AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 437 PM EDT THU AUG 25 2011 .SYNOPSIS... ONSHORE WINDS WILL BRING SHOWERS TOWARD THE COAST EARLY TODAY. HURRICANE IRENE WILL PRODUCE INCREASING WAVES AND STRENGTHENING RIP CURRENTS THROUGH TONIGHT...AND INCREASING RAIN CHANCES AND WIND FRIDAY AND SATURDAY. A COLD FRONT WILL APPROACH THE REGION FROM THE NORTH EARLY NEXT WEEK. && .NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM THURSDAY...TROPICAL STORM WATCH REMAINS IN EFFECT FOR COASTAL COUNTIES AND BLADEN AND COLUMBUS COUNTIES. WATCHES WILL LIKELY BE UPGRADED TO WARNINGS LATE THIS AFTERNOON. NOTE...MODEL CONSENSUS HAS SHIFTED WESTWARD AND THIS MAY REQUIRE AN EXPANSION OF WARNINGS A LITTLE FURTHER W. THERE IS ALSO THE POSSIBILITY THAT COASTAL NORTH CAROLINA AREAS MAY BE UPGRADED TO HURRICANE WARNINGS. THE NATIONAL HURRICANE CENTER IS NOT EXPECTED TO MAKE ANY CHANGES TO WATCHES AND WARNINGS UNTIL LATE THIS AFTERNOON...AFTER 5 PM. VERY ISOLATED CONVECTION SHOULD DIE OFF RATHER QUICKLY WITH LOSS OF HEATING THIS AFTERNOON. AS IRENE CONTINUES ITS APPROACH FROM THE S...REACHING A POSITION OFF THE NORTH COAST OF FL FRI MORNING...IT IS POSSIBLE THAT SOME OF THE OUTER RAIN BANDS MAY ENCROACH ONTO THE COAST AROUND DAYBREAK. HOWEVER...THE BRUNT OF SIGNIFICANT RAINFALL SHOULD REMAIN OFFSHORE UNTIL AFTER SUNRISE. DANGEROUS RIP CURRENTS WILL CONTINUE ALONG WITH BREAKING WAVES OF 5 TO 7 FT WITH THE APPROACH OF HIGH TIDE...AROUND 5 PM. WINDS ARE NOT EXPECTED TO SIGNIFICANTLY INCREASE ACROSS THE AREA UNTIL FRI EVE AND OVERNIGHT FRI. IRENE IS EXPECTED TO MAKE ITS CLOSEST APPROACH FRI NIGHT AND SAT. INCREASING CLOUD COVER AND DEEP AND INCREASING EASTERLY FLOW SHOULD KEEP MINIMUMS NEAR OF JUST ABOVE THE HIGHEST OF AVAILABLE TEMP && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...IRENE WILL BE IMPACTING THE AREA THROUGH THE PERIOD. KEEP IN MIND A SLIGHT SHIFT IN THE TRACK WEST OR EAST CAN HAVE A SIGNIFICANT IMPACT ON THE FORECAST. IRENE WAS LOCATED IN THE NORTHERN BAHAMAS JUST OVER 500 MILES SOUTH OF WILMINGTON AND WILL MOVE NORTH THROUGH THE FORECAST PERIOD. ON ITS CURRENT TRACK IT SHOULD MAKE ITS CLOSEST PASS TO CAPE FEAR EARLY SAT MORNING. THE LATEST FORECAST WILL PRODUCE A GREATER PERIOD OF INTENSE WINDS AND ABUNDANT MOISTURE AFFECTING OUR AREA. WINDS WILL BE INCREASING THROUGH THE DAY ON FRIDAY AND SHOULD REACH TROPICAL STORM FORCE BY FRI EVENING ALONG THE COAST...ESPECIALLY NORTH OF CAPE FEAR. OVERALL EXPECT GUSTY NORTHERLY WINDS SHIFTING TO TO A MORE N-NW DIRECTION SAT MORNING. THE GREATEST WINDS COULD REACH UP TO 55 TO 75 MPH IN COASTAL NEW HANOVER COUNTY AND UP TO 60 TO 80 MPH OVER COASTAL PENDER ON ITS CURRENT TRACK. WINDS WILL SHIFT AND BECOME OFF SHORE SAT AFTN AND DECREASE IN INTENSITY THROUGH LATE DAY SATURDAY. EXPECT THE GREATEST