458  
FXUS64 KMEG 181130  
AFDMEG  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE MEMPHIS TN  
630 AM CDT TUE AUG 18 2026  
   
..NEW AVIATION  
 
   
KEY MESSAGES  
 
ISSUED AT 630 AM CDT TUE AUG 18 2026  
 
- A HEAT ADVISORY REMAINS IN EFFECT THROUGH TUESDAY FOR PORTIONS  
OF EASTERN ARKANSAS AND NORTH MISSISSIPPI.  
 
- HEAT IS EXPECTED TO PERSIST THROUGH WEDNESDAY OVER PORTIONS OF  
THE MID-SOUTH WITH LITTLE IF ANY RELIEF EXPECTED UNTIL A COLD  
FRONT MOVES THROUGH THE AREA LATER THIS WEEK.  
 
 
   
DISCUSSION  
 
(TONIGHT THROUGH NEXT MONDAY)  
ISSUED AT 1126 PM CDT MON AUG 17 2026  
 
00Z UPPER AIR ANALYSIS CENTERS AN 597 DM RIDGE AXIS OVER PORTIONS  
OF THE SOUTHWEST U.S. AND THE SOUTHERN PLAINS. MEANWHILE, THE  
LOWER MISSISSIPPI VALLEY IS NOW WITHIN NORTHWEST FLOW ALOFT.  
LATEST SURFACE ANALYSIS SHOWS A WEAK QUASI-STATIONARY BOUNDARY  
BISECTING THE LOWER MISSISSIPPI VALLEY FROM MIDDLE TENNESSEE BACK  
THROUGH NORTH MISSISSIPPI AND SOUTHERN ARKANSAS. WARM AND HUMID  
AIR REMAINS IN PLACE ACROSS THE MID-SOUTH THIS EVENING WITH  
TEMPERATURES AND DEWPOINTS IN THE 70S.  
 
RAINFALL FROM LATE AFTERNOON CONVECTION OVER NORTH MISSISSIPPI  
HAS PRODUCED CONDITIONS FAVORABLE FOR THE DEVELOPMENT OF PATCHY  
FOG OVERNIGHT. THE WEAK FRONT IS EXPECTED TO SETTLE NEAR THE  
SOUTHWESTERN EDGE OF THE FORECAST AREA INTO TUESDAY. SHORT-TERM  
CAMS INDICATE A LOW POTENTIAL (<20% CHANCE) FOR ISOLATED SHOWERS  
AND THUNDERSTORMS OVERNIGHT INTO TUESDAY MORNING WEST OF THE  
MISSISSIPPI RIVER IN ASSOCIATION WITH A WEAK SHORTWAVE OVER  
WESTERN ARKANSAS. VERY HOT TEMPERATURES IN THE MIDDLE 90S TO  
APPROACHING 100 DEGREES ARE EXPECTED AGAIN ACROSS THE AREA MOSTLY  
ALONG AND SOUTH OF A LINE FROM JONESBORO TO TUPELO, INCLUDING THE  
MEMPHIS METRO AREA. HOWEVER, SLIGHTLY DRIER AIR WILL KEEP HEAT  
INDEX VALUES BELOW ADVISORY CRITERIA TO AN EXTENT ACROSS THE AREA  
WITH THE EXCEPTION OF PORTIONS OF NORTH MISSISSIPPI BORDERING  
CENTRAL MISSISSIPPI AND EAST ARKANSAS SOUTH OF I-40. A HEAT  
ADVISORY REMAINS IN EFFECT ACROSS THIS AFOREMENTIONED AREA WITH  
THE ADDITION OF CHICKASAW AND MONROE COUNTIES IN MISSISSIPPI  
THROUGH 8 PM TUESDAY. LATEST SHORT-TERM TRENDS SUGGEST ANY  
CONVECTIVE DEVELOPMENT MAY REMAIN JUST TO THE SOUTH AND WEST OF  
THE AREA ON TUESDAY DURING PEAK HEATING.  
 
