HV BEEN SUGGESTING A LATER
CHANGEOVER. ALSO MANY OF OUR AREA STREAMS ARE COVERED WITH ICE OR
EVEN PARTIALLY FROZEN. THESE EFFECTS WILL HAVE TO BE MONITORED FOR
A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS/HTS
NEAR TERM...ADS/HTS
SHORT TERM...HTS/BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ
MARINE...HTS/BAJ
HYDROLOGY...HTS/JE





000
FXUS61 KLWX 041414
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
914 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TODAY AND TONIGHT. HIGH
PRESSURE BUILDS OVERHEAD FRIDAY...THEN PERSISTS THROUGH THE
WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC ANALY DEPICTS A CPL OF BNDRYS IN THE PRES FIELDS THIS MRNG.
THE FIRST ONE RUNS FM BALT/DC TO CHO...THEN HEADS WSWWD ACRS TN TO
ARKANSAS. THIS BNDRY HAS LLVL THERMAL SUPPORT. THE LATTER
STRETCHES ACRS NW PA AND NRN OH. THE UPR JET DYNAMICS LIE HERE.

REGIONAL RADAR THIS MORNING ALREADY SHOWS THE DYNAMICAL...HIGH
MOISTURE CONTENT FRONTAL ZONE SAGGING OUR WAY. THERES PLENTY OF
MSTR W OF THE APLCNS ATTM...AND WL NEED TO MONITOR HOW MUCH OF
THIS CAN HOP THE MTNS.

IN SHORT...TODAY WILL FEATURE OCCASIONAL ROUNDS OF RAIN...MOST
PREVALENT ACROSS THE NORTHERN HALF OF THE CWA. WILL KEEP AN EYE ON
RAIN TOTALS...ESPECIALLY IN THE HIGHLANDS WHERE TEMPERATURES HAVE
WARMED AND THE HEAVIEST RAIN WILL FALL.

IN-SITU WEDGE WILL HOLD TEMPERATURES IN THE 40S ACROSS MUCH OF
AREA. GOING FCST HAS GOOD LAMP SUPPORT. NO TEMP CHGS ANTICIPATED
ATTM.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
SYNOPTIC PTTN FM LTST GDNC RUNS SEEM TO BE SIMLR TO THOSE YDA.
ONLY ADJUSTMENTS BASED ON SUBTLE THERMAL DIFFS. KEY FACTORS ARE A
SLGTLY SLOWER TIMING AND HIER QPF VALUE. BASED ON THAT...THE
MIDNIGHT SHIFT TRANSITIONED THE WINTER STORM WATCH TO A WARNING
FOR MOST OF THE CWFA. THE SRN FRINGE OF THE AREA IS THE EXCEPTION
DUE TO A LONGER PD OF TIME IN RAIN AND SLEET.

THE BNDRYS /MDL GDNC DOESNT DO A GOOD JOB DISTINCTLY RESOLVING
BOTH OF THEM/ WL CONT SLIDE SWD TNGT...ALLOWING THE ARCTIC AMS FM
THE GRTLKS TO OVERSPREAD THE AREA. MEANWHILE...A SATD MSTR STREAM
WL CONT SPREADING ENEWD...OVERRIDING THE COLDER AMS. DYNAMICS WL
BE FUELED BY THE RRQ OF THE UPR JETMAX AS WELL AS LLVL
BAROCLINICITY. ALL OF THIS SUPPORTS A TRANSITION FM RA TO PL AND
THEN TO SNW.

FCST BASED ON AN ENSEMBLE APPROACH...WHICH SUGGESTS A PD OF FVRBL
DENDRITIC GROWTH AS WELL AS FGEN FORCING IN A CORRIDOR BHD THE
SN/PL TRANSITION. THATS THE JUSTIFICATION FOR RAISING SNW TTLS
ACRS N-CENTRAL MD/ERN WVA/NRN SHEN VLY...AS THESE FEATURES WL
COINCIDE W/ SNWFL THE LONGEST. SUFFICIENT COLD AIR TO SUPPORT SNW
WL REACH THE SRN EDGE OF THE CWFA BY AFTN. WL BE MAKING THE
WRNG/ADVY DECISION FOR THE SRNMOST 5 CNTYS ONCE 12Z GDNC ARRIVES.

TAIL END OF SNOW THURSDAY EVENING IS A FEW MORE TENTHS INCH
FOR SRN MD BEFORE TAPERING OFF. SKIES CLEAR LATE IN THE NIGHT WITH
HIGH PRESSURE QUICKLY BUILDING OVERHEAD. GUSTY NW FLOW (AROUND 20
MPH) FOLLOWS THE COLD FRONT. WIND CHILLS REACH ZERO ACROSS THE CWA
WITH WIND CHILL ADVISORIES LIKELY OVER PORTIONS WEST OF INTERSTATE
95. AREAS WEST OF INTERSTATE 95 SHOULD DECOUPLE BEFORE SUNRISE WHICH
WILL ALLOW FOR SINGLE DIGIT MIN TEMPS...TEENS EAST.

SUNNY FRIDAY UNDER HIGH PRESSURE WITH TRANQUIL CONDITIONS AND MAX
TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH SNOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ONE OF THE LONGEST CONSISTENT WARMING PATTERNS IN AWHILE
SATURDAY THROUGH MIDDLE OF NEXT WEEK AS VERY BROAD EAST COAST TROUGH
SLOWLY DEAMPLIFIES. WELCOME CALM WEATHER PATTERN AS THE SUBTROPICAL
RIDGE BUILDS INTO THE SERN CONUS. A FEW DEGREES WARMER ON MAX TEMPS
EACH DAY IN SWLY FLOW...LOW 40S FOR SATURDAY...50S BY
MONDAY...60S...MAINLY SOUTH OF DC MONDAY THROUGH WEDNESDAY.
UNCERTAINTY DUE TO CLOUD COVER IN THE MIDDLE OF NEXT WEEK PREVENTED
A BOLDER FORECAST OF MID 60S SOUTH/MID 50S NORTH BY WEDNESDAY...AS
OF NOW IT IS AROUND 60F SOUTH AND AROUND 50 NORTH.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDS PREVALENT ACRS THE TERMINALS ATTM...BUT W/ PATCHES OF
IFR. SOLID FLGT RESTRICTIONS WL ARRIVE FOR THE AFTN PUSH...W/
CONSISTENT AOB IFR COINCIENT W/ A TRANSITION TO SNW AFTR MIDNGT.
AOB IFR SHUD CONT THRU THE DAY THU.

CONDS QUICKLY IMPROVE TO VFR THURSDAY EVENING FROM NW TO SE
WITH NW GUSTS AROUND 20 KT. SINGLE DIGITS MIN TEMPS THAT NIGHT FOR
MOST OF THE AREA. HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH
VFR/TRANQUIL CONDS. SWLY FLOW AND MORE HIGH PRESSURE THEN THROUGH
THE WEEKEND.

&&

.MARINE...
ALL WNDS AOB 10 KT ATTM. A TRANSITION TO NNWLY FLOW WL OCCUR LATER
TDA OR TNGT. WNDS WL INCREASE THEREAFTR...W/ SCA CONDS FOER THE
LATTER PART OF THE NGT INTO THU NGT.

SCA LIKELY TO EXTEND INTO FRIDAY BEFORE HIGH PRESSURE BUILDS
OVERHEAD. HIGH PRESSURE THEN THROUGH THE WEEKEND WITH SWLY FLOW
DEVELOPING FRIDAY NIGHT.

&&

.HYDROLOGY...
THERE HAS BEEN NOTEABLE SNOWMELT ACRS THE AREA THUS FAR. ADD IN
RAINFALL UP TO A HALF-INCH...AND RIVERS IN THE UPR PTMC BASIN HV
EXPERIENCED SGFNT W/IN BANK RISES. STILL DO NOT XPCT FLOODING...
BUT WL CONT TO MONITOR CLOSELY. AT THIS RATE...RAINFALL MAY REACH
1-2 INCHES.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP THIS EVENING OCCURS LATER THAN EXPECTED...
CONCERNS MAY BECOME HEIGHTENED. TRENDS HV BEEN SUGGESTING A LATER
CHANGEOVER. ALSO MANY OF OUR AREA STREAMS ARE COVERED WITH ICE OR
EVEN PARTIALLY FROZEN. THESE EFFECTS WILL HAVE TO BE MONITORED FOR
A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR DCZ001.
MD...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ003-501-502.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR MDZ004>006-011-503>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR MDZ013-014-016-018.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ017.
VA...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ028-503-504.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR VAZ025>027-029>031-040-501-505>508.
     WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 9 PM EST
     THURSDAY FOR VAZ038-039-050>055-502.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ036-037-056-057.
WV...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ050>052-055-501>506.
     WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 PM EST
     THURSDAY FOR WVZ053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS/HTS
NEAR TERM...ADS/HTS
SHORT TERM...HTS/BAJ
LONG TERM...BAJ
AVIATION...HTS/BAJ
MARINE...HTS/BAJ
HYDROLOGY...HTS/JE




000
FXUS61 KLWX 040901
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
401 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT AND SLOWLY
CROSS THROUGH THURSDAY. HIGH PRESSURE BUILDS OVERHEAD
FRIDAY...THEN PERSISTS THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WINTER STORM WATCH TO BE UPGRADED TO WARNING YET LATE TONIGHT FOR
MOST OF THE CWA. A WATCH WILL BE LEFT FOR ANY AREAS (FAR SE) THAT
CONFIDENCE IS NOT YET HIGH ENOUGH TO WARN FOR.

REGIONAL RADAR THIS MORNING ALREADY SHOWS THE DYNAMICAL...HIGH
MOISTURE CONTENT FRONTAL ZONE SAGGING OUR WAY FROM THE NORTHERN OHIO
VALLEY. TEMPERATURES CONTINUE TO RISE THIS MORNING ON A SOUTHERLY
FLOW AND WILL BE ABLE TO LET THE SHORT FUSE FZRA ADVISORY EXPIRE.

IN SHORT...TODAY WILL FEATURE OCCASIONAL ROUNDS OF RAIN...MOST
PREVALENT ACROSS THE NORTHERN HALF OF THE CWA. WILL KEEP AN EYE ON
RAIN TOTALS...ESPECIALLY IN THE HIGHLANDS WHERE TEMPERATURES HAVE
WARMED AND THE HEAVIEST RAIN WILL FALL. SOME SMALL STREAM RISES MAY
OCCUR. SEE HYDRO SECTION BELOW. EXPECTING ALL RAIN THROUGH THE DAY.
IN-SITU WEDGE WILL HOLD TEMPERATURES IN THE 40S ACROSS MUCH OF
AREA...50S SOUTH AND IN HIGHER ELEVATIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ARCTIC HIGH PRESSURE WILL QUICKLY BUILD IN THURSDAY NIGHT. THERE MAY
BE A PERIOD OF UPSLOPE SNOW SHOWERS IN THE EVENING. NAM INDICATES
SNOW SHOWERS WILL BE POSSIBLE EAST OF THE MOUNTAINS AS WELL AS A
VORT MAX PASSES...BUT HAVE NOT INCLUDED THIS IN THE FORECAST NOW.
TEMPERATURES HAVE TRENDED COLDER...SINGLE DIGITS EXCEPT IN THE
METROS/NEAR THE BAY AND BELOW ZERO IN THE HIGHLANDS. IF GRADIENT
DOES NOT RELAX...WIND CHILL ADVISORIES MAY BE NEEDED IN THE
HIGHLANDS.

THE HIGH WILL SLIDE EAST ACROSS THE AREA THROUGH SATURDAY. FRIDAY
WILL STILL BE QUITE COLD BUT TEMPERATURES BEGIN TO MODERATE
SATURDAY. MOISTURE STARVED COLD FRONTS TRAILING LOW PRESSURE CENTERS
WELL TO THE NORTH WILL MAKE RUNS AT THE AREA SATURDAY NIGHT AND
AGAIN MONDAY. FOR NOW HAVE ONLY INCLUDED POPS IN THE UPSLOPE AREAS.
THERE ALSO WILL BE LITTLE EFFECT ON TEMPERATURES...WITH READINGS
SLIGHTLY BELOW NORMAL EXPECTED.