IMPACTS ALONG THE COASTAL AREA WITH WINDS...BUT OUTER RAINBANDS COULD POTENTIALLY PRODUCE PERIODS OF VERY HEAVY RAIN AND GUSTY WINDS WELL INLAND. THERE WILL BE A TIGHT GRADIENT IN TERMS OF CLOUDS...RAIN AND WIND...BUT THE LATEST FORECAST PUSHES THE DRY SUBSIDENT SIDE OF THE STORM FARTHER INLAND OR MAINLY WEST OF FORECAST AREA. THE POUNDING EASTERLY WINDS ON THE NORTH AND EAST SIDE OF IRENE WILL PUSH PLENTY OF MOISTURE TOWARD THE AREA. PCP WATER VALUES REACH UP TO NEAR 3 INCHES FOR A PROLONGED PERIOD FRI NIGHT THROUGH EARLY SAT. THEREFORE A FLASH FLOOD WATCH WAS ISSUED AND EXPECT OUTER RAINBANDS TO REACH THE AREA BY FRI MORNING. THE POUNDING SURF AND STRONG WINDS AS HURRICANE IRENE PASSES AND STRONG EAST-SOUTHEAST SWELLS AHEAD OF HURRICANE IRENE WILL ALSO PRODUCE THE THREAT OF COASTAL FLOODING ESPECIALLY DURING TIMES OF HIGH TIDE LATE FRI AND EARLY SAT MORNING. STORM WILL EXIT THE AREA SAT NIGHT WITH DECREASING WESTERLY FLOW AND SUBSIDENCE IN THE WAKE OF THE STORM WITH DRIER AIR MOVING IN. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 3 PM THURSDAY...RAPIDLY IMPROVING CONDITIONS ON SUNDAY AS IRENE DEPARTS TO THE NORTHEAST. SUBSIDENCE AND DRY AIR BEHIND THE STORM WILL MAKE FOR A HOT DAY...WITH LOWER/MID 90S EXPECTED MOST LOCATIONS. WEAK HIGH PRESSURE TO OUR NORTH TAKES OVER FOR MUCH OF NEXT WEEK...WITH POPS LIMITED TO SLIGHT CHANCE AND TEMPS NEAR CLIMO. && .AVIATION /18Z THURSDAY THROUGH TUESDAY/... AS OF 18Z...SCATTERED TO BROKEN CUMULUS FIELD ACROSS THE TERMINALS WITH ISOLATED SHOWERS EMBEDDED WITHIN THIS AFTERNOON. THERE WILL CONTINUE TO BE A CHANCE OF VCSH/CB AT THE TERMINALS BUT FOR THE MOST PART THINK ACTIVITY WILL REMAIN VERY ISOLATED WITH LITTLE CHANCE OF ACTUALLY AFFECTING ANY ONE TERMINAL. OVERALL VFR EXPECTED THROUGH 00Z. PRECIPITATION DISSIPATES BY 00-02Z ACROSS INLAND AREAS. BUT AT THE COASTAL TERMINAL SHOWERS WILL APPROACH FROM THE SOUTHEAST AHEAD OF HURRICANE IRENE. THESE SHOWERS SHOULD REMAIN OFFSHORE BUT COULD WORK THEIR WAY INTO THE COASTAL TERMINALS AFTER MIDNIGHT. WINDS WILL BECOME GRADUALLY MORE EASTERLY DURING THE EVENING AND THEN NORTHEAST IN THE PRE-DAWN HOURS. HIGH PRESSURE/SUBSIDENCE ACROSS FLO/LBT TERMINALS MAY LEAD TO FOG DEVELOPMENT OVERNIGHT BUT THINK BOUNDARY LAYER WINDS WILL RESULT IN A BETTER CHANCE OF STRATUS CEILINGS DEVELOPING. AT THE COASTAL TERMINALS IF SHOWERS DO MOVE ONSHORE EXPECT A GOOD CHANCE OF MVFR CONDITIONS. AFTER SUNRISE MVFR CONDITIONS EXPECTED TERMINAL WIDE WITH THE BEST CHANCE OF TEMPO SHOWERS AT THE COASTAL TERMINALS. EXTENDED OUTLOOK...HURRICANE IRENE WILL AFFECT MAINLY THE ILM/CRE/MYR TERMINALS WITH GUSTY WINDS...IFR CONDITIONS IN SHOWERS AND ISOLATED THUNDERSTORMS LATE FRIDAY EXTENDING INTO INTO LATE SATURDAY. VFR DEVELOPING SUNDAY PERSISTING THROUGH TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 