THE AFOREMENTIONED SURFACE BOUNDARY IS EXPECTED TO RETURN BACK  
NORTH AS A WARM FRONT TUESDAY NIGHT INTO WEDNESDAY WITH HIGHER  
DEWPOINT AIR RETURNING ACROSS THE AREA. THIS MORE HUMID AIR  
COMBINED WITH TEMPERATURES NEAR OR EXCEEDING 100 DEGREES MAY  
NECESSITATE THE ISSUANCE OF A HEAT ADVISORY ACROSS MUCH OF THE  
MID-SOUTH ON WEDNESDAY WITH HEAT INDEX VALUES APPROACHING  
109 DEGREES.  
 
BY WEDNESDAY, A SERIES OF MID-LEVEL SHORTWAVES EMBEDDED WITHIN  
NORTHWEST FLOW ALOFT WILL DROP INTO THE LOWER MISSISSIPPI VALLEY  
INTO THURSDAY. A LARGE VARIANCE IN SOLUTIONS EXISTS DURING THIS  
PERIOD WITH THE NAM SUGGESTING WEAKENING CONVECTION DROPPING INTO  
THE MID-SOUTH DURING THE DAY WEDNESDAY AND DISSIPATING WITH GFS  
AND ECMWF SOLUTIONS HINTING AT CONVECTION DEVELOPING TOWARDS  
WEDNESDAY EVENING. OVERALL SHEAR AT THIS TIME APPEARS TO BE WEAK  
ACROSS THE REGION WITH MORE FAVORABLE SHEAR OCCURRING NORTH OF  
THE AREA. THIS WILL CONTINUE TO BE MONITORED AS ADDITIONAL DATA  
ARRIVES INTO TUESDAY.  
 
THANKFULLY, DETERMINISTIC AND ENSEMBLE SOLUTIONS REMAIN IN GOOD  
AGREEMENT WITH A MID-LEVEL TROUGH SETTLING ACROSS THE EASTERN U.S  
LATER THIS WEEK INTO THE UPCOMING WEEKEND. THIS WILL BRING  
SLIGHTLY COOLER AND DRIER AIR TO THE AREA THROUGH AT LEAST THE  
WEEKEND.  
 
 
   
AVIATION  
 
(12Z TAFS)  
ISSUED AT 630 AM CDT TUE AUG 18 2026  
 
VFR EXPECTED AT MEM/JBR/MKL THROUGH THE PERIOD. TUP COULD SEE  
MVFR VISIBILITIES FROM MIST THROUGH THE FIRST COUPLE HOURS OF THE  
TAF, BUT WILL ALSO OTHERWISE BE VFR THROUGH THE PERIOD. AN AREA  
OF RAIN SHOWERS OVER EAST-CENTRAL ARKANSAS WILL CONTINUE EAST  
THROUGH THE BEGINNING OF THE TAF PERIOD, EVENTUALLY MAKING ITS  
WAY TO MEM. HOWEVER, COVERAGE IS EXPECTED TO DWINDLE BY THAT TIME  
WITH ONLY ENOUGH COVERAGE TO WARRANT VCSH. WINDS WILL START OUT  
NORTHEASTERLY, BACKING TO A MORE NORTHERLY DIRECTION THROUGHOUT  
THE DAY, THEN BEGIN TO VEER SOUTHERLY THROUGH THE END OF THE TAF  
PERIOD AFTER 00Z WEDNESDAY.  
 
 
   
FIRE WEATHER  
 
ISSUED AT 1126 PM CDT MON AUG 17 2026  
 
FIRE DANGER IS EXPECTED TO REMAIN LOW THROUGH THE PERIOD DUE TO  
LIGHT 20 FT WINDS, ALTHOUGH MINIMUM RELATIVE HUMIDITY VALUES MAY  
DROP BELOW 40% IN SOME AREAS ON WEDNESDAY. FOG POTENTIAL REMAINS  
LOW DUE TO DRY SOILS WITH THE EXCEPTION OF NORTH MISSISSIPPI  
TUESDAY MORNING DUE TO RECENT LOCALIZED RAINFALL.  
 
 
 
   
MEG WATCHES/WARNINGS/ADVISORIES  
 
AR...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR ARZ049-058.  
 
MO...NONE.  
MS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR MSZ007-010>012-  
020>024.  
 
TN...NONE.  
 
 
 
 
PUBLIC FORECAST...CJC  
AVIATION...JAB  
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