375  
FXUS64 KSHV 280502  
AFDSHV  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SHREVEPORT LA  
1102 PM CST SAT FEB 27 2021  
   
AVIATION
 
 
FOR THE ARKLATEX TERMINALS THE WARM FRONT IS EDGING PAST  
KTXK/KELD WITH BETTER VSBY AND INCREASING S WIND. ALOFT, WE ARE  
S/SE 20-30KT AT 1-2KFT UP. SO THIS LIFR MAY BREAK FOR A SHORT  
WHILE THIS EVENING. HOWEVER, MORE MAY DVLP OVERNIGHT AREA WIDE.  
LOWERING CIGS AND NOT SO MUCH VSBY ISSUES ON THIS SIDE OF THE WARM  
FRONT WITH DVLPG SHWRS/TS SUNDAY LATE AHEAD OF OUR NEXT COLD  
FRONT ARRIVING LATE ON SUNDAY AFTN/EVE. SFC WINDS SHIFT TO N, BUT  
SW ALOFT KEEPS WITH RAIN INTO MON/TUES. /24/  
 

 
   
PREV DISCUSSION
 
/ISSUED 944 PM CST SAT FEB 27 2021/  
 
UPDATE...  
 
ADDED DENSE FOG ADVISORY TO THE OVERNIGHT AND LOWERED TEMPS NORTH.  
 
SHORT TERM...  
 
IT HAS BEEN SOLID WITH DENSE FOG OF 1/4 TO 1/2 MILE SINCE SUNSET  
FROM IDABEL TO EL DORADO, BUT IT APPEARS WE ARE ON THE FRINGE WITH  
GROUND FOG PERHAPS NOW LIFTING A BIT. WE WILL CONTINUE MONITOR  
FOR IMPROVEMENT, BUT LAST TO GO WILL BE THE VALLEYS AS THIS WARM  
FRONT EDGES NORTHWARD. SO ANOTHER UPDATE TO REMOVE SOME OF THIS  
ADVISORY HAS A LITTLE MORE OPTIMISM NOW, BUT THE FRONTAL BOUNDARY  
DID LOSE SOME GROUND LAST NIGHT SO POTENTIAL GOOD NEWS ONLY IF  
THE WARMER AIR CONTINUES TO ARRIVE. OTHERWISE HRRR SHOWING SOME  
DEVELOPMENT OF RAIN SHOWERS MAINLY ALONG AND NORTH OF I-30  
OVERNIGHT, SPREADING DOWN INTO THE I-20 CORRIDOR EARLY TOMORROW.  
/24/  
 
PREV DISCUSSION... /ISSUED 328 PM CST SAT FEB 27 2021/  
 
SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/  
 
THE AFOREMENTIONED WARM FRONT, CURRENTLY LOCATED JUST NORTH OF  
THE INTERSTATE 20 CORRIDOR, WILL CONTINUE TO PUSH NORTHWARD  
THROUGH THE EVENING HOURS OUT OF THE REGION. EARLIER CONVECTION  
THAT DEVELOPED NORTH OF THE FRONT HAS RAPIDLY MOVE NORTHWARD  
TODAY, AND IS ALMOST OUT OF THE REGION. CAN'T RULE OUT SOME  
ADDITIONAL CONVECTION GETTING INTO OUR EXTREME NW ZONES, AS  
DEVELOPING ISOLATED SHOWERS/T-STORMS SHIFT NORTHEASTWARD OUT OF  
NORTH TEXAS. ELSEWHERE ACROSS THE REGION, TEMPERATURES HAVE WARMED  
INTO THE 70S IN WAKE OF THE FRONTAL BOUNDARY. THERE HAS EVEN BEEN  
A FEW BREAKS IN CLOUD COVER. A FEW WARM AIR ADVECTION SHOWERS  
HAVE DEVELOPED ACROSS OUR CENTRAL AND NORTHEAST LOUISIANA  
PARISHES, BUT THIS ACTIVITY SHOULD DIMINISH BY SUNSET. EXPECT LOW  
CLOUDS TO RETURN OVERNIGHT WITH WARMER TEMPERATURES AREAWIDE, AS  
OVERNIGHT LOWS WILL RANGE FROM THE UPPER 50S NORTH, TO MID 60S  
ACROSS OUR SOUTHERN ZONES.  
 
