AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 430 PM EDT THU JUL 7 2011 .SYNOPSIS... BERMUDA HIGH PRESSURE WILL MAINTAIN A MOIST SOUTHERLY FLOW ACROSS THE EASTERN CAROLINAS INTO THE WEEKEND. A WEAK COLD FRONT MAY REACH THE AREA SATURDAY NIGHT BEFORE DISSIPATING ON SUNDAY. TROPICAL-LIKE MOISTURE MOVING NORTHWARD ACROSS THE EASTERN CAROLINAS WILL BRING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS INTO THE WEEKEND. SOME OF THIS RAIN WILL BE HEAVY AT TIMES. BERMUDA HIGH PRESSURE WILL BUILD BACK ACROSS THE AREA EARLY NEXT WEEK. A COLD FRONT MAY APPROACH THE AREA DURING THE MIDDLE OF NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 430 PM THURSDAY...NO CHANGES TO PRIOR FORECAST THOUGHTS...JUST UPDATING POPS/SKY FOR LATEST RADAR/SATELLITE TRENDS. PREVIOUS DISCUSSION FOLLOWS... CONVECTION BEGINNING TO BECOME MORE WIDESPREAD ALONG THE SEA BREEZE AS EXPECTED...AND THIS WILL GRADUALLY WORK INLAND DURING THE NEXT FEW HOURS...CONCURRENT WITH THE DEVELOPMENT OF STORMS ACROSS THE PIEDMONT. LATEST RUC SOUNDINGS STILL SHOW VERY FAVORABLE PARAMETERS FOR HEAVY RAIN IN THUNDERSTORMS...WITH CAPE OVER 2500 J/KG...PWATS AROUND 2 INCHES...WARM CLOUD DEPTH TO NEARLY 11 KFT...AND SLOW STORM MOTIONS...SO WILL CONTINUE LIKELY POP INLAND WHERE OUTFLOWS AND THESE BOUNDARIES WILL FIRE TSTMS ALL AFTN. THE COASTAL LOCATIONS WILL GRADUALLY SEE DECREASING COVERAGE OF TSTMS AS THE SEA BREEZE PUSHES WESTWARD. TRICKY TEMP FORECAST DUE TO RAIN COOLING OF AIR...BUT ENOUGH INSOLATION TO THEN REHEAT THE SURFACE...SO TEMPS WILL FLUCTUATE QUITE DRAMATICALLY DURING THE NEXT FEW HOURS IN LOCATIONS THAT DO RECEIVE RAINFALL. LATEST WV IMAGERY IS IMPRESSIVE ACROSS THE GOM WHERE HPC NOW HAS ANALYZED A CLOSED LOW WEST OF THE FLORIDA KEYS. LATEST NAM HAS COME INTO LINE WITH OTHER GUIDANCE...BRINGING A TROUGH/MOISTURE PLUME ALONG THE SE COAST LATE TONIGHT. HAVE CONTINUED LIKELY POP NEAR THE COAST AFTER MIDNIGHT...AND BACKED THE CHANCE POP FURTHER WEST TO ACCOUNT FOR THIS WESTWARD SHIFT AND DEPICTION OF PRECIP ON HIGH RES MODELS. WITH PWATS RISING TO NEARLY 2.5 INCHES...BELIEVE THE BEST RAINFALL AT THE COAST MAY BE LATE TONIGHT. HOWEVER...CONFIDENCE IS A BIT LOWER DUE TO UNCERTAINTY IN PLACEMENT OF BEST MOISTURE FETCH. HIGHS TODAY WILL BE IN THE MID 80S NEAR THE COAST...LOW 90S INLAND. CLOUD COVER AND VERY HIGH TD/S WILL LIMIT MINS FROM FALLING TOO FAR TONIGHT...WITH MID TO UPPER 70S EXPECTED AT THE COAST...TO AROUND 72 IN THE COOLEST SPOTS. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...TROPICAL-LIKE MOISTURE STREAMING NORTHWARD ACROSS THE EASTERN CAROLINAS SHOULD BRING AN INCREASING RISK FOR SHOWERS AND THUNDERSTORMS. THE PRIMARY CHARACTERISTIC OF THIS CONVECTION WILL BE VERY HEAVY RAIN WITH PRECIPITABLE WATER VALUES AROUND 2.25 INCHES. THE RISK FOR AT LEAST MINOR FLOODING WILL BE ON THE INCREASE...ESPECIALLY IN THOSE AREAS WHERE HEAVY RAIN HAS OCCURRED OVER THE LAST FEW DAYS. A WET MICROBURST WILL BE CAPABLE OF BRINGING STRONG WINDS TO THE SURFACE...ESPECIALLY