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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 251509 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1009 AM EST THU DEC 25 2014 .SYNOPSIS...
-- Changed Discussion --
MILD SOUTHERN HIGH PRESSURE WILL BUILD THIS AFTERNOON THROUGH FRIDAY MORNING...BEFORE MOVING OFFSHORE ON SATURDAY. 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.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
THE BACK EDGE OF THICK CLOUDS ASSOCD W/ CDFNT EXITING THE TIP OF SRN MD ATTM. HWVR...A STCU FIELD ASSOCD W/ MID-LVL TROF AXIS CURRENTLY SPREADING EWD. LAPSE RATES WL BE SLIGHTLY BETTER W OF THE BLURDG...AND PERHAPS THERE WL BE A PINCH MORE SUPPORT ACRS NRN MD. THESE AREAS WL BE A BIT CLOUDIER DURING THE MIDDAY. BY MID AFTN...SUBSIDENCE WL ASSIST IN THINNING CLD DECK. LTST GDNC CONTS GOING FCST IN TERMS OF THE WIND FCST. MOMENTUM IN COLUMN SHUD BE SUFFICIENT FOR OCNL 30 KT GUSTS...A BIT HIER IN THE MTNS. CLDS WL INTERFERE IN THE PROCESS. TEMP FCST ON TRACK TOO BASED ON 12Z RAOBS AND LTST LAMP. SOURCE RGN NOT THAT COLD AND TRAJ WONT BE CROSSING GRTLKS...SO THERES NOT A LOT OF MSTR FOR UPSLP PCPN. EVEN IF THERE WERE...EKN TEMP AT 38F SUGGESTS THEY WUDNT ALL BE SHSN ANYWAY. WL CONT FCST FOR CHC POPS AND RASN MIX. NO ACCUMS.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/... 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. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... 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. && .AVIATION /15Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
VFR CONDITIONS THRU VALID 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.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
WESTERLY WINDS WILL INCREASE AND GUST BETWEEN 20-30 KT FOR MUCH OF THE DAY. ON THE WHOLE...GDNC SUGGESTS THAT MOMENTUM TRANSFER WONT BE CAPABLE OF GLW. HWVR IF IDEAL CONDS REALIZED...THEN THERE WL BE A SMALL WINDOW OF OPPORTUNITY WITHIN A CPL HRS OF NOON FOR NRN WATERS. HV OPTED TO CAP WINDS AT 30 KT ATTM. WL MONITOR SITUATION. 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.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING...
-- Changed Discussion --
ANOMALIES NEAR 1 FT AND DROPPING AS WESTERLY WINDS TAKE OVER. GIVEN THE CURRENT WATER LEVEL TRENDS AND THE FACT THE MORNING HIGH TIDE IS LOWER ASTRONOMICALLY...THERE HAVE BEEN NO ISSUES WITH THIS MORNING TIDE CYCLE. EVEN CAUTION STAGE HASNT BEEN EXCEEDED THUS FAR. BY THE EVENING HIGH TIDE... ANOMALIES SHOULD HAVE DECREASED SUFFICIENTLY TO PRECLUDE FLOODING.
-- End Changed Discussion --
&& .EQUIPMENT...
-- Changed Discussion --
TEMPORARY REPAIRS HAVE BEEN MADE TO KLWX 88D. HOWEVER...TWO ADDITIONAL PARTS ARE ON EMERGENCY ORDER. THEY WILL BE REPLACED ONCE THEY ARRIVE ON FRIDAY. WHILE THE RADAR IS OPERATING AT THIS MOMENT...IT SHOULD STILL BE CONSIDERED UNSTABLE UNTIL THE PERMANENT FIX HAS BEEN MADE.
-- End Changed Discussion --
&& .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR ANZ530>543. && $$ SYNOPSIS...HTS/CAS NEAR TERM...HTS SHORT TERM...ADS LONG TERM...CAS AVIATION...HTS/ADS/CAS MARINE...HTS/ADS/CAS TIDES/COASTAL FLOODING...HTS/ADS EQUIPMENT...HTS

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