864  
FXUS64 KJAN 131421 AAB  
AFDJAN  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE JACKSON MS  
921 AM CDT SUN JUL 13 2025  
   
..NEW MESOSCALE UPDATE  
 
   
MESOSCALE UPDATE  
 
ISSUED AT 919 AM CDT SUN JUL 13 2025  
 
REST OF TODAY...HIGH PRESSURE ALOFT, CURRENTLY CENTERED TO THE  
SOUTHEAST OF THE FORECAST AREA, CONTINUES TO SLOWLY STRENGTHEN  
ACROSS THE LOWER MISSISSIPPI RIVER VALLEY TODAY AS IT BUILDS  
NORTHWEST INTO THE REGION. ALTHOUGH SOME SLIGHTLY DRIER AIR ALOFT  
HAS MADE ITS WAY INTO THE REGION, NOTED BY THE 1.88 INCH  
PRECIPITABLE H2O VALUE ON THE 12Z KJAN RAOB, HOT HUMID CONDITIONS  
WILL PERSIST ACROSS THE FORECAST AREA TODAY. HIGHS WILL WARM INTO  
THE LOW AND MIDDLE 90S, WITH AFTERNOON HEAT INDEX VALUES APPROACHING  
105F. THIS WILL AGAIN LEAD TO A "LIMITED" THREAT FOR HEAT STRESS  
ACROSS THE ENTIRE AREA THIS AFTERNOON.  
 
DIURNALLY DRIVEN SCATTERED SHOWERS AND STORMS WILL ALSO BE POSSIBLE  
THROUGH THE EVENING HOURS. ALONG WITH THE UNSTABLE AIRMASS DURING  
PEAK HEATING OF THE AFTERNOON, SOME SLIGHTLY BETTER FLOW ALOFT ALSO  
EXISTS ACROSS WESTERN PORTIONS OF THE CWA. AS A RESULT, A "MARGINAL  
RISK" FOR ISOLATED SEVERE STORMS WILL BE POSSIBLE ACROSS AREAS  
MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER. THERE, DAMAGING  
WIND GUSTS TO 60 MPH WILL BE THE PRIMARY CONCERN WITH STORMS, BUT  
HAIL TO THE SIZE OF QUARTERS IS ALSO POSSIBLE. ELSEWHERE, GUSTY  
WINDS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS. FREQUENT  
LIGHTING STRIKES AND HEAVY DOWNPOURS WILL ACCOMPANY ALL OF TODAY'S  
CONVECTION.  
 
THE ONGOING FORECAST IS IN GOOD SHAPE. OTHER THAN SOME TWEAKS TO  
HOURLY ELEMENTS OF THE FORECAST BASED ON CURRENT TRENDS, NO MAJOR  
CHANGES WILL BE MADE ON THIS MORNING'S UPDATE. /19/  
 
 
   
DISCUSSION  
 
ISSUED AT 1157 PM CDT SAT JUL 12 2025  
 
SUNDAY THROUGH SUNDAY NIGHT: AN UPPER LEVEL TROUGH OVER THE CENTRAL  
AND SOUTHERN PLAINS WILL TRY TO SHIFT EAST INTO OUR REGION BUT HIGH  
PRESSURE AT THE SURFACE AND ALOFT TO OUR SOUTHEAST WILL  
STRENGTHEN OVER OUR CWA THROUGH THE DAY. THIS WILL LEAD TO MORE  
ISOLATED TO SCATTERED COVERAGE OF MAINLY AFTERNOON AND EARLY  
EVENING CONVECTION AND A GRADUAL WARMING TREND. THE 00Z SUN JAN  
SOUNDING SHOWED A PWAT OF 2.03IN. THUS, A MOIST AIRMASS ACROSS  
OUR CWA WILL BE MAINTAINED THROUGH SUNDAY NIGHT. WITH THE LOWER  
RAIN CHANCES AND WARMER TEMPERATURES TOPPING OUT IN THE LOW TO MID  
90S, HEAT STRESS CONCERNS WILL INCREASE IN OUR WEST ALONG THE  
MISSISSIPPI RIVER ESPECIALLY. PEAK HEAT INDEX VALUES WILL BE  
AROUND 105F AGAIN SUNDAY. WE WILL CONTINUE TO HIGHLIGHT THIS AREA  
WITH A "LIMITED" FOR HEAT STRESS IN OUR GRAPHICS FOR NOW. /22/  
 
