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000
FXUS61 KLWX 171428
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1028 AM EDT THU APR 17 2014

.SYNOPSIS...
HIGH PRESSURE OVER NEW ENGLAND WILL STRETCH SOUTHWARD TOWARD THE
MID-ATLANTIC COAST THROUGH THE REMAINDER OF THE WEEK. AN AREA OF
LOW PRESSURE AND COLD FRONT MAY AFFECT THE AREA SATURDAY. A SECOND
COLD FRONT LOOKS TO MOVE THROUGH THE REGION TUESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE CENTERED OVER MAINE STRETCHES DOWN THROUGH THE MID-
ATLANTIC STATES. IT WAS ANOTHER COLD MORNING...BUT THE COLD AIR
MASS WILL MODIFY TODAY UNDER THE MID-APRIL SUN. WE ARE BEGINNING
THE DAY WITH SUNSHINE THROUGH HIGH CIRRUS. AM WATCHING SOME
STRATOCU ADVECT ONTO THE EASTERN SHORE...AND THESE MAY EXTEND WEST
OF THE BAY THIS AFTERNOON...AFFECTING AT LEAST CENTRAL AND
SOUTHERN MARYLAND FOR A TRANSITION TO PARTLY SUNNY...MAYBE EVEN
MOSTLY CLOUDY. MORE SUNSHINE WILL BE SEEN FURTHER WEST.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
THE QUESTION FOR TONIGHT IS WILL LIGHT FLOW PREVENT DECOUPLING AND
WILL LOW CLOUDS SPREAD ACROSS AT LEAST EASTERN SECTIONS OF THE CWA.
NAM FORECAST SOUNDINGS ARE CLOUDIER THAN GFS ONES...AND THUS MET
GUIDANCE MIN TEMPERATURES ARE HIGHER THAN MAV ONES. NORTH CENTRAL
MARYLAND SEEMS TO BE THE COLDEST AREAS WITH AN ACTIVE GROWING SEASON
TONIGHT. WITH MINS FORECAST IN THE LOW 30S...WENT AHEAD WITH A
FREEZE WATCH FOR FREDERICK MD TO HARFORD. DAY SHIFT WILL HAVE TO
DETERMINE IF A FROST/FREEZE OR NEITHER IS NECESSARY.

FRIDAY...MODIFICATION/MODERATION CONTINUES WITH MAX TEMPS IN THE UPR
50S EAST TO MID 60S WEST. CLOUD COVER WILL CONTINUE TO PLAY AN
IMPORTANT ROLE WITH THE SFC RIDGE AXIS NEARLY STATIONARY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MID ATLC HAS XPRNCD WHAT SEEMED LK A NEVERENDING SERIES OF WVS.
BUT FOR A CHG THE WX SHOULD BE RLVTLY BENIGN IN THE XTND - NO
WINTRY CONCERNS FOR ONE THING. OVERALL UPR LVL FLOW COULD BE
CHARACTERIZED AS A FAIRLY HIGH ZNL NEAR THE U.S./CANADIAN BORDER.
THIS WL AID IN KEEPING TEMPS ON THE MODERATE SIDE - NEITHER TOO
HOT OR COLD...MORE LK WHAT SHOULD BE OCCURRING IN MID APR. ONE
SHORT WV IS XPCTD TO PUSH THRU THE NERN U.S. BUT THIS IS LOOKING
LESS AND LESS LK A PCPN PRODUCER.

THE NEXT PCPN CHC LOOKS TO BE ON TUE W/ ANOTHER FROPA. NO COLD
TEMPS TO WORRY ABT - HIGHS IN THE L70S...LOWS IN THE U40S/L50S.

&&

.AVIATION /13Z THURSDAY THROUGH MONDAY/...
VFR AT LEAST INTO THE AFTERNOON ACROSS THE TERMINALS...WITH
STRATOCU AROUND 3-4K FT POSSIBLY MAKING THEIR WAY TO BWI/DCA THIS
AFTERNOON. RISK FOR MVFR CIGS DEVELOPING BEGINNING THIS
EVENING...CONTINUING INTO FRIDAY MORNING.

VFR CONDS ARE XPCTD FOR THE MAJORITY OF THE XTND PD.

&&

.MARINE...
HAVE MADE MINOR MODIFICATIONS TO SCA FOR TODAY. EASTERLY FLOW 10
TO 15 KT WILL BE IN PLACE...WITH GUSTS LIKELY NEAR 20 KT FOR THE
LOWER BAY/POTOMAC WHERE SCA IS IN EFFECT. SCA MAY EXPAND FURTHER
NORTH TONIGHT...AND KEPT HEADLINES THE SAME.

ONSHORE FLOW LOOKS TO BE SUB SCA FOR FRIDAY. WINDS MAY GUST TO 20
KT ON SAT. NO PROBS FORESEEN SUNDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...FREEZE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR
     MDZ004>007.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 3 AM EDT FRIDAY
     FOR ANZ531-536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL 3 AM EDT FRIDAY FOR ANZ532>534-537-
     540-541-543.

&&

$$
BPP/BAJ/WOODY!










000
FXUS61 KLWX 170800
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
400 AM EDT THU APR 17 2014

SYNOPSIS...

HIGH PRESSURE OVER NEW ENGLAND WILL RIDGE SOUTHWARD TOWARD THE
MID-ATLANTIC COAST THROUGH THE REMAINDER OF THE WEEK. AN AREA OF
LOW PRESSURE AND COLD FRONT MAY AFFECT THE AREA SATURDAY. A SECOND
COLD FRONT LOOKS TO MOVE THROUGH THE REGION TUESDAY.

&&

.NEAR TERM /TODAY/...

AS OF 07Z...1041MB SFC HIGH CENTERED OVER NRN MAINE WITH A SFC
RIDGE/COLD AIR DAMMING WEDGE EXTENDING SOUTHWEST DOWN THE PIEDMONT
TO THE DEEP SOUTH STATES. THE RIDGE AXIS ROUGHLY EXTENDS DOWN I-95
WITH ELY FLOW OVER THE BAY AND SRN MD AND MAINLY CALM CONDITIONS
ELSEWHERE. SKIES ARE CLEAR WITH OFFSHORE LOW CLOUDS ALONG THE GULF
STREAM/LABRADOR CURRENT BOUNDARY OFF THE DELMARVA (ACCORDING TO
GOES-EAST IR IMAGERY). TEMPERATURES ARE GENERALLY LOW TO MID 30S
WITH UPR 30S FOR NEARSHORE AND URBAN AREAS.

THE WEDGE PERSISTS TODAY. ABUNDANT SUNSHINE AGAIN...THOUGH EAST OF
THE RIDGE AXIS COULD SEE MARINE LAYER CLOUDS SPREAD IN FROM THE
OCEAN (THE DAY SHIFT WILL NEED TO MONITOR THIS). THE WARM MID APRIL
SUN WILL CONTINUE TO MODIFY THE AIRMASS WITH MAX TEMPS GENERALLY MID
50S ACROSS THE BALT-WASH METRO WITH UPR 50S TO LOW 60S OVER WEST AND
SOUTHWEST SECTIONS OF THE CWA. AREAS WEST OF THE BLUE RIDGE SHOULD
BE WELL PROTECTED FROM LOW CLOUDS AND COULD WARM INTO THE MID 60S.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY/...

THE QUESTION FOR TONIGHT IS WILL LIGHT FLOW PREVENT DECOUPLING AND
WILL LOW CLOUDS SPREAD ACROSS AT LEAST EASTERN SECTIONS OF THE CWA.
NAM FORECAST SOUNDINGS ARE CLOUDIER THAN GFS ONES...AND THUS MET
GUIDANCE MIN TEMPERATURES ARE HIGHER THAN MAV ONES. NORTH CENTRAL
MARYLAND SEEMS TO BE THE COLDEST AREAS WITH AN ACTIVE GROWING SEASON
TONIGHT. WITH MINS FORECAST IN THE LOW 30S...WENT AHEAD WITH A
FREEZE WATCH FOR FREDERICK MD TO HARFORD. DAY SHIFT WILL HAVE TO
DETERMINE IF A FROST/FREEZE OR NEITHER IS NECESSARY.

FRIDAY...MODIFICATION/MODERATION CONTINUES WITH MAX TEMPS IN THE UPR
50S EAST TO MID 60S WEST. CLOUD COVER WILL CONTINUE TO PLAY AN
IMPORTANT ROLE WITH THE SFC RIDGE AXIS NEARLY STATIONARY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...

MID ATLC HAS XPRNCD WHAT SEEMED LK A NEVERENDING SERIES OF WVS.
BUT FOR A CHG THE WX SHOULD BE RLVTLY BENIGN IN THE XTND - NO
WINTRY CONCERNS FOR ONE THING. OVERALL UPR LVL FLOW COULD BE
CHARACTERIZED AS A FAIRLY HIGH ZNL NEAR THE U.S./CANADIAN BORDER.
THIS WL AID IN KEEPING TEMPS ON THE MODERATE SIDE - NEITHER TOO
HOT OR COLD...MORE LK WHAT SHOULD BE OCCURRING IN MID APR. ONE
SHORT WV IS XPCTD TO PUSH THRU THE NERN U.S. BUT THIS IS LOOKING
LESS AND LESS LK A PCPN PRODUCER.

THE NEXT PCPN CHC LOOKS TO BE ON TUE W/ ANOTHER FROPA. NO COLD
TEMPS TO WORRY ABT - HIGHS IN THE L70S...LOWS IN THE U40S/L50S.

&&

.AVIATION /07Z THURSDAY THROUGH MONDAY/...

VFR AT LEAST INTO THE AFTERNOON ACROSS THE TERMINALS. A SFC RIDGE
WILL PERSIST OVER THE AREA WITH AN ONSHORE FLOW I-95 AND EAST. OCEAN
CLOUDS WITH MVFR CIGS MAY MOVE IN LATE TODAY/TONIGHT IN THIS ONSHORE
FLOW. RISK FOR MVFR CIGS ALSO FOR FRIDAY.

VFR CONDS ARE XPCTD FOR THE MAJORITY OF THE XTND PD.

&&

.MARINE...

ONSHORE FLOW ACROSS THE WATERS. OFTEN TIMES THIS FLOW IS STRONGER
THAN PROGGED BY MODELS. SO FAR HOWEVER...ELY FLOW HAS MAINLY BEEN
GUSTING TO 15 KT...LESS THAN PROGGED BY MODELS. STILL EXPECT IT TO
INCREASE THIS MORNING AS NELY FLOW OVERSPREADS THE WATERS. A BIT OF
A LULL DURING THE AFTERNOON...THEN ONSHORE FLOW INCREASES AGAIN. SCA
MOST OF THE MD PART OF THE BAY THIS MORNING...THEN SRN MD WATERS FOR
THE AFTERNOON. MOST OF THE WATERS IN AN SCA TONIGHT. ONSHORE FLOW
LOOKS TO BE SUB SCA FOR FRIDAY.

WINDS MAY GUST TO 20 KT ON SAT. NO PROBS FORESEEN SUNDAY.

&&

.CLIMATE...

RECORD LOWS FOR APRIL 17...
                     3 AM TEMP
BWI...26F IN 1962    33
DCA...26F IN 1875    41
IAD...27F IN 1983    30

&&

.EQUIPMENT...

MANASSAS NWR XTMR IS WORKING INTERMITTENTLY. PHONE TECHNICIANS HAVE
BEEN NOTIFIED.



&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR DCZ001.
MD...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR MDZ004>007-
     009>011-013-014-016>018.
     FREEZE WATCH FROM LATE TONIGHT THROUGH FRIDAY MORNING FOR
     MDZ004>007.
VA...FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR VAZ036>040-042-
     050>057-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 3 AM EDT FRIDAY FOR ANZ532>534-537-
     540-541-543.
     SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 3 AM EDT FRIDAY
     FOR ANZ531-536-538-539-542.
     SMALL CRAFT ADVISORY UNTIL 10 AM EDT THIS MORNING FOR ANZ530-
     531-538-539.

&&

$$
PRODUCTS...BAJ/WOODY!








000
FXUS61 KLWX 170129
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
929 PM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE OVER NEW ENGLAND WILL RIDGE SOUTHWARD TOWARD THE
MID-ATLANTIC COAST THROUGH THE REMAINDER OF THE WEEK. AN AREA OF
LOW PRESSURE AND COLD FRONT MAY AFFECT THE AREA SATURDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
A 1036 MB SFC HIGH THAT IS CENTERED OVER NRN NEW ENGLAND AT 00Z
RIDGES SWD INTO OUR REGION. WINDS HAD ALREADY DECOUPLED AT THE SFC
IN MOST LOCATIONS AFTER SUNSET AND MAINLY CLEAR SKIES ARE
PRESENT...SETTING THE STAGE FOR TEMPS TO DROP QUICKLY TNGT UNDER A
GOOD RADIATIONAL COOLING SETUP. EXCEPT FOR SOME LOCATIONS ALONG
THE WATERS AND IN THE CITIES...TEMPS WILL FALL AOB FREEZING OVNGT.
FOR THE SECOND STRAIGHT NIGHT...FREEZE WARNINGS ARE IN EFFECT FOR
ALL COUNTIES EAST OF THE BLUE RIDGE WHERE THE GROWING SEASON IS
ACTIVE. A HARD FREEZE IS POSSIBLE IN THE MORE RURAL AREAS WEST OF
I-95.

N-NELY WINDS AROUND THE HIGH WILL GRADUALLY VEER OUT OF THE EAST
LATE TNGT AND THU AS THE RIDGE AXIS SHIFTS TOWARD THE MID-ATLANTIC
COAST. MARINE LAYER IS EXPECTED TO ADVECT INLAND UNDER ONSHORE
FLOW IN THE LLVLS. MODELS SHOW MOISTURE TRAPPED BELOW SUBSIDENCE
INVERSION TO THE EAST OF THE BLUE RIDGE. HAVE INCREASED CLOUD
COVER ACCORDINGLY ACROSS THE ERN CWA DURING THE LATE MRNG AND
AFTN. MAX TEMPS WILL BE BELOW NORMAL AND IN THE 50S. SOME
SPOTS IN THE CENTRAL SHENANDOAH VLY AND VLYS OF THE POTOMAC
HIGHLANDS MAY REACH 60F WITH MORE SUNSHINE.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A WEDGE OF HIGH PRESSURE FROM NEW ENGLAND TO THE CAROLINAS WILL
INTERACT WITH AN INVERTED TROUGH OF LOW PRESSURE BETWEEN THE EAST
COAST AND BERMUDA TO PRODUCE A MODERATE NORTHEAST TO EAST FLOW.
WINDS WILL BE GUSTY THURSDAY EVENING BUT THEN DIMINISH OVERNIGHT.
LOW TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL.

AS THE HIGH PRESSURE PULLS AWAY TO THE NORTHEAST...THE PRESSURE
GRADIENT WILL RELAX. AN UPPER LEVEL SYSTEM WILL PIVOT ACROSS
EAST-CENTRAL CANADA FRIDAY AND FRIDAY NIGHT. A SURFACE COLD FRONT
WILL PUSH ACROSS THE REGION LATE FRIDAY NIGHT BUT SHOULD BE A DRY
FRONT AS THERE WILL BE VERY LITTLE LOW LEVEL MOISTURE. HIGH AND LOW
TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL ONCE AGAIN.

