Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 250857 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 357 AM EST THU DEC 25 2014 .SYNOPSIS...
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STRONG LOW PRESSURE WILL MOVE NORTH FROM THE NORTHERN GREAT LAKES INTO CANADA TODAY. THAT IS CURRENTLY PUSHING A COLD FRONT THROUGH OUR REGION. MILD SOUTHERN HIGH PRESSURE WILL MOVE IN FOR THE END OF THE WEEK. A WEAK COLD FRONT WILL PUSH IN FROM THE NORTHWEST SUNDAY. THEN LOW PRESSURE FROM THE DEEP SOUTH WILL RIDE UP ALONG THAT FRONT AND PASS JUST SOUTH OF US MONDAY. COLDER HIGH PRESSURE WILL FOLLOW FOR MID WEEK.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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SFC WIND SHIFT HAS MADE IT THROUGH MOST OF THE CWA...HOWEVER SHOWERS CONTINUE TO STREAM AHEAD THE SHARP MID LEVEL TROUGH AXIS. THESE HAVE GENERALLY BEEN OF THE LIGHT VARIETY AS LOWER LEVEL DRY AIR CUTS INTO THEM. EXPECT THE SHOWERS TO BE MOSTLY EAST OF THE CWA BY 8AM. WILL ALSO CANCEL THE WIND ADVISORY EARLY SINCE THE AVAILABLE OBS HAVE BEEN STAYING IN THE 20S FOR THE PAST FEW HOURS. SKIES WILL GRADUALLY CLEAR THIS MORNING EAST OF THE APPALACHIAN CREST...ALTHOUGH SOME STRATOCU MAY LINGER THROUGH THE DAY...ESPECIALLY ACROSS THE NORTH. A BREEZY DAY IS EXPECTED WITH CAA AND A DOWNSLOPE FLOW. GUSTS WILL GENERALLY BE IN THE 20S TO AROUND 30...ALTHOUGH SOME HIGHER GUSTS ARE POSSIBLE IN THE HIGHER ELEVATIONS. SOME UPSLOPE RAIN/SNOW SHOWERS ARE POSSIBLE IN THE WEST...BUT PREVIOUS FORECAST SEEM ON TRACK WITH CHANCE POPS AND MOISTURE THINNING OUT BY THIS AFTERNOON. THE AIR BEHIND THE FRONT IS NOT EXCEPTIONALLY COOL AND HIGH TEMPERATURES ARE STILL EXPECTED TO BE ABOVE NORMAL FOR THE LOWER ELEVATIONS.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
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A TRANQUIL AND MILD PERIOD IS IN STORE FOR THE NEXT COUPLE OF DAYS AS TRAJECTORIES REMAIN OF PACIFIC ORIGIN AND UPPER LEVEL RIDGING BEGINS TO BUILD OVER THE AREA. AT THE SFC...HIGH PRESSURE WILL EXPAND OUT OF THE DEEP SOUTH AND GRADUALLY SLIDE OFF THE CAROLINA COAST BY SATURDAY. WITH THE QUICKLY EXITING LOW...THE GRADIENT WILL RELAX QUICKLY AND WINDS WILL NOT BE NOTICEABLE AFTER THIS EVENING. USED A BLEND FOR TEMPERATURES...WHICH WILL REMAIN ABOVE NORMAL FOR THIS TIME OF YEAR...WITH HIGHS IN THE 50S AND LOWS AROUND FREEZING FOR MOST LOCALES.
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&& .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
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SUN AND MON...A COLD FRONT STALLS OVER THE AREA. LOW PRESSURE WILL FORM ALONG IT TO OUR SW AND MOVE EAST THRU THE CAROLINAS OR S VA MONDAY INTO MON NIGHT. GIVEN THE TRACK OF THE LOW TO OUR SOUTH AND COLDER AIR TO OUR NORTH...EXPECT THE RAIN SNOW LINE TO BE IN OUR AREA OR IN PA MONDAY INTO MON NIGHT. EXACTLY WHERE WILL HAVE TO BE REFINED...BUT OF COURSE BETTER CHANCES OF SEEING SOME SNOW AS YOU GO NW TOWARDS THE MASON DIXON LINE AND APPALACHIANS. ALL OF THAT SHOULD CLEAR OUT BY TUE AS A LARGE AIRMASS OF COOLER MORE SEASONABLE AIR PUSHES IN BEHIND THE LOW AND COVERS MUCH OF THE NATION.
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&& .AVIATION /09Z THURSDAY THROUGH MONDAY/...
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BAND OF SHOWERS WILL MOVE EAST OF THE TERMINALS BETWEEN 10 AND 12Z. ANY REMAINING LOWER CIGS WILL END WITH THE EXITING SHOWERS...ALTHOUGH VFR CIGS MAY LAST A FEW HOURS LONGER. VFR CONDITIONS ARE THEN EXPECTED THROUGH THE REMAINDER OF THE TAF PERIOD AS HIGH PRESSURE GRADUALLY BUILDS IN. WESTERLY WINDS WILL GUST TO AROUND 25-30KT TODAY...DIMINISHING WITH SUNSET. VFR THROUGH SATURDAY. WEST WINDS GRADUALLY BECOME SOUTH AT LESS THAN 10 KT. WEAK FRONT HANGING UP ON THE REGION WITH AN AREA OF LOW PRESSURE MOVING ALONG IT EARLY NEXT WEEK SHOULD ALLOW FOR AT LEAST MVFR CONDITIONS SUN AND MON WITH THE POSS OF IFR MONDAY. TUE AND WED VFR RETURNS WITH COOLER TEMPS.
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&& .MARINE...
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SHOWERS WILL PUSH EAST OF THE WATERS EARLY THIS MORNING. WESTERLY WINDS WILL INCREASE AND GUST BETWEEN 20-30 KT FOR MUCH OF THE DAY. WHILE SOLIDLY SCA CONDITIONS...DO NOT SEE STRONG ENOUGH WINDS TO WARRANT A GALE WARNING. THE WINDS WILL DIMINISH THIS EVENING...THEN REMAIN BELOW SCA LEVELS THROUGH SATURDAY AS HIGH PRESSURE BUILDS OVER THE WATERS. NO MARINE ISSUES ANTICIPATED FOR THE WEEKEND THROUGH EARLY NEXT WEEK.
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&& .TIDES/COASTAL FLOODING...
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ANOMALIES HAVE LEVELED OFF AND SHOULD HOLD STEADY OR SLOWLY FALL AS WESTERLY WINDS TAKE OVER. GIVEN THE CURRENT WATER LEVEL TRENDS AND THE FACT THE MORNING HIGH TIDE IS LOWER ASTRONOMICALLY...DO NOT THINK THERE WILL BE ANY MORE COASTAL FLOODING ISSUES...BUT WILL CONTINUE TO MONITOR THIS MORNING. BY THE EVENING HIGH TIDE... ANOMALIES SHOULD HAVE DECREASED SUFFICIENTLY TO PRECLUDE FLOODING.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ530>543.
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&& $$ SYNOPSIS...CAS NEAR TERM...ADS SHORT TERM...ADS LONG TERM...CAS AVIATION...CAS MARINE...CAS TIDES/COASTAL FLOODING...ADS/CAS

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