AFDAKQ AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WAKEFIELD VA 422 PM EDT FRI JUL 8 2011 .SYNOPSIS... A SLOW MOVING COLD FRONT WILL PUSH ACROSS THE REGION TONIGHT AND EARLY SATURDAY...THEN FINALLY PUSH OFF THE COAST AROUND MIDDAY. DRIER CONDITIONS WILL MOVE INTO THE AREA FROM SATURDAY EVENING THROUGH SUNDAY...AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. THE HIGH MOVES OFF THE COAST EARLY NEXT WEEK... WHILE ANOTHER COLD FRONT PUSHES INTO THE REGION LATE TUESDAY INTO EARLY WEDNESDAY. WEAK HIGH PRESSURE WILL THEN REBUILD INTO THE REGION FROM THE NORTH WEDNESDAY NIGHT AND ON THURSDAY. && .NEAR TERM /THROUGH SATURDAY/... 12Z MODEL SUITE REMAIN IN DECENT ACCORD IN TERMS OF TIMING THE SFC FRONT AND SFC/UPR LEVEL TROUGHS ACROSS THE FCST REGION TONIGHT AND EARLY SAT. UPPER DYNAMICS WITH THIS SYSTEM REMAIN RATHER IMPRESSIVE FOR EARLY JULY...WITH A DECENT SWATH OF RRQ UPPER JET FORCING (70-75 KT JET CORE AT 300 MB). ONCE AGAIN WITH THE 12Z MODEL RUNS... THE MODELS TEND TO FOCUS THE MOST FAVORABLE COMBINATION OF UPPER LEVEL DIVERGENCE AND ASSCD LOW-MID LEVEL FGEN/QVECTOR CONVERGENCE OVER ABOUT THE NORTHERN 1/3 OF THE CWA FROM 00-09Z TONIGHT. THEREFORE... HAVE CONTINUED WITH THE FLASH FLOOD WATCH FOR THESE AREAS... APPROXIMATED FROM FLUVANNA COUNTY EAST TO THE NRN NECK AND ON INTO THE MD ERN SHORE. ELSEWHERE...UPPER SUPPORT IS SLIGHTLY WEAKER (AND POTENTIAL FOR STORMS TO TRAIN LOOKS A BIT LOWER AS WELL). THE AREAL COVERAGE/FREQUENCY OF CONVECTION SOUTH OF THE CURRENT WATCH MAY NOT BE AS HIGH COMPARED TO NRN AREAS...HOWEVER...WITH THE DEEP LAYER MOISTURE SOLIDLY PLACE ACROSS THE FCST AREA AHEAD OF THE UPPER TROUGH (PWATS PEAKING FROM 2.25 TO NEAR 2.5")...ANY STRONGER CELLS WILL BE CAPABLE OF LOCALLY TORRENTIAL DOWNPOURS AND THUS A HEIGHTENED FLOOD POTENTIAL IN URBAN AREAS AND ALONG SMALL STREAMS. AS FOR SEVERE POTENTIAL...SHEAR CONTINUES TO INCREASE FROM N TO S THIS AFTN...WITH 40 KTS 0-6 KM BULK SHEAR OVER NRN VA. THE LIMITING FACTORS AT THIS POINT IN TERMS OF SEVERE WX CHANCES ARE A) HIGH FREEZING/WET BULB ZERO LEVELS (~15 KFT AND 14.5 KFT RESPECTIVELY)...ALONG WITH THE CONSIDERABLE CLOUDS AND OUTFLOWS (TEMPORARY LLVL STABILIZATION) FROM EARLIER CONVECTION. PER COORDINATION WITH SPC...WILL CONTINUE TO MONITOR TRENDS LATE THIS AFTN AND EARLY EVENING FOR THE POTENTIAL FOR A NEW SVR TSTM WATCH SOUTH OF THE CURRENT ONE (WATCH #610). SAT...MODELS (PARTICULARLY THE GFS) ARE A BIT SLOWER WITH THE DRYING TRENDS N-S. EVEN A NAM/SREF/ECMWF BLEND WOULD SUPPORT KEEPING BETTER THAN 50% POPS OVER S PORTIONS OF THE FCST AREA (S OF THE VA/NC BORDER) INTO THE AFTN HOURS. HIGHS A BIT COOLER... ESPECIALLY ALONG THE ATLC COAST (LOW-MID 80S). UPPER 80S ELSEWHERE FARTHER INLAND. && .SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/... SHORT TERM