Area Forecast Discussion
Issued by NWS Sterling, VA

Current Version | Previous Version | Text Only | 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
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
000 FXUS61 KLWX 161431 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1031 AM EDT WED APR 16 2014 .SYNOPSIS... HIGH PRESSURE WILL BUILD OVERHEAD DURING MIDWEEK...BEFORE MOVE OFFSHORE LATE IN THE WEEK. AN AREA OF LOW PRESSURE MAY AFFECT THE AREA SATURDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
HIGH PRESSURE BUILDS IN FROM OHIO THIS AFTERNOON. GUSTY WINDS THIS MORNING SHOULD DIMINISH INTO THE AFTERNOON AS THE GRADIENT RELAXES. ASIDE FROM A FEW CIRRUS THERE WILL BE PLENTY OF SUNSHINE TODAY BUT DESPITE THE SUNSHINE MAXIMA WILL STRUGGLE TO GET ABOVE THE 50 DEGREE MARK GIVEN THE COLD AIR MASS.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/... MIN TEMPS TONIGHT WILL BE MODERATED FROM NELY FLOW COMING OFF MID 40S OCEAN TEMPS AND LOW 50S BAY TEMPS. LEFT FREEZE WARNING DECISION TO DAY SHIFT SINCE MOST GUIDANCE HAS ZONES IN THE LOW 30S. PIEDMONT AND CENTRAL FOOTHILLS AREAS HAVE THE BEST CHANCE OF SEEING SUBFREEZING TEMPS TONIGHT. LOW CLOUDS SPREAD EAST INTO SRN MD THURSDAY AS THE ONSHORE FLOW SATURATES. MAX TEMPS GENERALLY INCREASE NE TO SW BASED ON ONSHORE FLOW...MID 50S FOR NERN MD TO UPR 50S/LOW 60S IN CNTRL SHEN VLY/KCHO. && .LONG TERM /FRIDAY THROUGH TUESDAY/... HIGH PRES OVR NEW ENGLAND WL BE TRACKING SLOWLY NE THU NGT AND FRI...LVG THE MID ATLC IN A WEDGING SITUATION WHICH IS XPCTD TO LEAD TO A PD OF CAD CONDITIONS - NERLY LO LVL WINDS WHICH WL CREATE A LOW CLD DECK OVR THE RGN E OF THE MTNS. THE SUNNIEST PLACE IN THE FCST AREA FRI WL LKLY BE W OF THE BLUE RDG. NO PCPN IS XPCTD - IF ANYTHING WERE TO DVLP IT WOULD BE DZ. LOWS THU NGT IN THE 30S/L40S. HIGHS FRI 55-60. ON SAT AN UPR LVL TROF WL TRACK N OF THE AREA...BUT WL DRAG A CD FNT THRU THE RGN. SOMETIMES CAD ENVIRONMENTS OF LO CLDS CAN HANG ARND IN THE MID ATLC UP TO 4 DAYS...BUT THIS DOES NOT LOOK TO BE THE CASE THIS TIME...AS CD FOPA IS PRBLY THE #1 WAY TO DISLODGE CAD. BUT W/ THIS WL ALSO COME THE PSBLTY OF RA. HIGHS SAT IN THE M60S. SUN LOOKING TO BE THE BETTER DAY OF THE WKND FOR OUTDOOR ACTIVITIES - SKIES SHOULD CLR AS HIGH PRES RETURNS. LOWS SAT NGT U30S/L40S. HIGHS IN THE LM60S. TEMPS XPCTD TO SLOWLY CLIMB DURG THE 1ST PART OF THE NEW WK W/ UPR LVL FLOW MORE OR LESS ZNL. BY TUE HIGH TEMPS SHOULD BE BACK ABV 70 ACROSS MUCH OF THE AREA. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
VFR THROUGH TAF PERIOD AND GUSTY INTO EARLY AFTERNOON AS HIGH PRESSURE BUILDS NORTHEAST ACROSS THE REGION. ONSHORE FLOW FROM COLD AIR DAMMING RIDGE TONIGHT...THURSDAY (CONTINUING INTO SATURDAY). A CAD SET UP IN XPCTD THU NGT/FRI. THIS WOULD LKLY LEAD TO CIGS IN THE MVFR RNG. A CD FNT IS XPCTD TO MOVE INTO THE AREA SAT WHICH COULD PSBLY SPAWN RA/RW. VFR CONDS XPCTD SUN AS HIGH PRES RETURNS.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
HAVE ALLOWED GALES TO EXPIRE AS WIND GUSTS HAVE DROPPED BELOW 30 KT...BUT SCA CONDITIONS ARE LIKELY TO LAST WELL INTO THE AFTERNOON BEFORE GRADIENT RELAXES ENOUGH. FLOW BECOMES NELY THIS EVENING...INCREASING TO 20 KT FOR LOWER SRN MD WATERS AFTER MIDNIGHT (WHEN AN SCA GOES INTO EFFECT)...THEN EXPANDING UP THE REST OF THE MD BAY BEFORE SUNRISE. ALL BUT THE UPPER TIDAL POTOMAC IN AN SCA FOR THE DAY THURSDAY WITH NELY FLOW GUSTING AROUND 20 KT. SMALL CRAFT ADVISORY LEVEL WIND GUSTS ARE POSSIBLE FOR PARTS OF THE WATERS SAT NIGHT IN A TIGHTENING PRESSURE GRADIENT BETWEEN LOW PRESSURE DEPARTING TO THE NORTH AND HIGH PRESSURE BUILDING IN FROM THE WEST.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING...
-- Changed Discussion --
STRONG NW WINDS HV CAUSED WATER LEVELS IN THE CHES BAY TO DROP TO 2 FT OR MORE FT BLO NRML. TIDAL BLOWOUT CONDITIONS ARE EXPECTED TO CONTINUE TODAY. MWS HAS BEEN ISSUED FOR THIS. WATER LVLS SHOULD BEGIN TO RECOVER THIS AFTN.
-- End Changed Discussion --
&& .CLIMATE... A VERY COLD AIRMASS FOR MID APRIL IS CAUSING TEMPS TO APPROACH RECORD MINIMUM TEMPERATURES THIS MORNING. BELOW IS A TABLE OF RECORD MINIMUM TEMPERATURES FOR APRIL 16 ALONG WITH THE 3 AM TEMPS. SITE...RECORD LOW TEMP 3 AM WED TEMP DCA....29 F IN 1928 35 BWI....30 F IN 1962 33 IAD....28 F IN 1981 32 && .LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR DCZ001. MD...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR MDZ004>007-009>011-013-014-016>018. VA...FREEZE WATCH FROM LATE TONIGHT THROUGH THURSDAY MORNING FOR VAZ036>040-042-050>057-501-502. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT THIS EVENING FOR ANZ531>534-537-539>541-543. SMALL CRAFT ADVISORY FROM 3 AM TO 6 PM EDT THURSDAY FOR ANZ530>533-538>541. SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR ANZ530- 535-536-538-542. SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM EDT THURSDAY FOR ANZ536- 542. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT THURSDAY FOR ANZ534-537-543.
-- End Changed Discussion --
&& $$ BPP/BAJ/WOODY!

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