3 PM THURSDAY...SEAS HAVE ONLY BUILT SLOWLY THROUGH THE DAY. HOWEVER...AS IRENE CONTINUES TO APPROACH FROM THE S...SEAS ARE EXPECTED TO RAMP UP QUICKLY TONIGHT IN RESPONSE TO STRENGTHENING 13 TO 15 SECOND ESE SWELL. NEAR DAYBREAK...MARINERS SHOULD EXPECT SEAS NEAR 10 FT BEYOND 15 NM WITH PERHAPS 15 FT AT FRYING PAN SHOALS. WINDS ARE NOT EXPECTED TO INCREASE SIGNIFICANTLY THROUGH THE OVERNIGHT. HOWEVER...BY MORNING...E WINDS OF 20 TO 25 KT SHOULD BE THE GENERAL RULE WITH WINDS INCREASING RATHER RAPIDLY THEREAFTER. CURRENT SMALL CRAFT ADVISORY WILL BE SUPERSEDED BY THE ISSUANCE OF TROPICAL STORM OR HURRICANE WARNINGS LATE THIS AFTERNOON. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 3 PM THURSDAY...CURRENT FORECAST FOR IRENE BRINGS TROPICAL STORM FORCE WINDS INTO LOCAL WATERS BY FRI EVENING AND HURRICANE FORCE WINDS REACHING INTO LOCAL WATERS NORTH OF NC/SC BORDER BY EARLY SAT MORNING. THE WIND DIRECTION WILL CHANGE FROM E-NE FRI AFTN TO NORTH BY SAT MORNING AND NW BY SAT AFTERNOON AS HURRICANE IRENE PASSES BY TO OUR EAST OVERNIGHT FRI INTO EARLY SAT AND THEN MOVES OFF TO THE NORTH BY SAT AFTN. AS IRENE MOVES NORTH FROM THE BAHAMAS IT WILL CONTINUE TO GENERATE LARGE SOUTHEAST TO EAST SWELLS. THESE LONGER PERIOD SWELLS WILL CONTINUE TO AFFECT OUR LOCAL WATERS PRODUCING INCREASING SEAS WELL AHEAD OF THE STORM. SEAS WILL BUILD RATHER QUICKLY ON FRI AS INCREASINGLY STRONGER WINDS COMBINE WITH PERSISTENT SE SWELLS. SEAS NEAR SHORE SHOULD BE UP TO 6 TO 8 FT FRI MORNING AND UP TO 14 FT IN OUTER WATERS. AS STORM MOVES CLOSER TO AREA BY SAT MORNING SEAS WILL BUILD TO 16 TO 20 IN WATERS NORTH OF CAPE FEAR CLOSEST TO THE CENTER OF IRENE WHICH SHOULD REMAIN TO THE EAST OF OUR COASTAL WATERS. GREATEST SEAS WILL BE FROM CAPE FEAR NORTH AND ANY PLACES EXPOSED TO EASTERLY WINDS AND SOUTHEAST TO EAST SWELLS. BY SAT MORNING AS STORM PASSES TO OUR EAST THE SEAS WILL BEGIN TO DROP AS WINDS TURN TO N-NW AND BECOME MORE OFF SHORE DECREASING IN INTENSITY THROUGH LATE SAT. ONCE THE STORM PASSES AND FLOW BECOMES OFFSHORE SAT NIGHT SEAS WILL START TO FALL FAIRLY QUICKLY. LONG TERM /SUNDAY THROUGH TUESDAY/... AS OF 3 PM THURSDAY...WEST WINDS WILL DIMINISH ON SUNDAY AS A WEAK TROUGH LINGERS OVER THE CAROLINAS AND MAINTAINS A WEAK PRESSURE GRADIENT IN THE WAKE OF IRENE. HIGH PRESSURE STARTS TO BUILD NORTH OF THE CAROLINAS ON MONDAY...RESULTING IN A VEERING TO A MORE EASTERLY WIND DIRECTION. SEABREEZE EACH DAY...STRONGER MON...WILL RESULT IN TYPICAL ONSHORE AFTERNOON FLOW. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...TROPICAL STORM WATCH FOR SCZ053>056. NC...TROPICAL STORM WATCH FOR NCZ096-099-105>110. MARINE...TROPICAL STORM WATCH FOR AMZ250-252-254-256. SMALL CRAFT ADVISORY UNTIL 8 AM EDT FRIDAY FOR AMZ250-252-254- 256. && $$