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-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KLWX 022033
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
333 PM EST MON MAR 2 2015

.SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE THEN WILL BUILD ACROSS THE AREA TONIGHT. A WARM
FRONT WILL PUSH THROUGH THE AREA TUESDAY NIGHT. A STRONG COLD
FRONT WILL APPROACH THE REGION LATE WEDNESDAY FOLLOWED BY COLD
HIGH PRESSURE FOR THURSDAY INTO THE WEEKEND.
-- End Changed Discussion --
&&

.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
HIGH PRESSURE WILL BUILD INTO THE MIDDLE ATLANTIC REGION TONIGHT.
WINDS WILL DIMINISH BY SUNSET AND WITH MOSTLY CLEAR
SKIES...TEMPERATURES WILL FALL OFF QUICKLY AND BOTTOM OUT IN THE
LOWER 20S IN MOST LOCATIONS EXCEPT TEENS OVER THE NORMALLY COLDER
AREAS WEST OF THE BLUE RIDGE.

CLOUDS WILL BE ON THE INCREASE FROM WEST TO EAST BY EARLY TUESDAY
MORNING AS THE NEXT WEATHER SYSTEM APPROACHES FROM THE WEST. LIGHT
PRECIPITATION IS EXPECTED TO BEGIN FIRST OVER THE WESTERN SLOPES OF
THE ALLEGHENY FRONT THEN SPREADING EAST ACROSS THE REMAINDER OF THE
FORECAST AREA MID TO LATE MORNING.

PROFILES INDICATE THERE IS ENOUGH COLD AIR FOR PRECIPITATION TO
START AS A MIXTURE OF SNOW AND SLEET BUT A FAIRLY QUICK TRANSITION
TO SLEET AND FREEZING RAIN IS EXPECTED BY MIDDAY TO EARLY AFTERNOON.
SNOWFALL AMOUNTS WILL BE LIGHT. CAD SITUATION EXPECTED ONCE AGAIN
WITH COLD HIGH TO THE NORTH AND EAST HELPING TO TRAP COLDER AIR IN
THE LOWER LEVELS. LIGHT FREEZING RAIN/FREEZING DRIZZLE WILL BECOME
THE MAIN P-TYPE BY AFTERNOON WITH A FEW HUNDREDTHS TO ONE TENTH OF
AN INCH OF ICE ACCRETION EXPECTED. SURFACE TEMPERATURES WILL BE COLD
ENOUGH FOR SOME SLIPPERY TRAVEL TO DEVELOP FOR THE AFTERNOON AND
EVENING COMMUTE. A WINTER WEATHER ADVISORY WILL BE ISSUED TO COVER
THIS THREAT.

WARMER AIR WILL GRADUALLY FILTER IN FROM SOUTH TO NORTH AS SOUTHERLY
WINDS INCREASE DURING THE LATE AFTERNOON AND EARLY EVENING. RAIN
WILL BECOME MORE LIKELY OVER CENTRAL AND SOUTHERN LOCATIONS. LIGHT
FREEZING RAIN WILL LIKELY HOLD ON LONGER FOR THE FAR NORTH AND WEST
SUBURBS OF BALTIMORE AND WASHINGTON DC INTO THE EVENING. HIGH
TEMPERATURES TOMORROW WILL ONLY RISE INTO THE 30S IN MOST LOCATIONS.
-- End Changed Discussion --
&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...

-- Changed Discussion --
COLD AIR MAY BE LINGERING INTO THE ELY EVNG N OF THE PTMC RIVER
TUE EVNG...OTRW WAA WL MAKE ITS WAY TO THE SFC. SHUD HV WARMING
TEMPS THRUT THE NGT. THEREFORE...WL BE RUNNING W/ A PTYPE OF RA...
W/ JUST A LITTLE LINGERING FZRA TO THE N.

THE MAIN PTYPE ISSUE FOR OVNGT TUE INTO WED WL BE RA. A SOLID
PLUME OF MSTR WL BE CHANNELED EWD FM THE WRN GLFMEX AHD OF AN
APPROACHING CDFNT. AM GOING W/ QPF ARND A HALF INCH...CLOSER TO
AN INCH FOR THE MTNS. MORE ON THIS IN THE HYDRO SECTION BELOW.

CFP WL COME LT IN THE DAY. WE WL BE STARTING FM A BASE IN THE UPR
40S NORTH TO UPR 50S SOUTH /BLENDED NEWER GDNC INTO THE ENSEMBLE
MAXT FCST/ SO EVEN AFTER FROPA...PCPN WL STILL BE RAIN. PROBLEM
IS...SFC TEMPS WL KEEP DROPPING THRU THE AFTN-EVNG WHILE THE PLUME
OF MSTR CONTS TO STREAM EWD ABV IT. THAT WUD SUPPORT PCPN CHGG
OVER TO SNW /OR PERHAPS SLEET/ WED NGT. QSTNS REVOLVE ARND THE
TIMING OF THAT TRANSITION ALONG W/ HOW MUCH MSTR WL BE AVBL AT
THAT TIME. AN UPR JET WL BE SUPPORTIVE OF PCPN GENERATION...AS WE
WL BE IN THE RRQ. AT THIS TIME...IT SEEMS APPARENT THAT THERE WL
BE MEASUREABLE SNOW WED NGT INTO THU MRNG. IT CUD BE MORE THAN
JUST A LTL. HV THIS IN THE HWO ATTM. REFER TO OUR PROBABLISTIC
DATA VIA OUR WEBSITE FOR THE RANGE OF POSSIBILITIES.

HV SNOW TAPERING OFF DURING THE DAY ON THU. DOUBT THERE WL BE MUCH
OF A TEMP RISE.
-- End Changed Discussion --

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...