TAIL END OF SNOW THURSDAY EVENING IS A FEW MORE TENTHS INCH
FOR SRN MD BEFORE TAPERING OFF. SKIES CLEAR LATE IN THE NIGHT WITH
HIGH PRESSURE QUICKLY BUILDING OVERHEAD. GUSTY NW FLOW (AROUND 20
MPH) FOLLOWS THE COLD FRONT. WIND CHILLS REACH ZERO ACROSS THE CWA
WITH WIND CHILL ADVISORIES LIKELY OVER PORTIONS WEST OF INTERSTATE
95. AREAS WEST OF INTERSTATE 95 SHOULD DECOUPLE BEFORE SUNRISE WHICH
WILL ALLOW FOR SINGLE DIGIT MIN TEMPS...TWEENS EAST.

SUNNY FRIDAY UNDER HIGH PRESSURE WITH TRANQUIL CONDITIONS AND MAX
TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH SNOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ONE OF THE LONGEST CONSISTENT WARMING PATTERNS IN AWHILE
SATURDAY THROUGH MIDDLE OF NEXT WEEK AS VERY BROAD EAST COAST TROUGH
SLOWLY DEAMPLIFIES. WELCOME CALM WEATHER PATTERN AS THE SUBTROPICAL
RIDGE BUILDS INTO THE SERN CONUS. A FEW DEGREES WARMER ON MAX TEMPS
EACH DAY IN SWLY FLOW...LOW 40S FOR SATURDAY...50S BY
MONDAY...60S...MAINLY SOUTH OF DC MONDAY THROUGH WEDNESDAY.
UNCERTAINTY DUE TO CLOUD COVER IN THE MIDDLE OF NEXT WEEK PREVENTED
A BOLDER FORECAST OF MID 60S SOUTH/MID 50S NORTH BY WEDNESDAY...AS
OF NOW IT IS AROUND 60F SOUTH AND AROUND 50 NORTH.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
RAIN IS FORECAST TO CHANGE TO SNOW THURSDAY NIGHT. VSBY/CIG
REDUCTIONS WILL CONTINUE AND MAY DROP TO LIFR IF MODERATE/HEAVY SNOW
DEVELOPS. THE SNOW WILL END ON THURSDAY. NO AVIATION HAZARDS
EXPECTED THEREAFTER.

CONDS QUICKLY IMPROVE TO VFR THURSDAY EVENING FROM NW TO SE
WITH NW GUSTS AROUND 20 KT. SINGLE DIGITS MIN TEMPS THAT NIGHT FOR
MOST OF THE AREA. HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH
VFR/TRANQUIL CONDS. SWLY FLOW AND MORE HIGH PRESSURE THEN THROUGH
THE WEEKEND.

&&

.MARINE...
A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY NIGHT. RAIN WILL
CHANGE TO SNOW BY THURSDAY MORNING. SCA CONDITIONS ARE POSSIBLE FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT BEHIND THE FRONT. WINDS
WILL SUBSIDE THEREAFTER UNDER HIGH PRESSURE.

SCA THROUGH THURSDAY NIGHT FOR NWLY GUSTS BEHIND COLD
FRONT...LIKELY TO EXTEND INTO FRIDAY BEFORE HIGH PRESSURE BUILDS
OVERHEAD. HIGH PRESSURE THEN THROUGH THE WEEKEND WITH SWLY FLOW
DEVELOPING FRIDAY NIGHT.

&&

.HYDROLOGY...
THROUGH THIS AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE
RAPPAHANNOCK AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE
SNOWPACK IS CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF
INCH OF WATER IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH
AND A HALF IN THE SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES
NOT ALL OF THIS SNOW WATER WILL BE RELEASED...ESPECIALLY GIVEN A
TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR DCZ001.
MD...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ016>018.
     FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     MDZ006-507-508.
VA...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...ADS
SHORT TERM...BAJ/ADS
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...LWX




000
FXUS61 KLWX 040901
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
401 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT AND SLOWLY
CROSS THROUGH THURSDAY. HIGH PRESSURE BUILDS OVERHEAD
FRIDAY...THEN PERSISTS THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WINTER STORM WATCH TO BE UPGRADED TO WARNING YET LATE TONIGHT FOR
MOST OF THE CWA. A WATCH WILL BE LEFT FOR ANY AREAS (FAR SE) THAT
CONFIDENCE IS NOT YET HIGH ENOUGH TO WARN FOR.

REGIONAL RADAR THIS MORNING ALREADY SHOWS THE DYNAMICAL...HIGH
MOISTURE CONTENT FRONTAL ZONE SAGGING OUR WAY FROM THE NORTHERN OHIO
VALLEY. TEMPERATURES CONTINUE TO RISE THIS MORNING ON A SOUTHERLY
FLOW AND WILL BE ABLE TO LET THE SHORT FUSE FZRA ADVISORY EXPIRE.

IN SHORT...TODAY WILL FEATURE OCCASIONAL ROUNDS OF RAIN...MOST
PREVALENT ACROSS THE NORTHERN HALF OF THE CWA. WILL KEEP AN EYE ON
RAIN TOTALS...ESPECIALLY IN THE HIGHLANDS WHERE TEMPERATURES HAVE
WARMED AND THE HEAVIEST RAIN WILL FALL. SOME SMALL STREAM RISES MAY
OCCUR. SEE HYDRO SECTION BELOW. EXPECTING ALL RAIN THROUGH THE DAY.
IN-SITU WEDGE WILL HOLD TEMPERATURES IN THE 40S ACROSS MUCH OF
AREA...50S SOUTH AND IN HIGHER ELEVATIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/...
ARCTIC HIGH PRESSURE WILL QUICKLY BUILD IN THURSDAY NIGHT. THERE MAY
BE A PERIOD OF UPSLOPE SNOW SHOWERS IN THE EVENING. NAM INDICATES
SNOW SHOWERS WILL BE POSSIBLE EAST OF THE MOUNTAINS AS WELL AS A
VORT MAX PASSES...BUT HAVE NOT INCLUDED THIS IN THE FORECAST NOW.
TEMPERATURES HAVE TRENDED COLDER...SINGLE DIGITS EXCEPT IN THE
METROS/NEAR THE BAY AND BELOW ZERO IN THE HIGHLANDS. IF GRADIENT
DOES NOT RELAX...WIND CHILL ADVISORIES MAY BE NEEDED IN THE
HIGHLANDS.

THE HIGH WILL SLIDE EAST ACROSS THE AREA THROUGH SATURDAY. FRIDAY
WILL STILL BE QUITE COLD BUT TEMPERATURES BEGIN TO MODERATE
SATURDAY. MOISTURE STARVED COLD FRONTS TRAILING LOW PRESSURE CENTERS
WELL TO THE NORTH WILL MAKE RUNS AT THE AREA SATURDAY NIGHT AND
AGAIN MONDAY. FOR NOW HAVE ONLY INCLUDED POPS IN THE UPSLOPE AREAS.
THERE ALSO WILL BE LITTLE EFFECT ON TEMPERATURES...WITH READINGS
SLIGHTLY BELOW NORMAL EXPECTED.

TAIL END OF SNOW THURSDAY EVENING IS A FEW MORE TENTHS INCH
FOR SRN MD BEFORE TAPERING OFF. SKIES CLEAR LATE IN THE NIGHT WITH
HIGH PRESSURE QUICKLY BUILDING OVERHEAD. GUSTY NW FLOW (AROUND 20
MPH) FOLLOWS THE COLD FRONT. WIND CHILLS REACH ZERO ACROSS THE CWA
WITH WIND CHILL ADVISORIES LIKELY OVER PORTIONS WEST OF INTERSTATE
95. AREAS WEST OF INTERSTATE 95 SHOULD DECOUPLE BEFORE SUNRISE WHICH
WILL ALLOW FOR SINGLE DIGIT MIN TEMPS...TWEENS EAST.

SUNNY FRIDAY UNDER HIGH PRESSURE WITH TRANQUIL CONDITIONS AND MAX
TEMPS MID TO UPR 20S DUE TO LITTLE MIXING AND FRESH SNOW.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ONE OF THE LONGEST CONSISTENT WARMING PATTERNS IN AWHILE
SATURDAY THROUGH MIDDLE OF NEXT WEEK AS VERY BROAD EAST COAST TROUGH
SLOWLY DEAMPLIFIES. WELCOME CALM WEATHER PATTERN AS THE SUBTROPICAL
RIDGE BUILDS INTO THE SERN CONUS. A FEW DEGREES WARMER ON MAX TEMPS
EACH DAY IN SWLY FLOW...LOW 40S FOR SATURDAY...50S BY
MONDAY...60S...MAINLY SOUTH OF DC MONDAY THROUGH WEDNESDAY.
UNCERTAINTY DUE TO CLOUD COVER IN THE MIDDLE OF NEXT WEEK PREVENTED
A BOLDER FORECAST OF MID 60S SOUTH/MID 50S NORTH BY WEDNESDAY...AS
OF NOW IT IS AROUND 60F SOUTH AND AROUND 50 NORTH.

&&

.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
RAIN IS FORECAST TO CHANGE TO SNOW THURSDAY NIGHT. VSBY/CIG
REDUCTIONS WILL CONTINUE AND MAY DROP TO LIFR IF MODERATE/HEAVY SNOW
DEVELOPS. THE SNOW WILL END ON THURSDAY. NO AVIATION HAZARDS
EXPECTED THEREAFTER.

CONDS QUICKLY IMPROVE TO VFR THURSDAY EVENING FROM NW TO SE
WITH NW GUSTS AROUND 20 KT. SINGLE DIGITS MIN TEMPS THAT NIGHT FOR
MOST OF THE AREA. HIGH PRESSURE BUILDS OVERHEAD FRIDAY WITH
VFR/TRANQUIL CONDS. SWLY FLOW AND MORE HIGH PRESSURE THEN THROUGH
THE WEEKEND.

&&

.MARINE...
A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY NIGHT. RAIN WILL
CHANGE TO SNOW BY THURSDAY MORNING. SCA CONDITIONS ARE POSSIBLE FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT BEHIND THE FRONT. WINDS
WILL SUBSIDE THEREAFTER UNDER HIGH PRESSURE.

SCA THROUGH THURSDAY NIGHT FOR NWLY GUSTS BEHIND COLD
FRONT...LIKELY TO EXTEND INTO FRIDAY BEFORE HIGH PRESSURE BUILDS
OVERHEAD. HIGH PRESSURE THEN THROUGH THE WEEKEND WITH SWLY FLOW
DEVELOPING FRIDAY NIGHT.

&&

.HYDROLOGY...
THROUGH THIS AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE
RAPPAHANNOCK AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE
SNOWPACK IS CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF
INCH OF WATER IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH
AND A HALF IN THE SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES
NOT ALL OF THIS SNOW WATER WILL BE RELEASED...ESPECIALLY GIVEN A
TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR DCZ001.
MD...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ016>018.
     FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     MDZ006-507-508.
VA...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...ADS
SHORT TERM...BAJ/ADS
LONG TERM...BAJ
AVIATION...BAJ/ADS
MARINE...BAJ/ADS
HYDROLOGY...LWX





000
FXUS61 KLWX 040715
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
215 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
HAD TO ISSUE A SHORT FUSE FREEZING RAIN ADVISORY FOR NORTHERN
BALTIMORE AND HARFORD COUNTIES AS LIGHT RAIN IS MOVING THROUGH
WITH MULTIPLE MESONETS AT 31-32 DEGREES. TRACE AMOUNTS OF ICE ON
COLD SURFACES.

PREVIOUS...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERESTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS
THE NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE
ACRS THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR DCZ001.
MD...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ016>018.
     FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     MDZ006-507-508.
VA...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$

UPDATE...ADS
PREVIOUS...WOODY!/KRW/HTS/MSE





000
FXUS61 KLWX 040715
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
215 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
HAD TO ISSUE A SHORT FUSE FREEZING RAIN ADVISORY FOR NORTHERN
BALTIMORE AND HARFORD COUNTIES AS LIGHT RAIN IS MOVING THROUGH
WITH MULTIPLE MESONETS AT 31-32 DEGREES. TRACE AMOUNTS OF ICE ON
COLD SURFACES.

