394  
FXUS64 KSHV 220929  
AFDSHV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SHREVEPORT LA  
429 AM CDT SUN APR 22 2018  
   
DISCUSSION
 
 
THE MORNING MOSAIC RADAR IMAGERY INDICATES THE CONVECTION GRADUALLY  
DIMINISHING FROM W TO E THIS MORNING ACROSS SCNTRL AR/N LA, AS DRY  
AIR CONTINUES TO ENTRAIN E AHEAD OF THE NEGATIVE TILT UPPER TROUGH AND  
ASSOCIATED CLOSED LOW OVER OK. THE 00Z NAM/GFS AND LATEST HRRR DEPICT  
THE BACK EDGE OF THE CONVECTION SHOULD BE EXITING THE ERN EDGE OF THE  
FORECAST AREA BY OR SHORTLY AFTER 12Z THIS MORNING, AND THUS HAVE  
TONED DOWN POPS THIS MORNING OVER THESE AREAS. HOWEVER, THE CLOSED LOW  
WILL WOBBLE ESE INTO WRN AR THIS AFTERNOON, WHICH MAY RESULT IN  
ISOLATED -SHRA REDEVELOPMENT OVER SE OK/SW AR AND PORTIONS OF NCNTRL  
LA LATE IN THE DAY. MEANWHILE, THE MORNING SFC ANALYSIS AND LATEST  
VOLUME SCANS FROM THE KSHV 88-D DEPICT A COLD FRONT MAKING STEADY  
PROGRESS E, EXTENDING FROM JUST E OF TXK, TO NEAR ASL, TO NEAR  
OCH/LFK, TO JUST S OF UTS AS OF 09Z. THIS FRONT WILL CONTINUE TO MAKE  
RAPID PROGRESS E ACROSS SCNTRL AR/N LA, EXITING THE REGION BY MID TO  
LATE MORNING. WRAP-AROUND STRATUS WILL PERSIST EVEN IN WAKE OF THE  
FROPA THIS MORNING, WITH SOME IMPROVEMENT TO CIGS POSSIBLE LATER THIS  
AFTERNOON OVER LOWER E TX. THIS CLOUD COVER AND NW WINDS 10-15KTS WITH  
HIGHER GUSTS OVER MUCH OF THE REGION WILL RESULT IN COOLER THAN NORMAL  
TEMPS THIS AFTERNOON, WITH THE WRAP-AROUND STRATOCU LIKELY LINGERING  
OVER MUCH OF THE REGION TONIGHT AND MONDAY AS THE CLOSED LOW  
TEMPORARILY SLOWS ITS EWD PROGRESS AND SPINS OVER THE MID-SOUTH  
REGION. SHOULD FINALLY START TO SEE CLEARING COMMENCE BY MONDAY NIGHT  
AS THIS LOW FINALLY DRIFTS FARTHER E INTO THE TN VALLEY.  
 
A DRY NW FLOW WILL LINGER IN WAKE OF THE LOW'S DEPARTURE TUESDAY,  
ALTHOUGH STRONG INSOLATION WILL RESULT IN A RETURN TO MORE SEASONAL  
TEMPS BY AFTERNOON AS READINGS CLIMB INTO THE UPPER 70S TO NEAR 80  
DEGREES. HOWEVER, THIS WILL BE SHORT-LIVED AS SHARPLY POSITIVE TILT  
SHORTWAVE RAPIDLY DROPS SSE THROUGH THE CNTRL PLAINS TUESDAY NIGHT  
INTO OK/AR WEDNESDAY, WHICH WILL REINFORCE A COLD FRONT QUICKLY SE  
THROUGH THE REGION WEDNESDAY. THE GFS REMAINS THE FASTER SOLUTION,  
BRINGING THE FRONT QUICKLY INTO THE AREA AFTER 06Z WEDNESDAY, EXITING  
THE AREA BY 18Z. THE ECMWF REMAINS ABOUT 6 HOURS SLOWER, BUT BOTH ARE  
IN AGREEMENT WITH POST-FRONTAL RAINS DEVELOPING TUESDAY NIGHT OVER  
PORTIONS OF OK/POSSIBLY N AND NW TX, ALTHOUGH CONSIDERABLE PLACEMENT  
OF THE RAINS DIFFER SIGNIFICANTLY AS WELL. HAVE KEPT THE FORECAST  
CONSISTENT WITH EARLIER RUNS, MAINTAINING SLIGHT CHANCE POPS LATE  
TUESDAY NIGHT FOR SE OK, BEFORE RAMPING MID AND HIGH CHANCE POPS UP  
WEDNESDAY ALONG/N OF I-20 OVER E TX/N LA. DO PREFER THE FASTER RUNS OF  
THE GFS/CANADIAN THOUGH GIVEN THE POSITIVE AMPLITUDE OF THE TROUGH,  
THUS TAPERING POPS OFF WEDNESDAY NIGHT.  
 
MODEL DISCREPANCIES INCREASE BY THE MID AND LATE WEEK TIMEFRAME WITH  
THE ECMWF MUCH SHARPER/FARTHER S AND A BIT SLOWER WITH A DEVELOPING  
LONGWAVE TROUGH E OF THE ROCKIES, AND ALSO WETTER WITH THE NEXT COLD  
FROPA. THIS TROUGH AMPLITUDE IS DEEPER/STRONGER THAN EARLIER RUNS OF  
THE ECMWF, BUT HAVE MAINTAINED SLIGHT CHANCE POPS AREAWIDE FRIDAY  
DESPITE THE DRY GFS/CANADIAN, WITH COOL NIGHTS/MILD AFTERNOONS  
EXPECTED IN WAKE OF THE FRONT NEXT WEEKEND, WHICH WOULD BE SEASONABLE  
FOR THIS TIME OF YEAR. FORTUNATELY, WITH THE PROGRESSIVE NATURE OF THE  
UPPER LEVEL FLOW THIS NEXT WEEK, SEVERE STORMS (OR EVEN THUNDER) ARE  
NOT EXPECTED THROUGH THE FORECAST PERIOD.  
 
PRELIMS TO FOLLOW BELOW...  
 
15  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
SHV 66 53 71 53 / 10 5 10 5  
MLU 73 53 69 53 / 50 10 20 10  
DEQ 63 50 70 48 / 20 10 10 5  
TXK 64 52 70 52 / 20 10 10 5  
ELD 68 52 69 51 / 30 10 20 10  
TYR 65 51 73 52 / 10 0 0 0  
GGG 65 52 72 52 / 10 0 0 0  
LFK 69 52 74 54 / 10 0 0 0  
 

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

 
 

 
 
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