AS THE SURFACE FRONT MOVES SOUTH AND EAST SATURDAY MORNING...HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN GREAT LAKES INTO THE MID
ATLANTIC REGION. WINDS WILL BECOME GUSTY OUT OF THE NORTHWEST
SATURDAY BUT SHOULD DIMINISH SATURDAY NIGHT WHEN HIGH PRESSURE
RIDGES SOUTHWARD ALONG THE EASTERN SLOPES OF THE MOUNTAINS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BRING DRY WEATHER WITH NEAR NORMAL TEMPERATURES
TO THE AREA FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK.
RIDGING ERODES BY MONDAY NIGHT WITH LOW PRESSURE APPROACHING FROM
THE MISSISSIPPI VALLEY BY TUESDAY. THIS LOW WILL BRING A CHANCE OF
SHOWERS TO THE AREA LATE MONDAY NIGHT THROUGH TUESDAY. RIDGING THEN
RE-ESTABLISHES ITSELF ACROSS THE AREA DURING THE MIDDLE OF NEXT WEEK
LEADING TO A RETURN TO DRY WEATHER.

&&

.AVIATION /01Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE BUILDS DOWN THROUGH THE MID-ATLANTIC THROUGH THURSDAY.
VFR CONDITIONS EXPECTED DURING THE VALID TAF PERIOD...WITH WINDS
VEERING FROM NORTHEAST TO EAST LATE TNGT AND THU. STRATOCU DECK
ASSOCIATED WITH MARINE LAYER MAY BECOME BKN AFTER 15Z THU OVER ERN
TERMINALS. CIGS WOULD LIKELY BE AROUND 4 KFT.

MARINE STRATOCU HOVERING NEAR VFR-MVFR LVLS THU NIGHT.

VFR FRI THROUGH SATURDAY. NORTHEAST WINDS MAY GUST 15 TO 20 KNOTS
THURSDAY NIGHT NEAR MTN...BWI AND DCA WITH A PRESSURE GRADIENT
ALONG THE COASTAL AREAS. LIGHT AND VARIABLE WINDS FRIDAY AND
FRIDAY NIGHT. WITH THE PASSAGE OF A COLD FRONT SATURDAY...WINDS
WILL BECOME NORTHWEST AND GUST 20 TO 30 KNOTS. VFR CONDITIONS ARE
EXPECTED SUNDAY WITH EASTERLY WINDS 5 TO 10 KNOTS.

&&

.MARINE...
WINDS HAVE SHIFTED OUT OF THE E-NE THIS EVE AND SUBSIDED TO 10-15
KT. WINDS MAY INCREASE A BIT LATER TONIGHT AS WINDS VEER TO THE
EAST AS THE PRESSURE GRADIENT STRENGTHENS EVER SO SLIGHTLY. SCA
IS EXPECTED TO EXPAND ACROSS THE WATERS ON THURSDAY.

NO MARINE HAZARDS EXPECTED THURSDAY NIGHT THROUGH SATURDAY MORNING.
SMALL CRAFT ADVISORY CONDITIONS MAY BE POSSIBLE SATURDAY AFTERNOON
WITH NORTHWEST WINDS EXPECTED TO GUST 20 TO 30 KNOTS. SUB-SMALL
CRAFT ADVISORY CONDITIONS ARE FORECAST SUNDAY INTO EARLY
NEXT WEEK.

&&

.TIDES/COASTAL FLOODING...
WATER LEVELS REMAIN 1 TO 2 FEET ABOVE NORMAL BUT AS WINDS HAVE
DIMINISHED AND THEN VEER TO THE EAST NEGATIVE DEPARTURES WILL
DECREASE THRU THU.

&&

.CLIMATE...
NEAR RECORD COLD TEMPERATURES THIS MORNING...

TWO OF THE THREE MAJOR METRO AREA AIRPORTS...BWI AND IAD...GOT CLOSE
TO THEIR DAILY RECORD LOW TEMPERATURES THIS MORNING.

AT REAGAN NATIONAL AIRPORT...DCA...A MORNING LOW OF 34F WAS WELL
ABOVE THE RECORD OF 29F SET ON THIS DATE IN 1928.

AT BALTIMORE-WASHINGTON INTERNATIONAL...BWI...A MORNING LOW TODAY OF
31F WAS JUST ONE DEGREE OFF THE RECORD LOW FOR THE DATE SET IN 1962.

AT DULLES...IAD...THE MIN OF 30F THIS MORNING WAS TWO DEGREES SHY OF
THE DAILY RECORD LOW OF 28F SET ON THIS DATE IN 1981.

REGARDING RECORD LOW DAILY MAX TEMPERATURES FOR APRIL 16...AS OF 3PM
TODAY...DULLES IS STILL TIED WITH ITS DAILY RECORD LOW-MAX OF 46F
BUT WITH SEVERAL HOURS LEFT OF SUN WILL LIKELY RISE ABOVE 46F. BOTH
BWI AND DCA HAVE RISEN ABOVE THEIR RESPECTIVE DAILY RECORD LOW-MAX
TEMPERATURES FOR APRIL 16.

RECORD LOWS FOR APRIL 17...

BWI...26F IN 1962
DCA...26F IN 1875
IAD...27F IN 1983

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR DCZ001.
MD...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR MDZ004>007-
     009>011-013-014-016>018.
VA...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR VAZ036>040-
     042-050>057-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 3 AM TO 6 PM EDT THURSDAY FOR
     ANZ530>533-538>541.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ536-
     542.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT THURSDAY FOR ANZ534-537-
     543.

&&

$$
SYNOPSIS...JRK/BPP
NEAR TERM...JRK
SHORT TERM...KLW
LONG TERM...DFH
AVIATION...JRK/KLW/DFH
MARINE...JRK/BPP/KLW/DFH
TIDES/COASTAL FLOODING...BPP/JRK
CLIMATE...SMZ









000
FXUS61 KLWX 161918
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
318 PM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD DURING MIDWEEK...BEFORE MOVING OFFSHORE
LATE IN THE WEEK. AN AREA OF LOW PRESSURE AND COLD FRONT MAY
AFFECT THE AREA SATURDAY.

&&

.NEAR TERM /THROUGH THURSDAY/...
DESPITE PLENTY OF SUNSHINE...COLD AIR MASS/NORTHERLY WINDS HAVE HELD
TEMPERATURES DOWN ACROSS THE MID-ATLANTIC TODAY. THIS WILL PAVE THE
WAY FOR ANOTHER COLD NIGHT AS THE CENTER OF HIGH PRESSURE SHIFTS
INTO NEW ENGLAND. CLEAR SKIES IN THE EVENING WILL PROMOTE DECENT
RADIATIONAL COOLING. SOME HIGH CLOUDS MAY INCREASE OVERNIGHT...BUT
LIKELY NOT ENOUGH TO PREVENT TEMPERATURES FROM DROPPING NEAR OR
BELOW FREEZING OVERNIGHT. FREEZE WARNING HAS BEEN ISSUED EAST OF THE
BLUE RIDGE WHERE THE GROWING SEASON IS OFFICIALLY UNDERWAY.
TEMPERATURES MAY BE A LITTLE MORE MARGINAL NEAR THE BAY IN SOUTHERN
MARYLAND BUT INTERIOR PORTIONS SHOULD BE AT OR BELOW FREEZING EVEN
IF THERE/S STILL A LIGHT WIND.

AFTER THE COLD START THURSDAY...MODIFIED AIR MASS AND MOSTLY SUNNY
SKIES SHOULD SUPPORT TEMPERATURES REBOUNDING INTO THE 50S. BUT
WITH A COLD WEDGE AND EASTERLY LOW LEVEL FLOW THIS WILL KEEP
TEMPERATURES BELOW NORMAL.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A WEDGE OF HIGH PRESSURE FROM NEW ENGLAND TO THE CAROLINAS WILL
INTERACT WITH AN INVERTED TROUGH OF LOW PRESSURE BETWEEN THE EAST
COAST AND BERMUDA TO PRODUCE A MODERATE NORTHEAST TO EAST FLOW.
WINDS WILL BE GUSTY THURSDAY EVENING BUT THEN DIMINISH OVERNIGHT.
LOW TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL.

AS THE HIGH PRESSURE PULLS AWAY TO THE NORTHEAST...THE PRESSURE
GRADIENT WILL RELAX. AN UPPER LEVEL SYSTEM WILL PIVOT ACROSS
EAST-CENTRAL CANADA FRIDAY AND FRIDAY NIGHT. A SURFACE COLD FRONT
WILL PUSH ACROSS THE REGION LATE FRIDAY NIGHT BUT SHOULD BE A DRY
FRONT AS THERE WILL BE VERY LITTLE LOW LEVEL MOISTURE. HIGH AND LOW
TEMPERATURES WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL ONCE AGAIN.

AS THE SURFACE FRONT MOVES SOUTH AND EAST SATURDAY MORNING...HIGH
PRESSURE WILL BUILD ACROSS THE EASTERN GREAT LAKES INTO THE MID
ATLANTIC REGION. WINDS WILL BECOME GUSTY OUT OF THE NORTHWEST
SATURDAY BUT SHOULD DIMINISH SATURDAY NIGHT WHEN HIGH PRESSURE
RIDGES SOUTHWARD ALONG THE EASTERN SLOPES OF THE MOUNTAINS.

&&

.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BRING DRY WEATHER WITH NEAR NORMAL TEMPERATURES
TO THE AREA FOR THE SECOND HALF OF THE WEEKEND INTO EARLY NEXT WEEK.
RIDGING ERODES BY MONDAY NIGHT WITH LOW PRESSURE APPROACHING FROM
THE MISSISSIPPI VALLEY BY TUESDAY. THIS LOW WILL BRING A CHANCE OF
SHOWERS TO THE AREA LATE MONDAY NIGHT THROUGH TUESDAY. RIDGING THEN
RE-ESTABLISHES ITSELF ACROSS THE AREA DURING THE MIDDLE OF NEXT WEEK
LEADING TO A RETURN TO DRY WEATHER.

&&

.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE BUILDS DOWN THROUGH THE MID-ATLANTIC THROUGH THURSDAY.
VFR CONDITIONS EXPECTED DURING THE VALID TAF PERIOD...WITH WINDS
VEERING FROM NORTH TO EAST OVER THE NEXT 24 HOURS.

VFR CONDITIONS THURSDAY NIGHT THROUGH SATURDAY. NORTHEAST WINDS MAY
GUST 15 TO 20 KNOTS THURSDAY NIGHT NEAR MTN...BWI AND DCA WITH A
PRESSURE GRADIENT ALONG THE COASTAL AREAS. LIGHT AND VARIABLE WINDS
FRIDAY AND FRIDAY NIGHT. WITH THE PASSAGE OF A COLD FRONT
SATURDAY...WINDS WILL BECOME NORTHWEST AND GUST 20 TO 30 KNOTS. VFR
CONDITIONS ARE EXPECTED SUNDAY WITH EASTERLY WINDS 5 TO 10 KNOTS.

&&

.MARINE...
SCA REMAINS IN EFFECT THROUGH THE REST OF THE AFTERNOON THROUGH MUCH
OF THE BAY AND LOWER TIDAL POTOMAC RIVER. WIND GUSTS SHOULD DIMINISH
LATE...BUT MAY INCREASE AGAIN LATER TONIGHT AS WINDS VEER TO THE
EAST. SCA IS EXPECTED TO EXPAND ACROSS THE WATERS ON THURSDAY.

NO MARINE HAZARDS EXPECTED THURSDAY NIGHT THROUGH SATURDAY MORNING.
SMALL CRAFT ADVISORY CONDITIONS MAY BE POSSIBLE SATURDAY AFTERNOON
WITH NORTHWEST WINDS EXPECTED TO GUST 20 TO 30 KNOTS. SUB-SMALL
CRAFT ADVISORY CONDITIONS ARE FORECAST SUNDAY INTO EARLY
NEXT WEEK.

&&

.TIDES/COASTAL FLOODING...
WATER LEVELS REMAIN 1 TO 2 FEET ABOVE NORMAL BUT AS WINDS DIMINISH
AND THEN VEER TO THE EAST NEGATIVE DEPARTURES WILL CONTINUE TO
EASE TONIGHT.

&&

.CLIMATE...
...NEAR RECORD COLD TEMPERATURES THIS MORNING...

TWO OF THE THREE MAJOR METRO AREA AIRPORTS...BWI AND IAD...GOT CLOSE
TO THEIR DAILY RECORD LOW TEMPERATURES THIS MORNING.

AT REAGAN NATIONAL AIRPORT...DCA...A MORNING LOW OF 34F WAS WELL
ABOVE THE RECORD OF 29F SET ON THIS DATE IN 1928.

AT BALTIMORE-WASHINGTON INTERNATIONAL...BWI...A MORNING LOW TODAY OF
31F WAS JUST ONE DEGREE OFF THE RECORD LOW FOR THE DATE SET IN 1962.

AT DULLES...IAD...THE MIN OF 30F THIS MORNING WAS TWO DEGREES SHY OF
THE DAILY RECORD LOW OF 28F SET ON THIS DATE IN 1981.

REGARDING RECORD LOW DAILY MAX TEMPERATURES FOR APRIL 16...AS OF 3PM
TODAY...DULLES IS STILL TIED WITH ITS DAILY RECORD LOW-MAX OF 46F
BUT WITH SEVERAL HOURS LEFT OF SUN WILL LIKELY RISE ABOVE 46F. BOTH
BWI AND DCA HAVE RISEN ABOVE THEIR RESPECTIVE DAILY RECORD LOW-MAX
TEMPERATURES FOR APRIL 16.

RECORD LOWS FOR APRIL 17...

BWI...26F IN 1962
DCA...26F IN 1875
IAD...27F IN 1983

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR DCZ001.
MD...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR MDZ004>007-
     009>011-013-014-016>018.
VA...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR VAZ036>040-
     042-050>057-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
     ANZ531>534-537-539>541-543.
     SMALL CRAFT ADVISORY FROM 3 AM TO 6 PM EDT THURSDAY FOR
     ANZ530>533-538>541.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ536-
     542.
     SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT
     THURSDAY FOR ANZ534-537-543.