PREVIOUS...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERESTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS
THE NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE
ACRS THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR DCZ001.
MD...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ016>018.
     FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     MDZ006-507-508.
VA...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$

UPDATE...ADS
PREVIOUS...WOODY!/KRW/HTS/MSE




000
FXUS61 KLWX 040715
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
215 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
HAD TO ISSUE A SHORT FUSE FREEZING RAIN ADVISORY FOR NORTHERN
BALTIMORE AND HARFORD COUNTIES AS LIGHT RAIN IS MOVING THROUGH
WITH MULTIPLE MESONETS AT 31-32 DEGREES. TRACE AMOUNTS OF ICE ON
COLD SURFACES.

PREVIOUS...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERESTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS
THE NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE
ACRS THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR DCZ001.
MD...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ016>018.
     FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     MDZ006-507-508.
VA...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$

UPDATE...ADS
PREVIOUS...WOODY!/KRW/HTS/MSE





000
FXUS61 KLWX 040715
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
215 AM EST WED MAR 4 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH TODAY/...
HAD TO ISSUE A SHORT FUSE FREEZING RAIN ADVISORY FOR NORTHERN
BALTIMORE AND HARFORD COUNTIES AS LIGHT RAIN IS MOVING THROUGH
WITH MULTIPLE MESONETS AT 31-32 DEGREES. TRACE AMOUNTS OF ICE ON
COLD SURFACES.

PREVIOUS...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERESTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS
THE NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE
ACRS THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR DCZ001.
MD...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR MDZ016>018.
     FREEZING RAIN ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
     MDZ006-507-508.
VA...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE TONIGHT THROUGH THURSDAY EVENING
     FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM THIS EVENING THROUGH THURSDAY EVENING
     FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM THURSDAY TO 6 AM EST FRIDAY FOR
     ANZ530>543.

&&

$$

UPDATE...ADS
PREVIOUS...WOODY!/KRW/HTS/MSE




000
FXUS61 KLWX 040256
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
956 PM EST TUE MAR 3 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

HV DROPPED THE RMNDR OF THE WINT WX ADVSRY. NOW...ON TO THE NEXT
SYSTEM...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE





000
FXUS61 KLWX 040256
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
956 PM EST TUE MAR 3 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

HV DROPPED THE RMNDR OF THE WINT WX ADVSRY. NOW...ON TO THE NEXT
SYSTEM...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE




000
FXUS61 KLWX 040256
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
956 PM EST TUE MAR 3 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

HV DROPPED THE RMNDR OF THE WINT WX ADVSRY. NOW...ON TO THE NEXT
SYSTEM...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE





000
FXUS61 KLWX 040256
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
956 PM EST TUE MAR 3 2015

.SYNOPSIS...
A COLD FRONT WILL MOVE INTO THE REGION WEDNESDAY NIGHT FOLLOWED
BY HIGH PRESSURE FOR THURSDAY NIGHT LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

HV DROPPED THE RMNDR OF THE WINT WX ADVSRY. NOW...ON TO THE NEXT
SYSTEM...

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO RAIN WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE




000
FXUS61 KLWX 040207
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
907 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

RMVD THE WINT WX ADVSRY DC/NRN VA WHERE TEMPS HV WARMED ABV FRZG
AND PCPN HAS ENDED. WL LV THE REMAINDER OF THE ADVSRY UP UNTIL 10
PM.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...
AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1


&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-501>508.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE




000
FXUS61 KLWX 040051
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
751 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

MUCH OF THE AREA CURRENTLY IN THE WINT WX ADVSRY...NRN 1/2 OF
CWA...IS PCPN FREE. IN DC/S OF PTMC TEMPS ARE SLTLY ABV FRZG W/
SRLY WINDS. WE MAY DROP SOME THE ADVSRY WHICH IS IN EFFECT UNTIL
10 PM ERLY.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...

SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...

AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-501>508.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE




000
FXUS61 KLWX 040051
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
751 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

MUCH OF THE AREA CURRENTLY IN THE WINT WX ADVSRY...NRN 1/2 OF
CWA...IS PCPN FREE. IN DC/S OF PTMC TEMPS ARE SLTLY ABV FRZG W/
SRLY WINDS. WE MAY DROP SOME THE ADVSRY WHICH IS IN EFFECT UNTIL
10 PM ERLY.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...

SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...

AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-501>508.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE





000
FXUS61 KLWX 040051
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
751 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

MUCH OF THE AREA CURRENTLY IN THE WINT WX ADVSRY...NRN 1/2 OF
CWA...IS PCPN FREE. IN DC/S OF PTMC TEMPS ARE SLTLY ABV FRZG W/
SRLY WINDS. WE MAY DROP SOME THE ADVSRY WHICH IS IN EFFECT UNTIL
10 PM ERLY.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...

SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...

AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-501>508.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE




000
FXUS61 KLWX 040051
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
751 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

MUCH OF THE AREA CURRENTLY IN THE WINT WX ADVSRY...NRN 1/2 OF
CWA...IS PCPN FREE. IN DC/S OF PTMC TEMPS ARE SLTLY ABV FRZG W/
SRLY WINDS. WE MAY DROP SOME THE ADVSRY WHICH IS IN EFFECT UNTIL
10 PM ERLY.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH
NORTH INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT
PREVIOUS GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN
CLOUD COVER AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY
TOP OUT IN THE 40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO
MIDDLE 50S CENTRAL VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL
DAY WEDNESDAY. PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS
THROUGH 00Z THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMALOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...

SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.CLIMATE...

AS EVERYONE CAN ATTEST THIS WAS ONE OF THE COLDEST FEBS ON
RECORD. W/ THE DC CHERRY BLOSSOM FESTIVAL PLANNED FOR 3/28-4/12 I
TOOK A LOOK AT PAST COLD FEBS AND WHEN PEAK BLOOM OCCURRED. GOING
BACK TO 1921...IT APPEARS THAT 2015 (AVG TEMP 30.3 AT DCA) HAD THE
4TH COLDEST FEB FOR THE PD.

THE FIVE COLDEST....AND THE PEAK BLOSSOM DATES (FM NPS.GOV WEB
SITE):

YR   FEB AVG TEMP    MAR AVG TEMP   PEAK BLOOM DATE

1934     24.6            41.2       4/15
1979     28.4            51.5       4/2
1936     29.6            50.3       4/7
2015     30.3            ??         ??
2007     30.9            47.7       4/1

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-501>508.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE





000
FXUS61 KLWX 032324
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
624 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AT 6 PM RCVD REPORT OF 1/16 INCH OF FZRA IN WRN ALLEGANY CO SO
ADDED THEM TO THE ADVSRY.

FIRST BATCH OF FREEZING RAIN MIXED WITH A LITTLE SLEET WILL PUSH
OUT OF THE BALTIMORE METRO AREA AND BE REPLACED WITH INTERMITTENT
FREEZING DRIZZLE/LIGHT FREEZING RAIN THIS EVENING. WARMER AIR HAS
BEEN SLOW TO PUSH NORTH AS WE HAVE SEEN MUCH OF THIS WINTER. THE
VAST MAJORITY OF THE WARMING HAS OCCURRED OVER WESTERN AND
SOUTHERN PORTIONS OF THE FORECAST AREA BUT COLD WEDGE HAS REMAINED
IN PLACE FURTHER NORTH.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE.

THERE IS STILL HIGH CONFIDENCE THAT WARM ADVECTION WILL WIN OUT AND
TEMPERATURES WILL GRADUALLY RISE ABOVE FREEZING LATER TONIGHT IN ALL
AREAS. AFTER MIDNIGHT...EXPECT LIGHT RAIN...SOME FOG AND MILDER
TEMPERATURES.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH NORTH
INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT PREVIOUS
GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN CLOUD COVER
AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY TOP OUT IN THE
40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO MIDDLE 50S CENTRAL
VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL DAY WEDNESDAY.
PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS THROUGH 00Z
THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMOLOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. LIGHT WINTRY PRECIPITATION WILL REMAIN POSSIBLE MAINLY
FROM KIAD NORTH TO KMRB...KBWI AND KMTN. FRZRA OR FZDZ WILL BE
MOST COMMON WITH THE MAJORITY OF ICING ISSUES AT KBWI AND KMTN.
ALL PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA WINDS NOT CURENTLY BEING XPRNCD ON THE WATERS. THIS WL BE
ALLOWED TO END AT 7 PM.

SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-501>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE




000
FXUS61 KLWX 032324
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
624 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
AT 6 PM RCVD REPORT OF 1/16 INCH OF FZRA IN WRN ALLEGANY CO SO
ADDED THEM TO THE ADVSRY.

FIRST BATCH OF FREEZING RAIN MIXED WITH A LITTLE SLEET WILL PUSH
OUT OF THE BALTIMORE METRO AREA AND BE REPLACED WITH INTERMITTENT
FREEZING DRIZZLE/LIGHT FREEZING RAIN THIS EVENING. WARMER AIR HAS
BEEN SLOW TO PUSH NORTH AS WE HAVE SEEN MUCH OF THIS WINTER. THE
VAST MAJORITY OF THE WARMING HAS OCCURRED OVER WESTERN AND
SOUTHERN PORTIONS OF THE FORECAST AREA BUT COLD WEDGE HAS REMAINED
IN PLACE FURTHER NORTH.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE.

THERE IS STILL HIGH CONFIDENCE THAT WARM ADVECTION WILL WIN OUT AND
TEMPERATURES WILL GRADUALLY RISE ABOVE FREEZING LATER TONIGHT IN ALL
AREAS. AFTER MIDNIGHT...EXPECT LIGHT RAIN...SOME FOG AND MILDER
TEMPERATURES.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH NORTH
INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT PREVIOUS
GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN CLOUD COVER
AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY TOP OUT IN THE
40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO MIDDLE 50S CENTRAL
VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL DAY WEDNESDAY.
PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS THROUGH 00Z
THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
GDNC CONTS TO PAINT AN ANOMOLOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. LIGHT WINTRY PRECIPITATION WILL REMAIN POSSIBLE MAINLY
FROM KIAD NORTH TO KMRB...KBWI AND KMTN. FRZRA OR FZDZ WILL BE
MOST COMMON WITH THE MAJORITY OF ICING ISSUES AT KBWI AND KMTN.
ALL PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...
SCA WINDS NOT CURENTLY BEING XPRNCD ON THE WATERS. THIS WL BE
ALLOWED TO END AT 7 PM.

SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...
THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-501>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
UPDATE...WOODY!
PRVS...KRW/HTS/MSE





000
FXUS61 KLWX 032029
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
329 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

FIRST BATCH OF FREEZING RAIN MIXED WITH A LITTLE SLEET WILL PUSH
OUT OF THE BALTIMORE METRO AREA AND BE REPLACED WITH INTERMITTENT
FREEZING DRIZZLE/LIGHT FREEZING RAIN THIS EVENING. ADDITIONAL
LIGHT FREEZING DRIZZLE/RAIN IS STILL POSSIBLE OVER THE REMAINDER
OF THE WINTER WEATHER ADVISORY AREA THIS AFTERNOON INTO THE EARLY
EVENING. WARMER AIR HAS BEEN SLOW TO PUSH NORTH AS WE HAVE SEEN
MUCH OF THIS WINTER. THE VAST MAJORITY OF THE WARMING HAS OCCURRED
OVER WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA BUT COLD
WEDGE HAS REMAINED IN PLACE FURTHER NORTH.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE. MOST IMPACTS WILL BE
TO ELEVATED STRUCTURES...SIDE WALKS AND UNTREATED ROADWAYS.

THERE IS STILL HIGH CONFIDENCE THAT WARM ADVECTION WILL WIN OUT AND
TEMPERATURES WILL GRADUALLY RISE ABOVE FREEZING LATER TONIGHT IN ALL
AREAS. AFTER MIDNIGHT...EXPECT LIGHT RAIN...SOME FOG AND MILDER
TEMPERATURES.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH NORTH
INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT PREVIOUS
GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN CLOUD COVER
AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY TOP OUT IN THE
40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO MIDDLE 50S CENTRAL
VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL DAY WEDNESDAY.
PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS THROUGH 00Z
THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...

