Skip Navigation Linksweather.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service Forecast Office   NWS emblem - Click to go to the NWS homepage
Sterling, VA banner image
navigation bar image  
  navigation bar image

[facebook] [twitter]

You are at: NWS >> ERH >> LWX >> Product Browser

Area Forecast Discussion

Latest versions:
[Current] [-1] [-2] [3] [-4] [-5] [-6] [-7] [-8] [-9]    [Glossary Off]
Clicking on the links in the product will popup a window with a definition.
 
FXUS61 KLWX 221914
AFDLWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC
314 PM EDT TUE APR 22 2014

.SYNOPSIS...
A COLD FRONT WILL PASS THROUGH THIS EVENING. HIGH PRESSURE RETURNS
FOR WEDNESDAY AND THURSDAY BEFORE MOVING OFF THE COAST FRIDAY. A
COLD FRONT IS EXPECTED TO PASS THROUGH THE AREA SATURDAY.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
18Z SFC ANALYSIS SHOWS A 998 MB LOW JUST NORTH OF THE ADIRONDACKS.  
A COLD FRONT EXTENDS TO THE SW OF THE LOW IN CENTRAL NY-WRN PA AND 
BACK TOWARD THE OH RVR. 

A BAND OF SHOWERS ASSOCIATED WITH A PRE-FRONTAL TROUGH AND MOISTURE 
PLUME WILL CONTINUE TO PROGRESS EWD THRU THE I-95 CORRIDOR BEFORE 
MOVING EAST OF THE CHSPK BAY LATE THIS AFTN. FARTHER UPSTREAM...A 
NARROW LINE OF CONVECTION HAS DEVELOPED ALONG THE COLD FRONT NEAR 
PIT. HI-RES REFLECTIVITY MODELS THAT CAPTURED THIS CONVECTION 
SIMULATE THIS LINE TO REACH THE ALLEGHENY FRONT BY 4 OR 5 PM BEFORE 
MOVING SEWD THRU PORTIONS OF THE CWA DURING THE ERY EVE. KEPT POPS 
HIGHEST ACROSS NRN PORTIONS OF THE CWA WHERE THE BEST FORCING 
ASSOCIATED WITH THE UPPER SHORTWAVE TROUGH WILL BRUSH. TSTM 
POTENTIAL IS LOW WITH PRE-FRONTAL SHOWERS AND CLOUD COVER LIMITING 
DESTABILIZATION. 

THE COLD FRONT WILL MOVE THRU THE AREA THIS EVE. GUSTY NW WINDS WILL 
USHER IN COLDER AIR BEHIND THE COLD FRONT. CLEARING SKIES FROM WEST 
TO EAST TNGT AS WELL...ALTHOUGH STRATOCU WILL KEEP SKIES MOSTLY 
CLOUDY ALONG THE WRN SIDE OF THE ALLEGHENY FRONT DUE TO UPSLOPE FLOW. 
WINDS WILL STAY MIXED SO ADVECTION WILL BE MAIN SOURCE OF AIRMASS 
COOLING TNGT. MIN TEMPS TNGT RANGE FROM THE NEAR 30F IN THE WRN 
HIGHLANDS TO MID AND UPPER 40S EAST OF THE BLUE RIDGE.

HIPRES BUILDS IN FROM THE GREAT LAKES ON WED. PRESSURE RISES WILL
BE ACCOMPANIED BY BREEZY NW WINDS THAT GUST 30-40 MPH DURING THE
DAY. COLD AIRMASS WILL BE MODERATED A BIT BY THE HIGH SUN ANGLE.
FCST WEIGHTED TOWARD THE WARMER BIAS CORRECT MARV GUIDANCE WITH
SUNNY SKIES AND DOWNSLOPING FLOW. MAX TEMPS GENERALLY RANGE FROM
THE MID 50S TO MID 60S EXCEPT FOR COOLER HIGHS IN THE 40S ALONG
HIGHER ELEVATIONS RIDGES.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
SFC LOW PRESSURE SHOULD BE MOVING TOWARDS NEWFOUNDLAND WED NIGHT AND 
HIGH PRESSURE WILL MOVE INTO THE MID ATLANTIC FROM THE WEST. THE 
PRESSURE GRADIENT RESPONSIBLE FOR THE GUSTY WINDS WEDNESDAY WILL 
DEPART TO OUR EAST WED EVENING. TEMPS WILL REACH THE LOW 30S WEST OF 
THE BLUE RIDGE AS CLEARING AND CALM WINDS WILL ALLOW FOR TEMPS TO 
DROP. ELSEWHERE...MID TO UPPER 30S EXPECTED TO AROUND 40 IN THE 
METROS. 

