Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 110750 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 350 AM EDT FRI JUL 11 2014 .SYNOPSIS... WEAK HIGH PRESSURE BUILDS OVERHEAD THROUGH SATURDAY...THEN A WARM FRONT IS EXPECTED TO LIFT NORTH ON SUNDAY. A COLD FRONT WILL APPROACH THE AREA MONDAY BEFORE PASSING THROUGH LATE TUESDAY. HIGH PRESSURE WILL RETURN FOR THE MIDDLE PORTION OF NEXT WEEK. && .NEAR TERM /THROUGH SATURDAY/... AN UPPER LEVEL TROUGH IS LOCATED ACROSS THE OHIO VALLEY THIS MORNING AS DRIER AIR ALOFT MOVES INTO THE MID ATLANTIC. WINDS ARE VARIABLE AS HIGH PRESSURE MOVES INTO THE REGION THIS MORNING. A SURFACE TROUGH STILL EXISTS TO THE SOUTH FROM THE TIDEWATER REGION TO CENTRAL NC. CLOUDS ARE DISSIPATING FROM WEST TO EAST AS DRIER AIR MOVES INTO THE MID-ATLANTIC. LIGHT WINDS AND SATURATED SFC CONDITIONS WILL LEAD TO FOG DEVELOPMENT ACROSS MUCH OF THE REGION EARLY THIS MORNING. LOW VISIBILITIES ARE POSSIBLE FOR THE MORNING COMMUTE INCLUDING THE BALT/DC CORRIDOR. THE UPPER LEVEL TROUGH AXIS WILL CROSS THE REGION BY AFTERNOON. SHOWERS AND THUNDERSTORMS ARE POSSIBLE AHEAD OF THE TROUGH AXIS EAST OF THE BLUE RIDGE AS DEWPTS REMAIN IN THE MID TO UPPER 60S. FURTHER WEST...TERRAIN CIRCULATIONS WILL ALSO LEAD TO ISO-SCT SHOWERS AND THUNDERSTORMS ALONG THE BLUE RIDGE AND WEST. LIGHT WINDS ALOFT WILL LEAD TO WEAK UPDRAFTS AND THEREFORE SVR WEATHER IS NOT EXPECTED TODAY. ACTIVITY WILL SUBSIDE WITH THE LOSS OF DAYTIME HEATING THIS EVENING. FCST MAX TEMPS ARE IN THE MID 80S TODAY. RIDGING WILL BEGIN TONIGHT AND DRY CONDITIONS ARE EXPECTED. LIGHT SRLY FLOW WILL CONTINUE TO DRAW IN MOISTURE AND FOG IS POSSIBLE IN VALLEY LOCATIONS EARLY SATURDAY MORNING. WEAK FLOW WILL LEAD TO TERRAIN CIRCULATIONS SATURDAY AFTERNOON AND ISO-SCT SHOWERS AND THUNDERSTORMS ARE POSSIBLE WEST OF THE BLUE RIDGE. FCST MAX TEMPS ARE IN THE MID TO UPPER 80S. && .SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/... CONVECTION...MAINLY WEST OF THE BLUE RIDGE...FROM SATURDAY AFTERNOON SHOULD BE DIURNAL IN NATURE AND DISSIPATE SATURDAY EVENING. A WARM FRONT IS EXPECTED TO LIFT NORTH BY SUNDAY...WITH A DECENT SOUTHERLY PUSH BRINGING AN INCREASE IN DEWPOINTS AND PRECIPITABLE WATERS /I.E. MOISTURE/. THIS WILL LIKELY LEAD TO AN INCREASE IN DIURNAL CONVECTION THAT WOULD ALSO EXHIBIT A FURTHER EASTWARD EXTENT...THUS CHANCE POPS ACROSS THE CWA. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... SOUTHERLY FLOW CONTINUES EARLY NEXT WEEK...WITH DEWPOINTS LIKELY NEAR 70 DEGREES AND THE POTENTIAL FOR PRECIPITABLE WATERS AROUND 2 INCHES. LEE TROUGH ON MONDAY WILL HELP TRIGGER AT LEAST SCATTERED CONVECTION AND GIVEN HIGH PW ENVIRONMENT THERE MAY BE HEAVY RAINFALL. IT/S POSSIBLE THAT CONVECTION LINGERS WELL INTO THE EVENING. COLD FRONT AND STRONG VORT MAX WILL THEN LIKELY SUPPORT NUMEROUS SHOWERS AND THUNDERSTORMS ON TUESDAY. GIVEN STRONG WIND FIELDS FROM AN UPPER JET...STRONG TO SEVERE THUNDERSTORMS MAY BE POSSIBLE. COLD FRONT MOVES THROUGH THE AREA BY TUESDAY NIGHT...WITH A DRIER AIR MASS MOVING IN FOR WEDNESDAY AND THURSDAY. && .AVIATION /08Z FRIDAY THROUGH TUESDAY/... FOG WILL CONTINUE TO DEVELOP THIS MORNING AND IFR CONDITIONS ARE EXPECTED AT CHO-MRB-IAD. MVFR IS POSSIBLE AT BWI-MTN. FOG WILL MIX OUT AFTER SUNRISE AND ISO TSRA IS POSSIBLE TODAY. LOW CIGS AND VSBYS WILL BE POSSIBLE EARLY SATURDAY MORNING. HIGH PRESSURE WILL CONTINUE ACROSS THE AREA SATURDAY. ISO TSRA ARE POSSIBLE ALONG THE RIDGELINES AND MAY IMPACT MRB-CHO SATURDAY AFTERNOON. WARM FRONT LIFTS TO THE NORTH ON SUNDAY...WITH AFTERNOON THUNDERSTORMS POSSIBLE. COLD FRONT THEN WILL AFFECT THE AREA EARLY NEXT WEEK WITH A CHANCE OF THUNDERSTORMS. && .MARINE... LIGHT NLRY WINDS ARE EXPECTED THIS MORNING BEFORE BECOMING SRLY THIS AFTERNOON. ISO SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON. HIGH PRESSURE WILL CONTINUE ACROSS THE AREA THROUGH SATURDAY. SOUTHERLY FLOW INCREASE ON SUNDAY...AND SCA CONDITIONS MAY BE POSSIBLE SUNDAY NIGHT ACROSS MUCH OF THE BAY AND PERHAPS THE LOWER TIDAL POTOMAC RIVER. THESE COULD CONTINUE EARLY NEXT WEEK AHEAD OF A COLD FRONT. FRONTAL PASSAGE LOOKS TO BE TUESDAY NIGHT. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...NONE. && $$ SYNOPSIS...HAS/BPP NEAR TERM...HAS SHORT TERM...BPP LONG TERM...BPP AVIATION...HAS/BPP MARINE...HAS/BPP

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