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 171819 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 219 PM EDT WED SEP 17 2014 .SYNOPSIS...
-- Changed Discussion --
HIGH PRESSURE WILL BUILD TOWARD THE EAST COAST THROUGH TONIGHT. A WEAK COLD FRONT WILL PASS THROUGH THE AREA THURSDAY AND HIGH PRESSURE WILL RETURN FOR FRIDAY AND SATURDAY. ANOTHER COLD FRONT WILL PASS THROUGH THE AREA SUNDAY NIGHT INTO MONDAY.
-- End Changed Discussion --
&& .NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --
HIGH PRESSURE WILL CONTINUE TO BRING DRY AND SEASONABLE CONDITIONS TO THE AREA LATE THIS AFTERNOON. THE HIGH WILL SLOWLY BUILD EAST TOWARD THE COAST TONIGHT WHILE A WEAK COLD FRONT APPROACHES FROM THE OHIO VALLEY AND WESTERN PENNSYLVANIA. A LIGHT SOUTHERLY FLOW AND SOME MORE CLOUD COVER WILL ALLOW MILDER CONDITIONS COMPARED TO TUESDAY NIGHT. MIN TEMPS WILL RANGE FROM THE MID TO UPPER 40S ALONG THE ALLEGHENY HIGHLANDS TO NEAR 60 IN WASHINGTON AND BALTIMORE. A WEAK COLD FRONT WILL PASS THROUGH THE REGION THURSDAY. THERE WILL BE SOME INSTABILITY DUE TO A SOUTHERLY FLOW AHEAD OF THE BOUNDARY...BUT FORCING AND MOISTURE WILL BE LIMITED. A COUPLE SHOWERS ARE POSSIBLE...BUT PRECIPITATION AMOUNTS WILL BE LIGHT AND MOST AREAS WILL END UP DRY. MAX TEMPS WILL RANGE FROM THE 60S IN THE MOUNTAINS TO THE MIDDLE 70S NEAR WASHINGTON AND BALTIMORE.
-- End Changed Discussion --
&& .SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
-- Changed Discussion --
THE COLD FRONT WILL DROP TO OUR SOUTH THURSDAY NIGHT BEFORE STALLING OUT OVER THE SOUTHEASTERN CONUS FRIDAY THROUGH SATURDAY. HIGH PRESSURE WILL BUILD INTO NEW ENGLAND THURSDAY NIGHT THROUGH FRIDAY BEFORE MOVING OFF THE COAST SATURDAY. THE SURFACE RIDGE AXIS WILL REMAIN OVER THE REGION DURING THIS TIME. THE RIDGE AXIS SHOULD REMAIN CLOSE ENOUGH TO BRING DRY CONDITIONS TO THE AREA DURING THIS TIME BUT CLOUDS MAY HANG AROUND DUE TO AN ONSHORE COMPONENT TO THE LOW-LEVEL FLOW...ESPECIALLY ACROSS THE SHENANDOAH VALLEY INTO THE POTOMAC HIGHLANDS. AN EAST TO NORTHEAST FLOW FRIDAY WILL CAUSE MAX TEMPS TO BE BELOW CLIMO...BUT WINDS SHOULD TURN TOWARD THE SOUTHEAST SATURDAY ALLOWING FOR WARMER CONDITIONS.
-- End Changed Discussion --
&& .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
-- Changed Discussion --
HIGH PRESSURE WILL REMAIN WEDGED SOUTHWARD BETWEEN THE APPALACHIAN MOUNTAINS AND EAST COAST SATURDAY NIGHT...KEEPING DRY CONDITIONS IN THE REGION. A COLD FRONT WILL MOVE FROM THE EASTERN GREAT LAKES TO THE EAST COAST SUNDAY AND SUNDAY NIGHT. THERE IS A CHANCE FOR SHOWERS ALONG THE FRONT WEST OF THE BLUE RIDGE SUNDAY AND IN ALL AREAS SUNDAY NIGHT. UPPER LEVEL SUPPORT SHOULD PIVOT NORTHEAST INTO EASTERN CANADA BY SUNDAY NIGHT...THE FRONT COULD STALL ACROSS THE DELMARVA PENINSULA AND TIDEWATER OF VIRGINIA BRIEFLY. A REINFORCING PUSH OF UPPER LEVEL ENERGY MONDAY SHOULD PUSH THE FRONT OFFSHORE BY LATE MONDAY. HIGH PRESSURE WILL GRADUALLY BUILD INTO THE REGION MONDAY NIGHT THROUGH WEDNESDAY TO ALLOW FOR THE NEXT PUSH OF COLDER AIR.
