Area Forecast Discussion
Issued by NWS Sterling, VA

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000 FXUS61 KLWX 291432 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 1032 AM EDT MON JUN 29 2015 .SYNOPSIS...
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HIGH PRESSURE OVER THE AREA THIS MORNING WILL SHIFT EAST TODAY. LOW PRESSURE WILL PERSIST OVER THE MIDWEST THROUGH TONIGHT AND THEN CROSS LAKES ERIE AND ONTARIO ON TUESDAY...PUSHING A WARM FRONT NORTHEAST ACROSS OUR AREA. A COLD FRONT WILL THEN PUSH SOUTHEAST ACROSS THE AREA ON WEDNESDAY BEFORE STALLING IN THE AREA ON THURSDAY THROUGH SATURDAY.
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&& .NEAR TERM /THROUGH TONIGHT/...
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AS OF 14Z...SKC ENTIRE CWA SAVE SOME RIDGE CU IN THE SRN ALLEGHENY HIGHLANDS UNDER WEAK HIGH PRESSURE (1016MB). HIGH PRESSURE SHIFTS EAST TODAY WITH AFTERNOON RETURN SLY FLOW. WITH THE STRONGEST SUN OF THE YEAR...MAX TEMPS ADJUSTED TO LOW TO MID 80S. ADDED CHANCE POPS FOR RAIN FOR ALLEGHENY/POTOMAC HIGHLANDS FOR THE DIMINISHING RAIN OVER OHIO SHIFTING EAST. LOW PRESSURE PIVOTS TOWARD LAKE ERIE TONIGHT...WITH AN EFFECTIVE WARM FRONT LIFTING TOWARD THE AREA. BEST LIFT AND MOISTURE WILL BE ACROSS WESTERN AREAS...EVENTUALLY SPREADING EAST ACROSS THE MASON- DIXON LINE. STILL NOT EXPECTING MUCH MORE THAN ISOLATED/SCATTERED SHOWERS HOWEVER...AS MAIN ENERGY WILL BE FOCUSED NORTH OF THE AREA. LOW TEMPERATURES WILL CREEP BACK UP INTO THE 60S AS SLIGHTLY HIGHER DEW POINTS RETURN.
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&& .SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/... THE REGION WILL ON THE EDGE OF THE WARM SECTOR OF A LOW PRESSURE SYSTEM MOVING THROUGH THE LOWER GREAT LAKES ON TUESDAY. MID AND UPPER TROUGH AXIS WILL BE LOCATED WEST OF THE AREA...BUT IMPULSES WITHIN THE FLOW WILL MOVE ACROSS THE AREA TO COMBINE WITH DIURNAL INSTBY TO PRODUCE SHOWERS AND STORMS. ACTUAL FRONT DOES NOT PUSH IN FROM THE WEST UNTIL EVENING...SO TERRAIN ALSO WILL PLAY A ROLE. THINK COVERAGE WILL BE FAIRLY LIMITED UNTIL MID AFTERNOON. DEEP LAYER SHEAR EXPECTED TO BE AOA 30 KT. AMOUNT OF INSTBY SHOULD BE ON THE LOWER END OF THE SPECTRUM...BUT COULD BE ENOUGH FOR SOME STRONGER STORMS TO DEVELOP. A MARGINAL RISK FOR SEVERE WX CONTINUES. TEMPERATURES RETURN CLOSER TO NORMAL...MID 80S TO AROUND 90. WARM FRONT WILL ADVANCE NORTHEAST ACROSS THE AREA TUESDAY NIGHT AS LOW PRESSURE TO THE NORTH PUSHES EASTWARD. DECENT CAPE AND SHEAR PRESENT AS A SHORTWAVE APPROACHES FROM THE WEST...SO THERE IS THE RISK OF SOME SEVERE WX IN THE EVENING BEFORE THE END OF INSOLATION ALLOWS CAPE TO WANE. THE LOW DRAGS A COLD FRONT SOUTHEAST INTO THE AREA WEDNESDAY WHICH STALLS OUT WEDNESDAY NIGHT. SEVERE PARAMETERS DON`T LOOK AS GOOD BY WEDNESDAY AFTERNOON WITH A BIT TOO MUCH OF A DRY LAYER AND LESS SHEAR...SO PROBABLY LESS RISK OF SEVERE WEATHER DESPITE THE STALLING FRONT...ESPECIALLY SINCE