PERIOD CHARACTERIZED BY INCREASING INFLUENCE FROM UPPER LVL RIDGE BUILDING IN FROM THE GREAT PLAINS...WITH THE RESULTANT EFFECT OF DRIER/WARMER DAYTIME TEMPERATURES...AND COOLER MORE COMFORTABLE NIGHTS. RAIN CHCS REMAIN LOW...WITH LTL MORE THAN AN ISOLATED SHOWER/TSTM CHC OVER NORTHERN TIER OF COUNTIES. LOOK FOR HIGHS IN THE LOW 90S INLAND...M80S TO NR 90 AT IMMEDIATE COASTAL ZONES. EARLY MORNING LOWS FALLING INTO THE 60S FOR MOST...TO NR 70 SE. && .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... GOING WITH A COMBINATION OF THE 12Z GFS/ECMWF FOR THE EXTENDED PERIOD. SFC HI PRES WILL CNTRD OVR THE SE U.S. MON NGT INTO TUE. A COLD FRNT WILL PUSH INTO AND ACRS THE REGION TUE AFTN INTO WED MORNG. THIS WILL RESULT IN ANOTHER CHC OF SHOWERS AND TSTMS. HI PRES WILL BLD BACK IN FM THE NNE FOR LATE WED THRU THU...THEN SLIDES OFF THE CST FOR THU NGT THRU FRI. MIN TEMPS WILL BE IN THE LWR TO MID 70S TUE MORNG...IN THE UPR 60S TO MID 70S WED MORNG...AND IN THE MID 60S TO NEAR 70 THU AND FRI MORNGS. MAX TEMPS WILL BE IN THE LWR TO MID 90S TUE...IN THE MID 80S TO NEAR 90 WED...AND IN THE MID TO UPR 80S THU AND FRI. && .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/... WIDESPREAD SHOWERS AND THUNDERSTORMS EXPECTED ACROSS AREA TERMINALS LATE THIS AFTERNOON INTO THIS EVENING. VFR CONDITIONS OVER NORTHERN TERMINALS WILL TRANSITION TO MVFR/TEMPO IFR CONDITIONS AFTER 23Z. HAVE INCLUDED CB REMARKS BEGINNING BETWEEN 19 AND 23Z...AND HV ADDED TEMPO GROUPS AT ALL BUT ECG FOR MOST LKLY PERIOD OF FLIGHT RESTRICTIONS IN TSRA. MVFR TO LCL IFR CONDITIONS WILL BE COMMON IN THE HEAVIEST THUNDERSTORMS LATE TODAY INTO TONIGHT AT RIC AND SBY...PUSHING TO PHF/ORF AFTER 00Z/TNGT...DEVELOPING AT ECG AFTER 03Z. PERIOD OF MVFR/IFR FOG JUST AHEAD OF FRONTAL PASSAGE LATE TONIGHT WITH CLEARING OCCURRING NEAR 12Z OVER THESE AREAS. FARTHER SOUTH...EXPECT CONVECTIVE SHOWERS TO TRANSITION TO MORE STRATIFORM SHRAS OVERNIGHT/ERY SATURDAY BEFORE CLEARING MIDDAY SATURDAY FROM S TO N. OUTLOOK...COLD FRONT WILL DROP SOUTH ACROSS THE REGION SATURDAY...WITH VFR/DRY CONDITIONS IN STORE FOR LTR SATURDAY THROUGH MONDAY. A CHC FOR MAINLY DIURNALLY DRIVEN TSTMS RETURNS FOR TUE/WED. && .MARINE... NO HEADLINES IN THE SHRT TERM TNGT THRU SUN. A FRNTL BNDRY WITH AREAS OF LO PRES MOVNG ALNG IT...WILL PUSH ACRS THE AREA TNGT THRU SAT. HI PRES WILL BLD BY TO OUR NNE AND OFF THE CST FOR SAT AFTN THRU MON. ANOTHER COLD FRNT WILL DROP INTO AND ACRS THE REGION TUE AFTN INTO WED MORNG. EXPECT WND SPDS/WAVES/SEAS TO REMAIN BELOW SCA LVLS THRU THE PERIOD. && .AKQ WATCHES/WARNINGS/ADVISORIES... MD...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR MDZ021>025. NC...NONE. VA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR VAZ048-049- 062>064-074>077. MARINE...NONE. && $$ SYNOPSIS...BKH