-- Changed Discussion --
AFTER A FEW BUSY WX DAYS...HIGH PRESSURE SETTLES INTO THE REGION
OVERNIGHT THURSDAY. EXPECT LIGHT WINDS WITH CLEARING SKIES...LEADING
TO STRONG RADIATIONAL COOLING AND VERY COLD
TEMPERATURES...ESPECIALLY IF THERE IS SNOW COVER FROM THE THURSDAY
SYSTEM. HIGH TEMPERATURES WILL REMAIN NEAR FREEZING FRIDAY DESPITE
THE RETURN OF WAA. AFTER ANOTHER COLD NIGHT FRIDAY...TEMPERATURES
BEGIN TO REBOUND SATURDAY AND EVEN MORE SUNDAY. HOWEVER...THEY WILL
REMAIN IN THE MID/UPPER 40S...WHICH IS BELOW AVERAGE FOR THIS TIME
OF YEAR.

AT THIS POINT LEFT WEEKEND PRECIP FREE. BUT...RECENT MODEL RUNS
APPEAR TO HAVE A SYSTEM DEVELOPING IN THE DEEP SOUTH AND PERHAPS
BEGINNING TO IMPACT OUR AREA ON SUNDAY. WOULD LIKE TO SEE MORE RUN
TO RUN CONSISTENCY BEFORE INTRODUCING POPS.
-- End Changed Discussion --

&&

.AVIATION /20Z MONDAY THROUGH SATURDAY/...

-- Changed Discussion --
VFR EXPECTED THROUGH 12Z TUESDAY. LIGHT PRECIPITATION WILL MOVE
IN FROM WEST TO EAST BY MID TO LATE MORNING. HAVE INTRODUCED LIGHT
SNOW/SLEET MIXTURE AT MOST TERMINALS AROUND MIDDAY BUT EXPECT
FREEZING RAIN TO BECOME THE MAIN P-TYPE BY AFTERNOON AND EVENING.
THE PRECIPITATION MAY CHANGE TO ALL RAIN CENTRAL AND SOUTH WITH
LIGHT FREEZING RAIN/FREEZING DRIZZLE HOLDING ON LONGER NEAR KBWI.

MVFR TO IFR FLGT CONDS SHUD BE WIDESPREAD TUE NGT THRU THU. MAINLY
RA TUE NGT AND WED. SNOW SHUD BE THE PRIMARY PTYPE WED NGT INTO
THU. DEPENDING UPON TIMING...LIFR PSBL.

AT THIS POINT NOT EXPECTING ANY AVIATION CONCERNS FROM THURSDAY
NIGHT THROUGH SUNDAY.
-- End Changed Discussion --
&&

.MARINE...

-- Changed Discussion --
SOLID SCA CONDITIONS OCCURRING THIS AFTERNOON WILL DIMINISH BY
SUNSET. ADDITIONAL SMALL CRAFT CONDITIONS COULD DEVELOP TUESDAY
NIGHT. VISIBILITY WILL BE REDUCED IN FROZEN PRECIPITATION TUESDAY
AFTERNOON INTO TUESDAY NIGHT.

THERE IS THE POTENTIAL FOR A BRIEF PERIOD OF SCA THURSDAY
AFTERNOON AND NIGHT BEFORE WINDS SUBSIDE. AFTER THIS NOT
EXPECTING MARINE CONCERNS THROUGH SUNDAY.
-- End Changed Discussion --

&&

.HYDROLOGY...
WE HAVE BEEN ADVERTISING THE POTENTIAL OF MIDWEEK FLOODING IN THE
HAZARDOUS WEATHER OUTLOOK. LIQUID PRECIP FCST FROM WPC PUTS MUCH OF
THE FCST AREA IN A MINIMA FOR AMOUNTS...AROUND AN INCH OR LESS IN
MANY AREAS. 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.

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.

WORTH NOTING...CURRENT FORECAST RAIN TOTALS ARE ON THE LOWER SIDE OF
THE ENSEMBLE SUITES OF THE GEFS AND SREF. PLEASE CONTINUE TO MONITOR
THE FORECAST FOR UPDATES AS THE EVENT GETS CLOSER.&&

.LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...WINTER WEATHER ADVISORY FROM 9 AM TO 10 PM EST TUESDAY FOR
     DCZ001.
MD...WINTER WEATHER ADVISORY FROM 7 AM TO 7 PM EST TUESDAY FOR
     MDZ501-502.
     WINTER WEATHER ADVISORY FROM 7 AM TO 10 PM EST TUESDAY FOR
     MDZ003.
     WINTER WEATHER ADVISORY FROM 9 AM TO 7 PM EST TUESDAY FOR
     MDZ016>018.
     WINTER WEATHER ADVISORY FROM 9 AM TO 10 PM EST TUESDAY FOR
     MDZ004>006-011-013-014-503>508.
VA...WINTER WEATHER ADVISORY FROM 7 AM TO 7 PM EST TUESDAY FOR
     VAZ025>031-503-504-507-508.
     WINTER WEATHER ADVISORY FROM 9 AM TO 7 PM EST TUESDAY FOR
     VAZ036>040-050>052-055>057-501-502.
     WINTER WEATHER ADVISORY FROM 9 AM TO 10 PM EST TUESDAY FOR
     VAZ053-054-505-506.
WV...WINTER WEATHER ADVISORY FROM 7 AM TO 7 PM EST TUESDAY FOR
     WVZ050-055-501>506.
     WINTER WEATHER ADVISORY FROM 7 AM TO 10 PM EST TUESDAY FOR
     WVZ051>053.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR
     ANZ530>543.
-- End Changed Discussion --

&&

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