GDNC CONTS TO PAINT AN ANOMOLOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. LIGHT WINTRY PRECIPITATION WILL REMAIN POSSIBLE MAINLY
FROM KIAD NORTH TO KMRB...KBWI AND KMTN. FRZRA OR FZDZ WILL BE
MOST COMMON WITH THE MAJORITY OF ICING ISSUES AT KBWI AND KMTN.
ALL PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...

SCA CONDITIONS POSSIBLE INTO EVENING ESPECIALLY OVER THE
BAY. SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...

THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-503>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KRW
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...KRW/HTS/MSE
MARINE...KRW/HTS/MSE
HYDROLOGY...JE




000
FXUS61 KLWX 032029
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
329 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

FIRST BATCH OF FREEZING RAIN MIXED WITH A LITTLE SLEET WILL PUSH
OUT OF THE BALTIMORE METRO AREA AND BE REPLACED WITH INTERMITTENT
FREEZING DRIZZLE/LIGHT FREEZING RAIN THIS EVENING. ADDITIONAL
LIGHT FREEZING DRIZZLE/RAIN IS STILL POSSIBLE OVER THE REMAINDER
OF THE WINTER WEATHER ADVISORY AREA THIS AFTERNOON INTO THE EARLY
EVENING. WARMER AIR HAS BEEN SLOW TO PUSH NORTH AS WE HAVE SEEN
MUCH OF THIS WINTER. THE VAST MAJORITY OF THE WARMING HAS OCCURRED
OVER WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA BUT COLD
WEDGE HAS REMAINED IN PLACE FURTHER NORTH.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE. MOST IMPACTS WILL BE
TO ELEVATED STRUCTURES...SIDE WALKS AND UNTREATED ROADWAYS.

THERE IS STILL HIGH CONFIDENCE THAT WARM ADVECTION WILL WIN OUT AND
TEMPERATURES WILL GRADUALLY RISE ABOVE FREEZING LATER TONIGHT IN ALL
AREAS. AFTER MIDNIGHT...EXPECT LIGHT RAIN...SOME FOG AND MILDER
TEMPERATURES.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH NORTH
INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT PREVIOUS
GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN CLOUD COVER
AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY TOP OUT IN THE
40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO MIDDLE 50S CENTRAL
VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL DAY WEDNESDAY.
PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS THROUGH 00Z
THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...

GDNC CONTS TO PAINT AN ANOMOLOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. LIGHT WINTRY PRECIPITATION WILL REMAIN POSSIBLE MAINLY
FROM KIAD NORTH TO KMRB...KBWI AND KMTN. FRZRA OR FZDZ WILL BE
MOST COMMON WITH THE MAJORITY OF ICING ISSUES AT KBWI AND KMTN.
ALL PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...

SCA CONDITIONS POSSIBLE INTO EVENING ESPECIALLY OVER THE
BAY. SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...

THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-503>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KRW
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...KRW/HTS/MSE
MARINE...KRW/HTS/MSE
HYDROLOGY...JE





000
FXUS61 KLWX 032029
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
329 PM EST TUE MAR 3 2015

.SYNOPSIS...
A WARM FRONT WILL LIFT THROUGH THE AREA TONIGHT. A COLD FRONT
WILL MOVE INTO THE REGION WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR
THURSDAY LASTING INTO THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

FIRST BATCH OF FREEZING RAIN MIXED WITH A LITTLE SLEET WILL PUSH
OUT OF THE BALTIMORE METRO AREA AND BE REPLACED WITH INTERMITTENT
FREEZING DRIZZLE/LIGHT FREEZING RAIN THIS EVENING. ADDITIONAL
LIGHT FREEZING DRIZZLE/RAIN IS STILL POSSIBLE OVER THE REMAINDER
OF THE WINTER WEATHER ADVISORY AREA THIS AFTERNOON INTO THE EARLY
EVENING. WARMER AIR HAS BEEN SLOW TO PUSH NORTH AS WE HAVE SEEN
MUCH OF THIS WINTER. THE VAST MAJORITY OF THE WARMING HAS OCCURRED
OVER WESTERN AND SOUTHERN PORTIONS OF THE FORECAST AREA BUT COLD
WEDGE HAS REMAINED IN PLACE FURTHER NORTH.

AREAS TO THE NORTH AND WEST OF BALTIMORE...ESPECIALLY NEAR
THE MASON DIXON LINE WILL SEE THE GREATEST IMPACT FROM ICING WHICH
COULD SEE UPWARDS OF 0.10-0.15 INCHES OF ICE. MOST IMPACTS WILL BE
TO ELEVATED STRUCTURES...SIDE WALKS AND UNTREATED ROADWAYS.

THERE IS STILL HIGH CONFIDENCE THAT WARM ADVECTION WILL WIN OUT AND
TEMPERATURES WILL GRADUALLY RISE ABOVE FREEZING LATER TONIGHT IN ALL
AREAS. AFTER MIDNIGHT...EXPECT LIGHT RAIN...SOME FOG AND MILDER
TEMPERATURES.

A COMPLEX FRONTAL SYSTEM WILL BEGIN TO IMPACT THE MIDDLE ATLANTIC
REGION ON WEDNESDAY. AHEAD OF THE FRONT...MILDER AIR WILL PUSH NORTH
INTO THE FORECAST AREA...THOUGH NOT TO THE EXTENT THAT PREVIOUS
GUIDANCE SUGGESTED. MUCH OF THE AREA WILL BE SHROUDED IN CLOUD COVER
AND PERIODS OF LIGHT RAIN. TEMPERATURES WILL LIKELY TOP OUT IN THE
40S IN MOST LOCATIONS WITH PERHAPS THE LOWER TO MIDDLE 50S CENTRAL
VA TO SOUTHERN MD. KEPT POPS CATEGORICAL ALL DAY WEDNESDAY.
PRECIPITATION SHOULD REMAIN AS LIQUID IN ALL AREAS THROUGH 00Z
THURSDAY.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...

GDNC CONTS TO PAINT AN ANOMOLOUS PICTURE...DRAINING COLD AIR SOUTH
WED NGT IN WAKE OF CDFNT. WHILE THERES NOT A STRONG LOW OR PVA...
THERES PLENTY OF FORCING AVBL THX TO STRONG BAROCLINIC ZONE AND RRQ
OF UPR JETMAX. A STREAM OF AMPLE MSTR WL BE OVERRUNNING THE COLD
AIR...SOURCED FROM THE WRN GLFMEX AND PACIFIC. THEREFORE...IT
SEEMS WELL WITHIN REASON TO HAVE QPF CONTG WHILE TEMPS DROP BELOW
FREEZING. THAT SUPPORTS A SCENARIO WHERE RAIN WILL CHG TO SNOW.

THERE ARE STILL TIMING QUESTIONS AS WELL AS WHETHER THE ENTIRE
COLUMN WILL COOL IN UNISON. IF NOT...THEN PTYPE MAY BE MORE PL AND
LESS SNOW. THAT IS MORE OF A CONCERN ACROSS CENTRAL VA AND SRN MD.
IN ADDITION...THERE IS STILL A RANGE OF SOLUTIONS WRT HOW MUCH QPF
WL FALL AS SOMETHING FROZEN. SOLUTIONS SEEM TO BE COMING IN COOLER
AND WETTER. GIVEN THE RANGE OF POSSIBILITIES...DO NOT WISH TO
UNDERSTIMATE POTENTIAL. FCST ACCUMS HV BEEN RAISED A BIT ACRS THE
NORTH...WHERE STDY SNOW SEEMS APPARENT. DID NOT DO LIKEWISE ACRS
THE S DUE TO THE PL POTENTIAL. REGARDLESS...AT THE 50 PCT
CONFIDENCE LVL...SEE ENUF EVIDENCE TO RAISE A WATCH FOR THE ENTIRE
AREA.

PCPN WL CONT INTO THU AFTN. COLD AIR CONTS TO STREAM SWD THU NGT
AFTR PCPN ENDS. STUCK CLOSE TO A PRVS FCST/MOS CONSENSUS FOR
MIN-T THU NGT. HV PLENTY OF LOWS IN THE SINGLE DIGITS.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
AFTER A VERY COLD START FRIDAY MORNING...TEMPERATURES WILL STRUGGLE
TO RISE DURING THE DAY IN THE CONTINUED WEAK CAA...WITH HIGHS
REMAINING BELOW FREEZING OVER MUCH OF THE AREA. DESPITE THE RETURN
OF SOUTHERLY WINDS OVERNIGHT FRIDAY...TEMPERATURES WILL STILL BE
VERY COLD. WENT A LITTLE WARMER THAN GUIDANCE FOR FRIDAY NIGHT AND
SATURDAY DUE TO THE INCREASED WEAK WAA.

WEAK COLD FRONT ASSOCIATED WITH LOW PRESSURE WELL TO OUR NORTH
SLIDES THROUGH THE AREA SATURDAY AFTERNOON/EVENING WITH LITTLE
EFFECT ON SENSIBLE WEATHER...EXCEPT FOR A WIND SHIFT. THERE IS A
CHANCE OF SOME UPSLOPE SNOW SHOWERS IN THE FAR WEST...BUT LEFT POPS
OUT OF FORECAST UNTIL A CLEARER SIGNAL APPEARS. BEYOND SATURDAY
MODEL GUIDANCE BECOMES NOISIER WITH VARYING MODEL SOLUTIONS...SO
WENT WITH A BLEND OF HPC AND MODEL GUIDANCE.

&&

.AVIATION /20Z TUESDAY THROUGH SUNDAY/...
SUB VFR CONDITIONS EXPECTED AT ALL TERMINAL SITES THROUGH
WEDNESDAY. LIGHT WINTRY PRECIPITATION WILL REMAIN POSSIBLE MAINLY
FROM KIAD NORTH TO KMRB...KBWI AND KMTN. FRZRA OR FZDZ WILL BE
MOST COMMON WITH THE MAJORITY OF ICING ISSUES AT KBWI AND KMTN.
ALL PRECIPITATION WILL TRANSITION TO PLAIN RAIN LATER THIS EVENING
EXCEPT LATER TONIGHT NEAR THE MASON DIXON LINE. PATCHY FOG...MVFR
TO IFR CIGS AND VSBYS EXPECTED INTO WEDNESDAY WITH PERIODS OF
LIGHT RAIN EXPECTED.

AOB IFR WL CONT WED NGT-THU DUE TO MAINLY SNOW. IMPRVG CONDS THU
NGT.

DO NOT ANTICIPATE ANY AVIATION CONCERNS THIS WEEKEND.

&&

.MARINE...

SCA CONDITIONS POSSIBLE INTO EVENING ESPECIALLY OVER THE
BAY. SCA CONDITIONS MAY BE POSSIBLE OVER A PORTION OF THE WATERS ON
WEDNESDAY. VISIBILITIES WILL BE REDUCED DUE TO SOME FROZEN
PRECIPITATION THIS EVENING THEN RAIN TONIGHT AND WEDNESDAY.

RAIN AT THE BGNG OF WED EVNG WL TRANSITION TO SNW AND PSBLY SOME
PL. AS COLD AIR DRAINS SWD...MIXING WL IMPRV. HV RAISED A SCA WED
NGT TO ACCT FOR THAT...WHICH LKLY WL NEED TO CONT INTO AT LEAST THU.

WITH LIGHT AND VARIABLE WINDS THROUGH MUCH OF THE PERIOD... DO
NOT ANTICIPATE ANY MARINE CONCERNS FRIDAY THROUGH SUNDAY.

&&

.HYDROLOGY...

THROUGH WEDNESDAY AFTERNOON...AROUND A HALF TO THREE QUARTERS OF AN
INCH OF RAIN IS EXPECTED...EXCEPT FOR HEAVIER AMOUNTS THAT COULD
APPROACH 1.0 - 1.5 INCHES ALONG THE ALLEGHENY FRONT. TEMPERATURES
WILL RISE WELL INTO THE 40S EVERYWHERE /AND 50S IN THE RAPPAHANNOCK
AND JAMES RIVER BASINS/...PROMOTING SNOWMELT. THE SNOWPACK IS
CURRENTLY ESTIMATED TO BE HOLDING ANYWHERE FROM A HALF INCH OF WATER
IN THE CACAPON/LOST RIVER BASIN TO AROUND AN INCH AND A HALF IN THE
SOUTH BRANCH POTOMAC BASIN. MODELING INDICATES NOT ALL OF THIS SNOW
WATER WILL BE RELEASED...ESPECIALLY GIVEN A TOTAL LACK OF SUNSHINE.