FRI AFTERNOON. A WEAK TROUGH WILL LIMP INTO THE AREA LATE SAT NIGHT. MAY SEE LOW STRATUS OR FOG DEVELOP AS WEAK FRONTAL BOUNDARY LIMPS INTO THE AREA LATE SAT NIGHT AND SUN MORNING...SHIFTING LIGHT WINDS TO NORTHERLY. THE LARGEST WILDFIRES REMAIN ACROSS NORTHERN PENDER COUNTY...IN THE HOLLY SHELTER GAME LAND AND NEAR THE BLADEN-CUMBERLAND COUNTY LINE. IF THESE NORTHERLY WINDS DO MATERIALIZE...SMOKE PLUMES WILL CHANGE THEIR ORIENTATION...BLOWING SMOKE FROM N TO S...INSTEAD OF FROM S TO N WHICH HAS BEEN THE CASE FOR MANY DAYS NOW. GIVEN THE EXTENT OF CLOUD COVER EXPECTED...AND CONSIDERING THE DEPTH OF MOISTURE...TENDED TO GO ABOVE GUIDANCE ON MINIMUMS AND AT OR BELOW THE COOLEST GUIDANCE FOR MAXIMUMS. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 3 PM THURSDAY...MID LEVEL RIDGE BUILDS OVER TN AND OHIO VALLEY ON SUNDAY AS WELL AS ACRS THE BAHAMAS. THERE IS SOME MODEL AGREEMENT THAT A SHORTWAVE SLIDES SOUTHWARD BETWEEN THE TWO AND THIS MAY BRING ONE LAST DAY OF SLIGHTLY ENHANCED RAINFALL CHANCES BEFORE THE LONG TERM SHIFTS LARGELY BACK TO A FORECAST OF CLIMATOLOGY. THIS UPPER FORCING WILL BE BOOSTED BY A SURFACE TROUGH LINGERING JUST INLAND FROM THE COAST AS WELL AS PLENTIFUL OUTFLOW BOUNDARIES FROM SATURDAYS POTENTIALLY ACTIVE DAY OF CONVECTION. AFTERNOON HIGHS WILL BE NEAR CLIMO OR JUST A FEW DEGREES BELOW ON ACCOUNT OF THE POSSIBILITY OF WIDESPREAD CLOUD COVER. AS THIS MID LEVEL FEATURE MOVES OFF INTO THE GOMEX HEIGHTS RISE LOCALLY AND SOME DRYING SOUTH OCCUR. THERE WILL BE LITTLE CHANGE IN SURFACE AND LOW LEVEL AIRMASS...AS TYPICAL FOR JULY. THIS WILL STILL LEAVE THE DOOR OPEN FOR VERY ISOLATED COVERAGE OF AFTERNOON THUNDERSTORMS ALONG MESOSCALE BOUNDARIES AND TEMPERATURES WILL AVERAGE A FEW DEGREES ABOVE CLIMATOLOGY MONDAY AND TUESDAY. MODEL AGREEMENT IN DEPICTING A COLD FRONT APPROACHING AND PERHAPS EVEN TRAVERSING THE AREA WEDNESDAY OR WEDNESDAY NIGHT APPEARS TO WARRANT SOME INCREASED CLOUD COVER AND RAIN CHANCES. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 18Z...HIGH CONFIDENCE IN VFR CONDITIONS THROUGH THE VALID PERIOD...WITH EXCEPTION OF SCATTERED SHOWERS AND THUNDERSTORMS TODAY...AND POTENTIAL MVFR CIG RESTRICTIONS DUE TO FOG EARLY FRIDAY MORNING. A FEW SHOWERS THAT TRIGGERED EARLIER TODAY HAVE ALREADY TAPERED OFF. EXPECT SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE REST OF TODAY...THUS HAVE INCLUDED VCSH/VCTS AT ALL TERMINALS. GIVEN LOW CONFIDENCE REGARDING THE OCCURRENCE OF THIS ACTIVITY...HAVE NOT INCLUDED ANY FLIGHT RESTRICTIONS ATTM. HOWEVER...BRIEF PERIODS OF REDUCED VSBYS...HEAVY RAIN AND WIND GUSTS WILL BE POSSIBLE WITH STRONGER STORMS. EXPECT SHRA/TSRA ACTIVITY TO DISSIPATE BY LATE EVENING. OVERNIGHT...CLOUDS WILL STICK AROUND. ATTM CONFIDENCE IS LOW REGARDING ANY MVFR/IFR RESTRICTIONS FRIDAY MORNING. HOWEVER...GIVEN LOW DEWPOINT DEPRESSIONS AT THE INLAND TERMINALS...AND THE POTENTIAL FOR A LLVL CLOUD DECK GIVEN ABUNDANT MOISTURE...CANNOT RULE OUT THE POSSIBILITY OF OCCURRENCE. FOR NOW...HAVE