863  
FXUS64 KSHV 152206  
AFDSHV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SHREVEPORT LA  
506 PM CDT SUN JUL 15 2018  
   
AVIATION
 
 
MUCH LESS CUMULUS TODAY COMPARED TO SAT AFTN AND AS A  
RESULT...MUCH LESS IN THE WAY OF CONVECTION TO DEAL WITH. WILL  
WATCH ISOLATED SHOWERS WHICH HAVE JUST RECENTLY DEVELOPED IN THE  
VICINITY OF THE LFK TERMINAL FOR THE POSSIBLE ADDITION OF A VCSH  
OR VCTS MENTION IN THE 00Z TAF CYCLE BUT OTHERWISE, SHOULD HAVE  
PREVAILING VFR CONDITIONS THROUGH THE NIGHT AND THROUGH THE DAY  
MONDAY.  
 
CU FIELD WILL AGAIN BEGIN BUILDING NEAR OR SHORTLY AFTER 15Z ON  
MON BUT NO CEILINGS ARE EXPECTED ATTM. THE 12Z NAM OUTPUT IS THE  
ONLY MODEL SUGGESTING THE LIKELIHOOD OF -TSRA IN THE VICINITY OF  
THE TXK/ELD TERMINALS LATE IN THE TAF PERIOD ON MONDAY SO WILL  
CHOOSE TO LEAVE OUT ANY MENTION OF THIS WEATHER FOR THIS CYCLE BUT  
MAY NEED TO INCLUDE A MENTION FOR THE 06Z TAF PACKAGE IF MORE  
MODEL CONSENSUS INDICATES.  
 
LOOK FOR LIGHT SOUTH TO SOUTHWEST WINDS OVERNIGHT WITH SPEEDS LESS  
THAN 10KTS. SOUTH TO SOUTHWEST WINDS WILL PREVAIL NEAR 6-10KTS  
AREAWIDE BEYOND 15Z MONDAY.  
 
13  
 

 
   
PREV DISCUSSION
 
/ISSUED 344 PM CDT SUN JUL 15 2018/  
 
SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/  
 
SURFACE HIGH PRESSURE ACROSS THE GULF OF MEXICO MAINTAINING SOUTH  
TO SOUTHWEST FLOW OF MOISTURE ACROSS THE REGION THIS AFTERNOON.  
CURRENT HEAT INDEX READINGS AVERAGING FROM 98 DEGREES IN LUFKIN TO  
105 DEGREES IN EL DORADO. A HEAT ADVISORY REMAINS IN EFFECT FOR  
PORTIONS OF SOUTHEAST OKLAHOMA, SOUTHERN ARKANSAS, AND NORTHEAST  
LOUISIANA THROUGH 7 PM.  
 
A SURFACE BOUNDARY ACROSS CENTRAL ARKANSAS INTO EASTERN OKLAHOMA,  
COMBINED WITH AN UPPER-TROUGH ACROSS THE NORTHERN PERIPHERY OF  
THE RIDGE, HAVE CONTRIBUTED TO ISOLATED TO WIDELY SCATTERED  
CONVECTION ACROSS MUCH OF THE REGION WITH BETTER COVERAGE ACROSS  
SOUTHERN ARKANSAS AND SOUTHEAST OKLAHOMA.  
 
ISOLATED ELEVATED CONVECTION TO LINGER INTO THE EVENING HOURS AND  
POSSIBLY OVERNIGHT ACROSS THE I-30 CORRIDOR DUE TO INSTABILITY  
ASSOCIATED WITH FRONT AND UPPER-LEVEL TROUGH AND POSSIBLE MCS  
DEVELOPMENT FURTHER UPSTREAM IN NORTHERN OKLAHOMA.  
 
FORECAST GETS SLIGHTLY MORE COMPLEX ON MONDAY AND REMAINS  
DEPENDENT ON FRONTAL POSITION AND WHAT APPEARS TO BE REMNANT MCS  
CONVECTION SHIFTING SOUTHEAST ACROSS SOUTHERN ARKANSAS. COOL POOL  
AIRMASS BEHIND OUTFLOW BOUNDARY COMBINED WITH INCREASED CLOUD  
COVER WILL LIMIT AFTERNOON HIGH TEMPERATURES ACROSS THESE AREAS TO  
THE LOWER TO MIDDLE 90S, THUS MITIGATING THE NEED FOR A HEAT  
ADVISORY. OTHERWISE, OVERNIGHT LOWS ON MONDAY NIGHT TO FALL INTO  
THE MID 70S.  
 
