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000 FXUS62 KILM 270001 CCA AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 702 PM EST THU NOV 26 2009 .SYNOPSIS... A STRONG COLD FRONT WILL SWEEP ACROSS THE EASTERN CAROLINAS TONIGHT...SPREADING CHILLY AIR AND BRISK WINDS INTO THE REGION OVERNIGHT THROUGH FRIDAY. DAYTIME WINDS WILL EASE BY SATURDAY AS A DEEP SURFACE LOW OVER NEW ENGLAND PULLS FARTHER AWAY. TEMPERATURES WILL REBOUND SUNDAY AND MONDAY AS HIGH PRESSURE PASSES OVERHEAD AND SETTLES OFFSHORE. THE NEXT CHANCE FOR RAIN WILL BE TUESDAY...AS A COLD FRONT DROPS SOUTHEAST ACROSS THE AREA. && .NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM THURSDAY...WE CAN BE THANKFUL FOR SUNSHINE OVER MOST OF THE ILM CWA...BUT STRATUS HAS BEEN VERY PERSISTENT OVER THE NORTHERN AND WESTERN ZONES AND THREATENED TO MAKE THIS A REAL TURKEY OF A FORECAST. MAIN STORY IN THE NEAR TERM IS A STRONG COLD FRONT NOW WORKING ITS WAY INTO THE WESTERN CAROLINAS WITH SOLID UPPER SUPPORT IN THE FORM OF A SHARP FULL-LATITUDE TROF NEAR 85W. THIS FRONT WILL PUSH EAST ACROSS THE EASTERN CAROLINAS DURING THE LATTER PART OF THE EVENING. MOISTURE IS QUITE LIMITED WITH PRECIPITABLE WATER ON THE ORDER OF A HALF INCH...AND THE BEST DYNAMICS WILL BE JUST SKIRTING THE NORTHERN PART OF THE CWA. BRIEF WINDOW AROUND MIDNIGHT WHERE WE COULD SEE A STRAY SHOWER IN THE NORTHERN ZONES...BUT MORE LIKELY SCENARIO IS SPRINKLES. INCLUDED A 20 POP JUST IN THE NORTH AND THINK IT WILL BE A LOW QPF EVENT IF IT DOES HAPPEN. TEMP FORECAST IS ACTUALLY CLOSE TO MOS GUIDANCE...WITH UPPER 30S INLAND AND LOWER 40S ALONG THE COAST. HOWEVER NO FROST IS EXPECTED AS WINDS WILL STAY UP THRU THE NIGHT...GENERALLY 10-15MPH...AND AT LEAST BRIEFLY GUSTING IN EXCESS OF 20 MPH IN THE INITIAL SURGE. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 230 PM THURSDAY...BY FRIDAY DAYBREAK A SMALL SAMPLING OF WINTER-LIKE WEATHER WILL BE FELT...AS A SHARP UPPER TROUGH PIVOTS ACROSS THE SOUTHEAST AND MID-ATLANTIC STATES. A SUNNY BRISK DAY ON TAP FRIDAY WITH MAX TEMPS TOPPING IN THE MID 50S. A FROST ADVISORY MAY BE NEEDED IN THE EARLY MORNING HOURS OF SATURDAY...BUT THE CONFIDENCE LEVEL RIGHT NOW IS NOT HIGH ENOUGH TO ISSUE A 3RD PERIOD ADVISORY BECAUSE LINGERING WINDS IN THE LOW LEVELS MAY SERVE TO INHIBIT FROST FORMATION. TEMPS DO NOT LOOK COLD ENOUGH AT THIS TIME TO ISSUE A FREEZE WATCH FOR EARLY SATURDAY...THOUGH IT IS LIKELY SOME LOCALIZED RURAL "COLD" MICRO-POCKETS WILL DIP BELOW 32 F