733  
FXUS62 KILM 120544  
AFDILM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WILMINGTON NC  
1244 AM EST TUE NOV 12 2019  
   
SYNOPSIS
 
 
SHOWERS ON TUESDAY WILL PRECEDE A STRONG COLD AIRMASS THAT  
ARRIVES TUESDAY NIGHT INTO WEDNESDAY. THURSDAY AND FRIDAY WILL  
NOT BE A COLD BUT STILL A BIT BELOW NORMAL. LATE WEEK RAIN  
CHANCES WILL BE ASSOCIATED WITH LOW PRESSURE THAT DEVELOPS AND  
MOVES TO THE NORTHEAST ON FRIDAY, THEN FOLLOWED BY ANOTHER THAT  
FORMS AND STALLS OVER THE WEEKEND.  
 

 
   
UPDATE
 
 
PUBLIC:  
HAVE UPDATED SKY CONDITIONS TO INCLUDE THE STRATOCU DECK  
DEVELOPING AND MOVING N-NE INTO THE ILM SC CWA WHICH WILL  
OVERSPREAD INTO THE ILM NC CWA. ABOVE THE SC DECK WILL CONTINUE  
TO SEE THIN CIRRUS MOVE ACROSS WHICH WILL BECOMING MORE OPAQUE  
AS THE NIGHT PROGRESSES. THIS WILL LIKELY RESULT IN MIN TEMPS  
ACTUALLY OCCURRING AROUND OR JUST AFTER MIDNIGHT, FOLLOWED BY  
STEADY TREND OR EVEN RISING TEMPS, ESPECIALLY CLOSER TO THE  
IMMEDIATE COAST. NO CHANGES TO THE ONSET OF PCPN.  
 
MARINE:  
SOME TWEAKING OF WINDSPEEDS APPLIED TO THE FORECAST. TAKING THE  
LATEST WIND TRENDS AND MESHING THEM WITH THE PRE-DAWN TUE  
FORECAST. OTHERWISE, NO CHANGES TO SEAS AND THE ONSET OF GALES.  
 

 
   
NEAR TERM /THROUGH TUESDAY NIGHT/
 
 
IN THE VERY NEAR TERM, CONTINUING CIRRUS CLOUDS WILL BE JOINED BY  
LOWER LEVEL STRATOCUMULUS OFF THE OCEAN, AFFECTING THE CAPE FEAR  
AREA AFTER MIDNIGHT. DEEPER MOISTURE WILL ALSO ARRIVE FROM THE WEST  
INTO THE PEE DEE REGION VERY LATE TONIGHT, WITH THE BULK OF ANY RAIN  
POTENTIAL HOLDING OFF UNTIL DURING THE DAY TUESDAY. MODELS ALL SEEM  
TOO QUICK TO BRING DEWPOINTS UP THIS AFTERNOON, SO I'M DOWNPLAYING  
SHOWER CHANCES TONIGHT. MOS LOW TEMPS LOOK GENERALLY TOO WARM GIVEN  
AT LEAST 4-6 HOURS OF RADIATIONAL COOLING BEFORE CLOUDS THICKEN UP,  
AND I'M FORECASTING AROUND 50 INLAND AND LOW-MID 50S ALONG THE COAST.  
 
1046 MB ARCTIC HIGH PRESSURE OVER THE HIGH PLAINS WILL PUSH A STRONG  
FRONT ACROSS THE CAROLINAS ON TUESDAY. THE FRONT SHOULD COME THROUGH  
IN TWO PIECES: AN INITIAL SHIFT TO NORTHWEST WINDS ROUGHLY  
COINCIDENT WITH START OF THE RAIN, THEN A SHIFT TO STRONG NORTH  
WINDS AND A SHARP TEMPERATURE FALL REACHING I-95 AROUND 1 PM AND THE  
COAST BETWEEN 3-4 PM. A NARROW BAND OF DEEP MOISTURE ORIGINATING  
FROM THE TROPICAL PACIFIC AND GULF OF MEXICO WILL MOVE IN AHEAD OF  
THE FRONT AND SHOULD BRING A 3-6 HOUR RAINFALL EVENT WITH QPF  
GENERALLY IN THE 1/4 TO 1/2 INCH RANGE. PRECIP SHOULD END A COUPLE  
HOURS AFTER THE FRONTAL PASSAGE WHEN LIFT ALONG THE 295K-305K  
ISENTROPIC SURFACES TURNS NEGATIVE.  
 
THE INCOMING ARCTIC AIRMASS IS QUITE SHALLOW, ONLY EXTENDING UP  
ABOUT 2500 FEET IN DEPTH. WINDS 1000-2000 FEET AGL SHOULD BE STRONG  
ENOUGH GIVEN STEEP LOW LEVEL THERMAL PROFILES IN THE COLD ADVECTION  
FOR GUSTS OF 25 MPH TO OCCUR FOR MOST OF TUESDAY NIGHT. THIS SHOULD  
BE THE FIRST FREEZE EVENT FOR THE COASTAL COUNTIES WHICH HAVE NOT  
YET EXPERIENCED SUB-FREEZING TEMPS THIS SEASON, AND A FREEZE WATCH  
HAS BEEN ISSUED. MY FORECAST LOWS ARE ON THE UPPER EDGE OF MOS  
GUIDANCE, PARTICULARLY AT THE COAST, GIVEN STEEP MIXING PROFILES  
EXPECTED ALL NIGHT.  
 

