000 FXUS61 KRNK 041400 AFDRNK AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BLACKSBURG VA 1000 AM EDT SAT JUL 4 2009 .SYNOPSIS... A WARM FRONT OVER THE MID MISSISSIPPI VALLEY WILL BEGIN MOVING TOWARD THE AREA BY TONIGHT. LOW PRESSURE WILL MOVE EASTWARD ALONG THE FRONT ON SUNDAY BRINGING A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... FEW CHANGES MADE IN THE MORNING UPDATE...IR SAT SHOWS MCS EXITING SE IOWA AT THIS TIME AND HEADING FOR THE OH VALLEY TODAY AND REACHING THE SOUTHERN APPALACHIANS TONIGHT. SHRA AND ISOLATED TRW MAY REACH THE FAR WESTERN CWA BY AROUND 00Z BUT BULK OF PRECIP A FEW HOURS LATER WHICH SHOULD ALLOW FIREWORK DISPLAYS TO PROCEED AS SCHEDULED AND CERTAINLY OVER THE EASTERN 2/3 THIS WILL BE THE CASE. ATMOSPHERE IS PRETTY WELL CAPPED ON THE 12Z SOUNDING AND WILL HAVE A DIFFICULT TIME EVEN GETTING AN ISOLATED TRW THIS AFTERNOON. MADE FEW CHANGES TO TEMPS WHICH ARE A BLEND OF LOCAL MOS/MET MOS. TONIGHT...POPS ARE CATEGORICAL IN THE FAR WEST AFTER MIDNIGHT...WITH LIKELY TO FOOTHILLS...PIEDMONT OF VA NORTH OF LYH...WITH CHANCE IN THE SE. ENHANCED LIFT SHOULD BE MOVING IN TWO PARTS...ONE AHEAD OF THE WARM FRONT IN THE CENTRAL APPS AND MID ATLANTIC THIS EVENING...THEN OVERNIGHT...STRONGER SW FLOW AHEAD OF THE MAIN COMPLEX OF STORMS ARRIVES IN THE KY/TN AREA AND SHIFTS EAST TO THE BLUE RIDGE BY 12Z SUNDAY. ATTM...NOT TOO IMPRESSED WITH THUNDER CHANCES...BUT WILL KEEP SCT THUNDER IN THERE DUE TO NATURE OF SYSTEM AND ELEVATED THUNDER THREAT. LOWS TONIGHT WILL BE MILDER AS THE PRECIP AND CLOUDS ALONG WITH RISING DEWPOINTS INHIBIT TEMP DROPS. MAINLY WITH CLOSER TO THE MAV MOS. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... MCS AND ASSOCIATED SURFACE LOW CONTINUE THEIR TREK INTO THE AREA ON SUNDAY. WILL HAVE CATEGORICAL POPS IN SE WV MOUNTAINS AND NEIGHBORING PORTIONS OF SW VA DURING THE MORNING WITH DECREASING CHANCES THE FARTHER EAST. HOWEVER...EVEN IN THE EAST...THOSE LOWER POPS WILL STILL BE IN THE LIKELY RANGE. BY THE AFTERNOON THE BEST CHANCES WILL BE IN THE EAST WITH THE LEAST IN THE WEST AS THE SYSTEM MOVES THROUGH. AS THE SURFACE LOW SHIFTS OFF SHORE...THE ASSOCIATED COLD FRONT WILL HEAD FARTHER SOUTH OF THE AREA AND SURFACE HIGH PRESSURE BEGINS TO BUILD INTO THE REGION. LOOK FOR PRECIPITATION CHANCES TO BECOME CONFINED TO SOUTHERN PARTS OF THE AREA NEAREST THE EXITING COLD FRONT. BY MONDAY AFTERNOON...WE WILL HAVE A DRY FORECAST. OUR DRY FORECAST WILL CONTINUE UNTIL TUESDAY AFTERNOON WHEN A SLIGHT CHANCE OF THUNDERSTORMS IS REINTRODUCED TO THE MOUNTAINS AS A QUICK MOVING NORTHWEST FLOW SHORTWAVE TROUGH MOVES THROUGH THE REGION. && .LONG TERM /TUESDAY THROUGH FRIDAY/... LONGWAVE PATTERN IS FORECAST TO GRADUALLY REAMPLIFY WITH THE MID CONUS RIDGE NOSING TOWARD CANADA AND TROUGHS ON BOTH COASTS. THIS WILL RESULT IN A NET SLOWING OF FRONTAL SYSTEMS ACROSS THE COUNTRY AND FOR US SHOULD SUPPRESS WARM FRONT BACK TO THE SOUTH LEAVING OUR FORECAST AREA DOMINATED BY NORTHWEST FLOW ALOFT AND MAINLY DRY SENSIBLE WEATHER. THE NET EFFECT FOR OUR CWA SHOULD BE A DRY WEEK WITH TEMPS NEAR NORMAL. CAN'T RULE OUT SOME ISOLATED DIURNAL SHOWERS...BUT THE PROBABILITY IS JUST TO LOW TO INCLUDE ATTM. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... VFR CONDITIONS CAN BE EXPECTED THROUGH TODAY. THE FOG AT LWB WILL DISSIPATE BY 1330Z. INCREASING HIGH CLOUDS WILL OCCUR TODAY. AN MCS OVER THE MIDWEST WILL BE IN THE SE WV MTNS BEFORE MIDNIGHT. LOOKING AT THIS SYSTEM PUSHING EAST OVER ROA/LYH/DAN AFTER 6Z. COVERAGE WILL BE GREATEST FROM ROA WEST TO THE BLF/LWB. ATTM...INSTABILITY APPEARS WEAK WITH IT...BUT WITH THIS SYSTEM THUNDER STILL A POSSIBILITY SO KEPT CB IN THE CLOUD GROUP. CIGS/VSBYS SHOULD DROP TO MVFR ONCE THE SHOWERS ARRIVE. POTENTIAL EXISTS FOR LOWER IN HEAVIER SHOWERS. VFR/MVFR CONDITIONS EXPECTED INTO SUNDAY NIGHT. AFTER MONDAY DEEP MOISTURE AND LIFT REMAINS WELL TO THE SOUTH OF THE FORECAST AREA SO VFR CONDITIONS ARE EXPECTED. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...NONE. NC...NONE. WV...NONE. && $$ SYNOPSIS...JJ/WP NEAR TERM...WP SHORT TERM...KM/PM LONG TERM...PM AVIATION...AMS/WP