SATURDAY MORNING. ALTHOUGH THE SURFACE HIGH WILL STILL BE OVER LAND SATURDAY...MINOR MODERATION OF THE AIR MASS IN PLACE SHOULD ALLOW MAXIMUM TEMPS SATURDAY TO REACH" onClick="return popup(this, 'notes')">REACH THE LOWER 60S...WITH PLENTY SUN BEAMING THROUGH BOTH FRIDAY AND SATURDAY. && .LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 230 PM THURSDAY...MEDIUM RANGE FORECAST MODELS STARTING TO COME TO A BETTER CONSENSUS FOR THE EVENTS OF NEXT WEEK. IT APPEARS THERE WILL BE TWO SEPARATE SYSTEMS AS THE SPLIT FLOW ALLOWS TWO DISTINCT SHORTWAVES TO PROGRESS THROUGH EACH BRANCH OF THE WESTERLIES. THE FIRST MOVES ACROSS TUESDAY AS A SINGLE COLD FRONT. MAINTAINED THE LOW CHANCE POPS WITH THIS SYSTEM. THE SECOND AND MORE POTENT OF THE SYSTEMS IS RIGHT ON ITS HEELS WEDNESDAY AS A DEEP MID LEVEL CLOSED LOW INDUCES DEEP CYCLOGENESIS IN THE GULF OF MEXICO WHICH EVENTUALLY MOVES UP THE EAST COAST. AFTER A SMALL DECREASE IN POPS FOR TUESDAY NIGHT/WEDNESDAY MORNING...INCREASED POPS TO CHANCE VALUES FOR ALL AREAS WEDNESDAY AND WEDNESDAY NIGHT. TEMPERATURES SHOULD BE SLIGHTLY ABOVE CLIMATOLOGY EARLY...SUNDAY AND MONDAY WITH READINGS TRENDING DOWN FROM THAT POINT ON DUE TO THE INCREASE IN MOISTURE AND A BRIEF INTRUSION FROM COOLER HIGH PRESSURE IN THE WAKE OF THE FIRST SYSTEM. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... COLD FRONT WILL CROSS THE REGION TONIGHT BRINGING GUSTY W/NW WINDS AND SOME MVFR CIGS...BUT VFR WILL BE THE RULE AT ALL TERMINALS TOMORROW. OTHER THAN SOME LIGHT FOG AT LBT...ALL TERMINALS REPORTING VFR TONIGHT...AND THIS FOG WILL SCOUR OUT WHEN THE FRONT PASSES THROUGH THIS EVENING. CURRENT COMPOSITE REFLECTIVITY SHOWING CONVECTION ASSOCIATED WITH THE COLD FRONT BACK NEAR CHARLOTTE. FORECAST SOUNDINGS SHOW SOME SLIGHT ELEVATED INSTABILITY TONIGHT...ESPECIALLY AT LBT/ILM...BUT MOST OF THE CURRENT CONVECTION IS SURFACE BASED AND WILL PROBABLY NOT HOLD TOGETHER AS IT HEADS EAST. WILL NOT COMPLETELY RULE OUT AN ISOLATED SHOWER AT THESE TWO TERMINALS...BUT HAVE NOT EVEN MENTIONED SHOWERS IN THE TAFS SINCE THERE IS ONLY A SLIGHT CHANCE. MORE LIKELY WILL BE THE DEVELOPMENT OF AN MVFR CIG AT ILM/LBT WITH VFR CIGS AT THE OTHER TERMINALS DURING THE FROPA. MAIN CONCERN WILL BE STRONG W/NW WINDS THROUGH THE PERIOD. BELIEVE ALL TERMINALS WILL SEE SOME 20 KT GUSTS TONIGHT WITH THE FROPA...CONTINUING INTO TOMORROW AS A DEEP ML DEVELOPS ALLOWING STRONG W/NW WINDS TO MIX DOWN THROUGH THE DAY. EXTENDED OUTLOOK" onClick="return popup(this, 