GIVEN THIS...THE COMBINATION OF SNOWMELT AND RAIN WILL PROMOTE RISES
ON AREA RIVERS...BUT AT THIS TIME STREAMS ARE LIKELY TO REMAIN
WITHIN-BANK.

SOME COMPLICATING FACTORS TO KEEP IN MIND...IF THE CHANGEOVER FROM
RAIN TO WINTRY PRECIP ON WEDNESDAY EVENING OCCURS LATER THAN
EXPECTED...CONCERNS MAY BECOME HEIGHTENED. ALSO MANY OF OUR AREA
STREAMS ARE COVERED WITH ICE OR EVEN PARTIALLY FROZEN. THESE EFFECTS
WILL HAVE TO BE MONITORED FOR A POTENTIAL ROLE IN AFFECTING RUNOFF.

LASTLY...AS WE SAW WITH THE RECENT RAIN/ICE/MINOR SNOWMELT...ANY
AMOUNT OF LIQUID PRECIPITATION STANDS A GOOD CHANCE OF CAUSING MINOR
POOR DRAINAGE FLOODING...AS NORMAL DRAINAGE PATTERNS MAY BE BLOCKED
BY PLOWED SNOW.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR DCZ001.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR MDZ003>006-011-013-014-501>508.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR MDZ016>018.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003>006-011-013-014-503>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR VAZ026>031-040-052>054-501-503>507.
     WINTER STORM WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     EVENING FOR VAZ025-036>039-050-051-055>057-502-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
WV...WINTER STORM WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY
     EVENING FOR WVZ050>053-055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 1 AM TO 7 AM EST THURSDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...HTS
NEAR TERM...KRW
SHORT TERM...HTS
LONG TERM...MSE
AVIATION...KRW/HTS/MSE
MARINE...KRW/HTS/MSE
HYDROLOGY...JE




000
FXUS61 KLWX 031536 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1036 AM EST TUE MAR 3 2015

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST OVER THE AREA BEFORE MOVING OFFSHORE
LATER TODAY. A WARM FRONT WILL LIFT THROUGH THE AREA THIS
AFTERNOON AND EVENING. A COLD FRONT WILL MOVE INTO THE REGION
WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR THURSDAY LASTING INTO THE
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
VERY CHALLENGING FORECAST THIS AFTERNOON AND EVENING.

LIFT FROM WARM AIR ADVECTION IS BEGINNING TO INCREASE ACROSS THE
FORECAST AREA BUT PRECIPITATION IS HAVING A TOUGH TIME REACHING
THE GROUND DUE TO DRY AIR AT THE MID LEVELS. THE COLUMN WILL
GRADUALLY MOISTEN UP BUT PRECIPITATION WILL LIKELY START A BIT
LATER THAN PREVIOUSLY EXPECTED. THE LATER START TIME WILL ALLOW
FOR TEMPERATURES TO WARM A FEW DEGREES ESPECIALLY SOUTH OF THE
METRO AREAS. THIS MAKES THE FORECAST PROBLEMATIC WITH MILDER
TEMPERATURES...ESPECIALLY OVER CENTRAL AND SOUTHERN LOCALES.

AREAS OF HIGHEST CONFIDENCE FOR ICING CONCERNS LOOK TO BE SETTING
UP TO THE NORTH AND WEST OF THE BALTIMORE AND WASHINGTON DC METRO
AREAS AND PORTIONS OF THE SHENANDOAH VALLEY AND HIGHLANDS. SHALLOW
COLD AIR WILL LIKELY HOLD IN LONGEST AND POSE THE GREATEST CONCERN
FOR SLIPPERY TRAVEL LATER THIS AFTERNOON INTO THIS EVENING. AREAS
CLOSEST TO THE MASON DIXON LINE OVER NE MARYLAND MAY HOLD SUB
FREEZING AIR INTO THE LATE EVENING. STILL CANNOT RULE OUT SOME
ICING TO THE SOUTH WITH DEWPOINT DEPRESSIONS RUNNING 10 OR MORE
DEGREES AND DRY POCKET ALOFT. PRECIPITATION WILL COOL THE COLUMN
AT LEAST INITIALLY.

P-TYPES NOW LOOK TO BE MOSTLY FREEZING RAIN WITH SOME SLEET AT THE
START. LATER START TIMES LEND TO WARMING ALOFT WITH LESS POTENTIAL
FOR SNOW. PRECIP IN ALL AREAS WILL BE LIGHT.

TEMPERATURES RISE ABOVE FREEZING LATER TONIGHT FOR THE ENTIRE
AREA. RAIN RATES INCREASE OVER ALLEGHENIES LATE...WILL NEED TO BE
ON THE LOOKOUT FOR LOCALIZED FLOODING CONCERNS GIVEN EXPECTED
SNOWPACK MELT WITH HIGHLAND TEMPERATURES RISING INTO THE 40S.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEDNESDAY...COLD FRONT ENTERS CWA FROM THE WEST IN THE MORNING
AND DRIFTS EAST. WARMEST AIR IN NEARLY A MONTH (60F AT KIAD ON FEB
8) AHEAD OF THE FRONT WITH LOW 50S (A LITTLE LOWER THAN PREVIOUS
FORECASTS) EXPECTED GIVEN WIDESPREAD RAIN OVER THE AREA AT THE TIME.
QPF QUARTER TO HALF INCH OF RAIN OVER THE AREA WEDNESDAY. MOST OF
THE AREA LOOKS TO BE BETWEEN SHORTWAVES IN THE AFTERNOON...REDUCING
RAIN RATES.

WEATHER IMPACTS WILL INCREASE WEDNESDAY NIGHT. SFC BOUNDARY MAY HAVE
PUSHED A GOOD PART OF THE WAY THROUGH DURING THE EVENING...AS A WEAK
SFC WAVE IS PROJECTED TO CROSS THE CAROLINAS OVERNIGHT. HOWEVER...
COLDER TEMPS...ESPECIALLY ALOFT...WILL BE SLOW TO WORK SOUTHWARD.
PER COORDINATION WITH WPC...A GFS/ECMWF SOLUTION IS FAVORED...WHICH
ALLOWS THERMAL PROFILES TO COOL A BIT MORE QUICKLY AMONGST THE MODEL
SUITE. THIS ALSO GIVES A MORE DEFINITIVE RAIN-TO-SNOW TRANSITION VS
A MORE PRONOUNCED WARM NOSE IN THE NAM (LIKELY DUE TO A STRONGER SSW
LLJ IM THE 850-600MB LAYER) AND MORE MIXED PRECIP. CANNOT RULE OUT A
PERIOD OF IP/FZRA...BUT DID NOT HAVE ENOUGH CONFIDENCE ON
TIMING/PLACEMENT TO INCLUDE IN THE FORECAST AT THIS TIME. ON THE
WHOLE THOUGH...THERE WAS A SLIGHT SLOWING TREND OVERALL IN THE
TIMING OF PRECIP THROUGHOUT THE EVENT. ALL AREAS ARE FORECAST TO BE
SNOW BY THURSDAY MORNING...WITH PRECIP ENDED NW-SE DURING THE DAY.
TEMPERATURES WILL HOLD STEADY OR FALL.

SNOWFALL AMOUNT FORECASTS WILL BE CHALLENGING GIVEN THE
UNCERTAINTIES WITH PTYPES...TIMING...AND HOW MUCH MOISTURE FALLS IN
THE COLD AIR. THERE WILL BE TREMENDOUS MOISTURE TRANSPORT WITH
THE LLJ AS WELL AS LIFT ASSOCIATED WITH UPPER JET...BUT THE AXIS
OF HIGHEST QPF WILL LIKELY BE VERY NEAR THE TRANSITION ZONE...WITH
POTENTIAL FOR COLDER BUT DRIER AIR TO BEGIN WORKING INTO THE BACK
SIDE. NOT MUCH CHANGE TO CURRENT FORECAST OVER PREVIOUS. IF THE
QPF INDEED FALLS AFTER THE TRANSITION TO SNOW...OUR CURRENT
FORECAST IS ON THE CONSERVATIVE SIDE. HOWEVER FEEL THERE IS STILL
TOO WIDE OF A SPREAD IN SOLUTIONS TO GO HIGHER. SEE OUR WEBPAGE
FOR THE PROB RANGES. WILL ALLOW DAYSHIFT TO DECIDE ON POTENTIAL
FOR WATCHES. HIGHEST CONFIDENCE IN LARGER SNOW TOTALS ARE OVER THE
HIGHLANDS AT THIS TIME.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ARCTIC HIGH PRESSURE WILL QUICKLY BUILD IN THURSDAY NIGHT. THERE MAY
BE A PERIOD OF UPSLOPE SNOW SHOWERS IN THE EVENING. NAM INDICATES
SNOW SHOWERS WILL BE POSSIBLE EAST OF THE MOUNTAINS AS WELL AS A
VORT MAX PASSES...BUT HAVE NOT INCLUDED THIS IN THE FORECAST NOW.
TEMPERATURES HAVE TRENDED COLDER...SINGLE DIGITS EXCEPT IN THE
METROS/NEAR THE BAY AND BELOW ZERO IN THE HIGHLANDS. IF GRADIENT
DOES NOT RELAX...WIND CHILL ADVISORIES MAY BE NEEDED IN THE
HIGHLANDS.

THE HIGH WILL SLIDE EAST ACROSS THE AREA THROUGH SATURDAY. FRIDAY
WILL STILL BE QUITE COLD BUT TEMPERATURES BEGIN TO MODERATE
SATURDAY. MOISTURE STARVED COLD FRONTS TRAILING LOW PRESSURE CENTERS
WELL TO THE NORTH WILL MAKE RUNS AT THE AREA SATURDAY NIGHT AND
AGAIN MONDAY. FOR NOW HAVE ONLY INCLUDED POPS IN THE UPSLOPE AREAS.
THERE ALSO WILL BE LITTLE EFFECT ON TEMPERATURES...WITH READINGS
SLIGHTLY BELOW NORMAL EXPECTED.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
LIGHT WINTRY MIX OVERSPREADS THE TERMINALS THROUGH THE AFTERNOON
AS A WARM FRONT APPROACHES. IFR CIGS EXPECTED LATE THIS AFTERNOON
INTO THE OVERNIGHT. LIGHT SLEET/FREEZING RAIN AT ONSET CHANGING
QUICKLY OVER TO FREEZING RAIN. WINTRY PRECIPITATION LIKELY TO
CHANGE OVER TO RAIN BY TONIGHT. IFR CONDITIONS EXPECTED.

RAIN IS FORECAST TO CHANGE TO SNOW THURSDAY NIGHT. VSBY/CIG
REDUCTIONS WILL CONTINUE AND MAY DROP TO LIFR IF MODERATE/HEAVY SNOW
DEVELOPS. THE SNOW WILL END ON THURSDAY. NO AVIATION HAZARDS
EXPECTED THEREAFTER.

&&

.MARINE...
SMALL CRAFT ADVISORY NOW IN EFFECT FOR ALL OF THE WATERS THIS
AFTERNOON INTO THIS EVENING. HIGH PRESSURE WILL MOVE OFFSHORE AND
SOUTHERLY FLOW WILL INCREASE. WINDS ARE EXPECTED TO DIP BELOW
ADVISORY LEVEL TONIGHT. VSBY RESTRICTIONS EXPECTED.

A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY NIGHT. RAIN WILL
CHANGE TO SNOW BY THURSDAY MORNING. SCA CONDITIONS ARE POSSIBLE FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT BEHIND THE FRONT. WINDS
WILL SUBSIDE THEREAFTER UNDER HIGH PRESSURE.