 
   
SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/
 
 
HIGHS WEDNESDAY IN THE MID 40S A GOOD 10 DEGREES BELOW  
CLIMATOLOGY...FOR THE HEART OF WINTER. SHALLOW COLD AIR POURING  
INTO THE REGION AT A DEPTH OF JUST 2500FT MAKING FOR SOME  
IMPRESSIVE/ODD FORECAST SOUNDINGS (WARMER AT 8000FT THAN AT THE  
SURFACE BY EVENING). THIS SETS UP A FAIRLY CLASSIC COLD WAVE  
SOUNDING WEDNESDAY NIGHT WITH A DEEP, SURFACE-BASED NEARLY  
ISOTHERMAL LAYER THAT WILL FOSTER LOWS IN THE UPPER 20S INLAND  
TO LOW TO MID 30S AT THE COAST.  
 

 
   
LONG TERM /THURSDAY THROUGH MONDAY/
 
 
THE MODIFIED ARCTIC HIGH WILL BE MOVING EASTWARD QUITE RAPIDLY  
THURSDAY ALLOWING FOR SOME LOW LEVEL THERMAL RECOVERY (THOUGH A  
RIDGE PERSISTENT RIDGE AXIS WILL TAPER ITS EFFECTS AT THE SURFACE).  
MOISTURE WILL POOL NEAR THE COAST THURSDAY IN A DEVELOPING SURFACE  
TROUGH. SOUTHERN BRANCH FEATURE THEN CAUSES MODERATELY STRONG  
CYCLOGENESIS OFFSHORE AND RAIN CHANCES INCREASE SUBSTANTIALLY AND  
COASTAL LOCALES WILL GROW A BIT BREEZY. THE UPPER WAVE CATCHES UP TO  
THE LOW LEVEL BAROCLINIC ZONE FRIDAY NIGHT INTO SATURDAY DEVELOPING  
A SECOND SURFACE LOW OFFSHORE THAT WILL STALL AND OCCLUDE, POSSIBLY  
TAKING ON HYBRID WARM/COLD CORE CHARACTERISTICS. GFS HAS THE WIND  
FIELD EXPANDING BUT THE PRECIPITATION MOVING LARGELY OFFSHORE. HAVE  
MAINTAINED POPS IN DEFERENCE TO OTHER SOLUTIONS AND PREVIOUS  
FORECAST.  
 

 
   
AVIATION /06Z TUESDAY THROUGH SATURDAY/
 
 
VFR CONDITIONS FOR THE AREA TERMINALS FOR THE NEXT 6 TO 12 HOURS  
AHEAD OF A STRONG COLD FRONT APPROACHING THE REGION. EXPECTING  
VISIBILITY REDUCTIONS IN MODERATE RAINFALL AND CEILING REDUCTIONS  
WITH INCREASING LOW LEVEL CLOUD COVER. FLIGHT RESTRICTIONS SHOULD  
BE LIFTED BETWEEN 00Z AND 03Z WEDNESDAY AS FRONT MOVES OFFSHORE.  
GUSTY WINDS UP TO 30 KTS ALSO ANTICIPATED THROUGH THE NEXT 24 HOURS.  
 
EXTENDED OUTLOOK...VFR THROUGH THE END OF THE WEEK.  
 

 
   
MARINE
 
 
THE MAJOR CONCERN FOR MARINE WEATHER IN THE NEAR TERM IS THE PASSAGE  
OF AN ARCTIC COLD FRONT TUESDAY AFTERNOON. COLD AIR BEHIND THE FRONT  
WILL ARRIVE ON STRONG NORTHERLY WINDS REACHING AT LEAST 30 KNOTS  
LATE TUESDAY AFTERNOON THROUGH ALL OF TUESDAY NIGHT. VIRTUALLY EVERY  
12Z MODEL'S VIRTUAL SOUNDINGS SHOW 35 KNOT WINDS ONLY 1000 FEET  
ABOVE THE WATER'S SURFACE TUESDAY EVENING, THE TIME WHEN FREQUENT  
GALE FORCE GUSTS HAVE THE BEST POTENTIAL TO BE OCCURRING. AFTER  
COLLABORATION WITH NWS MHX AND CHS, WE HAVE RAISED A GALE WARNING  
EVEN THOUGH ACTUAL SUSTAINED WIND SPEEDS SHOULD REMAIN BELOW 34  
KNOTS.  
 
NORTHERLY WINDS EASE WEDNESDAY AS THE GRADIENT WEAKENS GRADUALLY.  
ADVISORY FLAGS WILL BE IN EFFECT THROUGH MIDDAY OR EARLY AFTERNOON.  
BY THURSDAY A SHIFT TO NE EXPECTED AS COASTAL TROUGH DEVELOPS. LOW  
PRESSURE THEN DEVELOPS AND CLOSES OFF ALONG THE WELL OFFSHORE  
FRONTAL BOUNDARY AND CONDITIONS WILL ONCE AGAIN WORSEN TO ADVISORY  
LEVELS. THIS LOW MOVES OFF TO THE NORTHEAST BUT ANOTHER, POSSIBLY  
STRONGER ONE DEVELOPS AND STALLS ON SATURDAY. GALE WARNING APPEARS  
POSSIBLE.  
 

 
   
ILM WATCHES/WARNINGS/ADVISORIES
 
 
SC...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING  
FOR SCZ054>056-058.  
NC...FREEZE WATCH FROM LATE TUESDAY NIGHT THROUGH WEDNESDAY MORNING  
FOR NCZ106>110.  
MARINE...GALE WARNING FROM 3 PM TUESDAY TO 7 AM EST WEDNESDAY FOR  
AMZ250-252-254-256.  
 

 
 

 
SYNOPSIS...MBB  
UPDATE...DCH  
NEAR TERM...TRA  
SHORT TERM...MBB  
LONG TERM...MBB  
AVIATION...43  
MARINE...DCH/TRA/MBB  
 
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