'notes')">OUTLOOK...VFR THROUGH MONDAY. POSSIBLE IFR WITH RAIN TUESDAY. && .MARINE... NEAR TERM /THROUGH TONIGHT/... AS OF 230 PM THURSDAY...WEAK GRADIENT OVER THE COASTAL WATERS WITH WINDS GENERALLY OUT OF THE N/NW AT LESS THAN 10 KT. HOWEVER...SHORTWAVE SFC RIDGE HAS SHIFTED OFF THE SOUTH CAROLINA COAST AND WE SHOULD SEE WEST WINDS BY SUNSET. UPSTREAM OBS SHOW THE COLD FRONT JUST BARELY WORKING INTO THE WESTERN CAROLINAS AT 19Z. STILL EXPECT IT TO PUSH OFF THE COAST LATE THIS EVENING WITH A DRAMATIC AND IMMEDIATE W-NW SURGE BEHIND IT. WINDS SHOULD PICK UP TO AT LEAST MARGINAL SCA LEVELS...WITH A BRIEF PERIOD OF SOLID 25 KT AND GUSTS NEAR GALE FORCE. CURRENT ADVISORY STRUCTURE LOOKS LIKE IT WILL HOLD UP WELL. SEAS ARE TRICKY AS WE ARE RIGHT ON THE EDGE OF HAVING ENOUGH WESTERLY COMPONENT TO GET A LONGER FETCH ON FRYING PAN SHOALS. THINK THIS WILL BE BRIEF BEFORE WINDS COME AROUND TO NW...BUT JUST ENOUGH TO GET 6 FOOTERS NEAR THE SHOALS AND 7 FOOTERS AT 41013 LATER TONIGHT. OTHERWISE FORECAST SEAS ARE ABOUT A FOOT BELOW WHAT IS ADVERTISED BY SWAN...AT LEAST INITIALLY DUE TO WHAT SEEMS TO BE A BULLISH INITIALIZATION. SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... AS OF 230 PM THURSDAY...SMALL CRAFT ADVISORY FLAGS FROM MIDNIGHT TONIGHT THROUGH FRIDAY NIGHT FOR GUSTY WNW WINDS. THE ADVISORY MAY EXTEND INTO SATURDAY MORNING FROM CAPE FEAR TO SURF CITY DUE TO A FEW MORNING GUSTS TO 25 KNOTS OFFSHORE. IN THIS ROBUST OFFSHORE FLOW...THE NEAR SHORE SEAS WILL REMAIN FAIRLY DAMPENED BUT OFFSHORE SEAS WILL BECOME HAZARDOUS. BEYOND OUR LOCAL 0-20NM WATERS...THE OCEAN PREDICTION CENTER HAS POSTED GALE WARNINGS. SMALL CRAFT ARE ADVISED NOT TO VENTURE IN THE GULF STREAM FRIDAY THROUGH FRIDAY NIGHT. LONG TERM /SUNDAY THROUGH THURSDAY/... AS OF 230 PM THURSDAY...A RATHER BENIGN GRADIENT WILL YIELD 10 KNOTS OR LESS FROM THE SOUTHWEST INITIALLY ACROSS THE COASTAL WATERS. WINDS WILL GRADUALLY INCREASE THROUGH TUESDAY TO A HEALTHY 15-20 KNOTS AS A COLD FRONT APPROACHES FROM THE WEST. SEAS WILL FOLLOW A SIMILAR PATTERN WITH TWO FEET INITIALLY BUILDING TO POSSIBLY SCEC CRITERIA...FIVE FEET BY LATER TUESDAY ESPECIALLY ACROSS THE OUTER WATERS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...NONE. MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 1 AM EST SATURDAY FOR AMZ252-254-256. SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM EST SATURDAY FOR AMZ250. && $$ NEAR TERM...RAS SHORT TERM..MJC LONG TERM...SHK AVIATION....JDW