THE SHORTWAVE LOOKS TO HAVE CLEARED THE CWA BY MID AFTERNOON. TEMPERATURES WILL LIKELY SPIKE A BIT JUST AHEAD OF THE FRONT AND A FEW 90S CAN`T BE RULED OUT IN THE HOTTEST SPOTS. WITHOUT GOOD FORCING ALOFT...MOST OF WEDNESDAY NIGHT WILL TURN OUT DRY. && .LONG TERM /THURSDAY THROUGH SUNDAY/... THE FRONT APPEARS TO STALL OUT ACROSS THE GENERAL VICINITY FOR MOST OF THE LONG TERM...WITH MULTIPLE DISTURBANCES MOVING QUICKLY EAST ACROSS THE AREA IN THE WESTERLY FLOW ALOFT. THIS WILL KEEP THE WEATHER RELATIVELY UNSETTLED WITH LITTLE CHANCE OF HIGH HEAT BUT ALSO NOT A GREAT CHANCE OF SUSTAINED DRY WEATHER. INDIVIDUAL SHORTWAVE ORIENTATION AND FRONT POSITIONS WILL DICTATE ANY THREATS OF SEVERE WEATHER OR FLOODING...BUT THE RISK IS NOT ZERO. && .AVIATION /15Z MONDAY THROUGH FRIDAY/...
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VFR THROUGH TODAY UNDER HIGH PRESSURE...WITH LIGHT WINDS GRADUALLY TURNING FROM WEST TO SOUTH BY LATE AFTERNOON. FAIRLY HIGH PROBABILITY OF VFR THROUGH TONIGHT AS WELL ALTHOUGH MID LEVEL CIGS DEVELOP AHEAD OF LOW PRESSURE. SOUTHERLY WINDS INCREASE A BIT TUESDAY...WITH A FEW GUSTS TO 20 KT POSSIBLE. SCATTERED THUNDERSTORM ACTIVITY WILL BE MOST LIKELY FROM MID-AFTERNOON ONWARD...WITH THE POTENTIAL FOR MVFR/IFR CONDITIONS AND STRONG WIND GUSTS. OVERALL VFR THROUGH THE REMAINDER OF THE WEEK AND WEEKEND...HOWEVER THE THREAT OF THUNDERSTORMS WILL PERSIST EACH DAY WITH ANY STORM CAPABLE OF BRIEF IFR CIGS/VIS...GUSTY WINDS...AND HAIL. SOUTHWEST WINDS AHEAD OF A COLD FRONT WEDNESDAY WILL BECOME MORE VARIABLE LATER IN THE WEEK AS A FRONT LINGERS ACROSS THE REGION.
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&& .MARINE...
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WLY FLOW AROUND KT AS HIGH PRESSURE MOVES EAST FROM THE PIEDMONT. FLOW BECOMES SLY TONIGHT WITH CHANNELING TO 15 KT. SLY FLOW INCREASES TUESDAY AS LOW PRESSURE APPROACHES FROM THE WEST...AND SCA HAS BEEN ISSUED FOR ALL THE WATERS. THUNDERSTORM CHANCES INCREASE DURING THE MID TO LATE AFTERNOON HOURS AND COULD CONTAIN STRONG WIND GUSTS. MAY HAVE ISSUS WITH SCA CONDITIONS WEDNESDAY AS THE NEXT COLD FRONT SLIDES SOUTHEAST INTO THE AREA. AFTER THAT...THE FRONT WILL LINGER IN THE AREA AND INTERMITTENT SCA CONDITIONS WILL BE POSSIBLE AS INDIVIDUAL SYSTEMS RIDE ALONG THE FRONT. THE THREAT OF SHOWERS AND THUNDERSTORMS...WHILE NOT PARTICULARLY HIGH ANY DAY JUST YET...WILL NOT COMPLETELY GO AWAY THANKS TO THE PRESENCE OF THE FRONT THROUGH MOST OF THE LONG TERM.
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&& .LWX WATCHES/WARNINGS/ADVISORIES...
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DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 AM TO 6 PM EDT TUESDAY FOR ANZ530>543.
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&& $$ SYNOPSIS...BAJ/RCM NEAR TERM...ADS SHORT TERM...ADS/RCM LONG TERM...RCM AVIATION...BAJ/ADS/RCM MARINE...BAJ/ADS/RCM

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