FXUS62 KILM 202040 AFDILM AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE WILMINGTON NC 340 PM EST TUE JAN 20 2009 .SYNOPSIS... A VIGOROUS AND COLD UPPER TROUGH OVER THE REGION WILL ALLOW A SURFACE LOW OFFSHORE OF SOUTH CAROLINA TO RAPIDLY DEEPEN AND TRACK NORTHEAST OFF THE OUTER BANKS THIS EVENING. COLD AIR FILTERING FROM THE NORTH COMBINED WITH ADEQUATE MOISTURE WILL PRODUCE AREAS OF SNOW THIS EVENING...MOST FAVORED OVER THE NORTH CAROLINA COUNTIES. SNOW WILL END TONIGHT AS THE UPPER DISTURBANCE PULLS OFFSHORE. DRY BUT COOL CONDITIONS WILL PREVAIL WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS IN...FOLLOWED BY MILDER TEMPERATURES LATE IN THE WEEK AS SOUTHWESTERLY WINDS RETURN. AN APPROACHING COLD FRONT WILL BRING A SLIGHT CHANCE OF SHOWERS TO THE AREA OVER THE WEEKEND. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... AS 3 PM TUESDAY...AS LOW OFF THE NORTH CAROLINA COAST IS FORECAST TO RAPIDLY MOVE AWAY FROM SOUTHEAST NORTH CAROLINA. SNOWFALL IS BEGINNING TO TAPER OFF EXCEPT ALONG THE NORTHERN TIER OF OUR COUNTIES. SNOWFALL TOTALS OF 2 TO 4 INCHES ARE BEING REPORTED FROM MARLBORO TO BLADEN COUNTIES THIS AFTERNOON AND MOST SIGNIFICANT SNOWFALL HAS ENDED EXCEPT FOR PORTIONS OF PENDER AND BLADEN WITH LIGHT SNOW STILL SEEN OVER NORTHERN COLUMBUS AND NEW HANOVER COUNTIES. WILL CONTINUE WINTER STORM WARNING FOR BLADEN AND PENDER AND ADVISORY FOR COLUMBUS...BRUNSWICK AND NEW HANOVER. WILL CANCEL ALL OTHER ADVISORY AND WARNING. A SPECIAL WEATHER STATEMENT WILL ALSO BE ISSUED FOR ALL AREAS AS TEMPERATURES ARE AT OR BELOW FREEZING AND ARE EXPECTED TO REMAIN BELOW FREEZING THROUGH THE PERIOD. THIS WILL CAUSE ANY WATER ON THE ROADS FROM THE RAIN OR MELTING SNOW TO FREEZE AND THIS WILL CREATE HAZARDOUS DRIVING OVER NIGHT. AS THE LOW PUSHES AWAY AND HIGH PRESSURE BUILD INTO THE AREA OVERNIGHT EXPECT NORTHERLY WINDS TO CONTINUE AND SLOWLY DIMINISH TOWARDS MORNING. IF WE SEE CLEARING THIS WILL ALLOW FOR THE TEMPERATURES TO DROP INTO THE TEENS NORTH OF A FLORENCE TO SOUTHPORT LINE AND LOWER 20S TO THE SOUTH. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...CENTER OF SFC HIGH MEANDERS EASTWARD ALONG THE GULF COAST THROUGH THE PERIOD ENDING UP OVER FLORIDA BY . FLOW WILL BACK SLOWLY AROUND FROM NW TO START AROUND TO W-SW BY END OF PERIOD. THEREFORE WILL SEE A COLD START TO THE SHORT TERM PERIOD. TEMPS ON TUES MORNING WILL START OUT AROUND 20. POTENTIAL FOR ICING ON ROADWAYS WILL EXIST THROUGH THE MORNING HOURS UNTIL TEMPS CLIMB ABOVE FREEZING BY LATE MORNING. MAX CAA WILL SHUT OFF BY WED MORNING AROUND 12Z OR SO...BUT THICKNESSES INCREASE FROM AROUND 1260 M IN THE MORNING TO AROUND 1280 BY THE EARLY EVENING. THEREFORE DECIDED TO LOWER THE MAX TEMPS FOR WED WITH MID TO UPPER 30S MOST PLACES REACHING AROUND 40 SOUTH OF MYRTLE BEACH. AS FOR ANY PCP...DRY AIR WILL CONTINUE TO MAKE ITS WAY INTO LOCAL AREA THROUGH WED AFTN. PCP WATER VALUES WILL DROP TO BELOW A QUARTER OF AN INCH IN A DRY NW FLOW. BY LATE THURS MOISTURE WILL MAKE A SMALL COMEBACK AS WINDS BACK AROUND TO THE W-SW...BUT NOT ENOUGH TO PRODUCE ANY CLOUDS OR PCP. HEIGHTS WILL BE RISING THROUGH THE PERIOD. A SHORTWAVE WILL MOVE THROUGH EARLY THURS..WITH ZONAL FLOW TO FOLLOW THROUGH THE REMAINDER OF THE PERIOD. && .LONG TERM /FRIDAY THROUGH TUESDAY/... AS OF 3 PM TUESDAY...ACTIVE WEATHER PATTERN CONTINUES THROUGH THE LONG TERM AS ONE SYSTEM AFTER ANOTHER IMPACTS THE EASTERN CAROLINAS. NOT A PARTICULARLY HIGH CONFIDENCE FORECAST FROM SATURDAY ONWARD AS LONG RANGE GUIDANCE SHOWS SOME SIGNIFICANT VARIATION IN THE SURFACE PATTERN. HAVE RELIED ON HPC GUIDANCE FOR MUCH OF THE FORECAST DUE TO