755  
FXUS62 KILM 161528  
AFDILM  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE WILMINGTON NC  
1130 AM EDT TUE JUL 16 2019  
   
SYNOPSIS
 
 
HEAT AND HUMIDITY WILL CONTINUE THROUGH THE WEEK AS HIGH  
PRESSURE REMAINS OVER THE SOUTHEAST. A TROUGH WILL MOVE INTO THE  
AREA THURSDAY INTO FRIDAY, INCREASING AFTERNOON SHOWER AND  
THUNDERSTORM ACTIVITY. HIGH PRESSURE SHOULD BUILD BACK ACROSS  
THE AREA OVER THE WEEKEND.  
 

 
   
NEAR TERM /THROUGH WEDNESDAY/
 
 
AS OF 1000 AM TUESDAY...MAIN CONCERN FOR THE NEXT 36 HOURS IS  
AFTERNOON HIGH HEAT INDICES THAT COULD RESULT IN HEAT ILLNESSES.  
 
PREVIOUS FORECAST IS ON TRACK WITH ONLY A MINOR ADJUSTMENT TO  
THE SHWR/TSTM COVERAGE. BASICALLY EXPECT LOCALIZED CONVECTION  
WITH FOCUS ALONG SEA BREEZE BOUNDARY AS IT PUSHES INLAND AND  
ALONG THERMAL TROUGH INLAND. WITH LACK OF UPPER FORCING,  
COVERAGE WILL REMAIN MORE ISOLATED TO SCT AND WILL END AS  
HEATING OF THE DAY ENDS. SHOULD BE SLIGHTLY MORE COVERAGE THAN  
YESTERDAY AS MOISTURE THROUGH THE COLUMN HAS INCREASED UP TO 2  
INCHES. STEERING FLOW WILL BE OUT OF THE W-SW BUT VERY WEAK.  
THIS COULD PRODUCE SOME LOCALIZED FLOODING IN ANY STORMS THAT DO  
DEVELOP.  
 
PREVIOUS DISCUSSION:  
BUILDING HIGH PRESSURE ALOFT AND SOUTHERLY  
WIND FLOW AT GROUND LEVEL WILL ALLOW AFTERNOON TEMPERATURES TO  
RISE INTO THE MID TO UPPER 90S INLAND, WITH VALUES CLOSER TO THE  
COAST IN THE UPPER 80S TO LOWER 90S. REGARDLESS OF HOW HIGH  
AFTERNOON TEMPERATURES ACTUALLY REACH, THE COMBINATION WITH DEW  
POINTS IN THE MID TO UPPER 70S WILL RESULT IN AFTERNOON HEAT  
INDICES UP TO 106+ FOR MANY LOCATIONS. HEAT ILLNESSES ARE  
POSSIBLE FOR THOSE SPENDING TIME OUTDOORS DURING THE HOURS OF 12  
PM TO 7 PM THIS EVENING.  
 
AFTERNOON INSTABILITY REMAINS ACROSS THE AREA TODAY WITH PLENTY OF  
AFTERNOON HEATING, WHICH WILL LIKELY LEAD TO ANOTHER ROUND OF  
ISO TO WIDELY SCT SHOWERS AND THUNDERSTORMS DURING THE PEAK  
AFTERNOON HEATING. LATEST SHORT TERM HIGH RESOLUTION GUIDANCE  
ALSO HINTS AT PRECIPITATION DEVELOPMENT, BUT WITH LACK OF UPPER  
LEVEL WIND, STORMS ARE NOT EXPECTED TO BE SEVERE.  
 
HEAT AND CHANCES FOR AFTERNOON SHOWERS AND THUNDERSTORMS CONTINUE TO  
BE THE HEADLINES IN THE FORECAST FOR WEDNESDAY.  
 

 
   
SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/
 
 
AS OF 3 AM TUESDAY...PASSAGE OF SHORTWAVE TROUGH TO THE NORTH WED  
NIGHT INTO THU WEAKENS THE 5H RIDGE OVER THE SOUTHEAST AND HELPS  
MOVE A WEAK SURFACE TROUGH INTO THE AREA. THE DECREASE IN MID-LEVEL  
SUBSIDENCE, INCREASING MOISTURE ADVECTION AND DIURNAL INSTABILITY  
WILL LEAD TO AN INCREASE IN SHOWER AND THUNDERSTORM COVERAGE THU.  
ADDITIONALLY THE PRESENCE OF THE SURFACE TROUGH SHOULD WORK TO  
INCREASE COVERAGE OF DIURNAL CONVECTION. TEMPERATURES WILL CONTINUE  
ABOVE CLIMO WITH 850 TEMPS AROUND 20C KEEPING HIGHS IN THE MID TO  
UPPER 90S. BERMUDA HIGH CONTINUES TO PUMP MOISTURE OVER THE  
SOUTHEAST AND HEAT INDEX VALUES IN EXCESS OF 105, REQUIRING A HEAT  
ADVISORY, ARE LIKELY FOR AT LEAST A PORTION OF THE AREA. BOUNDARY  
LAYER MOISTURE/WINDS AND LINGERING DEBRIS CLOUDS WILL KEEP LOWS IN  
THE MID TO UPPER 70S.  
 

