363  
FXUS64 KSHV 192331  
AFDSHV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SHREVEPORT LA  
631 PM CDT SUN AUG 19 2018  
   
AVIATION
 
 
ANOTHER LOW CONFIDENCE FORECAST WITH THE 00Z TAF PACKAGE AS ONCE  
AGAIN, SHORT TERM PROGS ARE STRUGGLING WITH CURRENT CONVECTION AND  
FUTURE TRENDS. THE 18Z NAM OUTPUT SUGGESTS WE WILL SEE A LINE OF  
CONVECTION PUSH THROUGH THE ENTIRE REGION OVERNIGHT, EFFECTING ALL  
TERMINAL SITES AND THIS DOES NOT APPEAR LIKELY. GFS IS STRUGGLING  
ON CURRENT PLACEMENT OF CONVECTION AND APPEARS TO BE WELL OVERDONE  
AS WELL. HAVE BASED THE 00Z TAF PACKAGE ON THE LATEST RUN OF THE  
HRRR WHICH SUGGESTS THAT THE TXK/ELD/MLU TERMINALS HAVE THE MOST  
LIKELIHOOD OF SEEING EVENING CONVECTION BEFORE MOST IF NOT ALL  
CONVECTION DIES OFF LATE TONIGHT.  
 
WE WILL NEED TO WATCH FOR RENEWED CONVECTION BY LATE MORNING INTO  
THE AFTERNOON HOURS ALONG A SOUTHEASTWARD MOVING COLD FRONT ON  
MONDAY AND HAVE THUS ADDED VCTS TO ALL BUT THE TXK/TYR TERMINALS  
FOR THIS.  
 
SOUTH WINDS NEAR 10KTS OVERNIGHT WILL VEER QUICKLY TO THE  
SOUTHWEST ON MONDAY WITH SUSTAINED WINDS NEAR 10-15KTS WITH HIGHER  
GUSTS AHEAD OF THE SOUTHEASTWARD MOVING COLD FRONT.  
 
13  
 

 
   
PREV DISCUSSION
 
/ISSUED 323 PM CDT SUN AUG 19 2018/  
 
SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/  
UPPER-LEVEL DISTURBANCE ACROSS THE MIDWEST WITH TROUGH AXIS  
EXTENDING SOUTHWEST INTO THE RED RIVER VALLEY OF TEXAS TO ALLOW  
FOR SUFFICIENT DESTABILIZATION ACROSS MUCH OF THE INTERSTATE 30  
CORRIDOR THIS EVENING. SOME STRONG STORMS WILL BE POSSIBLE WITH  
GUSTY WINDS, LOCALLY HEAVY RAINFALL, AND SMALL HAIL BEING THE  
MAIN THREAT. OVERNIGHT LOW TEMPERATURES FORECAST TO FALL INTO THE  
MID TO UPPER 70S.  
 
SURFACE FRONTAL BOUNDARY TO SHIFT SOUTHEAST ACROSS THE REGION ON  
MONDAY ALLOWING FOR SCATTERED TO NUMEROUS SHOWERS AND  
THUNDERSTORMS MAINLY ACROSS EAST TEXAS, SOUTHERN ARKANSAS, AND  
NORTH LOUISIANA. SOME STRONG STORMS WILL BE POSSIBLE ALONG AND  
NORTH OF INTERSTATE 20 AS ATMOSPHERE DESTABILIZES DURING THE  
AFTERNOON WITH APPROACHING BROAD LEVEL TROUGH AND STEEPER LAPSE  
RATES. SEVERE THREAT REMAINS MARGINAL WITH DAMAGING WINDS AND HAIL  
BEING THE MAIN THREAT. AFTERNOON HIGH TEMPERATURES FORECAST TO  
CLIMB INTO THE LOWER TO MID 90S.  
 