BY SUNDAY, A LONGWAVE TROUGH WILL DIVE SE THROUGH THE ROCKIES AND  
INTO THE FOUR CORNERS REGION ON SUNDAY, BEFORE EVENTUALLY CLOSING  
OFF SUNDAY NIGHT OVER SOUTHERN NEW MEXICO. THE WILL ALLOW FOR DEEP  
SW FLOW ALOFT TO REMAIN OVER THE REGION THROUGH EARLY NEXT WEEK. AT  
THE SAME TIME, A COLD FRONT WILL DRIFT SE INTO THE REGION BY MIDDAY  
SUNDAY/SUNDAY AFTERNOON AND SLOWLY PUSH THROUGH THE REGION BY EARLY  
MONDAY MORNING BRINGING WIDESPREAD CONVECTION TO THE REGION.  
ALTHOUGH SFC INSTABILITY IS MARGINAL WITH THIS SYSTEM, EFFECTIVE  
BULK SHEAR IS OVER 50 KTS AND THERE COULD BE JUST ENOUGH ELEVATED  
INSTABILITY AND DECENT MID-LEVEL LAPSE RATES FOR SOME HAIL AND  
HIGH WINDS WITH ELEVATED CONVECTION. THERE IS ALSO THE POTENTIAL  
FOR ADDITIONAL HEAVY RAINS TO FALL ACROSS THE REGION. WITH ALREADY  
SATURATED AREAS OF NE TX/SW AR FROM PREVIOUS RAINFALL THIS PAST  
WEEK, MINOR FLOODING OF LOW LYING AND POOR DRAINAGE AREAS WILL BE  
POSSIBLE. AS OF NOW, MODELS SUGGEST QPF WILL BE JUST BELOW FLASH  
FLOOD GUIDANCE, SO WILL HOLD OFF ON ANY FLOOD WATCHES AT THIS  
TIME. WARM AND HUMID CONDITIONS ARE EXPECTED ON SUNDAY AHEAD OF  
THE FRONT, WITH TEMPS IN THE 70S AREAWIDE. COOLER CONDITIONS  
EXPECTED BY MONDAY MORNING IN WAKE OF THE FRONT, WITH POST  
FRONTAL PRECIP EXPECTED ACROSS THE REGION. /20/  
 
LONG TERM.../MONDAY THROUGH SATURDAY/  
 
BY MONDAY MORNING, THE COLD FRONT SHOULD BE EXITING THE REGION INTO  
SE TX/CNTRL LA, ALTHOUGH DEEP SW FLOW ATOP THE SHALLOW POST-FRONTAL  
AIR MASS WILL CONTINUE, AHEAD OF A CLOSED LOW THAT WILL ENTER NW TX.  
ELEVATED ISENTROPIC FORCING IS EXPECTED TO CONTINUE AHEAD OF THIS  
LOW MONDAY, THUS CONTINUING THE POST-FRONTAL RAINS OVER MUCH OF THE  
REGION EVEN AS THE LOW BEGINS TO OPEN UP INTO A MORE PROGRESSIVE  
WAVE UPON ENTERING OK. HAVE MAINTAINED LIKELY AND CATEGORICAL POPS  
OVER MUCH OF THE AREA MONDAY AND MONDAY NIGHT, WITH LARGE SCALE  
ASCENT INCREASING JUST AHEAD OF THE TROUGH MONDAY NIGHT. DID TAPER  
BACK MAX TEMPS MONDAY AFTERNOON FROM THE MILDER NBM MAINLY ALONG/S  
OF THE I-20 CORRIDOR GIVEN THE PERSISTENT RAINS AND WEAK COLD  
ADVECTION, WHILE ALSO TRENDING MAX TEMPS TUESDAY A BIT COOLER AS  
WELL TO DEPICT THE SLOWER MOVEMENT OF THE LOW FROM THE  
ECMWF/CANADIAN THAN THE MORE PROGRESSIVE GFS, WHICH SEEMS MORE  
LIKELY GIVEN THE INITIAL CLOSED SOLUTION AS IT DRIFTS E ACROSS OK/N  
TX.  
 
