928 FXUS62 KILM 271348 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 948 AM EDT SAT JUN 27 2015 .SYNOPSIS... ONE MORE HUMID DAY TODAY BEFORE A COLD FRONT BRINGS DRIER AIR INTO THE REGION ON SUNDAY. STRONG TO SEVERE THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND TONIGHT AHEAD OF THE COLD FRONT. THE FRONT WILL STALL NEAR THE COAST SUNDAY BEFORE DISSIPATING OFFSHORE MONDAY. REDEVELOPMENT OF BERMUDA HIGH PRESSURE MID THROUGH LATE WEEK WILL BRING HUMID CONDITIONS WITH LATE DAY THUNDERSTORMS. && .NEAR TERM /THROUGH TONIGHT/... AS OF 948 AM SATURDAY...UPSTREAM MCV GROUPINGS WERE SETTING OFF SCATTERED MORNING SHOWERS ACROSS SOUTH CAROLINA WESTWARD INTO EAST GEORGIA. LOW-ANGLE EARLY MORNING SUNLIGHT SHOWS WELL THE EMBEDDED CUMULUS TOWERS ASSOCIATED WITH THE IMPULSES. VAPOR CHANNEL SHOWS THESE PERTURBATIONS ARE NOW GETTING PICKED UP BY INCREASING SW SHEAR. OFF-SETTING THIS FACTOR HOWEVER IS DISPLAYED WELL IN VSBL ANIMATIONS THE POCKETS OF EARLY SUN WARMING THE GROUND. THE MCV FAMILY WILL BRING AN UPTICK IN POP VALUES INTO MIDDAY...AS THE FIRST SWIRL TRAVERSES MID TO LATE MORNING...THEN ANOTHER ON THE HEELS EARLY AFTERNOON. ALTHOUGH UPPER SUPPORT IS FADING WITH THE PERTURBATIONS...INTERACTION WITH THE SEA BREEZE BOUNDARY MAY ALLOW SHOWERS AND STORMS FILL IN ALONG IT. THE PRIMARY SEVERE WEATHER THREAT REMAINS TIED TO THE LINE OF STORMS EXPECTED TO DEVELOP ALONG AND AHEAD OF A COLD FRONT THIS EVENING...WHERE AN SPC ENHANCED RISK IS POSTED FOR THE PRIMARY THREAT OF DAMAGING WINDS. WINDS ALOFT NEARLY PARALLEL THE FRONTAL BOUNDARY OVERNIGHT WHICH SLOWS THE EASTWARD PROGRESSION OF THE FRONT...ALLOWING SHOWERS AND A FEW STORMS TO LINGER INTO EARLY SUNDAY OVER THE COASTAL INTERIOR TO THE BEACHES...CLEARING TO SEA THROUGH AFTERNOON. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... AS OF 300 AM SATURDAY...ANOMALOUSLY STRONG SPRING-LIKE COLD FRONT TO CROSS THE AREA SUNDAY...BUT THE TRUE AIRMASS CHANGE NOW...UNFORTUNATELY...LOOKS SLOWER AND LESS IMPRESSIVE THAN PREVIOUSLY THOUGHT. COLD FRONT WILL DRAG ACROSS THE AREA DURING EARLY SUNDAY AS A LARGE TROUGH DIVES ACROSS THE EASTERN CONUS. HOWEVER...THIS FRONT IS NOW PROGGED TO STALL ALONG OR JUST OFF THE COAST...TYPICAL FOR LATE JUNE...AND WILL NOT REALLY PUSH AWAY AND WASH OUT UNTIL A SECONDARY VORT SWINGS THROUGH SUNDAY NIGHT INTO MONDAY. THIS WILL KEEP CLOUDS/SHOWER CHANCES ALONG THE COAST THROUGH SUNDAY...WITH SHOWERS/CLOUDS POSSIBLY INCREASING BACK TO THE WEST LATE IN THE DAY AS THE SECONDARY VORT TRIES TO SPAWN WEAK LOW PRESSURE ALONG THE BOUNDARY. THIS IS DEPICTED BY THE LATEST WPC GRAPHICS...AND WOULD SUGGEST SUNDAY WILL REMAIN HUMID...ESPECIALLY ACROSS THE EASTERN HALF OF THE CWA. WILL SHOW A SLIGHT INCREASE IN POP AND TEMP BEFORE DRYING THINGS OUT FOR MONDAY...ALTHOUGH WITH THE TROUGH AXIS REMAINING TO OUR WEST ...MID-LEVEL FLOW STAYS W/SW AND EVEN MONDAY WILL NOT BE AS COOL AND DRY AS PREVIOUSLY ANTICIPATED. HOWEVER...SHOWER ACTIVITY IS NOT EXPECTED ON MONDAY. TEMPS SUNDAY WILL BE IN THE MID 80S NEAR THE COAST...TO THE UPR 80S WELL INLAND. EXPECT HIGHS TO BE 1-3 DEGREES WARMER ON MONDAY AS THE FRONT WASHES OUT OFFSHORE WITHOUT ANY SIGNIFICANT COOL ADVECTION...ALTHOUGH DEW POINT TEMPERATURES WILL LIKELY BE ABOUT 5- 10 DEGREES COOLER THAN THEY HAVE RECENTLY BEEN. THIS WILL ALLOW MINS SUNDAY NIGHT TO DROP INTO THE 65-70 DEGREE RANGE...THEN SLIGHTLY WARMER MONDAY NIGHT AS SOUTHERLY FLOW QUICKLY RETURNS. && .LONG TERM /TUESDAY THROUGH FRIDAY/... AS OF 828 AM SATURDAY...CONSENSUS AMONG THE GLOBAL MEMBERS AND ENSEMBLE PLOTS DEPICT LOW AMPLITUDE BUT PERSISTENT