 
   
LONG TERM /FRIDAY THROUGH MONDAY/
 
 
AS OF 3 AM TUESDAY...SURFACE TROUGH LINGERS IN THE AREA INTO NEXT  
WEEK UNDER SPRAWLING 5H RIDGE. MID-LEVEL RIDGE SLOWLY  
EXPANDS/STRENGTHENS OVER THE WEEKEND, FOLLOWING THE EXIT OF MID-  
LEVEL SHORTWAVE. RIDGING ALOFT WILL BE STRONGEST OVER THE  
WEEKEND, BUT THE PRESENCE OF ABUNDANT LOW LEVEL MOISTURE, A  
SURFACE TROUGH, AND ABOVE CLIMO TEMPS WILL RESULT IN DAILY  
AFTERNOON/EVENING SHOWERS/THUNDERSTORMS. LACK OF FORCING OUTSIDE  
OF HEATING AND THE TROUGH WILL KEEP CONVECTION DISORGANIZED AND  
MOSTLY CONFINED TO DAYLIGHT HOURS. EXCEPTION COULD BE NOCTURNAL  
CONVECTION OVER THE COASTAL WATERS.  
 
-PARTLY TO MOSTLY SUNNY SKIES AND 850 TEMPS OF 20-21C SUGGEST  
HIGHS IN THE MID TO UPPER 90S AWAY FROM THE COAST.  
 
-HEAT ADVISORIES MAY BE NEEDED EACH AFTERNOON.  
 
-LOW LEVEL MOISTURE, SOUTHERLY FLOW, AND LINGERING DEBRIS CLOUD  
WILL KEEP LOWS IN THE MID TO UPPER 70S.  
 
-POTENTIAL FOR HEAVY RAIN/LOCALIZED FLOODING WITH ANY STORMS  
THAT DEVELOP DUE TO SLOW STORM MOTION AND DEEP MOISTURE.  
 

 
   
AVIATION /18Z TUESDAY THROUGH SATURDAY/
 
 
AS OF 18Z...ATMOSPHERE TO REMAIN FAIRLY DRY THROUGH THE FORECAST  
PERIOD WITH ONLY ISOLATED CONVECTION ALONG THE RESULTANT BOUNDARY  
AROUND MAX HEATING. COVERAGE WILL BE SLIGHTLY BETTER THAN YESTERDAY.  
LIGHT SOUTHERLY FLOW IS EXPECTED. SOME GROUND FOG POSSIBLE TOWARD  
SUNRISE ON WEDNESDAY.  
 
EXTENDED OUTLOOK...VFR CONDITIONS ARE EXPECTED OUTSIDE ANY ISOLATED  
TO WIDELY SCATTERED CONVECTION THE FIRST PART OF THE UPCOMING WEEK.  
 

 
   
MARINE
 
 
AS OF 1000 AM TUESDAY...BENIGN MARINE CONDITIONS WILL CONTINUE  
WITH LIGHT SOUTHERLY WINDS. AFTERNOON GUSTS WILL DEVELOP UP TO  
20 KTS, MAINLY NEAR SHORE IN SEA BREEZE CIRCULATION. WAVE  
HEIGHTS BETWEEN 1 TO 3 FEET, MAINLY COMPRISED OF SHORT PERIOD  
WIND WAVES OUT OF THE SOUTHWEST AROUND 4 SECONDS WITH A SLIGHTLY  
LONGER PERIOD SE SWELL AROUND 10 SECONDS, MIXING IN.  
 
SOUTHWEST FLOW CONTINUES THROUGH THE END OF THE WEEK WITH WATERS ON  
THE WEST SIDE OF THE BERMUDA HIGH. SURFACE TROUGH LATER IN THE WEEK  
WILL INCREASE WINDS CLOSER TO A SOLID 15 KT, ESPECIALLY DURING THE  
AFTERNOON/EVENING HOURS. SEAS 2 TO 3 FT WED NIGHT BUILD TO 2 TO 4 FT  
THU AND 3 TO 4 FT THU NIGHT AND FRI, THERE AFTER SEAS WILL BE CLOSER  
TO 3 FT. WAVES WILL BE A MIX OF SOUTHERLY WIND WAVE AND EASTERLY  
SWELL.  
 

 
   
ILM WATCHES/WARNINGS/ADVISORIES
 
 
SC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR SCZ017-023-024-  
032-033-039-054>056-058-059.  
NC...HEAT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR NCZ087-096-099-  
105>110.  
MARINE...NONE.  
 

 
 

 
 
NEAR TERM...MCK/RGZ  
SHORT TERM...III  
LONG TERM...III  
AVIATION...43  
MARINE...III/MCK/RGZ  
 
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