&&

$$
SYNOPSIS...BPP
NEAR TERM...BPP
SHORT TERM...KLW
LONG TERM...DFH
AVIATION...BPP/KLW/DFH
MARINE...BPP/KLW/DFH
TIDES/COASTAL FLOODING...BPP
CLIMATE...SMZ









000
FXUS61 KLWX 161431
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1031 AM EDT WED APR 16 2014

.SYNOPSIS...
HIGH PRESSURE WILL BUILD OVERHEAD DURING MIDWEEK...BEFORE MOVE OFFSHORE
LATE IN THE WEEK. AN AREA OF LOW PRESSURE MAY AFFECT THE AREA SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE BUILDS IN FROM OHIO THIS AFTERNOON. GUSTY WINDS THIS
MORNING SHOULD DIMINISH INTO THE AFTERNOON AS THE GRADIENT
RELAXES. ASIDE FROM A FEW CIRRUS THERE WILL BE PLENTY OF SUNSHINE
TODAY BUT DESPITE THE SUNSHINE MAXIMA WILL STRUGGLE TO GET ABOVE
THE 50 DEGREE MARK GIVEN THE COLD AIR MASS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
MIN TEMPS TONIGHT WILL BE MODERATED FROM NELY FLOW COMING OFF MID
40S OCEAN TEMPS AND LOW 50S BAY TEMPS. LEFT FREEZE WARNING DECISION
TO DAY SHIFT SINCE MOST GUIDANCE HAS ZONES IN THE LOW 30S. PIEDMONT
AND CENTRAL FOOTHILLS AREAS HAVE THE BEST CHANCE OF SEEING
SUBFREEZING TEMPS TONIGHT.

LOW CLOUDS SPREAD EAST INTO SRN MD THURSDAY AS THE ONSHORE FLOW
SATURATES. MAX TEMPS GENERALLY INCREASE NE TO SW BASED ON ONSHORE
FLOW...MID 50S FOR NERN MD TO UPR 50S/LOW 60S IN CNTRL SHEN VLY/KCHO.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
HIGH PRES OVR NEW ENGLAND WL BE TRACKING SLOWLY NE THU NGT AND
FRI...LVG THE MID ATLC IN A WEDGING SITUATION WHICH IS XPCTD TO
LEAD TO A PD OF CAD CONDITIONS - NERLY LO LVL WINDS WHICH WL
CREATE A LOW CLD DECK OVR THE RGN E OF THE MTNS. THE SUNNIEST
PLACE IN THE FCST AREA FRI WL LKLY BE W OF THE BLUE RDG. NO PCPN
IS XPCTD - IF ANYTHING WERE TO DVLP IT WOULD BE DZ. LOWS THU NGT
IN THE 30S/L40S. HIGHS FRI 55-60.

ON SAT AN UPR LVL TROF WL TRACK N OF THE AREA...BUT WL DRAG A CD
FNT THRU THE RGN. SOMETIMES CAD ENVIRONMENTS OF LO CLDS CAN HANG
ARND IN THE MID ATLC UP TO 4 DAYS...BUT THIS DOES NOT LOOK TO BE
THE CASE THIS TIME...AS CD FOPA IS PRBLY THE #1 WAY TO DISLODGE
CAD. BUT W/ THIS WL ALSO COME THE PSBLTY OF RA. HIGHS SAT IN THE
M60S.

SUN LOOKING TO BE THE BETTER DAY OF THE WKND FOR OUTDOOR
ACTIVITIES - SKIES SHOULD CLR AS HIGH PRES RETURNS. LOWS SAT NGT
U30S/L40S. HIGHS IN THE LM60S.

TEMPS XPCTD TO SLOWLY CLIMB DURG THE 1ST PART OF THE NEW WK W/ UPR
LVL FLOW MORE OR LESS ZNL. BY TUE HIGH TEMPS SHOULD BE BACK ABV 70
ACROSS MUCH OF THE AREA.

&&

.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
VFR THROUGH TAF PERIOD AND GUSTY INTO EARLY AFTERNOON AS HIGH
PRESSURE BUILDS NORTHEAST ACROSS THE REGION. ONSHORE FLOW FROM
COLD AIR DAMMING RIDGE TONIGHT...THURSDAY (CONTINUING INTO
SATURDAY).

A CAD SET UP IN XPCTD THU NGT/FRI. THIS WOULD LKLY LEAD TO CIGS IN
THE MVFR RNG. A CD FNT IS XPCTD TO MOVE INTO THE AREA SAT WHICH
COULD PSBLY SPAWN RA/RW. VFR CONDS XPCTD SUN AS HIGH PRES RETURNS.

&&

.MARINE...
HAVE ALLOWED GALES TO EXPIRE AS WIND GUSTS HAVE DROPPED BELOW 30
KT...BUT SCA CONDITIONS ARE LIKELY TO LAST WELL INTO THE AFTERNOON
BEFORE GRADIENT RELAXES ENOUGH. FLOW BECOMES NELY THIS
EVENING...INCREASING TO 20 KT FOR LOWER SRN MD WATERS AFTER
MIDNIGHT (WHEN AN SCA GOES INTO EFFECT)...THEN EXPANDING UP THE
REST OF THE MD BAY BEFORE SUNRISE. ALL BUT THE UPPER TIDAL POTOMAC
IN AN SCA FOR THE DAY THURSDAY WITH NELY FLOW GUSTING AROUND 20
KT.


SMALL CRAFT ADVISORY LEVEL WIND GUSTS ARE POSSIBLE FOR PARTS OF
THE WATERS SAT NIGHT IN A TIGHTENING PRESSURE GRADIENT BETWEEN
LOW PRESSURE DEPARTING TO THE NORTH AND HIGH PRESSURE BUILDING IN
FROM THE WEST.

&&

.TIDES/COASTAL FLOODING...
STRONG NW WINDS HV CAUSED WATER LEVELS IN THE CHES BAY TO DROP TO
2 FT OR MORE FT BLO NRML. TIDAL BLOWOUT CONDITIONS ARE EXPECTED
TO CONTINUE TODAY. MWS HAS BEEN ISSUED FOR THIS. WATER LVLS SHOULD
BEGIN TO RECOVER THIS AFTN.

&&

.CLIMATE...
A VERY COLD AIRMASS FOR MID APRIL IS CAUSING TEMPS TO APPROACH
RECORD MINIMUM TEMPERATURES THIS MORNING. BELOW IS A TABLE OF RECORD
MINIMUM TEMPERATURES FOR APRIL 16 ALONG WITH THE 3 AM TEMPS.

SITE...RECORD LOW TEMP   3 AM WED TEMP
DCA....29 F IN 1928      35
BWI....30 F IN 1962      33
IAD....28 F IN 1981      32

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     DCZ001.
MD...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     MDZ004>007-009>011-013-014-016>018.
VA...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     VAZ036>040-042-050>057-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
     ANZ531>534-537-539>541-543.
     SMALL CRAFT ADVISORY FROM 3 AM TO 6 PM EDT THURSDAY FOR
     ANZ530>533-538>541.
     SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ530-
     535-536-538-542.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ536-
     542.
     SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT
     THURSDAY FOR ANZ534-537-543.

&&

$$
BPP/BAJ/WOODY!








000
FXUS61 KLWX 160758
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
358 AM EDT WED APR 16 2014

.SYNOPSIS...

HIGH PRESSURE WILL BUILD OVERHEAD DURING MIDWEEK...BEFORE MOVE OFFSHORE
LATE IN THE WEEK. AN AREA OF LOW PRESSURE MAY AFFECT THE AREA SATURDAY.

&&

.NEAR TERM /TODAY/...

AS OF 07Z...1028MB SFC HIGH CENTERED OVER SWRN OHIO WILL INTENSIFY
AS IT MOVES NORTHEAST ACROSS THE NRN MID-ATLANTIC TODAY. PRESSURE
GRADIENT SLOWLY DECREASES THROUGH THE DAY...WITH NWLY GUSTS OF 30 TO
35 MPH EASING THROUGH THE AFTERNOON AND BECOMING NLY. NELY FLOW
TONIGHT AS A SFC RIDGE STALLS OVER THE AREA...SETTING UP COLD AIR
DAMMING THAT WILL PERSIST INTO THE WEEKEND. MAX TEMPS AROUND 50F
TODAY CWA WIDE (LOW 50S S OF KCHO).

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY/...

MIN TEMPS TONIGHT WILL BE MODERATED FROM NELY FLOW COMING OFF MID
40S OCEAN TEMPS AND LOW 50S BAY TEMPS. LEFT FREEZE WARNING DECISION
TO DAY SHIFT SINCE MOST GUIDANCE HAS ZONES IN THE LOW 30S. PIEDMONT
AND CENTRAL FOOTHILLS AREAS HAVE THE BEST CHANCE OF SEEING
SUBFREEZING TEMPS TONIGHT.

LOW CLOUDS SPREAD EAST INTO SRN MD THURSDAY AS THE ONSHORE FLOW
SATURATES. MAX TEMPS GENERALLY INCREASE NE TO SW BASED ON ONSHORE
FLOW...MID 50S FOR NERN MD TO UPR 50S/LOW 60S IN CNTRL SHEN VLY/KCHO.

&&

.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...

HIGH PRES OVR NEW ENGLAND WL BE TRACKING SLOWLY NE THU NGT AND
FRI...LVG THE MID ATLC IN A WEDGING SITUATION WHICH IS XPCTD TO
LEAD TO A PD OF CAD CONDITIONS - NERLY LO LVL WINDS WHICH WL
CREATE A LOW CLD DECK OVR THE RGN E OF THE MTNS. THE SUNNIEST
PLACE IN THE FCST AREA FRI WL LKLY BE W OF THE BLUE RDG. NO PCPN
IS XPCTD - IF ANYTHING WERE TO DVLP IT WOULD BE DZ. LOWS THU NGT
IN THE 30S/L40S. HIGHS FRI 55-60.

ON SAT AN UPR LVL TROF WL TRACK N OF THE AREA...BUT WL DRAG A CD
FNT THRU THE RGN. SOMETIMES CAD ENVIRONMENTS OF LO CLDS CAN HANG
ARND IN THE MID ATLC UP TO 4 DAYS...BUT THIS DOES NOT LOOK TO BE
THE CASE THIS TIME...AS CD FOPA IS PRBLY THE #1 WAY TO DISLODGE
CAD. BUT W/ THIS WL ALSO COME THE PSBLTY OF RA. HIGHS SAT IN THE
M60S.

SUN LOOKING TO BE THE BETTER DAY OF THE WKND FOR OUTDOOR
ACTIVITIES - SKIES SHOULD CLR AS HIGH PRES RETURNS. LOWS SAT NGT
U30S/L40S. HIGHS IN THE LM60S.

TEMPS XPCTD TO SLOWLY CLIMB DURG THE 1ST PART OF THE NEW WK W/ UPR
LVL FLOW MORE OR LESS ZNL. BY TUE HIGH TEMPS SHOULD BE BACK ABV 70
ACROSS MUCH OF THE AREA.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...

VFR THROUGH TAF PERIOD AND GUSTY TODAY AS HIGH PRESSURE BUILDS
NORTHEAST ACROSS THE REGION. NW WINDS GUSTING AROUND 30 KT EARLY
THIS MORNING SLOWLY EASE THROUGH THE DAY. ONSHORE FLOW FROM COLD AIR
DAMMING RIDGE TONIGHT...THURSDAY (CONTINUING INTO SATURDAY).

A CAD SET UP IN XPCTD THU NGT/FRI. THIS WOULD LKLY LEAD TO CIGS IN
THE MVFR RNG. A CD FNT IS XPCTD TO MOVE INTO THE AREA SAT WHICH
COULD PSBLY SPAWN RA/RW. VFR CONDS XPCTD SUN AS HIGH PRES RETURNS.

&&

.MARINE...

NWLY GALES OBS HAVE BEEN FAIRLY FEW AND FAR BETWEEN...EXCEPT WHERE
CHANNELING IS OCCURRING (SUCH AS AT COVE PT WHICH HAS HAD GUSTS
AROUND 40 KT). DCA HAD A 240 AM PEAK GUST OF 34 KT...SO THE GALE
WARNING WILL REMAIN UP FOR NOW FOR ALL WATERS. WILL PROBABLY BE ABLE
TO DROP BEFORE 6AM FOR NWRN PORTIONS OF THE WATERS...BUT EXTENDED
UNTIL 9AM FOR LOWER SRN MD WATERS FOR CONTINUED CHANNELING. SCA FOR
ALL WATERS TO 2PM AND MOST MD BAY UNTIL 6PM. FLOW BECOMES NELY THIS
EVENING...INCREASING TO 20 KT FOR LOWER SRN MD WATERS AFTER MIDNIGHT
(WHEN AN SCA GOES INTO EFFECT)...THEN EXPANDING UP THE REST OF THE
MD BAY BEFORE SUNRISE. ALL BUT THE UPPER TIDAL POTOMAC IN AN SCA FOR
THE DAY THURSDAY WITH NELY FLOW GUSTING AROUND 20 KT.


SMALL CRAFT ADVISORY LEVEL WIND GUSTS ARE POSSIBLE FOR PARTS OF
THE WATERS SAT NIGHT IN A TIGHTENING PRESSURE GRADIENT BETWEEN
LOW PRESSURE DEPARTING TO THE NORTH AND HIGH PRESSURE BUILDING IN
FROM THE WEST.

&&

.TIDES/COASTAL FLOODING...

STRONG NW WINDS HV CAUSED WATER LEVELS IN THE CHES BAY TO DROP TO 1
TO 1.5 FT BLO NRML. TIDAL BLOWOUT CONDITIONS ARE EXPECTED TO CONTINUE
TODAY WITH ANOMALIES UP TO 2 FEET BELOW NORMAL. MWS HAS BEEN ISSUED FOR
THIS. WATER LVLS SHOULD BEGIN TO RECOVER THIS AFTN.

&&

.CLIMATE...

A VERY COLD AIRMASS FOR MID APRIL IS CAUSING TEMPS TO APPROACH
RECORD MINIMUM TEMPERATURES THIS MORNING. BELOW IS A TABLE OF RECORD
MINIMUM TEMPERATURES FOR APRIL 16 ALONG WITH THE 3 AM TEMPS.

SITE...RECORD LOW TEMP   3 AM WED TEMP
DCA....29 F IN 1928      35
BWI....30 F IN 1962      33
IAD....28 F IN 1981      32

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     DCZ001.
     FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR DCZ001.
MD...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     MDZ004>007-009>011-013-014-016>018.
     FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR MDZ011-013-014-
     016>018.
     FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR MDZ004>007-009-
     010.
VA...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR
     VAZ036>040-042-050>057-501-502.
     FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR VAZ052>057.
     FREEZE WARNING UNTIL 9 AM EDT THIS MORNING FOR VAZ036>040-042-
     050-051-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 PM EDT THIS
     EVENING FOR ANZ531-532-537-539>541.
     SMALL CRAFT ADVISORY FROM 3 AM TO 6 PM EDT THURSDAY FOR
     ANZ530>533-538>541.
     GALE WARNING UNTIL 6 AM EDT EARLY THIS MORNING FOR ANZ530>532-
     535>542.
     SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 2 PM EDT THIS
     AFTERNOON FOR ANZ530-535-536-538-542.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ536-
     542.
     SMALL CRAFT ADVISORY FROM 9 AM THIS MORNING TO 6 PM EDT THIS
     EVENING FOR ANZ533-534-543.
     SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT
     THURSDAY FOR ANZ534-537-543.
     GALE WARNING UNTIL 9 AM EDT THIS MORNING FOR ANZ533-534-543.

&&

$$
PRODUCTS...BAJ/WOODY!









