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 301858 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 158 PM EST FRI JAN 30 2015 .SYNOPSIS... HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR THE FIRST HALF OF THE WEEKEND. LOW PRESSURE WILL IMPACT THE AREA LATE SUNDAY INTO MONDAY. HIGH PRESSURE WILL RETURN FOR THE FIRST HALF OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
E OF THE MTNS TEMPS HV BEEN WARMING FASTER THAN XPCTD...AND HV BEEN ADJUSTED UPWARDS. STLT SHOWS WVS OF CLDS CONT TO STREAM INTO THE AREA FM THE NW. STEEP LOW LVL LAPSE RATES ON IAD 12Z SNDG - WE HV ALREADY SEEN ONE BAND OF SNSH MOVE THRU THE AREA. SUSPECT THAT WE SEE MORE THIS AFTN. HIGH PRES BLDG INTO THE AREA - THE STEEP LO LVL TEMP GRAD WL ALSO HELP TRANSLATE GUSTY WINDS TO SFC. WIND ADVSRY IS IN EFFECT FOR MAJORITY OF THE FCST AREA.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/... SFC HIGH PRESSURE PUSHES EAST OVER THE REGION IN THE WAKE OF THE COLD FRONT AS RIDGING BUILDS IN ALOFT. MAINLY DRY CONDITIONS TONIGHT THRU SAT NIGHT WITH THE EXCEPTION OF ANY LINGERING LIGHT UPSLOPING SNOW SHOWERS FIRST HALF OF TONIGHT. SUBSIDENCE ALOFT WILL RESULT IN MOSTLY CLEAR CONDITIONS TONIGHT...AND SUNNY CONDITIONS FOR SAT. THE MAIN CONCERN DURING THIS TIME FRAME WILL BE THE WELL BELOW NORMAL TEMPS BEING USHERED IN AS 850MB TEMPS DIP BELOW -10 DEGREES CELSIUS. USING A BLEND OF ADJMET/MOSGUIDE...TEMPS TONIGHT EXPECTED TO DROP INTO THE TEENS EVERYWHERE EXCEPT POTOMAC HIGHLANDS...WHICH SHOULD SEE LOWS INTO THE SINGLE DIGITS. THESE TEMPS COMBINED WITH THE ON GOING NW FLOW WILL PRODUCE WIND CHILLS INTO THE SINGLE DIGITS. THE POTENTIAL EXISTS FOR NEEDING A WIND CHILL ADVISORY OVER THE FAR WESTERN PORTIONS OF THE POTOMAC HIGHLANDS WITH WIND CHILLS DROPPING TO AROUND -12 DEGREES. HOWEVER...HAVE HELD OFF FOR ANY ISSUANCE AT THIS TIME WITH THE VALUES BEING BORDERLINE WITH THE CRITERIA AND IT BEING MAINLY AFTER 06Z TONIGHT. ELSEWHERE...THOUGH IT WILL BE VERY COLD...WIND CHILLS VALUES ARE EXPECTED TO REMAIN ABV CRITERIA LVLS. BY SATURDAY...WILL SEE GRADUAL WARMING AS THE HIGH NUDGES ACROSS THE AREA...WITH RETURN FLOW SETTING UP AND INJECTING IN WARMER AIR. DESPITE THE WARMING...TEMPS STILL EXPECTED TO REMAIN BELOW NORMAL THRU AT LEAST SAT NIGHT. 