MAINLY DRY CONDITIONS EXPECTED ON MONDAY NIGHT AS HIGH PRESSURE  
REBUILDS WITH TEMPERATURES RANGING FROM LOWS IN THE MID 60S ACROSS  
THE SOUTHERN OZARKS TO THE MID 70S ACROSS THE LAKES REGION OF  
DEEP EAST TEXAS. /05/  
 
LONG TERM.../TUESDAY THROUGH SATURDAY NIGHT/  
 
AS A STRONG UPPER TROUGH MOVES INTO THE GREAT LAKES REGION, THE FLOW  
ALOFT WILL TRANSITION TO NORTHWESTERLY IN RESPONSE TO A BUILDING  
UPPER RIDGE OVER SOUTHWEST TEXAS. THERE COULD STILL BE A FEW  
LINGERING SHOWERS OR STORMS ASSOCIATED WITH THE RECENT PASSAGE OF A  
COLD FRONT ACROSS OUR FAR SOUTHERN COUNTIES/PARISHES FROM DEEP EAST  
TEXAS EASTWARD INTO CENTRAL LOUISIANA, BUT THIS ACTIVITY SHOULD  
COMPLETELY EXIT THE AREA BY LATE TUESDAY AFTERNOON.  
 
FOR THE MOST PART, THE FORECAST SHOULD GENERALLY BE DRY FROM  
WEDNESDAY UNTIL SATURDAY. THE ONE EXCEPTION MIGHT BE DURING THE  
DAYTIME HOURS OF THURSDAY ALONG AND NORTH OF THE INTERSTATE 30  
CORRIDOR. THE GFS SUGGESTS A WEAK SHORTWAVE TROUGH EMBEDDED IN THE  
FLOW ALOFT MAY STEER CONVECTION SOUTHEAST INTO THE AREA FROM  
OKLAHOMA. HOWEVER, THE LATEST ECMWF BRINGS THE CENTER OF THE RIDGE  
OVERHEAD ON THURSDAY, WHICH SHOULD KEEP ANY PRECIP FAR REMOVED FROM  
OUR AREA. COMPARED TO YESTERDAY, IT APPEARS THE GFS IS GENERALLY  
TRENDING TOWARDS A DRIER FORECAST AND FALLING MORE IN LINE WITH THE  
ECMWF WITH EACH NEW MODEL RUN. THEREFORE, POPS WERE MAINTAINED  
DURING THE DAYTIME HOURS OF THURSDAY BUT WERE ONLY KEPT AT SLIGHT  
CHANCE.  
 
MEDIUM RANGE MODELS ARE IN GOOD AGREEMENT WITH BRINGING THE CENTER  
OF THE UPPER RIDGE VERY CLOSE TO THE AREA DURING THE WEEKEND. THE  
GFS KEEPS THE CENTER OVER NORTH TEXAS, WHILE THE ECMWF PLACES THE  
CENTER OVER SOUTHEAST ARKANSAS/NORTHEAST LOUISIANA. BASED ON THE  
ECMWF, DEEP LAYER ON-SHORE FLOW FROM THE GULF OF MEXICO SHOULD  
RESULT IN A RETURN OF DIURNAL THUNDERSTORM CHANCES NEXT WEEKEND  
ALONG AND SOUTH OF INTERSTATE 20, AS THIS TYPE OF SETUP IS VERY  
FAVORABLE FOR SEA-BREEZE ACTIVITY.  
 
DAYTIME TEMPERATURES WILL GENERALLY BE IN THE MID 80S IN SOUTHEAST  
OKLAHOMA TO MID 90S ALONG AND SOUTH OF I-20 TUESDAY AND WEDNESDAY. A  
GRADUALLY WARMING TREND IS EXPECTED AS THE RIDGE MOVES OVERHEAD AND  
RAIN CHANCES DECREASE. MID TO UPPER 90S ARE EXPECTED AREAWIDE BY  
FRIDAY. IF WETTING RAINS ARE NOT RECEIVED BEFORE THE LONG-TERM  
PERIODS BEGIN, TEMPERATURES COULD VERY WELL BE SEVERAL DEGREES  
WARMER THAN FORECAST IN THE LOCATIONS WHERE SOIL MOISTURE IS  
ALREADY LOW AND SEVERE TO EXTREME DROUGHT CONDITIONS PERSIST.  
 
CN  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
SHV 78 94 73 95 / 30 50 40 10  
MLU 77 92 73 93 / 20 50 40 10  
DEQ 73 90 66 89 / 50 10 10 0  
TXK 77 91 69 90 / 50 30 10 0  
ELD 77 92 70 90 / 40 50 40 10  
TYR 79 96 72 94 / 50 20 10 10  
GGG 78 95 71 94 / 40 40 20 10  
LFK 78 94 75 95 / 10 40 40 20  
 

 
   
SHV WATCHES/WARNINGS/ADVISORIES
 
 
AR...NONE.  
LA...NONE.  
OK...NONE.  
TX...NONE.  

 
 

 
 
CN/05/13  
 
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