000
FXUS61 KLWX 160109
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
909 PM EDT TUE APR 15 2014

.SYNOPSIS...
AN EXCEPTIONALLY COLD AIRMASS FOR THIS TIME OF YEAR WILL QUICKLY
TAKE HOLD OF THE AREA BY LATE THIS EVENING. HIGH PRESSURE WILL BUILD
OVERHEAD DURING THE MIDDLE OF THE WEEK...THEN MOVE OFFSHORE LATE IN
THE WEEK. AN AREA OF LOW PRESSURE MAY AFFECT THE AREA DURING THE
FIRST HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
THE COLD FRONT HAS MOVED OFF TO OUR EAST AND GUSTY NORTHWEST WINDS
TONIGHT WILL CONTINUE TO USHER IN UNUSUALLY COLD CONDITIONS
BEHIND THE BOUNDARY. PRECIPITATION NEAR AND EAST OF I-95 THIS
EVENING WILL GRADUALLY END FROM WEST TO EAST TOWARD MIDNIGHT.
THERE HAVE BEEN REPORTS OF SLEET AND SNOW AS COLDER AIR INTERACTS
WITH THE PRECIPITATION. ANY SNOW ACCUMULATION WILL BE CONFINED TO
GRASSY SURFACES...MAINLY NEAR THE MASON-DIXON LINE ACROSS THE
HIGHER ELEVATIONS. SNOWFALL ACCUMULATIONS AROUND AN INCH ARE
POSSIBLE ACROSS THESE AREAS. ELSEWHERE...LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED BEFORE PRECIPITATION ENDS LATE THIS
EVENING.

DRIER AIR WILL WORK ITS WAY INTO THE AREA LATE TONIGHT AS HIGH
PRESSURE APPROACHES FROM THE WEST. HOWEVER...IT WILL TURN OUT
BLUSTERY AND VERY COLD FOR THIS TIME OF YEAR. A FREEZE WARNING
REMAINS IN EFFECT FOR LOCATIONS EAST OF THE BLUE RIDGE MOUNTAINS
WHERE THE GROWING SEASON HAS BEGUN. MIN TEMPS WILL RANGE FROM
UPPER TEENS ALONG THE ALLEGHENY FRONT...TO THE MID AND UPPER 20S
IN THE WASHINGTON AND BALTIMORE SUBURBS...TO THE LOWER 30S IN
DOWNTOWN WASHINGTON AND BALTIMORE AS WELL AS SOUTHERN MARYLAND.

HIGH PRESSURE WILL BUILD OVER THE REGION WEDNESDAY...BRINGING DRY
CONDITIONS ALONG WITH PLENTY OF SUNSHINE. HOWEVER...IT WILL BE
CHILLY FOR THIS TIME OF YEAR. MAX TEMPS WILL RANGE FROM NEAR 40 IN
THE MOUNTAINS TO THE UPPER 40S AND LOWER 50S ELSEWHERE. THE MAX
TEMP FORECASTS ARE AROUND 15 TO 20 DEGREES BELOW CLIMO.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE WEDNESDAY NIGHT ALONG WITH CLEAR SKIES/LIGHT WINDS
WILL PRODUCE A MORE TYPICAL RADIATIONAL COOLING NIGHT AND
THEREFORE TEMPERATURES ARE EXPECTED TO BOTTOM OUT AGAIN. FREEZE
WATCH HAS BEEN ISSUED EAST OF THE BLUE RIDGE INTO THURSDAY
MORNING.

HIGH PRESSURE CENTER MOVES OFF THE NORTHEAST COAST AND THEN WEDGES
DOWN THROUGH THE MID-ATLANTIC TO END THE WEEK. TEMPS MAY REBOUND
SOME...BUT WILL STILL BE BELOW AVERAGE THROUGH FRIDAY. CLOUDS LIKELY
INCREASE THURSDAY NIGHT INTO FRIDAY WITH A WEAK DISTURBANCE OFF THE
COAST AND ALSO AHEAD OF THE NEXT UPSTREAM SHORTWAVE TROUGH BUT FAVOR
A DRY FORECAST ATTM.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A COUPLE AREAS OF LOW PRESSURE WILL BRUSH PAST THE REGION FOR THE
FIRST PART OF THIS WEEKEND...WITH A CHANCE OF RAIN MAINLY DURING THE
DAY SATURDAY. THE MODELS HAVE MOST RECENTLY TRENDED DOWNWARD WITH
THE PROBABILITY OF RAIN AND WITH RAINFALL AMOUNTS AS A RESULT OF
ENERGY FROM THE NORTHERN AND SOUTHERN BRANCHES OF THE JET STREAM
REMAINING SPLIT INSTEAD OF PHASING. THIS LEAVES TO TWO WEAKER WAVES
OF LOW PRESSURE...ONE PASSING TO THE NORTHWEST ACROSS THE GREAT
LAKES AND THE OTHER MOVING OFFSHORE INTO THE ATLANTIC.

ANOTHER PUSH OF COOL AIR WILL ACCOMPANY HIGH PRESSURE MOVING DOWN
FROM CENTRAL CANADA FOR THE SECOND HALF OF THE WEEKEND...THOUGH NOT
NEARLY AS COLD OF AN AIRMASS AS IS EXPECTED DURING THE MIDDLE OF
THIS WEEK.

LOW PRESSURE WILL APPROACH THE AREA FROM THE WEST EARLY NEXT WEEK
BRINGING A CHANCE OF RAIN MONDAY INTO TUESDAY.

&&

.AVIATION /01Z WEDNESDAY THROUGH SUNDAY/...
ANY LEFTOVER PRECIPITATION WILL END BY LATE THIS EVENING. VFR
CONDITIONS ARE EXPECTED OVERNIGHT WITH GUSTY NORTHWEST WINDS. VFR
CONDITIONS WILL CONTINUE THROUGH WEDNESDAY. WINDS WILL GRADUALLY
SHIFT TO THE EAST-NORTHEAST AND DECREASE IN SPEED WEDNESDAY
AFTERNOON.

HIGH PRESSURE WED MOVES OFF THE COAST TOWARD THE END OF THE WEEK.
ONSHORE FLOW MAY LEAD TO FLIGHT RESTRICTIONS IN LOW CLOUDS THURSDAY
NIGHT INTO FRIDAY.

SUB-VFR POSSIBLE IN RAIN SATURDAY...THEN VFR SUNDAY. EASTERLY
WINDS 5 TO 10 KNOTS SATURDAY BECOME WEST OR NORTHWEST AROUND 10
KNOTS BY SUNDAY.

&&

.MARINE...
WILL CONTINUE WITH A GALE WARNING FOR THE WATERS TONIGHT. THE
HIGHEST CONFIDENCE FOR GALE-FORCE WINDS WILL BE ACROSS THE MIDDLE
PORTION OF THE BAY AND LOWER TIDAL POTOMAC RIVER. ELSEWHERE...IT
WILL TURN OUT TO BE MORE MARGINAL WITH GUSTS AROUND 30 TO 35
KNOTS.

SCA CONTINUES FOR MUCH OF WEDNESDAY...BEFORE GRADIENT RELAXES LATER
IN THE AFTERNOON FOR DIMINISHING WINDS. NO SCA CONDITIONS ARE
EXPECTED WEDNESDAY NIGHT. MARGINAL SCA POSSIBLY AGAIN LATE
THURSDAY OR THURSDAY NIGHT WITH EAST WINDS.

SMALL CRAFT ADVISORY LEVEL WIND GUSTS ARE POSSIBLE FOR PARTS OF
THE WATERS SATURDAY NIGHT INTO SUNDAY IN A TIGHTENING PRESSURE
GRADIENT BETWEEN LOW PRESSURE DEPARTING TO THE NORTH AND HIGH
PRESSURE BUILDING IN FROM THE WEST.

&&

.TIDES/COASTAL FLOODING...
GUSTY NORTHWEST WINDS TONIGHT INTO WEDNESDAY WILL CAUSE WATER
LEVELS TO RAPIDLY DECREASE. TIDAL BLOWOUT CONDITIONS ARE EXPECTED
WEDNESDAY WITH ANOMALIES AROUND 2 FEET BELOW NORMAL.

&&

.CLIMATE...
JUST A DAY AFTER RECORD HIGH MINIMUM TEMPERATURES WERE OBSERVED...AN
EXCEPTIONALLY COLD AIRMASS FOR THIS TIME OF YEAR WILL APPROACH RECORD
MINIMUM TEMPERATURES EARLY WEDNESDAY MORNING. BELOW IS A TABLE OF
RECORD MINIMUM TEMPERATURES FOR APRIL 16 ALONG WITH THE FORECAST
MINIMUM TEMPERATURE FOR EARLY WEDNESDAY MORNING.

SITE...PREVIOUS RECORD...FORECAST MINIMUM...
DCA....29 F IN 1928......32 F...............
BWI....30 F IN 1962......29 F...............
IAD....28 F IN 1981......28 F...............

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     MORNING FOR DCZ001.
     FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR DCZ001.
MD...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     MORNING FOR MDZ004>007-009>011-013-014-016>018.
     FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR MDZ011-013-
     014-016>018.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     MDZ004>007-009-010.
VA...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     MORNING FOR VAZ036>040-042-050>057-501-502.
     FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR VAZ052>057.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     VAZ036>040-042-050-051-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR
     ANZ531>534-537-539>541-543.
     GALE WARNING UNTIL 6 AM EDT WEDNESDAY FOR ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 AM TO 2 PM EDT WEDNESDAY FOR
     ANZ530-535-536-538-542.

&&

$$
SYNOPSIS...DFH
NEAR TERM...BJL
SHORT TERM...BPP
LONG TERM...DFH
AVIATION...BJL/BPP/CAS
MARINE...BJL/BPP/CAS
TIDES/COASTAL FLOODING...BJL
CLIMATE...BJL









000
FXUS61 KLWX 151918
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
318 PM EDT TUE APR 15 2014

.SYNOPSIS...

AN EXCEPTIONALLY COLD AIRMASS FOR THIS TIME OF YEAR WILL QUICKLY
TAKE HOLD OF THE AREA BY LATE THIS EVENING. HIGH PRESSURE WILL BUILD
OVERHEAD DURING THE MIDDLE OF THE WEEK...THEN MOVE OFFSHORE LATE IN
THE WEEK. AN AREA OF LOW PRESSURE MAY AFFECT THE AREA DURING THE
FIRST HALF OF THE WEEKEND.

&&

.NEAR TERM /THROUGH WEDNESDAY/...

COLD FRONT HAS MADE IT THROUGH DCA AND BWI AS OF 2PM..AND PRESSING
QUICKLY SE. TEMPS DROP QUICKLY FROM THE 60S AND LOW 70S INTO THE
50S...WITH 40S SOON TO FOLLOW. DROPPED FROM 68 TO 53 HERE AT
STERLING VA IN 90 MINS. GOOD THING THE COLD FRONT DID WAS UNDERCUT
THE LINE OF CONVECTION THAT WAS DUMPING HEAVY RAIN FOR A TIME OVER
THE METRO AREAS. END OF THE PRECIP IS NOT EXPECTED UNTIL LATER
TONIGHT AND WITH THE COLD AIR CONTINUING TO COME IN...THERE WILL
BE SOME SNOW IN AREAS...MAINLY ABOVE 1500 FEET...BUT COULD EVEN BE
SOME WET NON ACCUM SNOWFLAKES IN THE METRO AREAS AFTER DARK BEFORE
THE PRECIP ENDS. FREEZE WARNING FOR LATE TONIGHT INTO WED MORNING
FOR VEGETATION...BUT ALSO COULD BE SOME ICY SPOTS WED MORN IN
AREAS THAT DONT DRY IN THE OVERNIGHT WIND. HIGHS ONLY AROUND 50 ON
WED UNDER SUNNY SKIES.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...

HIGH PRESSURE WEDNESDAY NIGHT ALONG WITH CLEAR SKIES/LIGHT WINDS
WILL PRODUCE A MORE TYPICAL RADIATIONAL COOLING NIGHT AND
THEREFORE TEMPERATURES ARE EXPECTED TO BOTTOM OUT AGAIN. FREEZE
WATCH HAS BEEN ISSUED EAST OF THE BLUE RIDGE INTO THURSDAY
MORNING.

HIGH PRESSURE CENTER MOVES OFF THE NORTHEAST COAST AND THEN WEDGES
DOWN THROUGH THE MID-ATLANTIC TO END THE WEEK. TEMPS MAY REBOUND
SOME...BUT WILL STILL BE BELOW AVERAGE THROUGH FRIDAY. CLOUDS LIKELY
INCREASE THURSDAY NIGHT INTO FRIDAY WITH A WEAK DISTURBANCE OFF THE
COAST AND ALSO AHEAD OF THE NEXT UPSTREAM SHORTWAVE TROUGH BUT FAVOR
A DRY FORECAST ATTM.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

A COUPLE AREAS OF LOW PRESSURE WILL BRUSH PAST THE REGION FOR THE
FIRST PART OF THIS WEEKEND...WITH A CHANCE OF RAIN MAINLY DURING THE
DAY SATURDAY. THE MODELS HAVE MOST RECENTLY TRENDED DOWNWARD WITH
THE PROBABILITY OF RAIN AND WITH RAINFALL AMOUNTS AS A RESULT OF
ENERGY FROM THE NORTHERN AND SOUTHERN BRANCHES OF THE JET STREAM
REMAINING SPLIT INSTEAD OF PHASING. THIS LEAVES TO TWO WEAKER WAVES
OF LOW PRESSURE...ONE PASSING TO THE NORTHWEST ACROSS THE GREAT
LAKES AND THE OTHER MOVING OFFSHORE INTO THE ATLANTIC.

ANOTHER PUSH OF COOL AIR WILL ACCOMPANY HIGH PRESSURE MOVING DOWN
FROM CENTRAL CANADA FOR THE SECOND HALF OF THE WEEKEND...THOUGH NOT
NEARLY AS COLD OF AN AIRMASS AS IS EXPECTED DURING THE MIDDLE OF
THIS WEEK.

LOW PRESSURE WILL APPROACH THE AREA FROM THE WEST EARLY NEXT WEEK
BRINGING A CHANCE OF RAIN MONDAY INTO TUESDAY.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...

IFR CONDITIONS UNDER SHOWERS THIS AFTERNOON INTO EVENING. THEN CLEARING.
WINDS ALREADY NW AND GUSTING 18 TO 32KT AT TAF SITES... EXCEPT MTN
WHICH IS IMMINENT.

HIGH PRESSURE WED MOVES OFF THE COAST TOWARD THE END OF THE WEEK.
ONSHORE FLOW MAY LEAD TO FLIGHT RESTRICTIONS IN LOW CLOUDS THURSDAY
NIGHT INTO FRIDAY.

SUB-VFR POSSIBLE IN RAIN SATURDAY...THEN VFR SUNDAY. EASTERLY
WINDS 5 TO 10 KNOTS SATURDAY BECOME WEST OR NORTHWEST AROUND 10
KNOTS BY SUNDAY.

&&

.MARINE...