MONDAY THROUGH FRIDAY:  
 
AS WE HEAD INTO THE NEW WORK WEEK, MODEL CONSENSUS FROM BOTH THE GFS  
AND THE EURO SHOW THE SURFACE HIGH STARTING TO GRADUALLY  
RETROGRADE ACROSS THE SOUTHEAST CONUS. AS THIS HIGH BEGINS TO PUSH  
NORTH INTO THE REGION, HUMID CONDITIONS WILL PERSIST ACROSS OUR  
CWA, WHICH IN TURN WILL LEAD TO INCREASING HEAT CONDITIONS THROUGH  
THE EXTENDED PERIOD. LOOKING AT CURRENT FORECAST TRENDS, IT  
APPEARS THAT HEAT INDICES WILL BE IN THE 105-110 RANGE NEXT  
TUESDAY THROUGH FRIDAY GIVEN DAYTIME HIGHS FORECASTED IN THE  
MID/UPPER 90S ALONG WITH DEWPOINTS IN THE MID TO UPPER 70S (A FEW  
SPOTS COULD POTENTIALLY SEE DEWPOINTS IN THE LOW 80S). THIS WILL  
LIKELY RESULT IN THE "LIMITED" RISK FOR HEAT STRESS BEING UPGRADED  
TO AN "ELEVATED" RISK IN OUR HWO GRAPHICS FOR THE TUESDAY-FRIDAY  
TIMEFRAME. IT IS POSSIBLE THAT A "SIGNIFICANT" RISK MAY BE  
INTRODUCED IN SUBSEQUENT UPDATES. FURTHERMORE, HEAT  
ADVISORIES/WARNINGS WILL EVENTUALLY BE NEEDED. AFTERNOON/EARLY  
EVENING SHOWERS AND T-STORMS WILL PROVIDE SOME RELIEF FROM THE  
HEAT GLOBAL GUIDANCE SHOWS CONVECTION DISSIPATING BY THE EVENING  
HOURS EACH DAY AS DAYTIME HEATING WANES. /CR/  
 
 
   
AVIATION  
 
(12Z TAFS)  
ISSUED AT 633 AM CDT SUN JUL 13 2025  
 
A FEW PATCHY AREAS OF IFR CATEGORY BR/FG ARE A THREAT EARLY THIS  
MORNING. THIS SHOULD DISSIPATED SHORTLY WITH FOCUS THEN SHIFTING  
TO POTENTIAL IMPACTS FROM ISOLATED DIURNALLY DRIVEN TSRA.  
OTHERWISE, VFR CONDITIONS AND LIGHT SOUTH-SOUTHWEST SURFACE WIND  
SHOULD PREVAIL THROUGH THE FORECAST PERIOD. /EC/  
 
 
   
PRELIMINARY POINT TEMPS/POPS  
 
JACKSON 95 74 94 75 / 30 20 40 0  
MERIDIAN 94 73 95 74 / 40 20 30 0  
VICKSBURG 94 75 94 75 / 30 20 30 0  
HATTIESBURG 96 75 97 75 / 50 20 40 0  
NATCHEZ 92 73 94 74 / 60 20 40 0  
GREENVILLE 93 74 93 74 / 20 20 40 0  
GREENWOOD 94 74 94 75 / 20 20 40 0  
 
 
   
JAN WATCHES/WARNINGS/ADVISORIES  
 
MS...NONE.  
LA...NONE.  
AR...NONE.  
 
 
 
 
19  
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