00Z MODEL SUITE IN PRETTY GOOD AGREEMENT OF ANY PCPN MOVING INTO THE REGION WITH THE NEXT LOW PRESSURE SYSTEM HOLDING OFF TILL AFTER 12Z SUNDAY AND HAVE THUS A DRY FORECAST THRU THIS TIME PERIOD. && .LONG TERM /SUNDAY THROUGH THURSDAY/... MDLS ARE TRACKING THE LOW PRES AREA SUN NGT/MON ACROSS THE CWA. ATTM THE BEST CHC FOR ACUMULATING SNOWS LOOKS TO BE ALONG THE M-D LN. NEXT WEEK WL START COLD AS THE CSTL LOW STRENGTHENS...DRAGGING DOWN COLD AIR. H8 TEMPS SHUD BE DROPPING TO -10 TO -14C. AT THAT RATE MON-TUE MAXT WL HV TROUBLE RISING ABV FRZG...AND MIN-T MAY DIP BELOW 0 DEGF ACRS NRN MD AND IN THE PTMC HIGHLANDS. GFS SUGGESTING THAT ANOTHER SRN STREAM LOW WL FLLW MIDWEEK HIPRES FOR A POTL STORMY THU. ITS STILL TBD IF WE WL RECEIVE THE LOW OR IT WL PASS S OF CWFA. WL BE KEEPING POPS LOW AS THERES A LOT OF WX TO GET THROUGH FIRST. && .AVIATION /19Z FRIDAY THROUGH WEDNESDAY/... VFR CONDITIONS THROUGH SAT. MAIN CONCERN TODAY STRONG NW FLOW. GUSTS START TIME +/- 1-2 HRS...GENERALLY IN THE 20S THIS MORNING...THEN INCREASING 30-40 KTS THIS AFTN/EVENING. WINDS WILL GRADUALLY DIMINISH TONIGHT...WITH GUSTS PSBL THOUGH THROUGH THE NIGHT. KCHO COULD SEE GUSTS ENDING AS EARLY AS 06Z. ISO SNOW SHOWER PSBL KMRB BUT TOO LOW CONFIDENCE TO INCLUDE...ESP WITH LITTLE IMPACT TO CONDITIONS. DECREASING WNW FLOW SAT WITH WINDS BCMG W SAT NIGHT. PSBL LOWERING CIGS LATE SAT NIGHT AS THE NEXT LOW PRESSURE SYSTEM APPROACHES. FLGT RESTRICTIONS APLENTY SUN AS LOPRES CROSSES TERMINALS. THE AFTN-NIGHT TIME HRS SHUD BE MOST AFFECTED. PTYPE ISSUES EXIST. ITS NO LONGER A CLEAR-CUT SNOW EVENT. THE LOW WL BE PULLING OFFSHORE MON. CONDS WL IMPRV THRU THE DAY...BUT SHUD HV SOME STRONG NW WIND GUSTS. VFR TUE UNDER HIPRES. && .MARINE... GALE WARNING IN EFFECT FOR THRU TONIGHT. COULD SEE LINGERING GALES PAST DAYBREAK SAT MORNING...BUT HAVE HELD AT 09Z TO ACCOUNT FOR UNCERTAINTY THEREAFTER. HIGH CONFIDENCE SCA CONDITIONS WILL SET IN SAT MORNING FOR CHESAPEAKE BAY...AND PSBL OVER THE TIDAL POTOMAC. SUB-SCA CONDITIONS EVERYWHERE FOR SAT NIGHT. LOPRES APPRCHS WATERS SUN DAY AND CROSSES SUN NGT. TRACK OF LOW WL PERMIT A MIXED BAG OF PTYPES AT NIGHT BEFORE CHGG BACK TO SNOW UPON EXIT MON. ALSO ON MON SHUD BE STIFF NW WINDS AS THE STORM STRENGTHENS AS IT PULLS AWAY. AT LEAST SCA PSBL. WUDNT COMPLETELY RULE OUT GLW...CONTINGENT UPON DETAILS THAT ARE STILL A LTL MURKY. HIPRES WL RETURN BY TUE. && .TIDES/COASTAL FLOODING... WINDS TURNED NW BHD A COLD FRONT. THIS WILL SUPPORT BLOW OUT TIDES. THEREFORE...WATER LEVELS XPCTD TO RETURN TO NORMAL TONIGHT. && .LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR DCZ001. MD...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MDZ003>006-011- 013-014-016>018-501>508. VA...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ025>031-040- 051>055-057-501>508. WV...WIND ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR WVZ050>053-055- 501>506. MARINE...GALE WARNING UNTIL 4 AM EST SATURDAY FOR ANZ530>543.
-- End Changed Discussion --
&& $$ UPDATE...WOODY!

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