165  
FXUS62 KCAE 030024  
AFDCAE  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE COLUMBIA SC  
824 PM EDT THU JUL 2 2026  
   
WHAT HAS CHANGED  
 
ISSUED A HEAT ADVISORY FOR COUNTIES ALONG AND NORTH OF THE I-20  
CORRIDOR TOMORROW. AVIATION DISCUSSION UPDATED FOR 18Z TAF'S.  
 
 
   
KEY MESSAGES  
 
- 1. ABOVE NORMAL TEMPERATURES CONTINUE, PEAKING DURING THE  
INDEPENDENCE DAY WEEKEND. A HEAT ADVISORY WILL BE IN EFFECT  
ALONG AND NORTH OF I-20 FROM 12PM-8PM FRIDAY WITH HEAT INDICES  
BETWEEN 105-108F POSSIBLE.  
 
- 2. INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS LATE THIS  
WEEKEND INTO NEXT WEEK.  
 
 
   
DISCUSSION  
 
KEY MESSAGE 1: ABOVE NORMAL TEMPERATURES CONTINUE, PEAKING  
DURING THE INDEPENDENCE DAY WEEKEND. A HEAT ADVISORY WILL BE IN  
EFFECT ALONG AND NORTH OF I-20 FROM 12PM-8PM FRIDAY WITH HEAT  
INDICES BETWEEN 105-108F POSSIBLE.  
 
THERE HAS NOT BEEN A SIGNIFICANT CHANGE TO THE FORECAST THE  
COMING DAYS WITH HOT/HUMID CONDITIONS PERSISTING. TEMPERATURES  
THIS AFTERNOON ARE ALREADY REACHING THE LOW TO MID 90S AND  
SHOULD TOP OUT IN THE MID TO UPPER 90S WITH HEAT INDICES  
APPROACHING 105F, THOUGH SOME SPOTS MAINLY IN LANCASTER COUNTY  
COULD REACH 108-110F, THUS THE HEAT ADVISORY REMAINS IN EFFECT  
THROUGH 8PM THIS EVENING HERE.  
 
HEADING INTO FRIDAY AND THE INDEPENDENCE DAY WEEKEND, THE  
ROBUST UPPER RIDGE (NEAR THE NAEFS 99.5TH PERCENTILE) IS PROGGED  
TO MOVE OVERHEAD IN THE CAROLINAS AS 850MB TEMPERATURES WARM  
FURTHER TOWARD 20-22C, KEEPING AFTERNOON HIGHS IN UPPER 90S TO  
NEAR 100F EACH DAY. SLIGHTLY DRIER AIR IS SHOWN IN MODEL  
GUIDANCE SHIFTING IN THIS WEEKEND WITH THE CENTER OF THE HIGH  
(PWAT'S LESS THAN 1.50"), BUT SURFACE DEWPOINTS SHOULD REMAIN IN  
THE UPPER 60S TO LOW 70S, POSSIBLY MIXING OUT INTO THE LOW TO  
MID 60S MAINLY SATURDAY WHEN THE DEEPEST MIXING IS EXPECTED. DUE  
TO THESE HOT/HUMID CONDITIONS, HEAT INDICES COULD NEAR 105-108F  
FRIDAY AFTERNOON, WHICH IS MARGINAL FOR HEAT ADVISORY CRITERIA,  
BUT WITH EXTENSIVE OUTDOOR ACTIVITIES FOR THE START OF THE  
HOLIDAY WEEKEND, AN INCREASED NUMBER OF INDIVIDUALS WILL LIKELY  
BE EXPOSED TO THE PROLONGED HEAT. DUE TO THE POTENTIAL IMPACTS  
FROM THIS HEAT, HAVE DECIDED TO ISSUE A HEAT ADVISORY FOR  
COUNTIES ALONG AND NORTH OF THE I-20 CORRIDOR, RUNNING FROM 12PM  
TO 8PM FRIDAY. DECIDED TO HOLD OFF FURTHER SOUTH AS THE AXIS OF  
925-850MB DEWPOINTS GREATER THAN 18C IS EXPECTED TO REMAIN  
NEAR/NORTH OF THE I-20 CORRIDOR WITH MORE MIXING OUT OF  
DEWPOINTS EXPECTED SOUTH OF HERE, LEADING TO SLIGHTLY LOWER HEAT  
INDICES.  
 