&&

.HYDROLOGY...
LIQUID PRECIP FCST FROM WPC WEDNESDAY AND WEDNESDAY NIGHT AREA ONE
TO ONE AND A HALF INCHES. WITH TEMPERATURES EXPECTED TO RISE INTO
THE 50S ON WEDNESDAY...THERE WILL BE SOME...POSSIBLY A LOT
OF...MELTING OF THE EXISTING SNOWPACK...WHICH COMPUTER MODELS AND
OBSERVATIONS INDICATE CONTAINS ANYWHERE FROM 3/4 INCH TO 2 INCHES
OF SNOW WATER EQUIVALENT. THIS COMBINATION MAY LEAD TO MINOR
FLOODING AS THE RAIN FALLS ON WEDNESDAY. FURTHER COMPLICATING THIS
FORECAST IS AN EXPECTED CHANGEOVER TO SNOW WEDNESDAY NIGHT FOR
MUCH OF THE AREA.

ALTHOUGH RIVER ICE IS NOT ESPECIALLY THICK...IT WILL HAVE TO BE
MONITORED FOR POTENTIAL ROLE IN AFFECTING RUNOFF. ALSO...PLOWED SNOW
IS LIKELY COVERING SOME OF THE DRAINS OUT THERE...WHICH COULD CAUSE
MORE POOR DRAINAGE FLOODING THAN WOULD OTHERWISE USUALLY BE
EXPECTED.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ501-
     502.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ004>006-011-013-014-503>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-036>040-050-051-501>504-507-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ052-
     055>057.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ050-
     055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...KRW
SHORT TERM...BAJ/ADS
LONG TERM...ADS
AVIATION...ADS/KRW
MARINE...ADS/KRW
HYDROLOGY...JE





000
FXUS61 KLWX 031536 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1036 AM EST TUE MAR 3 2015

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST OVER THE AREA BEFORE MOVING OFFSHORE
LATER TODAY. A WARM FRONT WILL LIFT THROUGH THE AREA THIS
AFTERNOON AND EVENING. A COLD FRONT WILL MOVE INTO THE REGION
WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR THURSDAY LASTING INTO THE
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
VERY CHALLENGING FORECAST THIS AFTERNOON AND EVENING.

LIFT FROM WARM AIR ADVECTION IS BEGINNING TO INCREASE ACROSS THE
FORECAST AREA BUT PRECIPITATION IS HAVING A TOUGH TIME REACHING
THE GROUND DUE TO DRY AIR AT THE MID LEVELS. THE COLUMN WILL
GRADUALLY MOISTEN UP BUT PRECIPITATION WILL LIKELY START A BIT
LATER THAN PREVIOUSLY EXPECTED. THE LATER START TIME WILL ALLOW
FOR TEMPERATURES TO WARM A FEW DEGREES ESPECIALLY SOUTH OF THE
METRO AREAS. THIS MAKES THE FORECAST PROBLEMATIC WITH MILDER
TEMPERATURES...ESPECIALLY OVER CENTRAL AND SOUTHERN LOCALES.

AREAS OF HIGHEST CONFIDENCE FOR ICING CONCERNS LOOK TO BE SETTING
UP TO THE NORTH AND WEST OF THE BALTIMORE AND WASHINGTON DC METRO
AREAS AND PORTIONS OF THE SHENANDOAH VALLEY AND HIGHLANDS. SHALLOW
COLD AIR WILL LIKELY HOLD IN LONGEST AND POSE THE GREATEST CONCERN
FOR SLIPPERY TRAVEL LATER THIS AFTERNOON INTO THIS EVENING. AREAS
CLOSEST TO THE MASON DIXON LINE OVER NE MARYLAND MAY HOLD SUB
FREEZING AIR INTO THE LATE EVENING. STILL CANNOT RULE OUT SOME
ICING TO THE SOUTH WITH DEWPOINT DEPRESSIONS RUNNING 10 OR MORE
DEGREES AND DRY POCKET ALOFT. PRECIPITATION WILL COOL THE COLUMN
AT LEAST INITIALLY.

P-TYPES NOW LOOK TO BE MOSTLY FREEZING RAIN WITH SOME SLEET AT THE
START. LATER START TIMES LEND TO WARMING ALOFT WITH LESS POTENTIAL
FOR SNOW. PRECIP IN ALL AREAS WILL BE LIGHT.

TEMPERATURES RISE ABOVE FREEZING LATER TONIGHT FOR THE ENTIRE
AREA. RAIN RATES INCREASE OVER ALLEGHENIES LATE...WILL NEED TO BE
ON THE LOOKOUT FOR LOCALIZED FLOODING CONCERNS GIVEN EXPECTED
SNOWPACK MELT WITH HIGHLAND TEMPERATURES RISING INTO THE 40S.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEDNESDAY...COLD FRONT ENTERS CWA FROM THE WEST IN THE MORNING
AND DRIFTS EAST. WARMEST AIR IN NEARLY A MONTH (60F AT KIAD ON FEB
8) AHEAD OF THE FRONT WITH LOW 50S (A LITTLE LOWER THAN PREVIOUS
FORECASTS) EXPECTED GIVEN WIDESPREAD RAIN OVER THE AREA AT THE TIME.
QPF QUARTER TO HALF INCH OF RAIN OVER THE AREA WEDNESDAY. MOST OF
THE AREA LOOKS TO BE BETWEEN SHORTWAVES IN THE AFTERNOON...REDUCING
RAIN RATES.

WEATHER IMPACTS WILL INCREASE WEDNESDAY NIGHT. SFC BOUNDARY MAY HAVE
PUSHED A GOOD PART OF THE WAY THROUGH DURING THE EVENING...AS A WEAK
SFC WAVE IS PROJECTED TO CROSS THE CAROLINAS OVERNIGHT. HOWEVER...
COLDER TEMPS...ESPECIALLY ALOFT...WILL BE SLOW TO WORK SOUTHWARD.
PER COORDINATION WITH WPC...A GFS/ECMWF SOLUTION IS FAVORED...WHICH
ALLOWS THERMAL PROFILES TO COOL A BIT MORE QUICKLY AMONGST THE MODEL
SUITE. THIS ALSO GIVES A MORE DEFINITIVE RAIN-TO-SNOW TRANSITION VS
A MORE PRONOUNCED WARM NOSE IN THE NAM (LIKELY DUE TO A STRONGER SSW
LLJ IM THE 850-600MB LAYER) AND MORE MIXED PRECIP. CANNOT RULE OUT A
PERIOD OF IP/FZRA...BUT DID NOT HAVE ENOUGH CONFIDENCE ON
TIMING/PLACEMENT TO INCLUDE IN THE FORECAST AT THIS TIME. ON THE
WHOLE THOUGH...THERE WAS A SLIGHT SLOWING TREND OVERALL IN THE
TIMING OF PRECIP THROUGHOUT THE EVENT. ALL AREAS ARE FORECAST TO BE
SNOW BY THURSDAY MORNING...WITH PRECIP ENDED NW-SE DURING THE DAY.
TEMPERATURES WILL HOLD STEADY OR FALL.

SNOWFALL AMOUNT FORECASTS WILL BE CHALLENGING GIVEN THE
UNCERTAINTIES WITH PTYPES...TIMING...AND HOW MUCH MOISTURE FALLS IN
THE COLD AIR. THERE WILL BE TREMENDOUS MOISTURE TRANSPORT WITH
THE LLJ AS WELL AS LIFT ASSOCIATED WITH UPPER JET...BUT THE AXIS
OF HIGHEST QPF WILL LIKELY BE VERY NEAR THE TRANSITION ZONE...WITH
POTENTIAL FOR COLDER BUT DRIER AIR TO BEGIN WORKING INTO THE BACK
SIDE. NOT MUCH CHANGE TO CURRENT FORECAST OVER PREVIOUS. IF THE
QPF INDEED FALLS AFTER THE TRANSITION TO SNOW...OUR CURRENT
FORECAST IS ON THE CONSERVATIVE SIDE. HOWEVER FEEL THERE IS STILL
TOO WIDE OF A SPREAD IN SOLUTIONS TO GO HIGHER. SEE OUR WEBPAGE
FOR THE PROB RANGES. WILL ALLOW DAYSHIFT TO DECIDE ON POTENTIAL
FOR WATCHES. HIGHEST CONFIDENCE IN LARGER SNOW TOTALS ARE OVER THE
HIGHLANDS AT THIS TIME.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ARCTIC HIGH PRESSURE WILL QUICKLY BUILD IN THURSDAY NIGHT. THERE MAY
BE A PERIOD OF UPSLOPE SNOW SHOWERS IN THE EVENING. NAM INDICATES
SNOW SHOWERS WILL BE POSSIBLE EAST OF THE MOUNTAINS AS WELL AS A
VORT MAX PASSES...BUT HAVE NOT INCLUDED THIS IN THE FORECAST NOW.
TEMPERATURES HAVE TRENDED COLDER...SINGLE DIGITS EXCEPT IN THE
METROS/NEAR THE BAY AND BELOW ZERO IN THE HIGHLANDS. IF GRADIENT
DOES NOT RELAX...WIND CHILL ADVISORIES MAY BE NEEDED IN THE
HIGHLANDS.

THE HIGH WILL SLIDE EAST ACROSS THE AREA THROUGH SATURDAY. FRIDAY
WILL STILL BE QUITE COLD BUT TEMPERATURES BEGIN TO MODERATE
SATURDAY. MOISTURE STARVED COLD FRONTS TRAILING LOW PRESSURE CENTERS
WELL TO THE NORTH WILL MAKE RUNS AT THE AREA SATURDAY NIGHT AND
AGAIN MONDAY. FOR NOW HAVE ONLY INCLUDED POPS IN THE UPSLOPE AREAS.
THERE ALSO WILL BE LITTLE EFFECT ON TEMPERATURES...WITH READINGS
SLIGHTLY BELOW NORMAL EXPECTED.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
LIGHT WINTRY MIX OVERSPREADS THE TERMINALS THROUGH THE AFTERNOON
AS A WARM FRONT APPROACHES. IFR CIGS EXPECTED LATE THIS AFTERNOON
INTO THE OVERNIGHT. LIGHT SLEET/FREEZING RAIN AT ONSET CHANGING
QUICKLY OVER TO FREEZING RAIN. WINTRY PRECIPITATION LIKELY TO
CHANGE OVER TO RAIN BY TONIGHT. IFR CONDITIONS EXPECTED.

RAIN IS FORECAST TO CHANGE TO SNOW THURSDAY NIGHT. VSBY/CIG
REDUCTIONS WILL CONTINUE AND MAY DROP TO LIFR IF MODERATE/HEAVY SNOW
DEVELOPS. THE SNOW WILL END ON THURSDAY. NO AVIATION HAZARDS
EXPECTED THEREAFTER.

&&

.MARINE...
SMALL CRAFT ADVISORY NOW IN EFFECT FOR ALL OF THE WATERS THIS
AFTERNOON INTO THIS EVENING. HIGH PRESSURE WILL MOVE OFFSHORE AND
SOUTHERLY FLOW WILL INCREASE. WINDS ARE EXPECTED TO DIP BELOW
ADVISORY LEVEL TONIGHT. VSBY RESTRICTIONS EXPECTED.

A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY NIGHT. RAIN WILL
CHANGE TO SNOW BY THURSDAY MORNING. SCA CONDITIONS ARE POSSIBLE FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT BEHIND THE FRONT. WINDS
WILL SUBSIDE THEREAFTER UNDER HIGH PRESSURE.

&&

.HYDROLOGY...
LIQUID PRECIP FCST FROM WPC WEDNESDAY AND WEDNESDAY NIGHT AREA ONE
TO ONE AND A HALF INCHES. WITH TEMPERATURES EXPECTED TO RISE INTO
THE 50S ON WEDNESDAY...THERE WILL BE SOME...POSSIBLY A LOT
OF...MELTING OF THE EXISTING SNOWPACK...WHICH COMPUTER MODELS AND
OBSERVATIONS INDICATE CONTAINS ANYWHERE FROM 3/4 INCH TO 2 INCHES
OF SNOW WATER EQUIVALENT. THIS COMBINATION MAY LEAD TO MINOR
FLOODING AS THE RAIN FALLS ON WEDNESDAY. FURTHER COMPLICATING THIS
FORECAST IS AN EXPECTED CHANGEOVER TO SNOW WEDNESDAY NIGHT FOR
MUCH OF THE AREA.

