Area Forecast Discussion


850 
FXUS61 KLWX 251450
AFDLWX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
1050 AM EDT SAT APR 25 2015
.SYNOPSIS...
LOW PRESSURE OVER MISSOURI WILL TRACK EAST TODAY AND PASS TO THE SOUTH
OF THE AREA TONIGHT INTO SUNDAY. AN UPPER-LEVEL TROUGH OF LOW
PRESSURE EXTENDING FROM MAINE DOWN THE EASTERN SEABOARD WILL
TRACK SLOWLY SOUTH MONDAY. HIGH PRESSURE WILL RETURN TUESDAY. LOW
PRESSURE MAY IMPACT THE REGION THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EARLY THIS MORNING...WE RECEIVED A FEW REPORTS OF SLEET AND SNOW
ACROSS NORTHERN MARYLAND THIS MORNING...EVEN AS FAR SOUTH AS
SOUTHERN BALTIMORE CITY. SOCIAL MEDIA SHOWED ONE CAR WITH A THIN
COATING OF SNOW THAT FELL IN THE TOWN OF LITTLE ORLEANS IN
EASTERN ALLEGANY COUNTY MD. EVEN HAD A FEW SPOTTER REPORTS OF
SLEET WITH NO ACCUM OVER RAPPAHANNOCK IN NORTH CENTRAL VIRGINIA.
THE 12Z IAD SOUNDING HAD SUB-FREEZING TEMPS ABOVE 850 HPA AND WITH
DRY SURFACE AIR...WEB BULB COOLING IS KEEP THE COLUMN ALMOST BELOW
FREEZING DOWN TO THE SURFACE...WHICH EXPLAINS A FEW RPTS OF SLEET.
RADAR TRENDS SHOW ADVANCE OF NORTHERN EDGE OF THE FIRST WAVE OF
LIGHT PRECIP AT 1430Z EXTENDING FROM GRANT/HARDY COUNTIES IN WV
SOUTHEAST ACROSS N-CENTRAL VA AND INTO LOWER SRN MD. PRECIP IS
VERY LIGHT...AND THERE COULD BE A LITTLE SLEET MIXED IN AT ONSET.
BASED ON RADAR...ADVANCED UP THE TIMING OF PRECIP SLIGHTLY FOR
THIS AFTERNOON. 12Z NAM MODEL SEEMS IN LINE WITH CURRENT FORECAST
IN TERMS OF TIMING AND NOT MUCH ADJUSTMENT MADE TO GOING FORECAST
FOR TIMING/AMOUNT OF PRECIP FOR THIS EVENT. HEAVIEST AMOUNTS WILL
OCCUR OVER THE SW PORTION OF OUR CWA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
TONIGHT...STATIONARY FRONT RETURNS SOUTH AS A COLD FRONT AFTER 
MIDNIGHT. PRECIP SHIFTS SOUTH ALONG WITH IT...WITH LIKELIES LIMITED 
TO THE SRN THIRD OF THE CWA FOR SUNDAY MORNING.  STORM TOTAL QPF 
QUARTER TO HALF INCH FOR SRN TWO THIRDS OF CWA...TENTH INCH OR SO 
FOR NERN MD. MIN TEMPS LOW TO MID 40S.
SUNDAY...NORTH WINDS AND SOMEWHAT CLEARING SKIES FROM NORTH TO SOUTH 
THROUGH THE DAY. JUST LOW CHANCE POPS FOR SRN ZONES FOR THE 
AFTERNOON. WITH A LITTLE DRIER FORECAST...RAISED MAX TEMPS TO LOW 
60S FOR MUCH OF THE AREA...A DEGREE ABOVE MAV/MET/GMOS BLEND.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AVG HIGH TEMPS IN LATE MAR ARE A70...LOWS M40S. IN THE XTND 70 IS
PRBLY THE BEST WE CAN HOPE FOR...AND LOWS SHOULD BE RIGHT ARND
NRML.
HV INCRSD THE CLD CVR CWA-WIDE/INTRODUCED RW INTO THE FCST MON
FOR THE NRN/ERN PART OF CWA. VERTICALLY STACKED LOW WL BE SPINNING
IN THE GULF OF ME...AND A SHARPENING TROF WL WORK ITS WAY SWD DOWN
THE E CST INTO THE MID ALTC MON. BLO NRML HIGHS XPCTD - GNRLY IN
THE U50S...PSBLY M60S IN THE CENTRAL SHEN VLLY.
WK INDUCED HIGH OVR THE AREA TUE/WED WL ALLOW FOR MORE SUNSHINE
AND TEMPS TO REBOUND BACK INTO M60S. AN AREA OF LOW PRES IS XPCTD
TO DVLP OVR THE GULF STATES THU...CAUSING INCRSG CLDS IN THE MID
ATLC ALONG W/ A CHC OF RAIN. THIS LOW IS XPCTD TO TRACK NE AND
COMBINE W/ A SHORT WV DESCENDING FM QUEBEC...FORMING ANOTHER GULF
OF ME LOW. THIS ONE IS XPCTD TO FORM TOO FAR OUT TO SEA TO HV ANY
IMPACT ON THE MID ATLC OUTSIDE OF KEEPING THE AREA IN COOL NRLY
FLOW.
THE WEEK SHOULD CLOSE OUT UNDER HIGH PRES.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
EXPECT VFR CONDITIONS THROUGH THROUGH MID TO LATE DAY. PRECIP
WILL MOVE IN AND CIGS WILL LOWER. THIS EVENING EXPECT MVFR TO
LOCALLY IFR CIGS IN PRECIP...EXPECT BWI/IAD/DCA CIGS TO RANGE FROM
2-3 KFT THIS EVENING...LOCALLY DOWN TO 1KFT IN HEAVIER PRECIP.
OVERNIGHT...BWI AND IAD COULD SEE CIGS BLO 1KFT. WINDS WILL BE
UNDER 10 KTS THROUGH THE PERIOD.
RW/PTNL MVFR CIGS PSBL MON...THEN NO PROBS XPCTD TUE/WED.
&&
.MARINE...
WINDS EXPECTED TO BE BELOW 10 KTS ACROSS THE WATERS TODAY AND
VARIABLE IN DIRECTION. RAIN WILL OVERSPREAD THE WATERS THIS
AFTERNOON INTO THIS EVENING
A FRONT STALLS TONIGHT WITH NORTH WINDS SUNDAY AS THE FRONT
RETURNS SOUTH AS A COLD FRONT. NORTHERLY CHANNELING POSSIBLE ON SUNDAY
AFTERNOON.
SCA CONDS WL BE LKLY MON AFTR A CD FNT MOVES THRU THE WATERS AND
THE PRES GRAD TIGHTENS.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...BAJ
LONG TERM...ABW
AVIATION...SMZ
MARINE...SMZ