572  
FXUS62 KILM 232246  
AFDILM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WILMINGTON NC  
545 PM EST SAT FEB 23 2019  
   
SYNOPSIS
 
 
HIGH PRESSURE TO THE NORTH WILL SHIFT OFF THE COAST OVERNIGHT,  
LIFTING A WARM FRONT ACROSS THE WATERS. SOUTHERLY WINDS INCREASE  
LATE TONIGHT AND SUNDAY AHEAD OF A COLD FRONT THAT CROSSES THE  
AREA SUNDAY EVENING. HIGH PRESSURE WILL THEN BUILD OVER THE  
REGION FROM THE NORTHWEST THROUGH WEDNESDAY WITH CHANCES OF RAIN  
INCREASING LATE WEDNESDAY INTO FRIDAY.  
 

 
   
NEAR TERM /THROUGH SUNDAY NIGHT/
 
 
AS OF 3 PM SATURDAY...FRONT STALLED SOUTH OF THE AREA WILL LIFT  
NORTH THROUGH THE EVENING AND OVERNIGHT AS SURFACE HIGH TO THE NORTH  
SHIFTS OFF THE COAST. FRONT IS NOT EXPECTED TO HAVE MUCH, IF ANY,  
RAINFALL WITH IT AS IT LIFTS NORTH. INCREASING SOUTHERLY FLOW IN THE  
WAKE OF THE EXITING FRONT WILL LEAD TO SLOWLY RISING TEMPS  
OVERNIGHT. LOWS WILL END UP WELL ABOVE CLIMO WITH MANY AREAS LIKELY  
TO EXPERIENCE SAT HIGHS AND SAT NIGHT LOWS AT THE SAME TIME. PRECIP  
CHANCES OVERNIGHT ARE LESS CERTAIN. THERE IS AN ABUNDANCE OF LOW-  
LEVEL MOISTURE, ALTHOUGH THIS IS RELATIVELY SHALLOW. ALMOST NO LIFT  
OR FORCING WILL BE PRESENT AND FORECAST SOUNDINGS CONTINUE TO SHOW  
AT LEAST SOME MID-LEVEL SUBSIDENCE HOLDING ON. HIGH RESOLUTION SHORT  
TERM GUIDANCE HAD BEEN SHOWING SOME WEAK CONVERGENCE MOVING INTO THE  
AREA OVERNIGHT, BUT HAS BACKED OFF ON THE STRENGTH OF THIS. THE  
SIGNAL LOOKED A LOT LIKE FEEDBACK ISSUES FROM CONVECTION IN THIS  
MORNING RUNS AND WEAKENING OF THE ACTIVITY IN FURTHER RUNS IS NOT  
UNEXPECTED. PLAN TO MAINTAIN SLIGHT CHANCE POP OVERNIGHT. BETTER  
RAIN CHANCES WILL BE ON SUN AS THE COLD FRONT CROSSES THE AREA.  
STRONG WARM ADVECTION OVERNIGHT WILL LIKELY RESULT IN FOG DEVELOPING  
ACROSS MUCH OF THE AREA.  
 
COLD FRONT MOVING ACROSS THE AREA SUN WILL BE MOVING INTO A  
WARM/MOIST AIRMASS. FORECAST SOUNDINGS SUGGEST CAPE COULD BE IN 500-  
600 J/KG RANGE FOR A PERIOD, RIGHT AHEAD OF THE FRONT. THIS IS ALSO  
WHERE PRECIPITABLE WATER JUMPS TO AROUND 1.6 INCHES. ALTHOUGH THE  
PARENT LOW MOVES THROUGH THE GREAT LAKES, KEEPING THE DYNAMICS WELL  
NORTH OF THE AREA, STRONG CONVERGENCE ALONG THE FRONT AND THE  
AFOREMENTIONED INSTABILITY SHOULD LEAD TO A LINE OF BROKEN  
CONVECTION. LESS CONFIDENT IN PROSPECTS FOR THUNDER WITH THE LINE.  
THERE IS MID-LEVEL DRY AIR (EVEN DURING THE TIMES OF HIGHEST DEEPER  
MOISTURE) AND LAPSE RATES IN THE CHARGE SEPARATION ZONE ARE VERY  
WEAK. THERE MAY NOT BE ENOUGH UPWARD MOTION TO GENERATE SUFFICIENT  
CHARGE SEPARATION. AT THIS POINT DO NOT HAVE THUNDER IN THE  
FORECAST, BUT CANNOT RULE OUT AN ISOLATED RUMBLE. STRONG WARM  
ADVECTION AHEAD OF THE FRONT WILL LEAD TO TEMPERATURES WELL ABOVE  
CLIMO, WITH HIGHS LIKELY OCCURRING AROUND MIDDAY FOR WESTERN  
PORTIONS OF THE FORECAST AREA.  
 
HIGH PRESSURE BUILDS IN BEHIND THE RAPIDLY EXITING FRONT LATE SUN  
INTO SUN EVENING. STRONG/DEEP WEST-NORTHWEST FLOW HELPS DRY OUT THE  
REGION SUN NIGHT INTO MON BUT DOES NOT REALLY PRODUCE ANY STRONG  
COLD ADVECTION. TEMPS DROP SUN NIGHT, BUT ONLY A SMALL PORTION OF  
THE DROP IS DUE TO COLD ADVECTION WITH THE BULK OF THE COLD AIR  
TRAPPED WELL NORTH OF THE AREA.  
 