GALES UP ON THE WATERS...FIRST FOR GUSTY SHOWERS...THEN FOR THE NW
BLAST AFTER THE FRONT WHICH BEGINS MOVING OVER THE WATERS DURING
THE MID AFTERNOON. GALE WARNING IN EFFECT THROUGH THE NIGHT.

SCA CONTINUES INTO MUCH OF WEDNESDAY...BEFORE GRADIENT RELAXES LATER
IN THE AFTERNOON FOR DIMINISHING WINDS. NO SCA CONDITIONS ARE
EXPECTED WEDNESDAY NIGHT. MARGINAL SCA POSSIBLY AGAIN LATE THURSDAY
OR THURSDAY NIGHT WITH EAST WINDS.

SMALL CRAFT ADVISORY LEVEL WIND GUSTS ARE POSSIBLE FOR PARTS OF
THE WATERS SATURDAY NIGHT INTO SUNDAY IN A TIGHTENING PRESSURE
GRADIENT BETWEEN LOW PRESSURE DEPARTING TO THE NORTH AND HIGH
PRESSURE BUILDING IN FROM THE WEST.

&&

.CLIMATE...

JUST A DAY AFTER RECORD HIGH MINIMUM TEMPERATURES WERE OBSERVED...AN
EXCEPTIONALLY COLD AIRMASS FOR THIS TIME OF YEAR COULD APPROACH
RECORD MINIMUM TEMPERATURES EARLY TOMORROW MORNING. BELOW IS A TABLE
OF RECORD MINIMUM TEMPERATURES FOR APRIL 16 ALONG WITH THE FORECAST
MINIMUM TEMPERATURE FOR EARLY TOMORROW MORNING.

SITE...PREVIOUS RECORD...FORECAST MINIMUM...
DCA....29 F IN 1928......33 F...............
BWI....30 F IN 1962......31 F...............
IAD....28 F IN 1981......31 F...............

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     MORNING FOR DCZ001.
     FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR DCZ001.
MD...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     MORNING FOR MDZ004>007-009>011-013-014-016>018.
     FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR MDZ011-013-
     014-016>018.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     MDZ004>007-009-010.
VA...FREEZE WATCH FROM LATE WEDNESDAY NIGHT THROUGH THURSDAY
     MORNING FOR VAZ036>040-042-050>057-501-502.
     FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR VAZ052>057.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     VAZ036>040-042-050-051-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR
     ANZ531>534-537-539>541-543.
     GALE WARNING UNTIL 6 AM EDT WEDNESDAY FOR ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 AM TO 2 PM EDT WEDNESDAY FOR
     ANZ530-535-536-538-542.

&&

$$
SYNOPSIS...DFH
NEAR TERM...CAS
SHORT TERM...BPP
LONG TERM...DFH
AVIATION...BPP/CAS
MARINE...BPP/CAS
CLIMATE...DFH








000
FXUS61 KLWX 151419
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1019 AM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE THROUGH THE MID-ATLANTIC REGION TODAY.
ARCTIC HIGH PRESSURE BUILDS INTO THE REGION TONIGHT AND WEDNESDAY.
THE CENTER OF THE HIGH SHIFTS NORTHEAST INTO NEW ENGLAND BUT
CONTINUES TO RIDGE SOUTHWARD INTO THE MID-ATLANTIC REGION LATE IN
THE WEEK.

&&

.NEAR TERM /UNTIL 7 PM THIS EVENING/...

STRONG COLD FRONT PASSING OVER OUR WESTERN COUNTIES IN THE
MOUNTAINS AT 10AM IS CAUSING A FEW THREATS TO DEAL WITH...

FIRST IS ENOUGH WIND SHEAR IN THE LOW LEVELS TO CAUSE SOME
ROTATING SEGMENTS IN LOWER S MD DURING THE MID TO LATE MORNING.
THERE IS A ISOLATED THREAT OF DAMAGING WINDS WITH THESE AS THEY
MOVE EAST. RADAR TEAM IS MONITORING. THING LIMITING THIS IS THE
LOW LEVEL STABILITY IN THE BOUNDARY LAYER AND THE VERY LIMITED
AMOUNT OF INSTAB OVER THAT.

SECOND IS ISOLATED FLOODING THREAT. THE ENHANCED AREAS ON RADAR
OVER THE ADJACENT BAY COUNTIES AND BALTIMORE AT 10AM ARE PRODUCING
A HALF INCH TO INCH OF RAIN IN ABOUT AN HOUR AS THEY PASS BY. AT
THIS TIME BASED ON 1 HR AND 3 HR FLASH FLOOD GUIDANCE...THINK
GENERALLY THE RAIN WILL BE ABSORBED BY THE SPRING GROUND AND
EMERGING VEGETATION. HOWEVER SOME ISOLATED AREAS OF LOCALIZED
FLOODING ARE POSSIBLE LATE THIS MORNING IN THESE COUNTIES AND
BALTIMORE.

THIRD IS COLD AIR COMING IN WITH PRECIP AROUND. LATEST MESO MODEL
GUIDANCE HAS SNOW CHANGEOVER IN THE POTOMAC HIGHLANDS IN OUR
HIGHEST SPOTS OUT WEST CHANGING OVER IN THE EARLY AFTERNOON. OTHER
THREAT OF CHANGEOVER AND SOME LIGHT ACCUMS ON THE BLUE RIDGE AND N
CENTRAL MD HIGHLANDS ISNT EXPECTED UNTIL EVENING JUST BEFORE THE
PRECIP KICKS OUT. AT THIS POINT NOT EXPECTING SNOWFLAKES OVER THE
METRO AREA...BUT SOME WET NON ACCUM FLAKES POSSIBLE AT THE END.

EXPECT THE MORNING LINE OF HEAVY PRECIP OVER THE BAY COUNTIES TO
KICK EAST DURING THE LATE MORNING. THAT SHOULD LEAVE A FEW HOURS
OF SCT SHOWERS BEFORE ANOTHER SHIELD OF PRECIP DEVELOPS OVER THE
AREA EARLY THIS AFTERNOON WHICH WILL LAST THE REST OF THE DAY.

&&

.SHORT TERM /7 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...

A SIGNIFICANT PRESSURE SURGE TO ACCOMPANY THE STRONG CAA WILL
PRODUCE GUSTY WINDS BEHIND THE FRONT. CONSIDERED A WIND ADVISORY...
PARTICULARLY FOR THE HIGHER ELEVATION RIDGES BUT WINDS AT THE TOP OF
THE MIXING LAYER ONLY MARGINALLY SUPPORTIVE OF ADVISORY LVL WIND
GUSTS. THE STRONGEST WINDS WILL OCCUR IN THE ERY EVE...ALLOWING THE
DAY SHIFT TO LOOK THRU THE LATEST TRENDS IN OBS AND NEAR-TERM
GUIDANCE.

MIN TEMPS TNGT AOB FREEZING FOR THE ENTIRE CWA EXCEPT IN THE CITIES
AND ALONG THE WRN SHORE OF THE CHSPK BAY. FREEZE WARNINGS ISSUED
FOR COUNTIES EAST OF THE BLUE RIDGE...WHERE THE GROWING SEASON HAS
ALREADY BEGUN.


WEDNESDAY...HIGH PRESSURE BUILDS NORTHEAST ACROSS THE NRN
MID-ATLANTIC...BECOMING A 1045 MB OR SO SFC HIGH OVER NEW ENGLAND
WEDNESDAY NIGHT. MAX TEMPS AROUND 50F ARE 15 OR SO DEGREES BELOW
NORMAL. SUNNY WITH PERHAPS SOME WISPY CIRRUS IN THE AFTERNOON
OVERRUNNING A LOW AMPLITUDE RIDGE TO OUR WEST. STRONG NWLY GUSTS
IN THE MORNING EASE THROUGH MIDDAY. PARTIAL DECOUPLING WEDNESDAY
NIGHT WITH MIN TEMPS AROUND 30F INLAND...MID TO UPR 30S URBAN AND
NEARSHORE. FREEZE WARNING LIKELY NEEDED...THOUGH MAYBE NOT FOR ALL
ZONES EAST OF THE BLUE RIDGE LIKE TONIGHT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
SFC PRESSURE RIDGE/COLD AIR DAMMING PERSISTS WEDNESDAY NIGHT INTO
SATURDAY...WHEN THE NEXT DISTURBANCE DISLODGES THE ONSHORE FLOW.
EXPECT BELOW NORMAL TEMPS TO CONTINUE WITH THE ONSHORE FLOW. AREAS
EAST OF THE RIDGE AXIS BECOME SATURATED BY FRIDAY WITH DRIZZLE OR
LIGHT RAIN POSSIBLE THEN THROUGH FRIDAY NIGHT. UNCERTAINTY ON
SOUTHWARD EXTEND OF THE UPPER TROUGH MOVING WEST ACROSS THE NERN
CONUS ON SATURDAY. CURRENTLY THE 00Z GFS IS MORE AMPLIFIED THAN THE
00Z ECMWF. THE COOL PATTERN CONTINUES THROUGH AT LEAST SUNDAY AS
CANADIAN HIGH PRESSURE BUILDING IN BEHIND THE SATURDAY SYSTEM.

&&

.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS AND VSBYS PREVAIL THROUGH THE DAY WITH INTERMITTENT IFR
IN HEAVIER RAIN. ISO THUNDER THREAT TDA EAST OF MRB AHEAD OF THE
FRONT. SLY FLOW GUSTS UP TO 30 KT AHEAD OF THE COLD FRONT THAT IS
APPROACHING FROM THE WEST. STRONG COLD FRONT CROSSES THE TERMINALS
LATE THIS MORNING THROUGH THE EARLY AFTERNOON WITH A QUICK NWLY
WIND SHIFT. GUSTS TO 35 KT LATE THIS AFTERNOON THROUGH TONIGHT
ACROSS THE TERMINALS WITH A FEW SNOWFLAKES POSSIBLE AT THE END OF
PRECIP WEST OF BALT-WASH CORRIDOR.

VFR WEDNESDAY AS HIGH PRESSURE BUILDS NORTHEAST ACROSS THE REGION
WEDNESDAY. GUSTY NW WINDS EASE THROUGH MIDDAY. ONSHORE FLOW FROM
COLD AIR DAMMING RIDGE THEN INTO SATURDAY WHEN THE NEXT LOW PASSES
THE REGION. SUB-VFR CONDS POSSIBLY SPREAD FROM THE EAST FRIDAY AS
THE ONSHORE FLOW SATURATES.

&&

.MARINE...
SLY SCA LEVEL WINDS ACROSS THE WATERS. HOWEVER...AT 6AM THE SCA
UPGRADES TO A GALE WARNING TO ACCOUNT FOR POSSIBLE SLY GALES IN
HEAVIER SHOWERS LATER THIS MORNING...AS WELL AN EXPECTED LATE AFTN
ONSET OF NWLY GALES BEHIND THE COLD FRONT. GALE WARNING THROUGH
TONIGHT WITH 30-40 KT GUSTS EXPECTED ACROSS THE WATERS.

GALES POSSIBLE FOR LOWER SRN MD WATERS EARLY WEDNESDAY MORNING...BUT
BUT HAD CONFIDENCE TO SIMPLY ISSUE AN SCA FOR ALL WATERS UNTIL
3PM AND MD BAY WATERS UNTIL 6PM WEDNESDAY AS HIGH PRESSURE BUILDS
NORTHEAST ACROSS THE REGION. ONSHORE FLOW THEN OVER THE REGION
INTO SATURDAY. ELY FLOW 15 TO 20 KT/SCA LIKELY FOR THURSDAY.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES REMAIN STEADY ERY THIS MRNG AROUND 3/4 FT
ALONG THE WRN SHORE OF THE CHSPK BAY AND BELOW 1/2 FT IN THE TIDAL
POTOMAC. NO COASTAL FLOODING EXPECTED.

NWLY GALES TUESDAY NIGHT AND STRONG SCA WINDS INTO WEDNESDAY
AFTERNOON WILL CAUSE BLOWOUT TIDE CONDITIONS FOR THE LOW TIDES ON
WEDNESDAY. OF PARTICULAR CONCERN IS THE MIDDAY/AFTERNOON LOW TIDE
CYCLE WHERE WATER LEVELS LOOK TO DROP TO AROUND 2 FEET BELOW MLLW.

&&

.CLIMATE...
RECORD DAILY HIGH MINIMUM TEMPERATURES WERE SET FOR DCA AND IAD...
AND TIED FOR BWI. BELOW IS A TABLE OF RECORDS FOR APRIL 14 AND LOW
TEMPERATURES OBSERVED.

SITE...PREV RECORD......LOW...
DCA....63F IN 1896......65F...
BWI....62F IN 1896......62F...
IAD....58F IN 1972......63F...

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR DCZ001.
MD...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR MDZ011-013-
     014-016>018.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     MDZ004>007-009-010.
VA...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR VAZ052>057.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     VAZ036>040-042-050-051-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR
     ANZ531>534-537-539>541-543.
     GALE WARNING UNTIL 6 AM EDT WEDNESDAY FOR ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 AM TO 2 PM EDT WEDNESDAY FOR
     ANZ530-535-536-538-542.

&&

$$
SYNOPSIS...BAJ/JRK
NEAR TERM...CAS
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/JRK/CAS
MARINE...BAJ/JRK/CAS
TIDES/COASTAL FLOODING...
CLIMATE...









000
FXUS61 KLWX 150923 AAA
AFDLWX

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
523 AM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE THROUGH THE MID-ATLANTIC REGION TODAY.
ARCTIC HIGH PRESSURE BUILDS INTO THE REGION TONIGHT AND WEDNESDAY.
THE CENTER OF THE HIGH SHIFTS NORTHEAST INTO NEW ENGLAND BUT
CONTINUES TO RIDGE SOUTHWARD INTO THE MID-ATLANTIC REGION LATE IN
THE WEEK.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRIMARY WX PLAYER FOR THE MID-ATLANTIC REGION IS A STRONG COLD FRONT
THAT WILL MOVE THRU THE AREA TDA. THIS FRONT WAS LOCATED ON THE WRN
SIDE OF THE APPALACHIANS AT 07Z AND IS MARKED BY A SHARP TEMP
GRADIENT AND WIND SHIFT FROM S TO NW.