UPPER TROUGHING ACROSS THE EASTERN CONUS TUESDAY THROUGH FRIDAY. CONFIGURATION WILL SUPPORT A STORM TRACK NEAR TO JUST NORTH OF THE AREA THAT MAY FOSTER IMPACTS FROM CONVECTIVE COMPLEXES...WHILE AIDING IN SURFACE TROUGHING INLAND AS A FOCUS FOR CONVECTIVE INITIATION IN DURING DIURNAL WARMING. SEVERAL SHORT-WAVES EMBEDDED IN THE TROUGHING WILL PROVIDE A DAILY CHANCE OF THUNDERSTORMS. COLUMN MOISTURE WILL BE INCREASING BEGINNING WEDNESDAY AS SUBSIDENCE ALOFT WANES. THE LOW-LEVEL WSW FLOW WILL LIKELY BRING MAXIMUM TEMPERATURES IN THE PERIOD NEAR TO SLIGHTLY ABOVE LATE JUNE/EARLY JULY STANDARDS. && .AVIATION /13Z SATURDAY THROUGH WEDNESDAY/... AS OF 12Z...CONDITION WILL BE HIGHLY VARIABLE TODAY WITH ABUNDANT MOISTURE. THE NAM SHOWS TO MAIN AREAS OF CONVECTION...THE FIRST AROUND LATE MORNING MOVING FROM SOUTHWEST TO NORTHEAST...AND THE SECOND THIS EVENING WITH THE FRONT. THE NAM IS SLOWER THAN THE OTHER MODELS...BUT IT IS SAFE TO SAY THE ENTIRE CWA WILL GET SOME DECENT RAIN...PERHAPS HEAVY. CEILINGS WILL LIKELY BE ALL OVER THE PLACE TODAY...BOUNCING FROM AROUND 5K ALL THE WAY DOWN TO IFR WITH IFR VISIBILITIES IN THE HEAVY CONVECTION. THE STORMS ARE LIKELY TO CONTINUE WELL INTO THE EVENING. EXTENDED OUTLOOK...MODERATE CONFIDENCE CONTINUES FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS CONTINUING INTO EARLY SUNDAY MORNING WITH TEMPO MVFR/IFR IN HEAVY RAIN. OTHERWISE EXPECT VFR. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 948 AM SATURDAY...S TO SW WINDS AROUND 15 KT THIS MORNING WILL RAMP UP TO 20 TO 25 KT THIS AFTERNOON AND CONTINUE TONIGHT. SEAS 3 TO 4 FT ATTM WILL BUILD TO 5 TO 7 FT BY TONIGHT. AN SCA IS IN EFFECT FOR ALL WATERS FROM NOON TODAY THROUGH NOON SUNDAY. SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ARE ALSO IN THE FORECAST AND MAY PRODUCE LOCALLY HIGHER WINDS AND SEAS. SEA SPECTRUM DOMINATED BY SW WAVES 3-4 FT EVERY 5 SECONDS TODAY AND SW WAVES 4-6 FT EVERY 6 SECONDS TONIGHT. TSTMS WILL BE CAPABLE OF GUSTS TO 50 KT TONIGHT INTO EARLY SUNDAY. MARINERS ARE ENCOURAGED TO OBTAIN A RADAR UPDATE BEFORE VENTURING OUT. SHORT TERM /SUNDAY THROUGH MONDAY/... AS OF 300 AM SATURDAY...COLD FRONT WILL APPROACH FROM THE WEST AND THEN STALL JUST INLAND OR RIGHT ALONG THE COAST MUCH OF SUNDAY. THIS WILL MAINTAIN SW WINDS ACROSS THE WATERS THROUGH THE LATTER HALF OF THE WKND...ALTHOUGH A VERY BRIEF TURN TO THE NORTH IS POSSIBLE LATE SUNDAY NIGHT INTO MONDAY ACROSS THE NORTHERN WATERS AS THE COLD FRONT SURGES SOUTHEAST. THIS WIND SHIFT WILL BE SHORT AND WITH VERY LIGHT SPEEDS...AS SW WINDS ARE EXPECTED TO RETURN AGAIN BY MONDAY AFTN. STRONGEST WINDS WILL BE AHEAD OF THE FRONT SUNDAY...WHEN SPEEDS WILL REACH 15-20 KTS...FALLING TO 10-15 KTS ON MONDAY. AN SCA IS IN EFFECT THROUGH NOON FOR A FEW 6 FT SEAS LEFTOVER FROM SATURDAY...BUT THESE WILL FALL THROUGH SUNDAY...AND BECOME 3-4 FT BY MONDAY WITH THE SW WIND CHOP REMAINING PREDOMINANT. LONG TERM /TUESDAY THROUGH THURSDAY/... AS OF 828 AM SATURDAY...MODERATE SW WINDS PREVAIL THIS PERIOD AS INLAND SURFACE TROUGHING INTERACTS WITH HIGH PRESSURE OFFSHORE YIELDING SW 10-20 KT FLOW. TSTMS MAY IMPACT INSHORE WATERS IN THE LATE AFTERNOONS THROUGH THE OVERNIGHT PERIODS. SEAS MAINLY 3-4 FT BUT UP TO 5 FT OFFSHORE AT TIMES...AS INLAND TROUGHING SHARPENS INTO MID-WEEK. SPECTRAL DATA SUGGEST SEAS WILL BE COMPRISED OF 3 FOOT WAVES FROM THE SSW EVERY 6 SECONDS...AND 1-2 FOOT WAVES FROM THE ESE EVERY 7-9 SECONDS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL NOON EDT SUNDAY FOR AMZ250-252-254- 256. && $$ NEAR TERM...MJC SHORT TERM...JDW LONG TERM...MJC AVIATION...DL