UPPER LEVEL RIDGING WILL MOVE OVERHEAD THURSDAY RESULTING IN A SUNNY 
DAY WITH TEMPS IN THE 60S. A WEAK COLD FRONT ASSOCIATED WITH LOW 
PRESSURE ACROSS THE NRN PLAINS WILL APPROACH THE REGION. CLOUDS WILL 
INCREASE FROM THE WEST THURSDAY AS HIGH PRESSURE WILL MOVES OFF THE 
COAST BY THURSDAY NIGHT. A BRIEF PERIOD OF RETURN FLOW WILL 
INCREASE ACROSS THE REGION THURSDAY NIGHT AND FRIDAY. TEMPS WILL 
REACH 70-75 DEGREES FRIDAY AFTERNOON. THE WEAK COLD FRONT WILL CROSS 
THE APPALACHIANS FRIDAY AFTERNOON AND SHOWERS ARE EXPECTED TO MOVE 
AHEAD OF THE FRONT. 

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AN UPPER-LEVEL TROUGH...ACCOMPANIED BY A SECONDARY COLD FRONT AND 
STRONG PRESSURE SURGE/COLD ADVECTION WILL MOVE THROUGH THE AREA TO 
BEGIN THE WEEKEND. THE BOUNDARY LOOKS MOISTURE STARVED...SO ANY 
ISOLATED SHOWER ACTIVITY WOULD REMAIN CONFINED TO AREAS ALONG THE 
MASON-DIXON LINE CLOSEST TO THE FORCING FROM THE SHORTWAVE TROUGH 
SATURDAY. THUS SLIGHT CHANCE POPS HAVE BEEN CONFINED TO THESE AREAS.

AT THE MOMENT...THE RANGE" onClick="return popup(this, 'notes');">MEDIUM RANGE GUIDANCE HAS COME INTO BETTER WITH 
THE TIMING AND STRENGTH OF THE FRONT. STRONG AND GUSTY WINDS ARE 
APPEARING INCREASINGLY LIKELY FOR SATURDAY...ESPECIALLY CONSIDERING 
THE STRONGEST WINDS ACCOMPANYING THE PRESSURE SURGE WILL OCCUR 
DURING PEAK HEATING WHEN LAPSE RATES ARE STEEPEST AND MIXING DOWN 
HIGHER WIND GUSTS WOULD BE EASIEST.

WINDS DIMINISH SATURDAY NIGHT INTO SUNDAY MORNING AS AN AREA OF HIGH 
PRESSURE NOSES OVER THE REGION...BUT ITS STAY OVER OUR AREA IS 
SHORT-LIVED AS A LARGE AND SLOW-MOVING AREA OF LOW PRESSURE APPROACH 
FROM THE WEST BRINGING A RETURN TO UNSETTLED WEATHER EARLY NEXT WEEK.

&&

.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
LGT SHRA AHEAD OF THE FRONT HAS SHIFTED EAST OF IAD AND WILL IMPACT 
DCA/BWI/MTN THRU ABOUT 21Z. INTENSITY HAS BEEN SO LGT THAT NO FLGT 
RESTRICTION WERE ACCOMPANIED WITH THIS ACTIVITY. WINDS HAVE SHIFTED 
OUT OF THE WEST AS THESE SHOWERS AND ASSOCIATED SFC TROUGH MOVE THRU 
BUT WILL BE LGT UNTIL THE COLD FRONT MOVES THRU THIS EVE. ANY TSRA
WITH THE FRONT THIS EVE WILL BE LOCALIZED AND PROBS TOO CHANCE TOO
LOW TO INCLUDE IN TAFS. NW WINDS 10-15 KT WILL GUST TO 25 KT BEHIND THE
FRONT THRU MUCH OF TNGT. NW WINDS INCREASE ON WED DUE TO DAYTIME
MIXING WITH GUSTS TO 35 KT POSSIBLE. VFR ON WED.

NW FLOW WILL SUBSIDE WED NIGHT. HIGH PRESSURE MOVES INTO THE REGION 
THURSDAY BEFORE MOVING OFF THE COAST AHEAD OF A WEAK COLD FRONT 
THURSDAY NIGHT. SHOWERS MAY CROSS THE TERMINALS FRIDAY.

MODERATE CONFIDENCE IN VFR CONDITIONS AND WESTERLY WINDS AROUND 10 
KNOTS FRIDAY NIGHT...WITH MODERATE CONFIDENCE IN WINDS INCREASING TO 
BETWEEN 15 AND 20 KNOTS WITH GUSTS UP TO 30 KNOTS DURING THE DAY 
SATURDAY.