STRONG SLY WINDS AND A DEEP POLEWARD MOISTURE TRANSPORT IN
PRE-FRONTAL WARM SECTOR HAVE RESULTED IN MILD AND MOIST CONDITIONS
ACROSS THE CWA WITH TEMPS IN THE MID TO UPPER 60S AND DEWPOINTS
NEAR 60S BEFORE SUNRISE. UPSTREAM COVERAGE OF SHOWERS HAVE
INCREASED OVER WRN NC/SWRN VA IN THE PAST FEW HRS AND WILL EXPAND
INTO THE CWA FROM SW TO NE THRU DAYBREAK. EXPECT WIDESPREAD
SHOWERS ALONG AND WEST OF I-95 FOR MUCH OF THE MRNG. ENVIRONMENT
FAIRLY STABLE ATTM BUT MODEST INSTABILITY WILL DEVELOP LATER
THIS MRNG AND AFTN AHEAD OF THE FRONT AS LLVL THETA-E RIDGE
PROGRESSES NWD INTO THE MID-ATLANTIC REGION. STRONG WIND FIELD
ALOFT WILL SUPPORT THE POTENTIAL FOR LOW-TOPPED CONVECTION THAT
COULD ORGANIZE INTO A LINE. IF CONVECTION DOES BECOME ORGANIZED...
0-3 KM SHERB VALUES ABOVE 1 INDICATE THE POTENTIAL FOR DAMAGING
WINDS ALONG AND EAST OF THE BLUE RIDGE LATE THIS MRNG AND ERY THIS
AFTN. WITH DENSE CLOUD COVER THIS MRNG...THE LIMITING INGREDIENT
FOR SEVERE WEATHER WILL BE INSTABILITY. FCST SBCAPE VALUES ONLY
AROUND 500 J/KG AS SEEN ON THE LATEST NAM/RAP SOUNDINGS. THE
LATER TIMING OF THE FROPA COULD ALLOW FOR A BIT MORE INSTABILITY
TO DEVELOP IN SRN MD THIS AFTN. RAINFALL AMOUNTS OF 1-2 INCHES
ARE EXPECTED ALONG AND EAST OF THE BLUE RIDGE. LOCALLY HIGHER
AMOUNTS COULD CAUSE ISO FLOODING PROBLEMS MAINLY IN POOR DRAINAGE
AREAS.

THE COLD FRONT WILL MOVE THRU THE MTS THIS MRNG AND EAST OF THE BLUE
RIDGE THIS AFTN. A SHARP TEMP DROP WILL OCCUR BEHIND THE FRONT AS
UNSEASONABLY COLD AIR MOVES IN. IT WILL ESSENTIALLY FEEL LIKE A
CHANGE IN SEASONS (FROM SPRING AHEAD OF THE FRONT TO MORE LIKE
WINTER) IN LESS THAN 12 HOURS. THERMAL PROFILES COOL FAST ENOUGH
TO SUPPORT RAIN CHANGING TO A BRIEF PERIOD OF SNOW FROM WEST TO
EAST LATE THIS AFTN INTO THIS EVE AT HIGHER ELEVATIONS AS FAR
EAST AS THE BLUE RIDGE AND EVEN EXTREME NRN CARROLL AND FREDERICK
COUNTIES BEFORE ENDING. A WARM GROUND IN MID APRIL WILL MAKE IT
CHALLENGING FOR SNOW TO ACCUMULATE BUT ITS CERTAINLY POSSIBLE FOR
LIGHT ACCUMULATIONS ON GRASSY SURFACES AT ELEVATIONS ABOVE 1000
FT. USPLOPE LIFT WILL SUPPORT SNOW TO CONTINUE LONGER ALONG THE
WRN SLOPES OF THE ALLEGHENY FRONT. SNOWFALL AMOUNTS AROUND AN INCH
ARE POSSIBLE OUT THERE.

A SIGNIFICANT PRESSURE SURGE TO ACCOMPANY THE STRONG CAA WILL
PRODUCE GUSTY WINDS BEHIND THE FRONT. CONSIDERED A WIND ADVISORY...
PARTICULARLY FOR THE HIGHER ELEVATION RIDGES BUT WINDS AT THE TOP OF
THE MIXING LAYER ONLY MARGINALLY SUPPORTIVE OF ADVISORY LVL WIND
GUSTS. THE STRONGEST WINDS WILL OCCUR IN THE ERY EVE...ALLOWING THE
DAY SHIFT TO LOOK THRU THE LATEST TRENDS IN OBS AND NEAR-TERM
GUIDANCE.

MIN TEMPS TNGT AOB FREEZING FOR THE ENTIRE CWA EXCEPT IN THE CITIES
AND ALONG THE WRN SHORE OF THE CHSPK BAY. FREEZE WARNINGS ISSUED
FOR COUNTIES EAST OF THE BLUE RIDGE...WHERE THE GROWING SEASON HAS
ALREADY BEGUN.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...HIGH PRESSURE BUILDS NORTHEAST ACROSS THE NRN
MID-ATLANTIC...BECOMING A 1045 MB OR SO SFC HIGH OVER NEW ENGLAND
WEDNESDAY NIGHT. MAX TEMPS AROUND 50F ARE 15 OR SO DEGREES BELOW
NORMAL. SUNNY WITH PERHAPS SOME WISPY CIRRUS IN THE AFTERNOON
OVERRUNNING A LOW AMPLITUDE RIDGE TO OUR WEST. STRONG NWLY GUSTS
IN THE MORNING EASE THROUGH MIDDAY. PARTIAL DECOUPLING WEDNESDAY
NIGHT WITH MIN TEMPS AROUND 30F INLAND...MID TO UPR 30S URBAN AND
NEARSHORE. FREEZE WARNING LIKELY NEEDED...THOUGH MAYBE NOT FOR ALL
ZONES EAST OF THE BLUE RIDGE LIKE TONIGHT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
SFC PRESSURE RIDGE/COLD AIR DAMMING PERSISTS WEDNESDAY NIGHT INTO
SATURDAY...WHEN THE NEXT DISTURBANCE DISLODGES THE ONSHORE FLOW.
EXPECT BELOW NORMAL TEMPS TO CONTINUE WITH THE ONSHORE FLOW. AREAS
EAST OF THE RIDGE AXIS BECOME SATURATED BY FRIDAY WITH DRIZZLE OR
LIGHT RAIN POSSIBLE THEN THROUGH FRIDAY NIGHT. UNCERTAINTY ON
SOUTHWARD EXTEND OF THE UPPER TROUGH MOVING WEST ACROSS THE NERN
CONUS ON SATURDAY. CURRENTLY THE 00Z GFS IS MORE AMPLIFIED THAN THE
00Z ECMWF. THE COOL PATTERN CONTINUES THROUGH AT LEAST SUNDAY AS
CANADIAN HIGH PRESSURE BUILDING IN BEHIND THE SATURDAY SYSTEM.

&&

.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS AND VSBYS PREVAIL THROUGH THE DAY WITH INTERMITTENT IFR
IN HEAVIER RAIN. ISO THUNDER THREAT TDA EAST OF MRB AHEAD OF THE
FRONT. SLY FLOW GUSTS UP TO 30 KT AHEAD OF THE COLD FRONT THAT IS
APPROACHING FROM THE WEST. STRONG COLD FRONT CROSSES THE TERMINALS
LATE THIS MORNING THROUGH THE EARLY AFTERNOON WITH A QUICK NWLY
WIND SHIFT. GUSTS TO 35 KT LATE THIS AFTERNOON THROUGH TONIGHT
ACROSS THE TERMINALS WITH A FEW SNOWFLAKES POSSIBLE AT THE END OF
PRECIP WEST OF BALT-WASH CORRIDOR.

VFR WEDNESDAY AS HIGH PRESSURE BUILDS NORTHEAST ACROSS THE REGION
WEDNESDAY. GUSTY NW WINDS EASE THROUGH MIDDAY. ONSHORE FLOW FROM
COLD AIR DAMMING RIDGE THEN INTO SATURDAY WHEN THE NEXT LOW PASSES
THE REGION. SUB-VFR CONDS POSSIBLY SPREAD FROM THE EAST FRIDAY AS
THE ONSHORE FLOW SATURATES.

&&

.MARINE...
SLY SCA LEVEL WINDS ACROSS THE WATERS. HOWEVER...AT 6AM THE SCA
UPGRADES TO A GALE WARNING TO ACCOUNT FOR POSSIBLE SLY GALES IN
HEAVIER SHOWERS LATER THIS MORNING...AS WELL AN EXPECTED LATE AFTN
ONSET OF NWLY GALES BEHIND THE COLD FRONT. GALE WARNING THROUGH
TONIGHT WITH 30-40 KT GUSTS EXPECTED ACROSS THE WATERS.

GALES POSSIBLE FOR LOWER SRN MD WATERS EARLY WEDNESDAY MORNING...BUT
BUT HAD CONFIDENCE TO SIMPLY ISSUE AN SCA FOR ALL WATERS UNTIL
3PM AND MD BAY WATERS UNTIL 6PM WEDNESDAY AS HIGH PRESSURE BUILDS
NORTHEAST ACROSS THE REGION. ONSHORE FLOW THEN OVER THE REGION
INTO SATURDAY. ELY FLOW 15 TO 20 KT/SCA LIKELY FOR THURSDAY.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES REMAIN STEADY ERY THIS MRNG AROUND 3/4 FT
ALONG THE WRN SHORE OF THE CHSPK BAY AND BELOW 1/2 FT IN THE TIDAL
POTOMAC. NO COASTAL FLOODING EXPECTED.

NWLY GALES TUESDAY NIGHT AND STRONG SCA WINDS INTO WEDNESDAY
AFTERNOON WILL CAUSE BLOWOUT TIDE CONDITIONS FOR THE LOW TIDES ON
WEDNESDAY. OF PARTICULAR CONCERN IS THE MIDDAY/AFTERNOON LOW TIDE
CYCLE WHERE WATER LEVELS LOOK TO DROP TO AROUND 2 FEET BELOW MLLW.

&&

.CLIMATE...
RECORD DAILY HIGH MINIMUM TEMPERATURES WERE SET FOR DCA AND IAD...
AND TIED FOR BWI. BELOW IS A TABLE OF RECORDS FOR APRIL 14 AND LOW
TEMPERATURES OBSERVED.

SITE...PREV RECORD......LOW...
DCA....63F IN 1896......65F...
BWI....62F IN 1896......62F...
IAD....58F IN 1972......63F...

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR DCZ001.
MD...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR MDZ011-013-
     014-016>018.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     MDZ004>007-009-010.
VA...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR VAZ052>057.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     VAZ036>040-042-050-051-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR
     ANZ531>534-537-539>541-543.
     GALE WARNING UNTIL 6 AM EDT WEDNESDAY FOR ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 AM TO 2 PM EDT WEDNESDAY FOR
     ANZ530-535-536-538-542.

&&

$$
SYNOPSIS...BAJ/JRK
NEAR TERM...JRK
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ/JRK
MARINE...BAJ/JRK
TIDES/COASTAL FLOODING...JRK/BAJ
CLIMATE...BAJ









000
FXUS61 KLWX 150803
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
403 AM EDT TUE APR 15 2014

.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE THROUGH THE MID-ATLANTIC REGION FROM
THE WEST TODAY. HIGH PRESSURE WILL MOVE NORTHEAST ACROSS THE
NORTHERN MID-ATLANTIC WEDNESDAY...WITH COLD AIR DAMMING LINGERING
UNTIL LOW PRESSURE AFFECTS THE REGION ON SATURDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
PRIMARY WX PLAYER FOR THE MID-ATLANTIC REGION IS A STRONG COLD FRONT
THAT WILL MOVE THRU THE AREA TDA. THIS FRONT WAS LOCATED ON THE WRN
SIDE OF THE APPALACHIANS AT 07Z AND IS MARKED BY A SHARP TEMP
GRADIENT AND WIND SHIFT FROM S TO NW.

STRONG SLY WINDS AND A DEEP POLEWARD MOISTURE TRANSPORT IN
PRE-FRONTAL WARM SECTOR HAVE RESULTED IN TEMPS IN MILD AND MOIST
CONDITIONS ACROSS THE CWA. UPSTREAM COVERAGE OF SHOWERS HAVE
INCREASED OVER WRN NC/SWRN VA IN THE PAST FEW HRS AND WILL EXPAND
INTO THE CWA FROM SW TO NE THRU THE MRNG. EXPECT WIDESPREAD SHOWERS
ALONG AND WEST OF I-95 FOR MUCH OF THE MRNG. THERE IS VERY LITTLE
INSTABILITY OVER THE AREA RIGHT NOW BUT INSTABILITY WILL INCREASE
LATER THIS MRNG AND THIS AFTN AHEAD OF THE FRONT AS LLVL THETA-E
RIDGE PROGRESSES NWD. DESPITE SBCAPE VALUES ONLY AROUND 500 J/KG AS
SEEN ON THE LATEST NAM/RAP SOUNDINGS...STRONG WIND FIELD ALOFT WILL
SUPPORT THE POTENTIAL FOR LOCALLY DAMAGING WINDS WITH ANY LOW-TOPPED
CONVECTION THAT DEVELOPS. A LINEAR MODE OF CONVECTION WOULD BE
FAVORED WITH THIS SETUP. IF CONVECTION DOES BECOME ORGANIZED...0-3
KM SHERB VALUES ABOVE 1 INDICATE THE POTENTIAL FOR DAMAGING WINDS
ALONG AND EAST OF THE BLUE RIDGE LATE THIS MRNG AND ERY THIS AFTN.
DAY 1 OUTLOOK FROM SPC HAS US IN A 5 PERCENT RISK OF DAMAGING WINDS.
LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE TDA. LOCALLY HVY
RAINFALL AMOUNTS AROUND 2 INCHES ARE POSSIBLE...AND COULD CAUSE SOME
ISO FLOODING PROBLEMS IN POOR DRAINAGE AREAS.

THE COLD FRONT WILL MOVE THRU THE MTS THIS MRNG AND EAST OF THE BLUE
RIDGE THIS AFTN. A SHARP TEMP DROP WILL OCCUR BEHIND THE FRONT AS
UNSEASONABLY COLD AIR MOVES IN. IT WILL ESSENTIALLY FEEL LIKE A
CHANGE IN SEASONS FROM LATE SPRING AHEAD OF THE FRONT TO MORE LIKE
WINTER IN LESS THAN 12 HOURS. A SIGNIFICANT POST-FRONTAL PRESSURE
SURGE AND STRONG CAA WILL PRODUCE GUSTY WINDS.

&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...HIGH PRESSURE BUILDS NORTHEAST ACROSS THE NRN
MID-ATLANTIC...BECOMING A 1045 MB OR SO SFC HIGH OVER NEW ENGLAND
WEDNESDAY NIGHT. MAX TEMPS AROUND 50F ARE 15 OR SO DEGREES BELOW
NORMAL. SUNNY WITH PERHAPS SOME WISPY CIRRUS IN THE AFTERNOON
OVERRUNNING A LOW AMPLITUDE RIDGE TO OUR WEST. STRONG NWLY GUSTS
IN THE MORNING EASE THROUGH MIDDAY. PARTIAL DECOUPLING WEDNESDAY
NIGHT WITH MIN TEMPS AROUND 30F INLAND...MID TO UPR 30S URBAN AND
NEARSHORE. FREEZE WARNING LIKELY NEEDED...THOUGH MAYBE NOT FOR ALL
ZONES EAST OF THE BLUE RIDGE LIKE TONIGHT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
SFC PRESSURE RIDGE/COLD AIR DAMMING PERSISTS WEDNESDAY NIGHT INTO
SATURDAY...WHEN THE NEXT DISTURBANCE DISLODGES THE ONSHORE FLOW.
EXPECT BELOW NORMAL TEMPS TO CONTINUE WITH THE ONSHORE FLOW. AREAS
EAST OF THE RIDGE AXIS BECOME SATURATED BY FRIDAY WITH DRIZZLE OR
LIGHT RAIN POSSIBLE THEN THROUGH FRIDAY NIGHT. UNCERTAINTY ON
SOUTHWARD EXTEND OF THE UPPER TROUGH MOVING WEST ACROSS THE NERN
CONUS ON SATURDAY. CURRENTLY THE 00Z GFS IS MORE AMPLIFIED THAN THE
00Z ECMWF. THE COOL PATTERN CONTINUES THROUGH AT LEAST SUNDAY AS
CANADIAN HIGH PRESSURE BUILDING IN BEHIND THE SATURDAY SYSTEM.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
MVFR CIGS AND VSBYS PREVAIL THROUGH THE DAY WITH INTERMITTENT IFR
IN HEAVIER RAIN. ISO THUNDER THREAT TODAY. SLY FLOW GUSTS UP TO
30 KT AHEAD OF THE COLD FRONT APPROACHING FROM THE WEST. STRONG
COLD FRONT CROSSES THE TERMINALS LATE THIS MORNING THROUGH THE
EARLY AFTERNOON WITH A QUICK NWLY WIND SHIFT. GUSTS TO 35 KT LATE
THIS AFTERNOON THROUGH TONIGHT ACROSS THE TERMINALS WITH A FEW
SNOWFLAKES AT END OF PRECIP WEST OF BALT-WASH CORRIDOR.

