Area Forecast Discussion
Issued by NWS Sterling, VA

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Remove Highlighting --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 261528 AAA AFDLWX AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1028 AM EST FRI DEC 26 2014 .SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE OVER THE AREA TODAY...MOVING OFFSHORE SATURDAY. A WEAK COLD FRONT WILL CROSS THE REGION LATE SUNDAY...WITH ANOTHER LOW PRESSURE SYSTEM APPROACHING FROM THE SOUTHEAST INTO MONDAY. COLDER HIGH PRESSURE WILL FOLLOW FOR MID WEEK.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
IN NEAR-PERFECT SYMMETRY...AN UPPER TROUGH ENCOMPASSES THE WRN HALF OF THE CONUS WHILE A HIGH PRESSURE RIDGE RESIDES OVER THE ERN HALF. AFTER AN ACTIVE PAST FEW DAYS OVER THE ERN SEABOARD...HIGH PRESSURE HAS WIPED AWAY MUCH OF THE AREA CLOUDS AND DROPPED OFF WINDS. BARELY A BREEZE AT THE SFC AND CERTAINLY NO DISCERNIBLE DIRECTION. THE SFC HIGH ITSELF IS ELONGATED OVER THE SRN APLCNS AND STRETCHES FROM ALABAMA TO SRN MARYLAND. THOUGH AT A MORE SRN LATITUDE AND TYPICALLY WARMER THAN AREAS TO THE NORTH...THE LOWER SHEN VLY AND PIEDMONT - KCHO AREA - ARE COOLER THAN THE DC/BALT METRO AREAS AND CLOSER TO THE BAY. MOST ALL GUIDANCE MEMBERS...INCLUDING ADJ AND BIAS-CORRECTED DERIVATIVES SHOW AN INVERSE OF THESE CONDITIONS...SO HOURLY TEMPS AS WELL AS THE EXPECTED MAX TEMPS WERE MODIFIED TO ACCOUNT FOR THESE DIFFERENCES. DEWPOINTS ARE FAIRLY UNIFORM IN THE L30S...KEEPING CONDITIONS FAIRLY MODERATED AND ALLOWING FOR ONLY A SLOW/STEADY TEMP CLIMB THIS AFTN. MOST AREAS WILL PEAK IN THE L-M50S W/ NEAR CALM WINDS FOR A COOL BUT WARMER THAN AVG LATE DEC DAY.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... HIGH PRESSURE WILL GRADUALLY SLIP EAST OFF THE CAROLINA COAST BY SATURDAY AS AN UPPER TROUGH DIGS INTO THE DESERT SOUTHWEST. AS THE JET STREAM STRENGTHENS AND SHIFTS BACK TO THE SOUTH...HIGH LEVEL CLOUDS WILL BEGIN TO SPILL ACROSS THE AREA...ESPECIALLY BY SATURDAY AFTERNOON. HOWEVER OVERALL THE WILL CONTINUE TO BE TRANQUIL AND MILD. TONIGHT SHOULD FEATURE EFFECTIVE RADIATIONAL COOLING AGAIN...ALTHOUGH THE SUBSIDENCE INVERSION WILL MEAN WARMER LOWS AT THE HIGHER ELEVATIONS. HIGH TEMPERATURES FOR SATURDAY INCH UP...WITH PERHAPS A FEW SPOTS TOPPING 60. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... LOW PRESSURE OVER THE GREAT LAKES SATURDAY NIGHT WILL MOVE ALONG THE TO THE CANADIAN MARITIMES BY 00Z/MON AND DRAG A WEAK COLD FRONT ACROSS THE REGION. LOW PRESSURE WILL FORM ACROSS THE LOWER MISSISSIPPI VALLEY EARLY SUNDAY AND MOVE NORTHEAST ALONG THE TRAILING FRONTAL BOUNDARY SUNDAY NIGHT. PRECIP CHANCES INCREASE AS DECENT UPLIFT MOVE ACROSS THE CWA LATE SUNDAY/SUNDAY NIGHT AS THIS LOW SYSTEM MOVES ACROSS THE CAROLINAS. TEMPERATURES WILL BE WARM ENOUGH TO KEEP PRECIP ALL RAIN ON SUNDAY...BUT TOWARDS THE MASON- DIXON LINE AT HIGHER ELEVATION AREAS...SOME WET SNOW COULD MIX IN AT TIMES. THE SURFACE LOW MOVES OFFSHORE MONDAY. THEN COLDER HIGH PRESSURE BUILDS ACROSS THE REGION LATE MONDAY AND CONTINUES FOR THE REMAINDER OF THE WEEK. THIS HIGH WILL FEATURE SEASONAL TO BELOW NORMAL TEMPERATURES FOR MUCH OF NEXT WEEK. BUT THE AIR MASS IS DRY SO NOT EXPECTING ANY PRECIP...EXCEPT FOR A FEW WESTERN MTN SNOW SHOWERS WED AND THUR. THE NEXT LOW PRESSURE SYSTEM THAT COULD IMPACT THE MID ATLANTIC IS STARTING TO SHOW UP IN THE MODEL FOR NEXT WEEKEND...BUT LOW CONFIDENCE AT THIS POINT. && .AVIATION /15Z FRIDAY THROUGH TUESDAY/...
-- Changed Discussion --
HIGH PRESSURE IN CONTROL THROUGH THE TAF PERIOD...WITH VFR CONDITIONS. LIGHT/VARIABLE WINDS WILL BECOME SOUTHERLY AROUND MIDDAY TODAY BUT REMAIN LESS THAN 10 KT. WINDS REMAIN LIGHT AND SOUTHERLY THROUGH SATURDAY...VFR LIKELY. MVFR TO LOCALLY IFR CONDITIONS EXPECTED SUNDAY AS PRECIP OVERSPREADS THE REGION.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
WINDS WILL REMAIN BELOW SCA-LEVELS THROUGH SATURDAY FROM GENERALLY A SOUTHERLY DIRECTION AS HIGH PRESSURE GRADUALLY MOVES OFFSHORE. A WEAK FRONT WILL CROSS THE REGION ON SUNDAY INTO MONDAY...WINDS ARE EXPECTED TO REMAIN BELOW SCA LEVELS.
-- End Changed Discussion --
&& .EQUIPMENT... KLWX 88D WILL REMAIN OUT OF SERVICE UNTIL SATURDAY...WHEN THE PARTS TO REPAIR THE RADAR ARE EXPECTED TO ARRIVE. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ UPDATE...GMS PREV DISCUSSION...ADS/SMZ

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.