/05/  
 
LONG TERM.../TUESDAY THROUGH SUNDAY/  
 
A COLD FRONT WILL SLOWLY MOVE SOUTH ACROSS THE PLAINS BEFORE  
STALLING IN SOUTHEAST OKLAHOMA, SOUTHERN ARKANSAS, AND NORTHEAST  
LOUISIANA BY LATE THURSDAY. SCATTERED CONVECTION SHOULD DEVELOP EACH  
DAY ALONG THIS FRONT. NORTHWEST FLOW ALOFT WILL STEER THE SHOWERS  
AND THUNDERSTORMS TOWARDS OUR AREA. ADDITIONAL DEVELOPMENT WILL BE  
POSSIBLE DURING PEAK DAYTIME HEATING ALONG REMNANT OUTFLOW  
BOUNDARIES. A SERIES OF WEAK SHORTWAVE TROUGHS MAY PROVIDE  
ADDITIONAL VERTICAL ASCENT TO AID IN CONVECTIVE DEVELOPMENT. RAIN  
CHANCES WILL GENERALLY BE CONFINED TO AREAS EAST OF A LINE FROM  
BROKEN BOW OK TO TOLEDO BEND DAM.  
 
BY LATE THURSDAY, AN UPPER RIDGE OVER THE FOUR CORNERS REGION WILL  
STRENGTHEN AND EXPAND OVER THE SOUTHERN PLAINS, AND THE FRONTAL  
BOUNDARY WILL MOVE BACK TO THE NORTH. INCREASED SUBSIDENCE FROM THE  
STRONG UPPER RIDGE WILL GENERALLY BRING THUNDERSTORM CHANCES TO AND  
END BY FRIDAY. THE LATEST GFS SUGGESTS THE RIDGE MAY RETROGRADE  
SLIGHTLY BACK TO THE WEST, WHICH MAY ALLOW THE FLOW ALOFT TO BRING  
ANOTHER BACK DOOR FRONT INTO THE REGION LATE IN THE WEEKEND AND A  
RETURN OF RAIN CHANCES ACROSS SOUTHEAST OKLAHOMA AND SOUTHERN  
ARKANSAS. ON THE FLIP SIDE, THE LATEST ECMWF BRINGS THE CENTER OF  
THE RIDGE CLOSER AND MAINTAINS A DRY FORECAST. GIVEN THE  
UNCERTAINTY, SLIGHT CHANCE POPS WILL BE IN THE FORECAST ON SUNDAY.  
 
IN EITHER CASE, THE EXPANSION OF THE RIDGE AND A DECREASE IN RAIN  
CHANCES WILL ALLOW THE HEAT TO BUILD. DAYTIME HIGH TEMPERATURES NEAR  
OR OVER 100 DEGREES F CAN BE EXPECTED ACROSS THE ENTIRE AREA BY  
FRIDAY. TEMPERATURES WILL LIKELY REACH THE CENTURY MARK OVER EAST  
TEXAS BY TUESDAY AS DRY WEATHER WILL RETURN MUCH SOONER. ANY  
VARIATIONS TO DAYTIME HIGH TEMPERATURES WILL GENERALLY BE DUE TO  
CLOUD COVER. THIS WILL ALSO LEAD TO HEAT INDEX VALUES OVER 100  
DEGREES F, MOST LIKELY OVER HEAT ADVISORY CRITERIA. THE ONE FACTOR  
THAT MAY KEEP HEAT INDEX VALUES A FEW DEGREES LOWER WILL BE THE  
STRENGTH OF VERTICAL MIXING EACH AFTERNOON, WHICH MAY BRING DRY AIR  
FROM ALOFT DOWN TO THE SURFACE.  
 
CN  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
SHV 78 98 78 100 / 10 10 10 20  
MLU 77 96 77 95 / 10 10 20 50  
DEQ 75 94 73 98 / 10 30 20 30  
TXK 78 95 76 98 / 10 20 20 30  
ELD 77 95 75 96 / 10 20 30 40  
TYR 76 96 76 100 / 10 10 10 10  
GGG 77 97 76 101 / 10 10 10 10  
LFK 76 96 75 99 / 10 10 10 10  
 

 
   
SHV WATCHES/WARNINGS/ADVISORIES
 
 
AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ARZ050-051-060-061-  
072-073.  
 
LA...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR LAZ004>006-013-014-  
019>022.  
 
OK...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR OKZ077.  
 
TX...NONE.  

 
 

 
 
CN/05/13  
 
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