VFR WEDNESDAY AS HIGH PRESSURE BUILDS NORTHEAST ACROSS THE REGION
WEDNESDAY. GUSTY NW WINDS EASE THROUGH MIDDAY. ONSHORE FLOW FROM
COLD AIR DAMMING RIDGE THEN INTO SATURDAY WHEN THE NEXT LOW PASSES
THE REGION. SUB-VFR CONDS POSSIBLY SPREAD FROM THE EAST FRIDAY AS
THE ONSHORE FLOW SATURATES.

&&

.MARINE...
SLY SCA LEVEL WINDS ACROSS THE WATERS. HOWEVER...AT 6AM THE SCA
UPGRADES TO A GALE WARNING TO ACCOUNT FOR POSSIBLE SLY GALES IN
RAIN LATER THIS MORNING...AS WELL AN EXPECTED 4PM ONSET OF NWLY
GALES BEHIND THE COLD FRONT. GALE WARNING THROUGH TONIGHT WITH 40
KT POSSIBLE OVER ALL OF THE WATERS.

GALES POSSIBLE FOR LOWER SRN MD WATERS EARLY WEDNESDAY MORNING...BUT
BUT HAD CONFIDENCE TO SIMPLY ISSUE AN SCA FOR ALL WATERS UNTIL
3PM AND MD BAY WATERS UNTIL 6PM WEDNESDAY AS HIGH PRESSURE BUILDS
NORTHEAST ACROSS THE REGION. ONSHORE FLOW THEN OVER THE REGION
INTO SATURDAY. ELY FLOW 15 TO 20 KT/SCA LIKELY FOR THURSDAY.

&&

.TIDES/COASTAL FLOODING...
NWLY GALES TUESDAY NIGHT AND STRONG SCA WINDS INTO WEDNESDAY
AFTERNOON WILL CAUSE BLOWOUT TIDE CONDITIONS FOR THE LOW TIDES ON
WEDNESDAY. OF PARTICULAR CONCERN IS THE MIDDAY/AFTERNOON LOW TIDE
CYCLE WHERE WATER LEVELS LOOK TO DROP TO AROUND 2 FEET BELOW MLLW.

&&

.CLIMATE...
RECORD DAILY HIGH MINIMUM TEMPERATURES WERE SET FOR DCA AND IAD...
AND TIED FOR BWI. BELOW IS A TABLE OF RECORDS FOR APRIL 14 AND LOW
TEMPERATURES OBSERVED.

SITE...PREV RECORD......LOW...
DCA....63F IN 1896......65F...
BWI....62F IN 1896......62F...
IAD....58F IN 1972......63F...

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR DCZ001.
MD...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR MDZ011-013-
     014-016>018.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     MDZ004>007-009-010.
VA...FREEZE WARNING FROM 3 AM TO 9 AM EDT WEDNESDAY FOR VAZ052>057.
     FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM EDT WEDNESDAY FOR
     VAZ036>040-042-050-051-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT WEDNESDAY FOR
     ANZ531>534-537-539>541-543.
     GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
     ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 AM TO 2 PM EDT WEDNESDAY FOR
     ANZ530-535-536-538-542.

&&

$$
SYNOPSIS...BAJ/JRK
NEAR TERM...JRK
SHORT TERM...BAJ
LONG TERM...BAJ
AVIATION...BAJ
MARINE...BAJ
TIDES/COASTAL FLOODING...BAJ
CLIMATE...BAJ









000
FXUS61 KLWX 150207
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1007 PM EDT MON APR 14 2014

.SYNOPSIS...
A COLD FRONT EXTENDING FROM SOUTHERN QUEBEC CANADA...ACROSS THE
EASTERN GREAT LAKES AND EASTERN OHIO VALLEY...AND INTO THE
TENNESSEE VALLEY WILL PUSH ACROSS THE APPALACHIAN MOUNTAINS
OVERNIGHT. THIS FRONT WILL PUSH ACROSS OUR REGION DURING THE DAY
ON TUESDAY. HIGH PRESSURE WILL BUILD EAST INTO THE NORTHERN MID-
ATLANTIC WEDNESDAY AND REMAIN OVER THE AREA THROUGH FRIDAY. LOW
PRESSURE MAY IMPACT THE REGION ON SATURDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
EVEN AT THIS HOUR IN THE EVENING...TEMPERATURES ARE IN THE UPPER
60S TO LOWER 70S ACROSS MUCH OF THE REGION AHEAD OF A STRONG COLD
FRONT. DEWPOINT TEMPERATURES HAVE INCREASED IN MANY LOCATIONS INTO
THE LOWER TO MIDDLE 50S INDICATING GOOD LOW LEVEL MOISTURE. DON`T
ANTICIPATE MUCH OF A RAPID CHANGE IN EITHER OVERNIGHT DUE TO WARM
ADVECTION OF BOTH ELEMENTS IN BALANCE WITH NOCTURNAL COOLING.
TEMPERATURES AND DEWPOINT TEMPERATURES MAY RISE A FEW DEGREES AT BEST.

WE ARE THINKING CHANCE POPS IN THE NORTHERN AND EASTERN PORTIONS
OF THE REGION THE REMAINDER OF THIS EVENING AS A FEW RAIN SHOWERS
MOVE ACROSS THE REGION. RAIN AMOUNTS LESS THAN ONE TENTH OF AN
INCH. LIKELY POPS ACROSS THE CENTRAL SHENANDOAH VALLEY AND
VIRGINIA PIEDMONT THIS EVENING AND OVERNIGHT WILL LEAD TO ABOUT
ONE QUARTER OF AN INCH OF RAIN IN PLACES.

ALTHOUGH SOUTHERLY WINDS HAVE DECREASED DURING THE PAST FEW
HOURS...EXPECT SOUTHERLY WINDS TO INCREASE ONCE AGAIN LATER IN THE
OVERNIGHT HOURS INTO TUESDAY MORNING AHEAD OF THE COLD FRONT WITH
ADDITIONAL DAYTIME HEATING AND MIXING. ADDITIONAL RAIN SHOWERS AND
DEVELOPING THUNDERSTORMS WILL OCCUR AHEAD OF THE MAIN COLD FRONT
FROM WEST TO EAST TUESDAY MORNING THROUGH MID AFTERNOON.

THE COLD FRONT IS EXPECTED TO CROSS THE POTOMAC HIGHLANDS AROUND
12Z...REACH THE I-95 CORRIDOR AROUND 18Z...BEFORE MOVING EAST OF
THE CHESAPEAKE BAY AND ALONG THE DELMARVA EAST COAST BY 00Z
WEDNESDAY. ALONG AND AHEAD OF THIS FRONT...GUSTY RAIN SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP. RAIN AMOUNTS DURING THE DAY
TUESDAY WILL AVERAGE ONE HALF TO ONE INCH WITH ISOLATED HIGHER
AMOUNTS IN SHOWERS AND THUNDERSTORMS.

DESPITE A LOT OF RAIN WITH THIS ACTIVITY...THE MAIN THREAT FROM
THESE SHOWERS AND STORMS WILL BE GUSTY WINDS...GUSTING IN EXCESS
OF 50 MPH. SOUTHERLY WINDS WILL BECOME GUSTY EVEN BEFORE THE
HEAVIEST RAIN AND THUNDERSTORMS DEVELOP. SOUTHERLY WINDS WILL
GUST 20 TO 30 MPH AHEAD OF THIS ACTIVITY AND ITS COLD FRONT. ONCE THE
SURFACE COLD FRONT PASSES AND ITS UPPER LEVEL SUPPORT SWINGS
ACROSS THE REGION...NORTHWEST WINDS WILL BECOME STRONG AND GUSTING
30 TO 40 MPH FREQUENTLY LATE TUESDAY. THESE STRONG WINDS WILL
USHER IN UNSEASONABLY CHILLY AIR.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
COLD FRONT MOVES OFFSHORE THROUGH THE EARLY EVENING HOURS ON
TUESDAY. STRONG COLD AIR ADVECTION CONTINUES TO SUPPORT FALLING
TEMPERATURES. FOLLOWED SREFS FOR POPS DECREASING FROM WEST TO EAST
THROUGH EARLY EVENING. IF COLD AIR CAN CATCH UP TO THE BACK EDGE OF
PRECIP QUICKLY ENOUGH...A FEW WET SNOWFLAKES COULD OCCUR BUT THE
BULK OF THE PRECIP WILL END AS RAIN.

FOCUS THEN TURNS TO THE COLD AIR. WITH COLD ADVECTION...MOMENTUM
TRANSFER WILL KEEP GUSTY NORTHWEST WINDS GOING INTO THE NIGHT. BUT
ITS THESE NORTHWEST WINDS THAT ARE BRINGING IN A MUCH COLDER AIR
MASS AND DESPITE THE WIND TEMPERATURES HAVE THE POTENTIAL TO DROP
BELOW FREEZING BY DAYBREAK ESPECIALLY IN THE SUBURBS. THE GROWING
SEASON WILL BEGIN APRIL 15TH EAST OF THE BLUE RIDGE...WHICH MEANS
THESE AREAS WILL BE CANDIDATES FOR FROST/FREEZE HEADLINES.
CONSIDERING FORECAST MINIMA...WILL BE ISSUING A FREEZE WATCH FOR
TUESDAY NIGHT/WEDNESDAY MORNING.

HIGH PRESSURE BUILDS IN FOR WEDNESDAY. SUNSHINE WILL RETURN BUT
MAXIMA MAY STRUGGLE TO REACH 50. HIGH PRESSURE WEDNESDAY NIGHT
WILL ALSO PAVE THE WAY FOR ANOTHER COLD NIGHT WITH RADIATIONAL
COOLING IN PLAY. ADDITIONAL FREEZE HEADLINES MAY BECOME NECESSARY
WEDNESDAY NIGHT INTO THURSDAY MORNING. MODERATING TREND SHOULD
BEGIN THURSDAY WITH HIGH PRESSURE MOVING OFF THE COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
SURFACE HIGH PRESSURE WILL DEPART INTO THE NORTH ATLANTIC THURSDAY
NIGHT...LEAVING BEHIND A SURFACE RIDGE AXIS WEDGED AGAINST THE
EASTERN SLOPES OF THE APPALACHIANS. THIS WILL RESULT IN A CONTINUED
ONSHORE FLOW THROUGH FRIDAY.

AN UPPER-LEVEL TROUGH AND SURFACE LOW PRESSURE APPROACH THE AREA
FROM THE WEST LATE FRIDAY NIGHT INTO SATURDAY. THE LATEST GUIDANCE
SHOWS A WIDE SPREAD IN THE DEPTH OF THE APPROACHING TROUGH AND
STRENGTH OF LOW PRESSURE AT THE SURFACE. RAIN IS LIKELY FOR AT LEAST
PART OF THE AREA SATURDAY...BUT THERE IS A MODERATE TO HIGH LEVEL OF
UNCERTAINTY IN INTENSITY/COVERAGE.

WEAK RIDGING AND MILDER WEATHER LOOKS TO BUILD INTO THE AREA LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.

&&

.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
VFR CONDITIONS EXPECTED AT ALL TERMINALS THE REMAINDER OF THE
EVENING WITH A 5 TO 10 KNOT SOUTHERLY WIND AND OCCASIONAL GUSTS TO
20 KNOTS.

INCREASING RAIN SHOWER COVERAGE IN THE SOUTHWEST OVERNIGHT COULD
BRIEFLY BRING ABOUT MVFR CONDITIONS AT CHO. OTHERWISE...VFR
CONDITIONS ARE ALL TERMINALS UNTIL AROUND 8Z WHEN WE ANTICIPATE
RAIN SHOWERS TO BECOME MORE IN COVERAGE AND POSSIBLY BE
ACCOMPANIED BY A FEW RUMBLES OF THUNDER. MVFR CONDITIONS WITH RAIN
ACTIVITY.

IFR CONDITIONS SEEM MORE PROBABLE BETWEEN 14Z AND 20Z WITH
INCREASING RAIN SHOWER AND THUNDERSTORM COVERAGE AS A STRONG COLD
FRONT PASSES ACROSS THE REGION.

WHILE RAIN ACTIVITY DECREASES FROM WEST TO EAST...WINDS WILL SHIFT
TO THE NORTHWEST AND BECOME QUITE GUSTY. GUSTS BETWEEN 30 AND 40
KNOTS EXPECTED LATE TUESDAY AND TUESDAY NIGHT.

HIGH PRESSURE BUILDS IN FOR LESS WIND WEDNESDAY. NO SIGNIFICANT WX
EXPECTED TO END THE WEEK.

&&

.MARINE...
A SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH THE OVERNIGHT
HOURS AND MUCH OF TUESDAY.

A STRONG COLD FRONT WILL SWING ACROSS THE WATERS BY LATE AFTN
TUE...SPREADING NEAR GALE GUSTS ON TUE AFTN. HIGHEST CONFIDENCE IN
GALES IS BEHIND THE FRONT WITH A NORTHWEST SURGE AND GALE WARNING
HAS BEEN ISSUED FOR THIS PERIOD.

HIGH PRESSURE BUILDS IN FOR WEDNESDAY. SMALL CRAFT ADVISORY
LEVEL WIND GUSTS ARE POSSIBLE FOR PARTS OF THE WATERS THURSDAY
NIGHT...AND AGAIN OVER THE WEEKEND DEPENDING ON THE EVOLUTION OF
LOW PRESSURE MOVING NEAR THE AREA.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES REMAIN IN THE 1/2-3/4 FOOT RANGE FOR THE
WRN SHORES OF THE MD CHSPK BAY. THE STEADY AND GUSTY SLY WINDS WILL
KEEP THESE LEVELS STEADY OVERNIGHT AND THRU EARLY TUESDAY MRNG. A
FULL MOON UPCOMING...LIKELY HELPING WATER LEVELS TO APPROACH MINOR
FLOOD CRITERIA AT THE MORE SENSITIVE LOCATIONS AROUND TIMES OF THE
HIGHER HIGH TIDES EARLY TUESDAY MRNG. CBOFS GUIDANCE HOWEVER FCSTS
TIDAL LVLS BELOW MINOR COASTAL FLOODING THRESHOLDS AT ALL SITES.