DRIER AIR ALOFT WILL QUICKLY ENTRAIN E BENEATH THE DEPARTING TROUGH  
TUESDAY AFTERNOON, WITH SFC RIDGING OVER THE OZARKS INTO ECNTRL TX  
BUILDING S INTO THE REGION. THIS SHOULD SET THE STAGE FOR GOOD  
RADIATIONAL COOLING WEDNESDAY NIGHT (ASSUMING ANY LINGERING STRATUS  
NEAR AND E OF THE MS RIVER DOESN'T ADVECT BACK WSW INTO THE AREA),  
RESULTING IN WHAT SHOULD BE THE COOLEST TEMPS EXPECTED THROUGH THE  
FORECAST PERIOD AS MIN TEMPS FALL INTO THE 30S TO NEAR 40 DEGREES.  
THIS RIDGING WILL WEAKEN AS IT DRIFTS OFF TO THE E THURSDAY, AS WE  
AWAIT THE APPROACH OF ANOTHER CLOSED LOW THAT WILL SHIFT E INTO THE  
SRN PLAINS LATE THURSDAY. A SW FLOW ALOFT WILL AGAIN DEVELOP AHEAD  
OF THIS APPROACHING LOW, WITH A GRADUAL INCREASE IN LARGE SCALE  
FORCING RESULTING IN THE DEVELOPMENT OF ELEVATED SHRA, WHICH WOULD  
HAVE TO SATURATE THE AIR MASS FROM THE TOP DOWN, GIVEN THE WEAK LOW  
LEVEL MOISTURE ADVECTION EXPECTED TO BE IN PLACE. HAVE GRADUALLY  
STEPPED UP THE POPS FOR THE THURSDAY TIMEFRAME, WITH CHANCE POPS  
RETURNING THURSDAY AFTERNOON AND ESPECIALLY THURSDAY NIGHT. AGAIN  
PREFER THE SLOWER ECMWF/CANADIAN CONSENSUS THAN THE MORE PROGRESSIVE  
GFS, WHICH CLEARS THE RAINS OUT ABOUT 12HRS FASTER. THUS, HAVE  
MAINTAINED CHANCE POPS INTO MUCH OF FRIDAY, BEFORE DRIER AIR AND  
INCREASING SUBSIDENCE TAPER THE RAINS IN WAKE OF THE ATTENDANT COLD  
FRONT THAT ENTERS THE REGION LATE IN THE DAY. THIS FRONT LOOKS TO  
HAVE LITTLE SENSIBLE EFFECT ON TEMPS FOR LATE WEEK INTO NEXT  
WEEKEND, WITH READINGS NEAR THE SEASONABLE NORMS. /15/  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
SHV 66 77 51 54 / 10 60 90 80  
MLU 68 78 52 55 / 10 40 90 80  
DEQ 54 72 44 56 / 40 90 70 30  
TXK 59 74 47 53 / 30 90 90 50  
ELD 60 76 45 53 / 20 80 90 70  
TYR 66 74 49 53 / 10 80 90 80  
GGG 65 76 49 54 / 10 80 90 80  
LFK 66 78 56 60 / 10 40 90 90  
 

 
   
SHV WATCHES/WARNINGS/ADVISORIES
 
 
AR...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR ARZ050-051-059>061-  
070>073.  
 
LA...NONE.  
OK...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR OKZ077.  
 
TX...DENSE FOG ADVISORY UNTIL 9 AM CST SUNDAY FOR TXZ096-097.  
 

 
 

 
 
24/20/15  
 
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