 
   
SHORT TERM /MONDAY THROUGH MONDAY NIGHT/
 
 
AS OF 330 PM SATURDAY...DRY WEATHER FOR THE SHORT TERM PERIOD  
AS SURFACE HIGH PRESSURE BUILDS IN FROM THE NORTHWEST. WITH VERY  
LITTLE MOISTURE IN THE ZONAL FLOW ALOFT, EXPECT A MAINLY  
SUNNY/CLEAR SKY. TEMPS WILL BE CLOSE TO NORMAL FOR LATE  
FEBRUARY...HIGHS MONDAY IN THE LOW 60S, WITH LOWS MONDAY NIGHT  
35-40.  
 

 
   
LONG TERM /TUESDAY THROUGH SATURDAY/
 
 
AS OF 330 PM SATURDAY...CONTINUED DRY TO START OFF THE LONG  
TERM PERIOD WITH SURFACE HIGH PRESSURE SLIDING OFFSHORE. THERE  
WILL BE A GENERAL TREND TOWARDS INCREASING CHANCES OF RAIN LATE  
IN THE WEEK AS MOISTURE INCREASES, HOWEVER A STRONG HIGH TO THE  
N/NE (E.G. 12Z ECMWF) COULD DELAY PRECIP CHANCES. CAPPED POPS AT  
30% FOR NOW WITH A LOT OF UNCERTAINTY OVER THE TIMING OF  
PRECIP. TEMPS WILL CONTINUE NEAR NORMAL...HIGHS IN THE UPR 50S  
TO MID 60S EACH DAY.  
 

 
   
AVIATION /00Z SUNDAY THROUGH THURSDAY/
 
 
AS OF 00Z....A SCENARIO IS SETTING UP WHERE DENSE FOG IS IN PLAY.  
WARM AIR ADVECTION JUST OFF THE DECK WILL KEEP TEMPS NEAR STEADY,  
PERHAPS WARMING AFTER MIDNIGHT. DEWPOINTS WILL RISE AS WELL, WITH  
SOME POSSIBLE VLIFR FOG POSSIBLE AFTER 04Z.  
 
TOWARD MORNING, SOUTHERLY FLOW WILL INCREASE AS A WARM FRONT RIDES  
NORTH OF THE CWA. AT SOME POINT THE WINDS WILL BE STRONG ENOUGH TO  
MIX OUT THE FOG, PROBABLY AFTER DAYBREAK. LOOK FOR GUSTY SOUTHWEST  
WINDS WITH SOME LIGHT SCATTERED CONVECTION POSSIBLE BY MID MORNING.  
 
EXTENDED OUTLOOK...VFR LATE SUNDAY THROUGH EARLY WEDNESDAY. POSSIBLE  
SUB-VFR LATE WEDNESDAY AND THURSDAY.  
 

 
   
MARINE
 
 
AS OF 3 PM SATURDAY...EASTERLY WINDS THIS EVENING WILL BECOME  
SOUTHERLY OVERNIGHT AS FRONT LIFTS NORTH OF THE WATERS. SOUTH TO  
SOUTHWEST FLOW IN THE WAKE OF THE FRONT WILL START TO INCREASE LATE  
TONIGHT AND SUN AS THE GRADIENT TIGHTENS AHEAD OF AN APPROACHING  
COLD FRONT. AHEAD OF THE FRONT WINDS WILL BE 20 TO 25 KT, BUILDING  
SEAS TO 5 TO 7 FT AS EARLY AS MIDDAY SUN. BOTH WINDS AND SEAS ARE  
LIKELY TO WARRANT SMALL CRAFT ADVISORY CONTINUING THROUGH AT LEAST  
SUN NIGHT WITH FLOW IN THE WAKE OF THE FRONT BECOMING OFFSHORE.  
SPEEDS WILL REMAIN 20 TO 25 KT SUN NIGHT WHILE THE OFFSHORE  
TRAJECTORY HELPS DROP SEAS FROM 4 TO 6 FT IN THE EVENING TO 2 TO 4  
FT BY MON MORNING.  
 
SUB-SMALL CRAFT ADVISORY CONDITIONS EARLY TO MID NEXT WEEK WITH  
HIGH PRESSURE OVER THE WATERS. WINDS MAINLY UNDER 10 KT WITH 1-2  
FT SEAS, BEFORE SOME INCREASE INTO WEDNESDAY...10-15 KT NE WINDS  
WITH 2-3 FT SEAS.  
 

 
   
ILM WATCHES/WARNINGS/ADVISORIES
 
 
SC...NONE.  
NC...NONE.  
MARINE...SMALL CRAFT ADVISORY FROM NOON SUNDAY TO 7 AM EST MONDAY FOR  
AMZ250-252-254-256.  
 

 
 

 
SYNOPSIS...MAS  
NEAR TERM...III  
SHORT TERM...MAS  
LONG TERM...MAS  
AVIATION...43  
MARINE...III/MAS  
 
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