&&

.MARINE...
SCA REMAINS IN EFFECT FOR THE WATERS THRU TNGT. SCA LVL REPORTS ONLY 
ISOLATED THUS FAR BUT ANY SHOWERS MOVING THRU COULD DRAG DOWN 
LOCALLY HIGHER WINDS. WINDS BECOME GUSTY FOLLOWING A COLD FROPA
DURING THE MID TO LATE EVE AND INTO THE OVNGT. WIDESPREAD SCA 
CONDITIONS EXPECTED BEHIND THE FRONT. A GALE WARNING IS IN EFFECT 
WEDNESDAY FOR ALL OF THE WATERS WITH GUSTS UP TO 35 KT EXPECTED 
DURING THE DAY. THE GALE WARNING MAY BE ABLE TO BE DOWNGRADING 
SOMETIME DURING THE AFTN AS THE PRESSURE GRADIENT AND ASSOCIATED 
WIND FIELD WEAKENS A BIT.

NORTHWEST WINDS WILL CONTINUE ON THE WATERS WEDNESDAY NIGHT AND A 
SCA IS IN EFFECT. WINDS WILL SUBSIDE FROM WEST TO EAST THEREFORE THE 
SCA FOR THE UPPER TIDAL POTOMAC WILL DROP LATE WED NIGHT. WINDS WILL 
CONTINUE TO CAUSE SCA CONDITIONS ACROSS THE BAY INTO THURSDAY. A SCA 
MAY BE EXTENDED FOR THURSDAY. HIGH PRESSURE MOVES INTO THE REGION 
THURSDAY AND THURSDAY NIGHT. SOUTHERLY FLOW WILL INCREASE ACROSS THE 
WATERS FRIDAY. 

A PERIOD OF HIGH-END SMALL CRAFT ARE EXPECTED BEHIND A STRONG BUT
MOISTURE-STARVED COLD FRONT SATURDAY. WINDS DIMINISH THROUGH THE
NIGHT SATURDAY AND LIKELY DROP BELOW SMALL CRAFT LEVELS DURING THE
DAY SUNDAY.

&&

.FIRE WEATHER...
A COLD FRONT WILL PASS THROUGH THE AREA THIS EVENING AND GUSTY 
NORTHWEST WINDS ARE EXPECTED BEHIND THE COLD FRONT WEDNESDAY. A DEEP 
MIXING LAYER WILL ALLOW FOR DRIER AIR TO MIX DOWN...CAUSING LOW 
RELATIVE HUMIDITY VALUES DURING THE LATE MORNING THROUGH THE 
AFTERNOON. THE COMBINATION OF GUSTY WINDS...LOW FUEL MOISTURE AND 
LOW RELATIVE HUMIDITY WILL ENHANCE THE THREAT FOR THE SPREAD OF 
WILDFIRES WEDNESDAY. AFTER COORDINATION WITH STATE OFFICIALS AND
SURROUNDING WFOS...A FIRE WEATHER WATCH WAS ISSUED.

&&

.TIDES/COASTAL FLOODING...
POSITIVE TIDAL ANOMALIES REMAIN STEADY AROUND THREE-QUARTERS OF A
FOOT THIS AFTN. SLY WINDS WILL BECOME WLY WITHIN THE NEXT FEW HRS
AND ANOMALIES WILL DECREASE SUBSEQUENTLY.

GUSTY NORTHWEST WINDS WILL DEVELOP TONIGHT AND CONTINUE THROUGH 
WEDNESDAY. BLOWOUT TIDES ARE EXPECTED WEDNESDAY.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY 
     EVENING FOR DCZ001.
MD...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY 
     EVENING FOR MDZ003>007-009>011-013-014-016>018-502.
VA...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY 
     EVENING FOR VAZ025>031-036>040-042-050>057-501-502-504.
WV...FIRE WEATHER WATCH FROM WEDNESDAY MORNING THROUGH WEDNESDAY 
     EVENING FOR WVZ050>053-055-502-504-506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO 6 AM EDT THURSDAY 
     FOR ANZ530>534-537>543.
     GALE WARNING FROM 6 AM TO 6 PM EDT WEDNESDAY FOR ANZ530>543.
     SMALL CRAFT ADVISORY FROM 6 PM WEDNESDAY TO MIDNIGHT EDT 
     WEDNESDAY NIGHT FOR ANZ535-536.

&&

$$
SYNOPSIS...JRK
NEAR TERM...JRK
SHORT TERM...HAS
LONG TERM...DFH
AVIATION...JRK/HAS/DFH
MARINE...JRK/HAS/DFH
FIRE WEATHER...JRK
TIDES/COASTAL FLOODING...JRK






National Weather Service
Weather Forecast Office Baltimore/Washington
43858 Weather Service Rd.
Sterling, VA 20166
Phone: (703) 996-2200
Webmaster: lwxwebmaster@noaa.gov
Page last modified: Sep 24, 2008 2:00 PM EDT
Disclaimer
About Us
Credits
Privacy Policy
Career Opportunities
Glossary