531 FXUS61 KLWX 151924 AFDLWX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BALTIMORE MD/WASHINGTON DC 324 PM EDT TUE MAY 15 2012 .SYNOPSIS... A TROUGH OF LOW PRESSURE WILL MOVE ACROSS THE AREA THIS AFTERNOON AND EVENING. A COLD FRONT WILL CROSS THE REGION ON WEDNESDAY. HIGH PRESSURE WILL BUILD INTO THE REGION LATE IN THE WEEK AND WILL REMAIN IN PLACE THROUGH THE WEEKEND. && .NEAR TERM /THROUGH WEDNESDAY/... SLIGHT COOLG/DRYING AT M/ULVLS THIS AFTN AS SUBTLE SHRTWV TROF APPROACHES FROM SW. AFOREMENTIONED CHARACTERISTICS ALOFT COMBINED WITH SFC HEATING...TEMPS IN U70S/L80S TRANSLATING TO SBCAPE VALUES AOA 1500 J/KG ACRS MUCH OF CWA. WITH MOIST LLVLS...SHWRS DVLPG ALONG/E OF SFC TROF WHICH RESIDES IN VICINITY OF BLUE RIDGE. XPCT SCT/NUM CVRG OF SHWRS THIS AFTN/ERY EVE...WITH CNVCTN ALSO PSBL. VERTICAL SHEAR ISNT TOO IMPRESSIVE...BUT SHUD BE SUFFICIENT FOR SOME ORGANIZATION OF UPDRAFTS INTO CLUSTERS. DIURNALLY DRIVEN TSTMS WILL DIMINISH AFTR SUNSET...BUT UNTIL THEN...STRONGER CELLS/LINE SEGMENTS WILL BE CAPABLE OF PRODUCING LOCALLY DMGG WINDS AND LARGE HAIL. SLIGHT RISK CONTS FOR LOCATIONS ALONG/E OF BLUE RIDGE. AS SHRTWV TROF IS ABSORBED INTO BROADER CYCLONIC ULVL FLOW...SHWRS WILL GRADUALLY DIMINISH FROM W TO E OVNGT AS SFC TROF DRAGS EWD TWD CHESAPEAKE BAY. MINIMA TNGT WILL BE WELL ABV NRML...50S W OF BLUE RIDGE...60S E. SHRTWV TROF ASSOCIATED WITH NRN JET/ULVL LOPRES ABV HUDSON BAY WILL DIG SEWD OUT OF GREAT LAKES INTO NRN NEW ENGLAND WED. ATTENDANT SFC FRONT WILL APPROACH NWRN CWA LATE TMW. MOST MOISTURE WILL HAVE BEEN SHUNTED OFFSHORE BY SFC TROF...AND BEST DYNAMICS WELL N OF MID-ATLC. STILL...CANT RULE OUT ISOLATED CNVCTN...ESPECIALLY WITH MAXIMA PROGGED TO NEAR 85F AND STEEPENING LAPSE RATES THRU WED. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/... REINFORCING COLD FRONT MOVES ACROSS THE CHESAPEAKE BAY AREA WEDNESDAY EVENING. THERE WILL BE A SLIGHT CHANCE OF SHOWERS NEAR AND TO THE EAST OF THE INTERSTATE 95 CORRIDOR INTO THE EVENING UNTIL THE FRONT CLEARS THE AREA. THROUGH THE END OF THE WEEK...SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. RESULT WILL BE MOSTLY CLEAR SKIES AND TEMPERATURES NEAR CLIMO THURSDAY THROUGH FRIDAY. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... SURFACE HIGH MIGRATES OFF THE EAST COAST OVER THE WEEKEND/EARLY NEXT WEEK...AS UPPER RIDGE INTENSIFIES OVER THE EASTERN SEABOARD/WESTERN ATLANTIC. EVENTUALLY MOISTURE WILL INCREASE AND A COLD FRONT WILL APPROACH FROM THE WEST AS THE RIDGE STARTS TO GIVE WAY. BUT THIS MAY NOT BE UNTIL TUESDAY OR WEDNESDAY OF NEXT WEEK. MAY START TO SEE TERRAIN CONVECTION BY MONDAY...BUT WILL FOLLOW HPC WITH CHANCE POPS FOR SHOWERS/THUNDERSTORMS ARRIVING ON TUESDAY ACROSS THE REST OF THE CWA. && .AVIATION /19Z TUESDAY THROUGH SUNDAY/... SCT/BKN 2-4KFT CU XPCD UNTIL SUNSET...WITH SCT/NUM SHWRS EVOLVING INTO TSTMS. TIMING AND CVRG OF ACTIVITY IS IN DOUBT...SO VCTS PREFERRED IN TAF ATTM. AS PCPN DVLPS AND IMPACTS ON TERMINALS BCMS CLEARER...AMENDMENTS TO ACCOUNT FOR LOCAL FLIGHT RESTRICTIONS MAY BE PRUDENT. AFTER SUNSET...SHWRS WILL DIMINISH AND SKIES WILL CLEAR. THEN...FG/BR WILL FORM AFTER MIDNIGHT IN CALM WINDS AND SATURATED BOUNDARY LYR. MVFR CONDS BRACKET FOR SVRL HRS IFR VSBYS THAT PREVAIL FROM 8-13Z. RAPID IMPROVEMENTS BY MID-MRNG WED. ISOLATED SHWRS/TSTMS PSBL WED ACRS TERMINALS...BUT XPCD CVRG FAR TO LOW TO MENTION IN TAFS FOR NOW. REINFORCING COLD FRONT MOVES EAST OF THE AREA WEDNESDAY EVENING...THEN HIGH PRESSURE BUILDS IN THROUGH THE END OF THE WEEK AND HOLDS THROUGH THE WEEKEND FOR NO SIGNIFICANT WEATHER. && .MARINE... ADZY DROPPED EARLY FOR ALL XCPT MD CHESAPEAKE BAY S OF DRUM POINT...WHERE 20 KT SLY GUSTS STILL PSBL UNTIL AROUND MIDNIGHT. SCT/NUM SHWRS AND TSTMS DVLPG THIS AFTN AND WILL PERSIST INTO EVE...BEFORE DIMINISHING. LOCALLY STRONG WINDS PSBL WITH THIS ACTIVITY. THEREAFTER...SFC TROF WILL MOVE OVHD...LEADING TO L/V WINDS TNGT/WED MRNG...THEN NW WINDS ON TROFS BACK SIDE FOR WED. FRONT MOVES EAST OF THE BAY WEDNESDAY EVENING. MARGINAL SCA GUSTS ARE POSSIBLE LATE WEDNESDAY NIGHT/THURSDAY MORNING OVER THE BAY...OTHERWISE HIGH PRESSURE BUILDS IN THROUGH THE END OF THE WEEK THEN MOVES OFF THE COAST OVER THE WEEKEND. && .LWX WATCHES/WARNINGS/ADVISORIES... DC...NONE. MD...NONE. VA...NONE. WV...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EDT WEDNESDAY FOR ANZ534-543. && $$ SYNOPSIS...SBK/BPP NEAR TERM...SBK SHORT TERM...BPP LONG TERM...BPP AVIATION...SBK/BPP MARINE...SBK/BPP