ALTHOUGH RIVER ICE IS NOT ESPECIALLY THICK...IT WILL HAVE TO BE
MONITORED FOR POTENTIAL ROLE IN AFFECTING RUNOFF. ALSO...PLOWED SNOW
IS LIKELY COVERING SOME OF THE DRAINS OUT THERE...WHICH COULD CAUSE
MORE POOR DRAINAGE FLOODING THAN WOULD OTHERWISE USUALLY BE
EXPECTED.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ501-
     502.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ004>006-011-013-014-503>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-036>040-050-051-501>504-507-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ052-
     055>057.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ050-
     055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...KRW
SHORT TERM...BAJ/ADS
LONG TERM...ADS
AVIATION...ADS/KRW
MARINE...ADS/KRW
HYDROLOGY...JE




000
FXUS61 KLWX 031536 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1036 AM EST TUE MAR 3 2015

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST OVER THE AREA BEFORE MOVING OFFSHORE
LATER TODAY. A WARM FRONT WILL LIFT THROUGH THE AREA THIS
AFTERNOON AND EVENING. A COLD FRONT WILL MOVE INTO THE REGION
WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR THURSDAY LASTING INTO THE
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
VERY CHALLENGING FORECAST THIS AFTERNOON AND EVENING.

LIFT FROM WARM AIR ADVECTION IS BEGINNING TO INCREASE ACROSS THE
FORECAST AREA BUT PRECIPITATION IS HAVING A TOUGH TIME REACHING
THE GROUND DUE TO DRY AIR AT THE MID LEVELS. THE COLUMN WILL
GRADUALLY MOISTEN UP BUT PRECIPITATION WILL LIKELY START A BIT
LATER THAN PREVIOUSLY EXPECTED. THE LATER START TIME WILL ALLOW
FOR TEMPERATURES TO WARM A FEW DEGREES ESPECIALLY SOUTH OF THE
METRO AREAS. THIS MAKES THE FORECAST PROBLEMATIC WITH MILDER
TEMPERATURES...ESPECIALLY OVER CENTRAL AND SOUTHERN LOCALES.

AREAS OF HIGHEST CONFIDENCE FOR ICING CONCERNS LOOK TO BE SETTING
UP TO THE NORTH AND WEST OF THE BALTIMORE AND WASHINGTON DC METRO
AREAS AND PORTIONS OF THE SHENANDOAH VALLEY AND HIGHLANDS. SHALLOW
COLD AIR WILL LIKELY HOLD IN LONGEST AND POSE THE GREATEST CONCERN
FOR SLIPPERY TRAVEL LATER THIS AFTERNOON INTO THIS EVENING. AREAS
CLOSEST TO THE MASON DIXON LINE OVER NE MARYLAND MAY HOLD SUB
FREEZING AIR INTO THE LATE EVENING. STILL CANNOT RULE OUT SOME
ICING TO THE SOUTH WITH DEWPOINT DEPRESSIONS RUNNING 10 OR MORE
DEGREES AND DRY POCKET ALOFT. PRECIPITATION WILL COOL THE COLUMN
AT LEAST INITIALLY.

P-TYPES NOW LOOK TO BE MOSTLY FREEZING RAIN WITH SOME SLEET AT THE
START. LATER START TIMES LEND TO WARMING ALOFT WITH LESS POTENTIAL
FOR SNOW. PRECIP IN ALL AREAS WILL BE LIGHT.

TEMPERATURES RISE ABOVE FREEZING LATER TONIGHT FOR THE ENTIRE
AREA. RAIN RATES INCREASE OVER ALLEGHENIES LATE...WILL NEED TO BE
ON THE LOOKOUT FOR LOCALIZED FLOODING CONCERNS GIVEN EXPECTED
SNOWPACK MELT WITH HIGHLAND TEMPERATURES RISING INTO THE 40S.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEDNESDAY...COLD FRONT ENTERS CWA FROM THE WEST IN THE MORNING
AND DRIFTS EAST. WARMEST AIR IN NEARLY A MONTH (60F AT KIAD ON FEB
8) AHEAD OF THE FRONT WITH LOW 50S (A LITTLE LOWER THAN PREVIOUS
FORECASTS) EXPECTED GIVEN WIDESPREAD RAIN OVER THE AREA AT THE TIME.
QPF QUARTER TO HALF INCH OF RAIN OVER THE AREA WEDNESDAY. MOST OF
THE AREA LOOKS TO BE BETWEEN SHORTWAVES IN THE AFTERNOON...REDUCING
RAIN RATES.

WEATHER IMPACTS WILL INCREASE WEDNESDAY NIGHT. SFC BOUNDARY MAY HAVE
PUSHED A GOOD PART OF THE WAY THROUGH DURING THE EVENING...AS A WEAK
SFC WAVE IS PROJECTED TO CROSS THE CAROLINAS OVERNIGHT. HOWEVER...
COLDER TEMPS...ESPECIALLY ALOFT...WILL BE SLOW TO WORK SOUTHWARD.
PER COORDINATION WITH WPC...A GFS/ECMWF SOLUTION IS FAVORED...WHICH
ALLOWS THERMAL PROFILES TO COOL A BIT MORE QUICKLY AMONGST THE MODEL
SUITE. THIS ALSO GIVES A MORE DEFINITIVE RAIN-TO-SNOW TRANSITION VS
A MORE PRONOUNCED WARM NOSE IN THE NAM (LIKELY DUE TO A STRONGER SSW
LLJ IM THE 850-600MB LAYER) AND MORE MIXED PRECIP. CANNOT RULE OUT A
PERIOD OF IP/FZRA...BUT DID NOT HAVE ENOUGH CONFIDENCE ON
TIMING/PLACEMENT TO INCLUDE IN THE FORECAST AT THIS TIME. ON THE
WHOLE THOUGH...THERE WAS A SLIGHT SLOWING TREND OVERALL IN THE
TIMING OF PRECIP THROUGHOUT THE EVENT. ALL AREAS ARE FORECAST TO BE
SNOW BY THURSDAY MORNING...WITH PRECIP ENDED NW-SE DURING THE DAY.
TEMPERATURES WILL HOLD STEADY OR FALL.

SNOWFALL AMOUNT FORECASTS WILL BE CHALLENGING GIVEN THE
UNCERTAINTIES WITH PTYPES...TIMING...AND HOW MUCH MOISTURE FALLS IN
THE COLD AIR. THERE WILL BE TREMENDOUS MOISTURE TRANSPORT WITH
THE LLJ AS WELL AS LIFT ASSOCIATED WITH UPPER JET...BUT THE AXIS
OF HIGHEST QPF WILL LIKELY BE VERY NEAR THE TRANSITION ZONE...WITH
POTENTIAL FOR COLDER BUT DRIER AIR TO BEGIN WORKING INTO THE BACK
SIDE. NOT MUCH CHANGE TO CURRENT FORECAST OVER PREVIOUS. IF THE
QPF INDEED FALLS AFTER THE TRANSITION TO SNOW...OUR CURRENT
FORECAST IS ON THE CONSERVATIVE SIDE. HOWEVER FEEL THERE IS STILL
TOO WIDE OF A SPREAD IN SOLUTIONS TO GO HIGHER. SEE OUR WEBPAGE
FOR THE PROB RANGES. WILL ALLOW DAYSHIFT TO DECIDE ON POTENTIAL
FOR WATCHES. HIGHEST CONFIDENCE IN LARGER SNOW TOTALS ARE OVER THE
HIGHLANDS AT THIS TIME.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ARCTIC HIGH PRESSURE WILL QUICKLY BUILD IN THURSDAY NIGHT. THERE MAY
BE A PERIOD OF UPSLOPE SNOW SHOWERS IN THE EVENING. NAM INDICATES
SNOW SHOWERS WILL BE POSSIBLE EAST OF THE MOUNTAINS AS WELL AS A
VORT MAX PASSES...BUT HAVE NOT INCLUDED THIS IN THE FORECAST NOW.
TEMPERATURES HAVE TRENDED COLDER...SINGLE DIGITS EXCEPT IN THE
METROS/NEAR THE BAY AND BELOW ZERO IN THE HIGHLANDS. IF GRADIENT
DOES NOT RELAX...WIND CHILL ADVISORIES MAY BE NEEDED IN THE
HIGHLANDS.

THE HIGH WILL SLIDE EAST ACROSS THE AREA THROUGH SATURDAY. FRIDAY
WILL STILL BE QUITE COLD BUT TEMPERATURES BEGIN TO MODERATE
SATURDAY. MOISTURE STARVED COLD FRONTS TRAILING LOW PRESSURE CENTERS
WELL TO THE NORTH WILL MAKE RUNS AT THE AREA SATURDAY NIGHT AND
AGAIN MONDAY. FOR NOW HAVE ONLY INCLUDED POPS IN THE UPSLOPE AREAS.
THERE ALSO WILL BE LITTLE EFFECT ON TEMPERATURES...WITH READINGS
SLIGHTLY BELOW NORMAL EXPECTED.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
LIGHT WINTRY MIX OVERSPREADS THE TERMINALS THROUGH THE AFTERNOON
AS A WARM FRONT APPROACHES. IFR CIGS EXPECTED LATE THIS AFTERNOON
INTO THE OVERNIGHT. LIGHT SLEET/FREEZING RAIN AT ONSET CHANGING
QUICKLY OVER TO FREEZING RAIN. WINTRY PRECIPITATION LIKELY TO
CHANGE OVER TO RAIN BY TONIGHT. IFR CONDITIONS EXPECTED.

RAIN IS FORECAST TO CHANGE TO SNOW THURSDAY NIGHT. VSBY/CIG
REDUCTIONS WILL CONTINUE AND MAY DROP TO LIFR IF MODERATE/HEAVY SNOW
DEVELOPS. THE SNOW WILL END ON THURSDAY. NO AVIATION HAZARDS
EXPECTED THEREAFTER.

&&

.MARINE...
SMALL CRAFT ADVISORY NOW IN EFFECT FOR ALL OF THE WATERS THIS
AFTERNOON INTO THIS EVENING. HIGH PRESSURE WILL MOVE OFFSHORE AND
SOUTHERLY FLOW WILL INCREASE. WINDS ARE EXPECTED TO DIP BELOW
ADVISORY LEVEL TONIGHT. VSBY RESTRICTIONS EXPECTED.

A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY NIGHT. RAIN WILL
CHANGE TO SNOW BY THURSDAY MORNING. SCA CONDITIONS ARE POSSIBLE FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT BEHIND THE FRONT. WINDS
WILL SUBSIDE THEREAFTER UNDER HIGH PRESSURE.

&&

.HYDROLOGY...
LIQUID PRECIP FCST FROM WPC WEDNESDAY AND WEDNESDAY NIGHT AREA ONE
TO ONE AND A HALF INCHES. WITH TEMPERATURES EXPECTED TO RISE INTO
THE 50S ON WEDNESDAY...THERE WILL BE SOME...POSSIBLY A LOT
OF...MELTING OF THE EXISTING SNOWPACK...WHICH COMPUTER MODELS AND
OBSERVATIONS INDICATE CONTAINS ANYWHERE FROM 3/4 INCH TO 2 INCHES
OF SNOW WATER EQUIVALENT. THIS COMBINATION MAY LEAD TO MINOR
FLOODING AS THE RAIN FALLS ON WEDNESDAY. FURTHER COMPLICATING THIS
FORECAST IS AN EXPECTED CHANGEOVER TO SNOW WEDNESDAY NIGHT FOR
MUCH OF THE AREA.

