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 271501 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1001 AM EST THU NOV 27 2014 .SYNOPSIS... AN UPPER-LEVEL DISTURBANCE WILL PASS THROUGH THE AREA TODAY AND HIGH PRESSURE WILL BUILD OVERHEAD FRIDAY. THE HIGH WILL MOVE OFF THE COAST DURING THE WEEKEND. A COLD FRONT IS EXPECTED TO MOVE THROUGH MONDAY. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
FOG IS BEGINNING TO LIFT...BUT AREAS OF DENSE FOG CONTINUE ACROSS PORTIONS OF THE SHENANDOAH VALLEY AND POTOMAC HIGHLANDS. THEREFORE...THE DENSE FOG ADVISORY WILL CONTINUE UNTIL 11 AM. AN UPPER-LEVEL DISTURBANCE WILL PASS BY TO OUR SOUTH THIS MORNING AND A REINFORCING COLD FRONT IS EXPECTED TO PASS THROUGH THE REGION THIS AFTERNOON. THESE SYSTEMS MAY BRING A FEW SHOWERS TO THE AREA TODAY...BUT PRECIPITATION AMOUNTS WILL BE LIGHT. FOR THIS MORNING...THE BEST CHANCE FOR SHOWERS WILL BE ACROSS SOUTHERN MARYLAND AND THE VIRGINIA PIEDMONT...CLOSER TO THE TRACK OF THE UPPER-LEVEL DISTURBANCE. THE COLD FRONT MAY TRIGGER A COUPLE RAIN OR SNOW SHOWERS THIS AFTERNOON...BUT PRECIPITATION AMOUNTS WILL BE LIGHT AND LITTLE OR NO SNOW ACCUMULATION IS EXPECTED. THE ONE EXCEPTION WILL BE FOR LOCATIONS ALONG AND WEST OF THE ALLEGHENY FRONT...WHERE SNOW SHOWERS WILL BE MORE WIDESPREAD. EVEN ACROSS THESE AREAS PRECIIPTATION AMOUNTS WILL BE LIGHT SO LITTLE SNOWFALL ACCUMULATION IS EXPECTED. MAX TEMPS WILL RANGE FROM THE UPPER 20S AND LOWER 30S IN THE MOUNTAINS TO THE LOWER AND MIDDLE 40S NEAR WASHINGTON AND BALTIMORE. SURFACE HIGH PRESSURE WILL BUILD TOWARD THE REGION TONIGHT BEHIND THE COLD FRONT...BUT ANOTHER UPPER-LEVEL DISTURBANCE WILL SWING THROUGH THE AREA DURING THIS TIME. A PRESSURE SURGE WILL CAUSE BLUSTERY CONDITIONS AND IT WILL BE COLD DUE TO A NORTHWEST FLOW. AN UPSLOPE NORTHWESTERLY FLOW WILL BRING ACCUMULATING SNOW TO LOCATIONS ALONG AND WEST OF THE ALLEGHENY FRONT. A FEW SNOW SHOWERS MAY SPILL EAST OF THE MOUNTAINS ACROSS NORTHERN MARYLAND...EXTREME NORTHERN VIRGINIA AND EASTERN WEST VIRGINIA...BUT LITTLE OR NO SNOW ACCCUMULATION IS EXPECTED. FCST MIN TEMPS WILL RANGE FROM THE LOW 20S IN THE MTNS TO THE LOW 30S NEAR THE CITIES.
-- End Changed Discussion --
&& .SHORT TERM /FRIDAY THROUGH SATURDAY/... STILL MAY HAVE A FEW UPSLOPE SNOW SHOWERS ONGOING TO START FRIDAY OTHERWISE SURFACE HIGH BUILDS IN FROM THE WEST FOR DRY CONDITIONS/SOME SUNSHINE BUT BELOW NORMAL TEMPERATURES. SURFACE HIGH SHIFTS OFFSHORE FRIDAY NIGHT. SHORTWAVE IN 500 MB FLOW WILL BRING INCREASING CLOUDS FRIDAY NIGHT INTO EARLY SATURDAY. MUCH OF THE CWA SHOULD BE DRY ALTHOUGH THERE WILL BE A SLIGHT CHANCE OF SNOW SHOWERS OVER THE ALLEGHENY/POTOMAC HIGHLANDS. TEMPERATURES START TO MODERATE A LITTLE FOR SATURDAY. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... RETURN FLOW AROUND HIGH PRESSURE LOCATED OFFSHORE WILL MODERATE TEMPERATURES MORE SATURDAY NIGHT INTO SUNDAY. A WARM FRONT WILL LIKELY PUSH NORTH FOR SUNDAY. THERE WILL BE SOME CLOUDS BUT CHANCE OF PRECIP APPEARS MINIMAL. ABOVE NORMAL TEMPERATURES ARE LIKELY TO PERSIST INTO MONDAY. A COLD FRONT WILL MOVE ACROSS THE AREA WITH A CHANCE OF RAIN SHOWERS. COLDER AIR IS THEN EXPECTED TO MOVE IN BEHIND THE FRONT FOR THE MID-WEEK PERIOD. && .AVIATION /15Z THURSDAY THROUGH MONDAY/...
-- Changed Discussion --
MVFR/IFR CONDITIONS AT KMRB AND KCHO WILL IMPROVE TO VFR LEVELS BY THIS AFTERNOON. VFR CONDITIONS WILL PERSIST THROUGH TONIGHT. HIGH PRESSURE BUILDS IN FOR FRIDAY THEN MOVES OFFSHORE FOR THE WEEKEND. NO SIGNIFICANT WX IS EXPECTED.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
WEAK LOW PRESSURE WILL MOVE SOUTH OF THE WATERS TODAY LEADING TO NW WINDS 10-15KTS. NRLY WINDS BEHIND THE LOW WILL INCREASE AND SCA CONDITIONS ARE EXPECTED TONIGHT FOR PORTIONS OF THE WATERS THROUGH FRIDAY. NORTHWEST WINDS BEHIND A SHORTWAVE SHOULD BE ABLE TO MIX DOWN FOR SCA CONDITIONS ON FRIDAY. HIGH PRESSURE BUILDS IN FOR LESS WIND FRIDAY NIGHT. RETURN FLOW ON SATURDAY COULD THEN INCREASE INTO SCA TERRITORY.
-- End Changed Discussion --
&& .LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...NONE. MD...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR MDZ502. VA...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR VAZ025>031- 504. WV...DENSE FOG ADVISORY UNTIL 11 AM EST THIS MORNING FOR WVZ050-055- 502-504-506. MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 PM EST FRIDAY FOR ANZ530>534-536-537-539>541-543. SMALL CRAFT ADVISORY FROM 8 AM TO 6 PM EST FRIDAY FOR ANZ535- 538-542.
-- End Changed Discussion --
&& $$ SYNOPSIS...BPP/HAS NEAR TERM...BJL/HAS SHORT TERM...BPP LONG TERM...BPP AVIATION...BJL/BPP/HAS MARINE...BJL/BPP/HAS

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