Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 241411 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1011 AM EDT FRI JUL 24 2015 .SYNOPSIS... HIGH PRESSURE OVER THE OHIO VALLEY WILL CONTINUE TO DOMINATE THE WEATHER TODAY. IT WILL SHIFT EAST OVER THE AREA ON SATURDAY AND CONTINUE SHIFTING EAST INTO THE WESTERN ATLANTIC OCEAN ON SUNDAY. A WEAK COLD FRONT WILL SLIDE INTO THE AREA FROM THE NORTHWEST SUNDAY NIGHT AND MONDAY BEFORE DISSIPATING TUESDAY. ANOTHER COLD FRONT WILL APPROACH FROM THE NORTHWEST ON THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... FORECAST AREA IS SITUATED ON EASTERN SIDE OF BROAD SFC HIGH PRESSURE STRETCHING FROM THE GREAT LAKES TO MID-ATLANTIC. A STATIONARY FRONT REMAINS OVER THE SOUTHEASTERN STATES. ANOTHER QUIET WEATHER DAY IS IN STORE...AND VERY FEW CHANGES WERE REQD IN THE DATABASE. ATMOSPHERE APPEARS DRY ENOUGH FOR ONLY A FEW CLOUDS. HIGH TEMPS WILL LIKELY BE A DEGREE OR TWO HIGHER THAN THURSDAY...BUT STILL BELOW 90F IN MOST LOCATIONS. TONIGHT...RIDGE AXIS AT THE SFC AND ALOFT MOVE NEARLY OVERHEAD...RESULTING IN MAINLY CLEAR SKIES AND CALM WINDS. DEW POINTS WILL STILL BE LOW ENOUGH TO SUPPORT UPPER 50S TO LOWER 60S IN THE TYPICALLY COOLER OUTLYING AREAS...WITH MID 60S ELSEWHERE AND NEAR 70 IN URBAN CENTERS. && .SHORT TERM /SATURDAY THROUGH MONDAY/... THE SFC HIGH BEGINS TO MOVE OFFSHORE ON SATURDAY...WHILE THE MID AND UPPER RIDGE BEGIN TO BE SUPPRESSED BY APPROACHING TROUGH IN ONTARIO. IN TERMS OF SENSIBLE WEATHER...THIS JUST LEADS TO A FEW MORE CLOUDS AND A FEW MORE DEGREES TO THE HIGH TEMPERATURE...WHICH COULD HIT 90F IN A FEW SPOTS IN THE EAST. HOWEVER DEW POINTS WILL REMAIN IN THE LOWER TO MID 60S. THINK DEPICTIONS OF TERRAIN- BASED CONVECTION ARE OVERDONE GIVEN WARM AND DRY MID-LEVELS...SO HAVE MAINTAINED A DRY FORECAST. HIGH PRESSURE SHIFTS FURTHER EAST SATURDAY NIGHT AND SUNDAY AS A WEAKENING COLD FRONT APPROACHES FROM THE NORTHWEST. THE RETURN SOUTHWEST FLOW WILL BRING AN INCREASE IN HUMIDITY AND HOLD TEMPS UP SOMEWHAT ON SATURDAY NIGHT...WITH TEMPS RETURNING TO THE LOW 90S IN MANY AREAS ON SUNDAY ALONG WITH HIGHER HUMIDITY. ESSENTIALLY...A RETURN TO SOMETHING MORE TYPICAL FOR JULY. THE FRONT WILL STALL IN THE AREA SUNDAY NIGHT AND MONDAY. THE THREAT OF STORMS IS GREATEST DURING THE AFTERNOON HOURS MONDAY AS THE STRONGEST IN A SERIES OF FAIRLY WEAK SHORTWAVES PUSHES SOUTHEAST ACROSS THE AREA. TEMPERATURES WILL COOL A LITTLE MONDAY COMPARED TO SUNDAY DUE TO MODEST COLD ADVECTION AND INCREASED CLOUDS/PRECIP COVERAGE...BUT STILL WARM AND SOMEWHAT MUGGY. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... THE WEAKENING FRONT WILL REMAIN IN THE AREA TUESDAY AS IT DISSIPATES. A FEW SCATTERED THUNDERSTORMS ARE STILL POSSIBLE WITH THE WEAKENING BOUNDARY AS A TRIGGER BUT COVERAGE LOOKS LOWER THAN MONDAY WITH LESS SUPPORT ALOFT. AFTER THE FIRST FRONT DISSIPATES...THE RIDGE TO THE SOUTHWEST WILL BUILD NORTHEAST BRIEFLY ON WEDNESDAY WITH DRIER AND WARMER WEATHER...BEFORE THE NEXT COLD FRONT APPROACHES FROM THE NORTHWEST ON THURSDAY. SOUTHWESTERLY FLOW AHEAD OF THE THAT FRONT WILL CONTINUE TO ADVECT WARM AIR NORTHWARD...AND THURSDAY CURRENTLY LOOKS LIKE THE HOTTEST DAY SINCE EARLY THIS PAST WEEK WITH WIDESPREAD LOW-MID 90S EXPECTED. THUNDERSTORMS WILL BECOME A RISK AS THE FRONT APPROACHES LATER IN THE DAY. && .AVIATION /14Z FRIDAY THROUGH TUESDAY/... VFR EXPECTED TODAY UNDER HIGH PRESSURE. NW WINDS LESS THAN 10 KT DURING THE DAY. WINDS CALM TONIGHT. STILL DOES NOT LOOK LIKE A GOOD FOG SET- UP WITH A RATHER DRY ATMOSPHERE. VFR CONTINUES SATURDAY AS THE HIGH PUSHES OFFSHORE...WITH SE WINDS LESS THAN 10 KT. THE MAIN CONCERN SUNDAY THROUGH TUESDAY APPEARS TO BE SCATTERED THUNDERSTORMS WITH POTENTIAL BRIEF MVFR/IFR CIGS AND VIS AS A COLD FRONT APPROACHES LATER SUNDAY...WITH THE THREAT OF STORMS CONTINUING MONDAY AND TUESDAY AS THE FRONT STALLS IN THE AREA AND THEN DISSIPATES. WINDS WILL BE MOSTLY 10 KNOTS OR LESS...EXCEPT POSSIBLY SW 10-20 KNOTS LATER SUNDAY AS THE FRONT APPROACHES. && .MARINE... HIGH PRESSURE WILL PROVIDE DRY WEATHER AND WINDS GENERALLY 10 KT OR LESS THROUGH SATURDAY. PREVAILING WINDS WILL BE NW OR N THROUGH TONIGHT...BECOMING SE BY SATURDAY AFTERNOON. WINDS MAY APPROACH SCA LEVELS LATER SUNDAY AS A COLD FRONT APPROACHES FROM THE NORTHWEST. OTHERWISE...WINDS ARE EXPECTED TO REMAIN BELOW SCA LEVELS THROUGH THE LONG TERM. THE MAIN CONCERN APPEARS TO BE SCATTERED THUNDERSTORMS LATER SUNDAY...WITH THE THREAT OF STORMS CONTINUING MONDAY AND TUESDAY. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...RCM NEAR TERM...ADS/HTS SHORT TERM...ADS/RCM LONG TERM...RCM AVIATION...HTS/ADS/RCM MARINE...ADS/RCM

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