ALTHOUGH RIVER ICE IS NOT ESPECIALLY THICK...IT WILL HAVE TO BE
MONITORED FOR POTENTIAL ROLE IN AFFECTING RUNOFF. ALSO...PLOWED SNOW
IS LIKELY COVERING SOME OF THE DRAINS OUT THERE...WHICH COULD CAUSE
MORE POOR DRAINAGE FLOODING THAN WOULD OTHERWISE USUALLY BE
EXPECTED.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ501-
     502.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ004>006-011-013-014-503>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-036>040-050-051-501>504-507-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ052-
     055>057.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ050-
     055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...KRW
SHORT TERM...BAJ/ADS
LONG TERM...ADS
AVIATION...ADS/KRW
MARINE...ADS/KRW
HYDROLOGY...JE





000
FXUS61 KLWX 031536 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1036 AM EST TUE MAR 3 2015

.SYNOPSIS...
HIGH PRESSURE WILL PERSIST OVER THE AREA BEFORE MOVING OFFSHORE
LATER TODAY. A WARM FRONT WILL LIFT THROUGH THE AREA THIS
AFTERNOON AND EVENING. A COLD FRONT WILL MOVE INTO THE REGION
WEDNESDAY FOLLOWED BY HIGH PRESSURE FOR THURSDAY LASTING INTO THE
WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
VERY CHALLENGING FORECAST THIS AFTERNOON AND EVENING.

LIFT FROM WARM AIR ADVECTION IS BEGINNING TO INCREASE ACROSS THE
FORECAST AREA BUT PRECIPITATION IS HAVING A TOUGH TIME REACHING
THE GROUND DUE TO DRY AIR AT THE MID LEVELS. THE COLUMN WILL
GRADUALLY MOISTEN UP BUT PRECIPITATION WILL LIKELY START A BIT
LATER THAN PREVIOUSLY EXPECTED. THE LATER START TIME WILL ALLOW
FOR TEMPERATURES TO WARM A FEW DEGREES ESPECIALLY SOUTH OF THE
METRO AREAS. THIS MAKES THE FORECAST PROBLEMATIC WITH MILDER
TEMPERATURES...ESPECIALLY OVER CENTRAL AND SOUTHERN LOCALES.

AREAS OF HIGHEST CONFIDENCE FOR ICING CONCERNS LOOK TO BE SETTING
UP TO THE NORTH AND WEST OF THE BALTIMORE AND WASHINGTON DC METRO
AREAS AND PORTIONS OF THE SHENANDOAH VALLEY AND HIGHLANDS. SHALLOW
COLD AIR WILL LIKELY HOLD IN LONGEST AND POSE THE GREATEST CONCERN
FOR SLIPPERY TRAVEL LATER THIS AFTERNOON INTO THIS EVENING. AREAS
CLOSEST TO THE MASON DIXON LINE OVER NE MARYLAND MAY HOLD SUB
FREEZING AIR INTO THE LATE EVENING. STILL CANNOT RULE OUT SOME
ICING TO THE SOUTH WITH DEWPOINT DEPRESSIONS RUNNING 10 OR MORE
DEGREES AND DRY POCKET ALOFT. PRECIPITATION WILL COOL THE COLUMN
AT LEAST INITIALLY.

P-TYPES NOW LOOK TO BE MOSTLY FREEZING RAIN WITH SOME SLEET AT THE
START. LATER START TIMES LEND TO WARMING ALOFT WITH LESS POTENTIAL
FOR SNOW. PRECIP IN ALL AREAS WILL BE LIGHT.

TEMPERATURES RISE ABOVE FREEZING LATER TONIGHT FOR THE ENTIRE
AREA. RAIN RATES INCREASE OVER ALLEGHENIES LATE...WILL NEED TO BE
ON THE LOOKOUT FOR LOCALIZED FLOODING CONCERNS GIVEN EXPECTED
SNOWPACK MELT WITH HIGHLAND TEMPERATURES RISING INTO THE 40S.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
WEDNESDAY...COLD FRONT ENTERS CWA FROM THE WEST IN THE MORNING
AND DRIFTS EAST. WARMEST AIR IN NEARLY A MONTH (60F AT KIAD ON FEB
8) AHEAD OF THE FRONT WITH LOW 50S (A LITTLE LOWER THAN PREVIOUS
FORECASTS) EXPECTED GIVEN WIDESPREAD RAIN OVER THE AREA AT THE TIME.
QPF QUARTER TO HALF INCH OF RAIN OVER THE AREA WEDNESDAY. MOST OF
THE AREA LOOKS TO BE BETWEEN SHORTWAVES IN THE AFTERNOON...REDUCING
RAIN RATES.

WEATHER IMPACTS WILL INCREASE WEDNESDAY NIGHT. SFC BOUNDARY MAY HAVE
PUSHED A GOOD PART OF THE WAY THROUGH DURING THE EVENING...AS A WEAK
SFC WAVE IS PROJECTED TO CROSS THE CAROLINAS OVERNIGHT. HOWEVER...
COLDER TEMPS...ESPECIALLY ALOFT...WILL BE SLOW TO WORK SOUTHWARD.
PER COORDINATION WITH WPC...A GFS/ECMWF SOLUTION IS FAVORED...WHICH
ALLOWS THERMAL PROFILES TO COOL A BIT MORE QUICKLY AMONGST THE MODEL
SUITE. THIS ALSO GIVES A MORE DEFINITIVE RAIN-TO-SNOW TRANSITION VS
A MORE PRONOUNCED WARM NOSE IN THE NAM (LIKELY DUE TO A STRONGER SSW
LLJ IM THE 850-600MB LAYER) AND MORE MIXED PRECIP. CANNOT RULE OUT A
PERIOD OF IP/FZRA...BUT DID NOT HAVE ENOUGH CONFIDENCE ON
TIMING/PLACEMENT TO INCLUDE IN THE FORECAST AT THIS TIME. ON THE
WHOLE THOUGH...THERE WAS A SLIGHT SLOWING TREND OVERALL IN THE
TIMING OF PRECIP THROUGHOUT THE EVENT. ALL AREAS ARE FORECAST TO BE
SNOW BY THURSDAY MORNING...WITH PRECIP ENDED NW-SE DURING THE DAY.
TEMPERATURES WILL HOLD STEADY OR FALL.

SNOWFALL AMOUNT FORECASTS WILL BE CHALLENGING GIVEN THE
UNCERTAINTIES WITH PTYPES...TIMING...AND HOW MUCH MOISTURE FALLS IN
THE COLD AIR. THERE WILL BE TREMENDOUS MOISTURE TRANSPORT WITH
THE LLJ AS WELL AS LIFT ASSOCIATED WITH UPPER JET...BUT THE AXIS
OF HIGHEST QPF WILL LIKELY BE VERY NEAR THE TRANSITION ZONE...WITH
POTENTIAL FOR COLDER BUT DRIER AIR TO BEGIN WORKING INTO THE BACK
SIDE. NOT MUCH CHANGE TO CURRENT FORECAST OVER PREVIOUS. IF THE
QPF INDEED FALLS AFTER THE TRANSITION TO SNOW...OUR CURRENT
FORECAST IS ON THE CONSERVATIVE SIDE. HOWEVER FEEL THERE IS STILL
TOO WIDE OF A SPREAD IN SOLUTIONS TO GO HIGHER. SEE OUR WEBPAGE
FOR THE PROB RANGES. WILL ALLOW DAYSHIFT TO DECIDE ON POTENTIAL
FOR WATCHES. HIGHEST CONFIDENCE IN LARGER SNOW TOTALS ARE OVER THE
HIGHLANDS AT THIS TIME.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ARCTIC HIGH PRESSURE WILL QUICKLY BUILD IN THURSDAY NIGHT. THERE MAY
BE A PERIOD OF UPSLOPE SNOW SHOWERS IN THE EVENING. NAM INDICATES
SNOW SHOWERS WILL BE POSSIBLE EAST OF THE MOUNTAINS AS WELL AS A
VORT MAX PASSES...BUT HAVE NOT INCLUDED THIS IN THE FORECAST NOW.
TEMPERATURES HAVE TRENDED COLDER...SINGLE DIGITS EXCEPT IN THE
METROS/NEAR THE BAY AND BELOW ZERO IN THE HIGHLANDS. IF GRADIENT
DOES NOT RELAX...WIND CHILL ADVISORIES MAY BE NEEDED IN THE
HIGHLANDS.

THE HIGH WILL SLIDE EAST ACROSS THE AREA THROUGH SATURDAY. FRIDAY
WILL STILL BE QUITE COLD BUT TEMPERATURES BEGIN TO MODERATE
SATURDAY. MOISTURE STARVED COLD FRONTS TRAILING LOW PRESSURE CENTERS
WELL TO THE NORTH WILL MAKE RUNS AT THE AREA SATURDAY NIGHT AND
AGAIN MONDAY. FOR NOW HAVE ONLY INCLUDED POPS IN THE UPSLOPE AREAS.
THERE ALSO WILL BE LITTLE EFFECT ON TEMPERATURES...WITH READINGS
SLIGHTLY BELOW NORMAL EXPECTED.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
LIGHT WINTRY MIX OVERSPREADS THE TERMINALS THROUGH THE AFTERNOON
AS A WARM FRONT APPROACHES. IFR CIGS EXPECTED LATE THIS AFTERNOON
INTO THE OVERNIGHT. LIGHT SLEET/FREEZING RAIN AT ONSET CHANGING
QUICKLY OVER TO FREEZING RAIN. WINTRY PRECIPITATION LIKELY TO
CHANGE OVER TO RAIN BY TONIGHT. IFR CONDITIONS EXPECTED.

RAIN IS FORECAST TO CHANGE TO SNOW THURSDAY NIGHT. VSBY/CIG
REDUCTIONS WILL CONTINUE AND MAY DROP TO LIFR IF MODERATE/HEAVY SNOW
DEVELOPS. THE SNOW WILL END ON THURSDAY. NO AVIATION HAZARDS
EXPECTED THEREAFTER.

&&

.MARINE...
SMALL CRAFT ADVISORY NOW IN EFFECT FOR ALL OF THE WATERS THIS
AFTERNOON INTO THIS EVENING. HIGH PRESSURE WILL MOVE OFFSHORE AND
SOUTHERLY FLOW WILL INCREASE. WINDS ARE EXPECTED TO DIP BELOW
ADVISORY LEVEL TONIGHT. VSBY RESTRICTIONS EXPECTED.

A COLD FRONT WILL PASS THROUGH THE WATERS WEDNESDAY NIGHT. RAIN WILL
CHANGE TO SNOW BY THURSDAY MORNING. SCA CONDITIONS ARE POSSIBLE FROM
LATE WEDNESDAY NIGHT THROUGH THURSDAY NIGHT BEHIND THE FRONT. WINDS
WILL SUBSIDE THEREAFTER UNDER HIGH PRESSURE.

&&

.HYDROLOGY...
LIQUID PRECIP FCST FROM WPC WEDNESDAY AND WEDNESDAY NIGHT AREA ONE
TO ONE AND A HALF INCHES. WITH TEMPERATURES EXPECTED TO RISE INTO
THE 50S ON WEDNESDAY...THERE WILL BE SOME...POSSIBLY A LOT
OF...MELTING OF THE EXISTING SNOWPACK...WHICH COMPUTER MODELS AND
OBSERVATIONS INDICATE CONTAINS ANYWHERE FROM 3/4 INCH TO 2 INCHES
OF SNOW WATER EQUIVALENT. THIS COMBINATION MAY LEAD TO MINOR
FLOODING AS THE RAIN FALLS ON WEDNESDAY. FURTHER COMPLICATING THIS
FORECAST IS AN EXPECTED CHANGEOVER TO SNOW WEDNESDAY NIGHT FOR
MUCH OF THE AREA.

ALTHOUGH RIVER ICE IS NOT ESPECIALLY THICK...IT WILL HAVE TO BE
MONITORED FOR POTENTIAL ROLE IN AFFECTING RUNOFF. ALSO...PLOWED SNOW
IS LIKELY COVERING SOME OF THE DRAINS OUT THERE...WHICH COULD CAUSE
MORE POOR DRAINAGE FLOODING THAN WOULD OTHERWISE USUALLY BE
EXPECTED.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     DCZ001.
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ501-
     502.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ003.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     MDZ004>006-011-013-014-503>508.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     MDZ016>018.
VA...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR
     VAZ025>031-036>040-050-051-501>504-507-508.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     VAZ053-054-505-506.
     WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ052-
     055>057.
WV...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ050-
     055-501>506.
     WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 PM EST THIS EVENING FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BAJ/ADS
NEAR TERM...KRW
SHORT TERM...BAJ/ADS
LONG TERM...ADS
AVIATION...ADS/KRW
MARINE...ADS/KRW
HYDROLOGY...JE




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