AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 305 PM EDT WED MAY 11 2011 .SYNOPSIS... A SERIES OF UPPER DISTURBANCES DROPPING SOUTHWARD OVER THE CAROLINAS ALONG WITH A STALLED SURFACE BOUNDARY OVER THE AREA...WILL MAINTAIN SCATTERED THUNDERSTORMS. STORMS LATER TODAY COULD BECOME SEVERE OVER INLAND SOUTH CAROLINA. HIGH PRESSURE WILL BUILD FROM THE NORTH TONIGHT INTO LATE WEEK. LOW PRESSURE AND AN ASSOCIATED FRONTAL SYSTEM WILL IMPACT THE EASTERN CAROLINAS THIS WEEKEND. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM WEDNESDAY...HIGH PRESSURE WILL CONTINUE TO RIDGE DOWN THE CAROLINA COAST WITH AN E-NE FLOW SHIFTING AROUND TO E-SE THROUGH THE NIGHT. SOME DRIER AIR HAS PUSHED DOWN INTO NORTH CAROLINA WITH DEWPOINT TEMPS IN THE LOW 50S REACHING DOWN INTO NORTHERN TIER OF CWA. STILL LEFT WITH A FAIRLY JUICY ATMOSPHERE TOWARD SOUTHERN TIER OF FORECAST AREA IN SOUTH CAROLINA WHERE DEWPOINTS WERE REACHING INTO THE 60S. SFC BASED CAPES RUN UP TO 2000 J/KG THIS AFTN JUST ALONG OUR SC WESTERN CWA BORDER. PLENTY OF CU DEVELOPMENT OVER SC THIS AFTERNOON WITH LINGERING MOISTURE FROM RAINFALL YESTERDAY. LOOKS LIKE MAIN ACCESS OF MOISTURE AND INSTABILITY WILL RUN THROUGH CENTRAL SC BUT SOUTH AND WEST OF OUR CWA. SOME PERTURBATIONS IN MID TO UPPER FLOW MAY TRIGGER SOME STORMS OVER INTERIOR MOUNTAINS AND WILL THEN GET STEERED SOUTHWARD BUT SHOULD EITHER SKIRT OR MISS SC ZONES LATER THIS AFTERNOON. OVERALL LOOKS LIKE STORMS WILL BE AFFECT MAINLY SC FROM BENNETTSVILLE TO FLORENCE AND SOUTHEAST BUT NOT COUNTING ON ANY WIDESPREAD SHWRS/TSTMS THIS AFTERNOON. STEERING FLOW WILL KEEP ANY STORMS THAT DO DEVELOP MOVING FROM NW TO SE. SPC KEEPING SLIGHT RISK SOUTH AND WEST OF ILM CWA. SHOWERS WILL DISSIPATE THIS EVENING. DEEP NORTHERLY FLOW WILL DRY OUT THE MID LEVELS TONIGHT BUT SHALLOW MOISTURE WILL REMAIN. CLOUDS WILL BREAK UP THROUGH THIS EVENING BUT ANOTHER PERTURBATION IN THE MID TO UPPER LEVEL FLOW MAY PRODUCE MORE CLOUDS BY MORNING. TEMPS WILL REACH THE MID TO UPPER 70S OVER MOST OF AREA WITH TEMPS IN THE LOWER 80S CLOSER TO FLORENCE. OVERNIGHT TEMPS MAY BE A BIT TRICKY WITH LOWER DEWPOINTS NOSING IN DOWN THE NC COAST AND POSSIBILITY OF CLOUDS. TEMPS SHOULD DROP TO MID 50S NORTH AND LOWER TO MID 60S OVER SC. && .SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 PM WEDNESDAY...THE UPPER RIDGE AND SURFACE FEATURE WILL SHIFT EAST THROUGH THE PERIOD WITH SOUTHERLY FLOW EXPECTED TO SET UP BY FRIDAY. PRESENTLY...WE ARE CARRYING A DRY FORECAST THURSDAY AND THURSDAY NIGHT BUT IT SHOULD BE NOTED THAT ISOLATED STORMS ARE POSSIBLE IN THE AFTERNOON AND EVENING. AS THE STORM SYSTEM APPROACHING FROM THE MID SECTIONS OF THE COUNTRY GETS A LITTLE CLOSER FRIDAY...THERE IS A SLIGHTLY BETTER CHANCE FOR SHOWERS AND THUNDERSTORMS FRIDAY AFTERNOON AND EVENING. TEMPERATURES WILL WARM SLIGHTLY THROUGH THE PERIOD...GOING FROM 75 TO AROUND 80 THURSDAY TO UPPER 70S TO LOWER 80S FRIDAY. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... AS OF 3 PM WEDNESDAY...STILL A LOW-CONFIDENCE FORECAST AND AN UNSETTLED WEATHER PATTERN AS SURFACE AND UPPER TROFINESS WILL PERSIST THROUGH THE EXTENDED. STATIONARY FRONT WILL BE ORIENTED NORTHEAST-TO-SOUTHWEST SOMEWHERE ACROSS THE CAROLINAS...AND THE TIMING OF ANY UPPER IMPULSES ALOFT WILL DETERMINE WHEN OUR RAIN CHANCES WILL ACTUALLY OCCUR. KNOWING THAT WE CANNOT NAIL DOWN SAID TIMING THIS FAR OUT...WILL BLANKET THE EXTENDED PERIOD WITH CHANCE POPS. CLOUD COVER AND MOIST SOUTHERLY FLOW WILL LIMIT DIURNAL TEMP RANGES...SO TEMPS NEAR OR SLIGHTLY BELOW NORMAL BY DAY...AND JUST ABOVE BY NIGHT. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/... AS OF 18Z...MODERATE CONFIDENCE FORECAST TODAY DUE TO UNCERTAINTY IN TSTM COVERAGE AND EVOLUTION OF CIGS. EXPANSIVE CONVECTIVE DEBRIS CI HAS LIMITED THE ABILITY OF CU TO DEVELOP THUS FAR...BUT EXPECT BKN MVFR CU ACROSS SC...VFR ACROSS NC...TO FILL IN ACROSS THE AREA THIS AFTN. SLOWER HEATING MEANS LESS OF A CHANCE FOR STRONG CONVECTION THIS AFTN BUT TSTMS MAY STILL DEVELOP BY THIS EVE. GFS AND HRRR...BOTH OF WHICH PERFORMED WELL YESTERDAY...ARE CONTINUING TO INDICATE THAT SHRA/TSRA WILL DEVELOP AND CONTINUE INTO THE NIGHT. WITH THE UPPER AND SURFACE PATTERN REMAINING FAIRLY SIMILAR TO YESTERDAY...THERE IS A GOOD CHANCE OF THIS OCCURRING. HOWEVER...BEST SBCAPE IS CONTINUING TO BE MODELED FURTHER WEST SO HAVE ONLY MENTIONED CB AT FLO...BUT CONFIDENCE NOT HIGH ENOUGH FOR EVEN AN SHRA MENTION IN THE TAF. OTRW VFR SHOULD PERSIST TODAY. LOW CONFIDENCE IN CIGS OVERNIGHT SINCE MOISTURE ADVECTION WOULD SUGGEST SOME FOG AND OR STRATUS...BUT NONE OF THE GUIDANCE IS DEPICTING THIS. EAST FLOW MAY BE TOO DEEP TO ALLOW A RESTRICTIVE STRATUS LAYER...SO INSTEAD HAVE BKN AT VFR LEVEL...BUT AGAIN CONFIDENCE IS LOW. SOME MVFR STRATUS MAY DEVELOP ACROSS THE REGION. FOG IS NOT ANTICIPATED DUE TO AMPLE CLOUD COVER. ANY STRATUS WILL BURN OFF AFTER SUNRISE BUT DIURNAL CU WILL RAPIDLY DEVELOP AGAIN. WINDS WILL REMAIN LIGHT FROM THE E/SE AOB 10 KTS. EXTENDED OUTLOOK...SCATTERED AFTERNOON AND EVENING CONVECTION POSSIBLE EACH DAY THROUGH SATURDAY. MORE WIDESPREAD SHOWERS ARE POSSIBLE SUNDAY AND MONDAY. LOCALIZED IFR POSSIBLE EACH MORNING. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM WEDNESDAY...GUSTY EASTERLY WINDS WHICH PUSHED SEAS UP TO 3 TO 4 FT IN OUTER WATERS THIS AFTERNOON WILL SLOWLY SUBSIDE THROUGH TONIGHT. SEAS WILL BE IN THE 2 TO 4 FT RANGE THROUGH MUCH OF THE NIGHT. WILL REMAIN IN EASTERLY FLOW AS HIGH PRESSURE CONTINUES TO RIDGE DOWN INTO THE LOCAL WATERS THROUGH TONIGHT BUT OVERALL SPEED WITH DIMINISH TO AROUND 10 KTS. SHORT TERM /THURSDAY THROUGH FRIDAY/... AS OF 3 PM WEDNESDAY...WITH THE SURFACE RIDGE DRIFTING TO THE EAST THROUGH THE PERIOD...EXPECT WINDS TO GRADUALLY SHIFT FROM NE TO E THROUGH SE TO S. SPEEDS THROUGH THE PERIOD WILL BE 15 KT OR LESS WITH SEAS GENERALLY RUNNING 4 FT OR LESS. .LONG TERM /SATURDAY THROUGH MONDAY... AS OF 3 PM WEDNESDAY...HIGH CONFIDENCE IN A SOUTHERLY COMPONENT TO THE WINDS BUT FAIRLY LOW CONFIDENCE IN EVERYTHING ELSE. WILL INITIALIZE WITH A SE WIND ON SATURDAY...BUT COMING AROUND TO DUE SOUTH BY SATURDAY AFTERNOON AND REMAINING OUT OF THE S-SSW FOR THE REST OF THE PERIOD. ANY WAVES OF LOW PRESSURE DEVELOPING ALONG THE STATIONARY FRONT OVER THE CAROLINAS WILL AFFECT THE DIRECTION...AND WIND SPEEDS WILL BE DEPENDENT ON HOW CLOSE THE FRONT IS TO THE COAST. AT THIS POINT 15-20 KT APPEARS TO BE THE UPPER LIMIT. SEAS SHOULD STAY BELOW SCA THRESHOLDS...GENERALLY 3-4 FT BUT COULD TOUCH 5 FT AT TIMES...ESPECIALLY ALONG FRYING PAN SHOALS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...NONE. && $$