FORECAST SOUNDINGS INDICATE DEEP MIXING ON INDEPENDENCE DAY,  
WHICH COULD BRING SURFACE DEWPOINTS TOWARD THE LOW TO MID 60S,  
BUT HEAT INDICES SHOULD STILL APPROACH 100-105F. THE POTENTIAL  
NEED FOR ANOTHER MORE SO IMPACT BASED HEAT ADVISORY WILL  
CONTINUE TO BE EVALUATED IN COMING FORECAST PACKAGES, BUT  
CONFIDENCE IN NEEDING THIS IS LOW AS HEAT INDICES SHOULD BE EVEN  
MORE MARGINAL THAN FRIDAY. MOISTURE IS EXPECTED TO UPTICK  
SLIGHTLY SUNDAY AND INTO THE EARLY WEEK AS LOW LEVEL FLOW  
BECOMES INCREASINGLY SOUTHERLY, BRINGING MULTIPLE DAYS WITH HEAT  
INDICES ABOVE 100F AND THE POSSIBLE NEED FOR MORE HEAT  
PRODUCTS.  
 
EXERCISE CAUTION THIS HOLIDAY WEEKEND WHEN SPENDING AN EXTENDED  
PERIOD OF TIME OUTDOORS AND MAKE SURE TO TAKE APPROPRIATE HEAT  
SAFETY MEASURES. THE ELDERLY, YOUNG CHILDREN, PETS, AND THOSE  
WITHOUT INDOOR COOLING WILL BE AT PARTICULAR RISK THIS WEEKEND  
AND OVER THE COMING WEEK.  
 
KEY MESSAGE 2: INCREASING CHANCES FOR SHOWERS AND THUNDERSTORMS  
LATE THIS WEEKEND INTO NEXT WEEK.  
 
THE SIGNAL PERSISTS ACROSS ENSEMBLE AND GLOBAL MODELS THAT THE  
UPPER RIDGE WILL BECOME INCREASINGLY SUPPRESSED SUNDAY INTO NEXT  
WEEK AS A SHORTWAVE TROUGH WORKS INTO THE GREAT LAKES REGION.  
THIS WILL ALLOW FOR SOME WEAK HEIGHT FALLS AND SHORTWAVE ENERGY  
TO MOVE INTO THE REGION EARLY IN THE WEEK WITH PWAT'S TICKING  
BACK UP NEAR 2". WITH THE CONTINUED HEAT AND NOW INCREASED  
MOISTURE EARLY NEXT WEEK, SEASONABLE TO STRONG DIURNAL  
INSTABILITY COULD DEVELOP WITH DAILY SHOWERS AND STORMS  
POSSIBLE. SOME STRONG TO SEVERE STORMS CANNOT BE RULED OUT AS  
HIGHLIGHTED IN CSU ML GUIDANCE AND NCAR AI GUIDANCE.  
 
 
   
AVIATION /00Z FRIDAY THROUGH TUESDAY/  
 
VFR CONDITIONS GENERALLY EXPECTED THROUGH THE TAF PERIOD.  
 
UPPER RIDGING REMAINS THE DOMINANT FEATURE OVER THE TERMINALS  
WHICH HAS LIMITED AND WILL CONTINUE TO LIMIT STORMS INTO THE DAY  
TOMORROW. OVERALL, EXPECT VFR CONDITIONS, ALTHOUGH BRIEF MVFR  
VISIBILITIES ARE POSSIBLE AROUND SUNRISE AT FOG PRONE AGS/OGB.  
OTHERWISE, EXPECT WINDS BECOMING LIGHT WITH MOSTLY CLEAR SKIES.  
WINDS INCREASE OUT OF THE SOUTHEAST TOMORROW ONCE AGAIN BETWEEN  
5-10 KNOTS.  
 
EXTENDED AVIATION OUTLOOK...RAINFALL UNLIKELY THROUGH SATURDAY  
AS RIDGING BUILDS OVERHEAD. BRIEF EARLY MORNING VSBY  
RESTRICTIONS POSSIBLE. RAIN CHANCES AND POSSIBLE RESTRICTIONS  
START TO INCREASE SUNDAY INTO EARLY NEXT WEEK.  
 
 
   
CAE WATCHES/WARNINGS/ADVISORIES  
 
SC...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR SCZ016-018-  
020>022-025>028-030-115-116.  
GA...HEAT ADVISORY FROM NOON TO 8 PM EDT FRIDAY FOR GAZ040-063>065.  
 
 
 
 
 
DISCUSSION...DH  
AVIATION...96  
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