&&

.CLIMATE...
DEPENDING ON HOW LOW TEMPERATURES GET THIS EVENING...RECORD DAILY
HIGH MINIMUM TEMPERATURES COULD BE TIED OR BROKEN AT DCA...BWI AND
IAD. BELOW IS A TABLE OF RECORDS FOR THE DAY AND LOW TEMPERATURES
OBSERVED SO FAR.

SITE...PREVIOUS RECORD...LOW SO FAR...
DCA....63 F IN 1896......65 F.........
BWI....62 F IN 1896......62 F.........
IAD....58 F IN 1972......63 F.........

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR DCZ001.
MD...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR MDZ004>007-009>011-013-014-016.
VA...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR VAZ036>040-042-050>057-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ530>543.
     GALE WARNING FROM 6 PM TUESDAY TO 6 AM EDT WEDNESDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...KLW
NEAR TERM...KLW
SHORT TERM...BPP
LONG TERM...DFH
AVIATION...BPP/KLW/DFH
MARINE...BPP/KLW/DFH
TIDES/COASTAL FLOODING...
CLIMATE...









000
FXUS61 KLWX 141935
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
335 PM EDT MON APR 14 2014

.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFF THE EAST COAST THIS EVENING. A COLD
FRONT WILL CROSS THE APPALACHIANS LATE TONIGHT AND MOVE THROUGH
THE AREA TUESDAY. HIGH PRESSURE WILL BUILD EAST INTO THE NORTHERN
MID-ATLANTIC WEDNESDAY AND REMAIN OVER THE AREA THROUGH FRIDAY.
LOW PRESSURE MAY IMPACT THE REGION ON SATURDAY.

&&

.NEAR TERM /THROUGH TUESDAY/...
A POWERFUL SPRING STORM SYSTEM HAS BEEN SWINGING ACROSS A BETTER
PART OF THE CONUS YESTERDAY INTO TODAY. A DEEP AND COLD UPPER TROUGH
HAS SPENT MUCH OF TODAY PUSHING DOWN THE LENGTH OF THE PLAINS FROM
CNTRL CANADA...DOWN TO THE TX GULF COAST. TO GET A FEEL FOR WHAT`S
ON THE WAY...EVEN IF THE EFFECTS AREN`T SIMILAR - THE COLD FRONT HAS
BEEN DROPPING TEMPS A SOLID 20-30F DEG IN JUST A FEW HRS ALONG MUCH
OF THE BOUNDARY.

THE PRECIP AMOUNTS W/ THIS LARGE-SCALE HAVEN`T BEEN TOO TERRIBLY
HIGH...MAINLY OVER THE GULF COAST STATES WHERE MOST OF THE MOISTURE
FETCH REMAINS BUT THIS WILL PLAY INTO OUR AREA GETTING MODERATE
AMOUNTS OF QPF ON TUE. THE SFC LOW PRESSURE SYSTEM RESPONSIBLE FOR
THE INITIAL PUSH OF COLD AIR YESTERDAY AND TODAY WILL ESSENTIALLY
TAKE-OFF TOWARD THE NE TONIGHT AND LARGELY AWAY FROM OUR AREA INTO
THE OVERNIGHT HRS. THE SFC LOW HERE IN THE MID AFTN HRS IS ALREADY
MOVING UP THE NRN SIDE OF THE ST. LAWRENCE CHANNEL. THE COLD FRONT
ASSOCIATED W/ THIS STORM SYSTEM WILL ALSO BE TAKEN AWAY W/ THE
PARENT SFC LOW LATER TONIGHT...UNTIL ANOTHER SECONDARY SFC LOW
DEVELOPS OVER THE CNTRL APLCNS OVERNIGHT. THIS FEATURE...IN CONCERT
W/ YET ANOTHER SFC LOW DEVELOPING OVER SRN APLCNS EARLY TUE WILL
THEN BRING A REJUVENATED COLD FRONT ACROSS OUR REGION MIDDAY
TUE...BRINGING A NOTICEABLE AND SWIFT TANKING OF TEMPS TOMORROW.

BEFORE THE SHARP TEMP DROP...WE`LL HAVE PERIODS OF RAIN MOVING
ACROSS THE AREA - STARTING LATE TONIGHT FROM WEST TO EAST. THE MEAN
LAYER SHEAR IS SWLY...WHICH WILL CAUSE THE INITIAL WAVES OF LIGHT TO
MODERATE RAIN FROM SW-TO-NE ACROSS THE HIGHER TERRAIN AND PARTS OF
THE SHENANDOAH VLY TONIGHT. AREAS EAST OF THE BLUE RIDGE TO THE
COAST WILL BE THE LAST TO GET PRECIP MOVING IN...MORE TOWARD
MIDNIGHT OR LATER. MOST OF THE ACTIVITY AFFECTING THE AREA FROM LATE
TONIGHT INTO THE OVERNIGHT WILL BE SCATTERED...SHORT-LIVED...AND
FAIRLY LIGHT. TOWARD THE PREDAWN HRS TUE...MORE WIDESPREAD SHIELD OF
RAIN WILL MAKE THEIR WAY FROM THE SW AND OVER THE CWA...SPREADING
GENERALLY LIGHT TO MODERATE RAIN OVER THE AREA UNDER TEMPS IN THE
50S AND 60S.

THE GUSTY S-SWLY WINDS WILL CONTINUE TO SQUEEZE UP THE ERN SEABOARD
AHEAD OF THE STRENGTHENING LOW PRES SYSTEM...EVEN BRINGING SOME
AREAS OF THE I-95 CORRIDOR AND EAST INTO THE L70S BY DAWN. THIS WILL
MAXIMIZE THE CONVECTIVE POTENTIAL DURING THE EARLY MRNG HRS. LOW
CAPE VALUES IN THE COUPLE-FEW HUNDREDS WILL BE AVAILABLE FOR MUCH OF
THE AREA - ESPEC THE SERN SECTION OF THE CWA...ALONG W/ A POTENT
40-50KT LOW LEVEL JET I-95 AND EAST FOR AMPLE LINEAR SUPPORT. THE
CONVECTIVE NATURE OF THE PRECIP WILL THEN LIKELY TURN INTO A MORE
STABLE AND STRATIFORM RAIN AS THE COLD FRONT BEGINS TO BARREL ACROSS
THE AREA FROM THE POTOMAC HIGHLANDS TOWARD THE METRO AREAS LATE
MRNG/EARLY AFTN. WINDS WILL BE GUSTY ANYWAY...BUT THEY`LL TURN FROM
A WARM SLY BREEZE TO DRY AND COLD NW FLOW DIRECTLY BEHIND THE FRONT.
TEMPS WILL START TO DROP SEVERAL DEGREES EACH HR THRU THE
AFTN...DROPPING WELL INTO THE 30S/40S OVER THE WRN ZONES AND INTO
THE 40S/50S E OF THE MTNS.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
COLD FRONT MOVES OFFSHORE THROUGH THE EARLY EVENING HOURS ON
TUESDAY. STRONG COLD AIR ADVECTION CONTINUES TO SUPPORT FALLING
TEMPERATURES. FOLLOWED SREFS FOR POPS DECREASING FROM WEST TO EAST
THROUGH EARLY EVENING. IF COLD AIR CAN CATCH UP TO THE BACK EDGE OF
PRECIP QUICKLY ENOUGH...A FEW WET SNOWFLAKES COULD OCCUR BUT THE
BULK OF THE PRECIP WILL END AS RAIN.

FOCUS THEN TURNS TO THE COLD AIR. WITH COLD ADVECTION...MOMENTUM
TRANSFER WILL KEEP GUSTY NORTHWEST WINDS GOING INTO THE NIGHT. BUT
ITS THESE NORTHWEST WINDS THAT ARE BRINGING IN A MUCH COLDER AIR
MASS AND DESPITE THE WIND TEMPERATURES HAVE THE POTENTIAL TO DROP
BELOW FREEZING BY DAYBREAK ESPECIALLY IN THE SUBURBS. THE GROWING
SEASON WILL BEGIN APRIL 15TH EAST OF THE BLUE RIDGE...WHICH MEANS
THESE AREAS WILL BE CANDIDATES FOR FROST/FREEZE HEADLINES.
CONSIDERING FORECAST MINIMA...WILL BE ISSUING A FREEZE WATCH FOR
TUESDAY NIGHT/WEDNESDAY MORNING.

HIGH PRESSURE BUILDS IN FOR WEDNESDAY. SUNSHINE WILL RETURN BUT
MAXIMA MAY STRUGGLE TO REACH 50. HIGH PRESSURE WEDNESDAY NIGHT
WILL ALSO PAVE THE WAY FOR ANOTHER COLD NIGHT WITH RADIATIONAL
COOLING IN PLAY. ADDITIONAL FREEZE HEADLINES MAY BECOME NECESSARY
WEDNESDAY NIGHT INTO THURSDAY MORNING. MODERATING TREND SHOULD
BEGIN THURSDAY WITH HIGH PRESSURE MOVING OFF THE COAST.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
SURFACE HIGH PRESSURE WILL DEPART INTO THE NORTH ATLANTIC THURSDAY
NIGHT...LEAVING BEHIND A SURFACE RIDGE AXIS WEDGED AGAINST THE
EASTERN SLOPES OF THE APPALACHIANS. THIS WILL RESULT IN A CONTINUED
ONSHORE FLOW THROUGH FRIDAY.

AN UPPER-LEVEL TROUGH AND SURFACE LOW PRESSURE APPROACH THE AREA
FROM THE WEST LATE FRIDAY NIGHT INTO SATURDAY. THE LATEST GUIDANCE
SHOWS A WIDE SPREAD IN THE DEPTH OF THE APPROACHING TROUGH AND
STRENGTH OF LOW PRESSURE AT THE SURFACE. RAIN IS LIKELY FOR AT LEAST
PART OF THE AREA SATURDAY...BUT THERE IS A MODERATE TO HIGH LEVEL OF
UNCERTAINTY IN INTENSITY/COVERAGE.

WEAK RIDGING AND MILDER WEATHER LOOKS TO BUILD INTO THE AREA LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.

&&

.AVIATION /19Z MONDAY THROUGH SATURDAY/...
WE`RE STILL UNDER A HIGH PRESSURE REGIME...BUT THE STRENGTH OF A
POWERFUL STORM SYSTEM OVER THE PLAINS AND UPPER MIDWEST IS CAUSING
SLY WINDS AROUND THE BACKSIDE OF THE HIGH TO REMAIN GUSTY...WELL
INTO THE 20-30KT RANGE. SUSTAINED SFC WINDS ARE ALSO RELATIVELY
HIGH...A SIGN THAT THE LOW LEVELS ARE - AND WILL REMAIN - GUSTY
THROUGHOUT THE REST OF THE DAY AND INTO THE OVERNIGHT.

THE STORM SYSTEM TO OUR WEST WILL MAKE A COUPLE OF LARGE-SCALE
TRANSITIONS BEFORE MOVING ACROSS THE REGION EARLY TUE - BUT ONCE IT
DOES...A STRONG COLD FRONT WILL MOVE THRU AREA REGION FROM LATE
MRNG INTO EARLY AFTN...W/ PERIODS OF RAIN OUT AHEAD OF AND ALONG
W/ THE FRONT. WINDS WILL ALSO SHIFT FROM SLY TO NWLY W/ THE SAME
POTENCY OF GUSTS IN THE 25-30KT RANGE.

HIGH PRESSURE BUILDS IN FOR LESS WIND WEDNESDAY. NO SIGNIFICANT WX
EXPECTED TO END THE WEEK.

&&

.MARINE...
WINDS IN SOLID SCA RANGE THIS AFTN WILL ESSENTIALLY STAY IN THE
20-30KT RANGE THROUGHOUT THE EVE AND OVERNIGHT HRS OUT OF THE SOUTH.
A STRONG COLD FRONT WILL THEN SWING ACROSS THE WATERS BY LATE AFTN
TUE...SPREADING NEAR GALE GUSTS ON TUE AFTN. HIGHEST CONFIDENCE IN
GALES IS BEHIND THE FRONT WITH A NORTHWEST SURGE AND GALE WARNING
HAS BEEN ISSUED FOR THIS PERIOD.

HIGH PRESSURE BUILDS IN FOR WEDNESDAY. SMALL CRAFT ADVISORY
LEVEL WIND GUSTS ARE POSSIBLE FOR PARTS OF THE WATERS THURSDAY
NIGHT...AND AGAIN OVER THE WEEKEND DEPENDING ON THE EVOLUTION OF
LOW PRESSURE MOVING NEAR THE AREA.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES REMAIN IN THE 1/2-3/4 FOOT RANGE FOR THE
WRN SHORES OF THE MD CHSPK BAY. THE STEADY AND GUSTY SLY WINDS WILL
KEEP THESE LEVELS STEADY INTO THE OVERNIGHT HRS AND THRU EARLY
TUESDAY MRNG. A FULL MOON UPCOMING...LIKELY HELPING WATER LEVELS TO
APPROACH MINOR FLOOD CRITERIA AT THE MORE SENSITIVE LOCATIONS AROUND
TIMES OF THE HIGHER HIGH TIDES EARLY TUESDAY MRNG. CBOFS GUIDANCE
HOWEVER FCSTS TIDAL LVLS BELOW MINOR COASTAL FLOODING THRESHOLDS AT
ALL SITES.

&&

.CLIMATE...
UNUSUALLY WARM CONDITIONS WERE OBSERVED ACROSS THE AREA EARLY THIS
MORNING. LOW TEMPERATURES WERE AROUND 20 DEGREES ABOVE NORMAL.
DEPENDING ON HOW LOW TEMPERATURES GET THIS EVENING...RECORD DAILY
HIGH MINIMUM TEMPERATURES COULD BE TIED OR BROKEN AT DCA...BWI AND
IAD. BELOW IS A TABLE OF RECORDS FOR THE DAY AND LOW TEMPERATURES
OBSERVED SO FAR.

SITE...PREVIOUS RECORD...LOW SO FAR...
DCA....63 F IN 1896......65 F.........
BWI....62 F IN 1896......62 F.........
IAD....58 F IN 1972......63 F.........

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR DCZ001.
MD...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR MDZ004>007-009>011-013-014-016.
VA...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING
     FOR VAZ036>040-042-050>057-501-502.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT TUESDAY FOR ANZ530>543.
     GALE WARNING FROM 6 PM TUESDAY TO 6 AM EDT WEDNESDAY FOR
     ANZ530>543.

&&

$$
SYNOPSIS...BPP
NEAR TERM...GMS
SHORT TERM...BPP
LONG TERM...DFH
AVIATION...GMS/BPP/DFH
MARINE...GMS/BPP/DFH
TIDES/COASTAL FLOODING...GMS
CLIMATE...DFH









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