-- End Changed Discussion --
&& .AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
A WEAK COLD FRONT WILL APPROACH THE TERMINALS TONIGHT BEFORE PASSING THROUGH THURSDAY. VFR CONDITIONS AND LIGHT WINDS ARE EXPECTED MOST OF THE TIME...BUT PATCHY BR IS POSSIBLE LATE TONIGHT INTO EARLY THURSDAY AND A STRAY SHOWER CANNOT BE RULED OUT THURSDAY AFTERNOON. HIGH PRESSURE WILL RETURN FOR FRIDAY AND SATURDAY...BRINGING MORE VFR CONDITIONS. VFR CONDITIONS SATURDAY NIGHT THROUGH SUNDAY WITH LIGHT AND VARIABLE WINDS.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
HIGH PRESSURE WILL SLOWLY BUILD TOWARD THE COAST TONIGHT AND A WEAK COLD FRONT WILL PASS THROUGH THE WATERS THURSDAY. AN ISOLATED SHOWER IS POSSIBLE THURSDAY AFTERNOON. HIGH PRESSURE WILL BUILD TOWARD THE WATERS THURSDAY NIGHT AND FRIDAY. A PRESSURE SURGE WILL CAUSE NORTH-NORTHEAST WINDS TO INCREASE. A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE MARYLAND CHESAPEAKE BAY AND LOWER TIDAL POTOMAC RIVER LATE THURSDAY NIGHT THROUGH FRIDAY MORNING. THE FLOW WILL TURN TOWARD THE SOUTHEAST LATER FRIDAY THROUGH SATURDAY. WINDS MAY BE CLOSE TO SCA CRITERIA AT TIMES...BUT GUSTS HAVE BEEN CAPPED AT 15 KNOTS FOR NOW SINCE THE GRADIENT IS EXPECTED TO WEAKEN A BIT. NO MARINE HAZARDS SATURDAY NIGHT. SMALL CRAFT ADVISORIES ARE POSSIBLE SUNDAY WITH AN AREA OF LOW PRESSURE NEAR THE TIDEWATER OF VIRGINIA AND THE MAIN STEM CHESAPEAKE BAY.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING...
-- Changed Discussion --
HIGH PRESSURE WILL CONTINUE TO BUILD TOWARD THE COAST TONIGHT. THE FLOW WILL TURN TOWARD THE SOUTHEAST DURING THIS TIME...CAUSING TIDAL ANOMALIES TO INCREASE. TIDAL ANOMALIES UP TO A FOOT ABOVE NORMAL ARE EXPECTED TONIGHT AND THIS WILL CAUSE MINOR TIDAL FLOODING FOR SENSITIVE AREAS NEAR HIGH TIDE. A COASTAL FLOOD ADVISORY IS IN EFFECT TONIGHT FOR THE MARYLAND CHESAPEAKE BAY FROM ANNE ARUNDEL COUNTY THROUGH ST MARYS COUNTY. ELSEWHERE...MINOR FLOODING IS POSSIBLE WITH THE HIGH TIDE CYCLE LATE TONIGHT INTO EARLY THURSDAY BUT A COASTAL FLOOD ADVISORY HAS NOT BEEN ISSUED AT THIS TIME DUE TO SLIGHTLY HIGHER THRESHOLDS. A WEAK COLD FRONT WILL PASS THROUGH THE WATERS THURSDAY AND HIGH PRESSURE WILL BUILD OVER NEW ENGLAND BEHIND THIS FRONT. AN EASTERLY COMPONENT TO THE WIND IS EXPECTED TO CONTINUE DURING THIS TIME AND IT WILL LIKELY LAST THROUGH THE WEEKEND. THEREFORE...MINOR TIDAL FLOODING IS POSSIBLE NEAR TIMES OF HIGH TIDE THROUGH THE WEEKEND. THE BEST CHANCE FOR MINOR TIDAL FLOODING WILL BE DURING THE LATE EVENING AND MORNING HIGH TIDE CYCLE WHICH IS THE HIGHER OF THE TWO.
-- End Changed Discussion --
&& .LWX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
DC...NONE. MD...COASTAL FLOOD ADVISORY FROM 9 PM THIS EVENING TO 4 AM EDT THURSDAY FOR MDZ014-017-018. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO NOON EDT FRIDAY FOR ANZ530>534-537-539>541-543.
-- End Changed Discussion --
&& $$ SYNOPSIS...BJL NEAR TERM...BJL SHORT TERM...BJL LONG TERM...BJL/KLW AVIATION...BJL/KLW MARINE...BJL/KLW TIDES/COASTAL FLOODING...BJL

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