THIS. ONE THING LOOKS REASONABLY CERTAIN THROUGH THE LONG TERM AND THAT IS THAT WITH A MOSTLY ZONAL H5 FLOW PATTERN THROUGH THE PERIOD...IE...NO DEEP TROUGHS MOVING THROUGH...TEMPERATURES WILL BE FAIRLY CLOSE TO CLIMATOLOGY. NO EXCEPTIONALLY LOW OR HIGH TEMPERATURES THROUGH THIS PERIOD. HPC GUIDANCE MOVES A COLD FRONT THROUGH ON SATURDAY WHICH THEN STALLS TO OUR SOUTH...MOVING NORTH AS A WARM FRONT MONDAY NIGHT. LOW CHANCE POPS IN FOR THESE EVENTS...ALL OF THE LIQUID VARIETY. && .AVIATION /21Z TUESDAY THROUGH SUNDAY/... UPDATED CURRENT SET OF TAFS TO PUSH BACK THE TIMING OF THE TRANSITION TO SNOW ALONG THE COAST ALONG WITH REMOVING THE CHANCE FOR ICE PELLETS. WHILE A FEW PELLETS HAVE BEEN REPORTED ACROSS HORRY COUNTY...ON THE WHOLE THIS IS A TRANSITION FROM RAIN TO SNOW. IFR CEILINGS ARE POSSIBLE PRIMARILY INLAND DURING THE HEAVIEST INTENSITY OF SNOW. CLOSER TO THE COAST CEILINGS MAY DROP TOWARD 15Z WITH THE ARRIVAL OF THE SNOW. AS THE PREVIOUS FORECASTER MENTIONED THE BEST SNOW GROWTH (-10 TO -20) IS NOT ORIENTED WITH THE BEST LIFT AND SATURATION...THEREFORE SNOWFALL INTENSITY IS NOT EXPECTED TO BE HEAVY. WITH THAT IN MIND I WILL KEEP VISIBILITIES IN THE MVFR RANGE. ONE EXCEPTION MAY BE IN THE KLBT AREA WHERE A PERIOD OF MODERATE SNOW MAY DROP VISIBILITIES TO IFR...ESPECIALLY OVER THE NEXT FEW HOURS. BY AFTERNOON THE SNOW DIMINISHES AND THE WIND PICKS UP. WIND GUSTS TO 20 KTS ARE LIKELY THROUGHOUT ALL OF THE TERMINALS. SKIES CLEAR OVERNIGHT WITH VFR WEATHER EXPECTED. EXTENDED OUTLOOK THROUGH SATURDAY...VFR WEDNESDAY THROUGH FRIDAY. CHANCE OF PRECIPITATION SATURDAY. && .MARINE... .NEAR TERM /THROUGH 6 AM WEDNESDAY/... AS OF 3 PM TUESDAY...WITH LOW NORTH OF FRYING PAN SHOALS WINDS ARE BLOWING OFFSHORE AT 20 TO 25 KNOTS AND SEAS REACHING 8 FEET AT THE BUOY. SEAS ARE SEEN AT 5 FEET AT THE CORMP BUOY. WIND LOW PULLING AWAY AND PRESSURE GRADIENT WEAKENING SEAS SHOULD DROP BELOW 6 FEET BY MIDNIGHT. THIS IS IN LINE WITH THE WAVEWATCH SEAS AND GFS WINDS. SO WILL CONTINUE SMALL CRAFT CONDITIONS UNTIL MIDNIGHT. .SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/... AS OF 3 PM TUESDAY...MAX CAA WILL CUT OFF WED MORNING...BUT STILL PLENTY OF COLD AIR OVER LOCAL WATERS THROUGH THE DAY WED. NW TRAJECTORY WILL BACK AROUND TO THE W-SW THROUGH THE PERIOD. THE OFF SHORE FLOW UP TO 20 KTS AT THE START OF PERIOD WILL CREATE LARGER GRADIENT FROM NEAR SHORE TO OFF SHORE THROUGH WED AFTN. EXPECT SEAS 2 FT OR LESS NEAR SHORE AND UP TO 4 FT OUTER WATERS EARLY WED WITH A DECREASING TREND IN BOTH WINDS AND SEAS THROUGH EARLY THURS. MAY SEE A LONGER PERIOD EASTERLY SWELL UP TO 12SEC MIX IN FOR A BRIEF TIME EARLY THURS. AS CENTER OF HIGH MOVES EAST OVER FLORIDA WINDS WILL BACK AROUND TO THE SW UP TO 15 KTS THURS AFTN INCREASING TO NEAR 20 KTS BY END OF PERIOD. THIS WILL HELP TO DRIVE SEAS UP AGAIN BY END OF PERIOD TO 2 TO 4FT. NOT EXPECTING ANY FLAGS THROUGH THE PERIOD. .LONG TERM /FRIDAY THROUGH SUNDAY/... AS OF 3 PM TUESDAY...COLD FRONT PUSHES SOUTH ACROSS THE WATERS ON SATURDAY THEN STALLS WELL TO THE SOUTH ON SUNDAY. COLD SURGE WILL BE SLOW TO DEVELOP BUT WILL LIKELY SEE 6 FT SEAS DEVELOP SUNDAY MORNING AS A STEADY NELY FETCH DEVELOPS WITH HIGH PRESSURE PUSHING SOUTH BEHIND FRONT. WINDS WILL TOP OUT AT AROUND 20 KTS. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...NONE. NC...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR NCZ099>101. WINTER STORM WARNING UNTIL 10 PM EST THIS EVENING FOR NCZ096- 097. MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR AMZ250-252- 254-256. && $$ SYNOPSIS...REK NEAR TERM...DRH SHORT TERM...RGZ LONG TERM...REK AVIATION...EH