INCLUDED MVFR CIG RESTRICTIONS AT INLAND TERMINALS. ADDITIONALLY...SCATTERED SHOWERS AND TSTMS MAY ADVECT INLAND FROM THE WATERS BEGINNING LATE TONIGHT AND PERSISTING THROUGH THE END OF THIS VALID PERIOD. FOR NOW HAVE INDICATED SCT AT MVFR LEVEL WITH VCSH AND WILL UPDATE WITH LATER ISSUANCES. SOUTHWEST WINDS WILL GRADUALLY SHIFT MORE SOUTH/SOUTHWEST BY THIS AFTERNOON. NOT EXPECTING A WELL-DEFINED SEA BREEZE TODAY...BUT WINDS WILL SLIGHTLY SHIFT MORE TOWARDS THE SOUTH...WITH POSSIBLE GUSTS UP 18KT AT THE COAST. OVERNIGHT...WIND SPEEDS WILL DECREASE WITH A CONTINUED SOUTHWEST FLOW. EXTENDED OUTLOOK...WIDESPREAD SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH THE WEEKEND. DECREASING CHANCES FOR CONVECTION BY EARLY NEXT WEEK. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM THURSDAY...SOUTHERLY FLOW WILL CONTINUE...INCREASING TO 15 KTS THIS AFTN/EVE AS GRADIENT TIGHTENS. MERGING FETCH BETWEEN PERSISTENT BERMUDA HIGH AND DEVELOPING TROPICAL WAVE NEAR FLORIDA WILL GRADUALLY ENHANCE SEAS TODAY. SEAS ALREADY 3 TO 4 FT WILL INCREASE TO 4 TO 5 FT BY THIS EVE...WITH A FEW 6 FT SEAS POSSIBLE IN THE 30 TO 40 NM RANGE...AND WIND WAVES DOMINATING THE WAVE SPECTRUM. LATE IN THE PERIOD A TROUGH OF LOW PRESSURE WILL MOVE NEAR THE COAST BRINGING THE POTENTIAL FOR WIDESPREAD SHOWERS AND THUNDERSTORMS TONIGHT...WITH CONFUSED SEAS LIKELY NEAR ANY THUNDERSTORM. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...WINDS FRI WILL BE FROM THE SSW...VEERING TO SW FRI NIGHT INTO SAT NIGHT AND THEN BECOMING LIGHT AND VARIABLE OR EVEN FOR A TIME SHIFTING TO A NORTHERLY DIRECTION LATE SAT NIGHT AND SUN MORNING. STRONGEST WINDS THIS PERIOD WILL OCCUR FRI AFTERNOON INTO SAT AFTERNOON COINCIDENT WITH TIGHTEST PRESSURE GRADIENT AHEAD OF UPSTREAM TROUGH. PRESSURE GRADIENT WILL THEN RELAX GIVEN THE PROXIMITY OF TROUGH SAT NIGHT. THE WAVE SPECTRUM WILL BE DOMINATED BY WIND WAVES FOR MOST OF THE PERIOD...HOWEVER A SE SWELL WILL BE PRESENT. WE WILL BE CLOSE TO SMALL CRAFT ADVISORY CONDITIONS FRI AND FRI NIGHT AS SEAS BUILD. WILL CAP SEAS AT 5 FT WITHIN 20 NM...ALTHOUGH 6 FT SEAS ARE FORECAST JUST BEYOND 20 NM. HIGHEST WINDS WILL BE IN 15 TO 20 KT RANGE...ALTHOUGH SOME GUSTS NEAR 25 KT ARE POSSIBLE LATER FRI AND FRI NIGHT. AT THIS TIME...IT APPEARS CONDITIONS WILL REACH SMALL CRAFT SHOULD EXERCISE CAUTION LEVELS...BUT FALL JUST SHORT OF SMALL CRAFT ADVISORY LEVELS. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 3 PM THURSDAY...A WEAK SURFACE TROUGH JUST WEST OF THE COASTAL WATERS PAIRED WITH A SPRAWLING HIGH IN THE WEST ATLANTIC WILL BRING A SOUTHERLY COMPONENT TO THE WIND FLOW REGIME. THE PRESENCE OF THE TROUGH WILL PUSH THE BEST GRADIENT OUT TO SEA AND WIND WILL REMAIN QUITE LIGHT. BY MONDAY THIS BOUNDARY WILL WASH OUT LEAVING A MORE TYPICAL SOUTHWESTERLY GRADIENT WIND INDUCED BY THE STALWART BERMUDA HIGH. THE DEVELOPMENT OF A PIEDMONT TROUGH ON TUESDAY INCREASE THE WIND SPEED BY JUST A FEW KNOTS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$