AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 153 AM EDT MON JUL 11 2011 .SYNOPSIS... HIGH PRESSURE WILL REMAIN IN PLACE OVER THE MID-ATLANTIC REGION BEFORE SLIDING OFF THE COAST TONIGHT AND MONDAY. A COLD FRONT WILL APPROACH THE AREA FOR MIDWEEK...WITH WEAK HIGH PRESSURE REBUILDING OVER THE REGION FROM THE NORTH FOR THE LATTER HALF OF THE WEEK. && .NEAR TERM /THROUGH TODAY/... SFC HIGH PRESSURE WILL CONTINUE TO GRADUALLY SLIDE OFF THE MID- ATLANTIC COAST OVERNIGHT. MAINLY CLEAR SKIES WITH SOME PATCHY FOG POSSIBLE TOWARDS DAWN OVER SOUTH CENTRAL VIRGINIA/HAMPTON ROADS. LOWS GENERALLY IN THE MID TO UPPER 60S...TO NR 70 ALONG IMMEDIATE COASTAL AREAS. UPPER LVL RIDGE OVER THE LOWER MISSISSIPPI VALLEY WILL SHIFT SLOWLY TO THE EAST INTO THE TN VALLEY BY 00Z/TUESDAY. THIS WILL BRING AN INCREASE IN HIGH TEMPS/HUMIDITY FOR MONDAY. RAIN CHANCES REMAIN LOW (<10%) W/LCL LOW LEVEL THICKNESS TOOLS SUPPORTING HIGHS IN THE LOW/MID 90S MONDAY. && .SHORT TERM /TONIGHT THROUGH WEDNESDAY/... HEAT AND HUMIDITY VALUES GET TURNED UP FOR TUESDAY/WED WITH FLOW VEERING AROUND TO S-SW AHEAD OF SLOW/WEAK COOL FRONT PASSAGE. GOOD MODEL CONSENSUS WRT MID-UPR LVL PATTERN. THE UPPER RIDGE LOOKS TO GET SHUNTED BACK SOUTH INTO THE LWR MISSISSIPPI VLY AS STRONG SHORTWAVE TROUGH PUSHES FROM THE EASTERN GRT LAKES INTO NORTHERN NEW ENGLAND...PUSHING THE ATTENDANT WEAK COOL FRONT TOWARDS THE REGION FOR TUE/WED. LIKELY TO SEE A COUPLE OF THUNDERSTORMS DEVELOP OVER THE OH VLY CROSSING INTO THE MTNS...WHICH MAY DRIFT EASTWARD INTO NORTHERN PORTIONS OF OUR CWA ON NW FLOW ALOFT. HV NOT INCLUDED THIS ACTIVITY IN FORECAST JUST YET...BUT WL HAVE TO WATCH THIS POTENTIAL FOR INCOMING MCS ACTIVITY TUESDAY MORN. THIS COULD IMPACT THE FORECAST IN A COUPLE OF WAYS...LEAVING REMNANT CLOUDINESS/SHRAS THAT COULD AT THE VERY LEAST DAMPEN TEMPS SLIGHTLY FOR TUESDAY. FOR NOW...HV KEPT MONDAY NGT/TUESDAY DRY BUT RETAINED SLIGHT CHC TO LOW CHC POP FOR TUESDAY AFTN. LOWEST POP REMAINS OVER SOUTHERN ZONES WHERE LLVL MOISTURE/SHEAR WL BE MOST LIMITED. WEDNESDAY... HIGHER CHC/SCT POPS FOR WEDNESDAY AS FRONT DROPS SOUTH INTO THE REGION. EXPECTED STRONG SFC HEATING...INVERTED-V LOOK TO WED AFTN FORECAST SOUNDINGS AND K-INDICES ON THE ORDER OF 30 TO 40 WOULD INDICATE DECENT AMOUNT OF DRY AIR PRESENT IN MIDLVLS FOR CHC OF STRONG TO SVR THUNDERSTORMS. FOR TEMPS...H85 TEMPS ~20-22C TUE (18-22C WED) SHOULD YIELD MAXIMA INTO THE MID 90S TUE (LOW-MID 90S WED). RECORD TO NEAR RECORD HIGH TEMPERATURES ARE POSSIBLE (SEE CLIMO SECTION BELOW). HEAT INDEX VALUES INTO THE LOW 100S EXPECTED BOTH AFTN. MILD LOW TEMPERATURES IN THE UPR 60S TO MID 70S. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... A COLD FRONT WILL BE DROPPING THRU SRN PORTIONS OF THE AREA THEN DWN INTO THE CAROLINAS WED NGT THRU THU. WILL CARRY SML CHC (30) POPS OVR SRN PARTS OF NE NC ZNS WED NGT AND SLGT CHC (20) POPS OVR THE REMAINDER OF THE SRN PORTION OF THE CWA. WILL HAVE JUST SLGT CHC POPS OVR SRN THIRD OF THE CWA ON THU. HI PRES WILL BLD DWN INTO AND OVR THE REGION DURING THU INTO FRI MORNG. THE HI WILL THEN SLIDE OFF THE NRN MID ATLC CST FOR FRI AFTN THRU SUN. MIN TEMPS WILL BE IN THE MID 60S TO LWR 70S THU MORNG...RANGE THRU THE 60S FRI AND SAT MORNGS...AND RANGE FM THE MID 60S TO ARND 70 SUN MORNG. MAX TEMPS WILL BE MAINLY IN THE MID TO UPR 80S THRU THE PERIOD. && .AVIATION /06Z MONDAY THROUGH 06Z TUESDAY/... FOG DEVELOPMENT IS POSSIBLE TOWARD DAYBREAK AS SURFACE HIGH PRESSURE SITS OVER THE MID-ATLANTIC REGION. VISIBILITIES SHOULD REMAIN IN MVFR TO VFR RANGES...EXCEPT NEAR KECG WHERE VISIBILITIES COULD DROP BELOW 3 MILES FOR A SHORT TIME JUST AFTER DAWN. SURFACE HIGH PRESSURE WILL BREAK DOWN LATER TODAY AS A DISTURBANCE PUSHES ACROSS THE REGION TONIGHT. AN INCREASE IN SKY COVER SHOULD BE THE MAIN IMPACT BUT CANNOT RULE OUT A CHANCE FOR RAIN SHOWERS OVERNIGHT MONDAY INTO TUESDAY. && .MARINE... NO HEADLINES IN THE SHRT TERM TNGT THRU TUE. HI PRES WILL SLIDE OFF THE CST FOR TNGT INTO MON NGT. SE-S WNDS 10 KT OR LESS TNGT WILL BECOME S OR SW AT 10 TO 15 KT BY MON NGT. A COLD FRNT WILL APPROACH FM THE NW MON NGT...THEN PUSH INTO AND ACRS THE REGION TUE AFTN INTO WED EVENG. HI PRES WILL BLD BACK IN FM THE NNE LATE WED NGT THRU THU NGT...THEN MOVES OFF THE NRN MID ATLC CST ON FRI. SW WNDS 10 TO 20 KT IN ADVANCE OF THE FRNT...THEN SHIFTING TO THE NNE EVERYWHERE BY LATE WED/NGT. NE WNDS 10 TO 15 KT ON THU. EXPECT WND SPDS/WAVES/SEAS TO REMAIN BELOW SCA LVLS THRU THE PERIOD. USED LCL GUID FOR WAVES ON THE BAY/SND...WAVEWATCH ON OCEAN. && .CLIMATE... DAILY MAX TEMP RECORDS FOR JULY 11-JULY 12. JULY 11 JULY 12 RIC 100/1990 98/1986 ORF 102/1879 101/1992 SBY 98/1911 96/1925 ECG 98/1993 99/1993 && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...AIR QUALITY ALERT FROM 10 AM THIS MORNING TO 10 PM EDT THIS EVENING FOR MDZ021>025. NC...NONE. VA...NONE. MARINE...NONE. && $$ SYNOPSIS...MAM/MAS