286
FXUS64 KSHV 212325
AFDSHV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
625 PM CDT THU OCT 21 2021
AVIATION
FOR THE 21/00Z TAFS...THE CU FIELD THAT WAS SEEN THROUGH THE
AFTERNOON FOR AREAS SOUTH OF I-20 IS QUICKLY VANISHING THIS
EVENING ACROSS THE REGION. LEFT BEHIND ARE ONLY SOME PASSING HIGH
CLOUDS FOR AREAS SOUTH OF I-20. VFR CONDITIONS ARE EXPECTED TO
PREVAIL THROUGH MUCH OF THIS TAF PERIOD AS DRIER AIR IS FILTERING
IN BEHIND THE PASSING FRONT. STILL HAVE MENTION OF SOME PATCHY FOG
BEING POSSIBLE ACROSS PORTIONS OF DEEP EAST TEXAS TOWARDS DAYBREAK
THAT COULD BRING SOME MVFR CONDITIONS TO KLFK. /33/
PREV DISCUSSION
/ISSUED 310 PM CDT THU OCT 21 2021/
SHORT TERM.../TONIGHT THROUGH FRIDAY NIGHT/
A WEAK COLD FRONT WITH LITTLE FANFARE CONTINUES TO MAKE SLOW SE
PROGRESS ACROSS THE REGION THIS AFTERNOON. OTHER THAN A N/NW WIND
SHIFT AND SLIGHTLY LOWER DEW POINTS, THERE IS LITTLE ELSE TO NOTE
WITH THIS FRONT AS DAYTIME AMBIENT TEMPERATURES HAVE BEEN LARGELY
UNAFFECTED WHERE THE FRONT HAS ALREADY CLEARED ACROSS OUR NORTHERN
ZONES. ALONG I-20 AND POINTS SOUTH, HIGH TEMPERATURES HAVE REALLY
SPIKED THIS AFTERNOON WITH MID TO UPPER 80S AND EVEN A FEW LOW 90S
HAVE BEEN NOTED AHEAD OF THE COLD FRONT WITH A HEALTHY CU FIELD IN
PLACE. LOOK FOR TEMPERATURES TO DROP OFF NICELY THIS EVENING IN
WAKE OF THE FRONT WITH LOWS RANGING FROM THE UPPER 40S NORTH AND
MAINLY 50S ELSEWHERE EXCEPT FOR OUR EXTREME SOUTHERN ZONES WHERE
LOWER 60S MAY HANG ON BEFORE FROPA LATER FRIDAY MORNING.
POST-FRONTAL CONDITIONS WILL REMAIN DRY AS TEMPERATURES MODERATE
SLIGHTLY CLOSER TO SEASONAL AVERAGES IN THE UPPER 70S TO MID 80S
ON FRIDAY. THE AFOREMENTIONED FRONTAL BOUNDARY IS EXPECTED TO
STALL OUT TO OUR SOUTH ON LATE FRIDAY AND THEN GRADUALLY BEGIN TO
LIFT BACK NORTHWARD ON FRIDAY NIGHT. AS A RESULT, EXPECT CLOUDS TO
BEGIN RETURNING ACROSS OUR SW ZONES FRIDAY NIGHT INTO SATURDAY
MORNING WITH LOWS RANGING FROM THE MID 50S NORTH TO MID 60S SOUTH.
/19/
LONG TERM.../SATURDAY THROUGH WEDNESDAY NIGHT/
A NEARLY ZONAL FLOW ALOFT WILL BE IN PLACE AT THE START OF THE
PERIOD BUT WILL BE TRANSITIONING TO SOUTHWESTERLY. OTHERWISE, A DEEP
SOUTHERLY FLOW FROM THE GULF WILL BE PROVIDING A STEADY SOURCE OF
MOISTURE AND WARM AIR ADVECTION INTO THE REGION. UNSEASONABLY WARM
TEMPERATURES CAN BE EXPECTED TO CONTINUE THROUGH AT LEAST TUESDAY OR
WEDNESDAY. THE WARMEST DAY OF THE LONG-TERM PERIOD SHOULD BE MONDAY
AS COMPRESSIONAL WARMING AHEAD OF A FAST-MOVING COLD FRONT ADDS
ANOTHER FEW DEGREES ONTO THE WARMING TREND AND HELPING MOST
LOCATIONS SOUTH OF INTERSTATE 30 WARM INTO THE MID TO UPPER 80S,
POSSIBLY VERY CLOSE TO 90 DEGREES F.
IT WILL SEEM VERY MUCH LIKE LATE SUMMER FOR THE FIRST HALF OF THE
WEEKEND. IN ADDITION TO THE VERY WARM TEMPERATURES, STEADY ONSHORE
FLOW WILL LIKELY RESULT IN AFTERNOON SEA BREEZE CONVECTION FOR
PORTIONS OF THE AREA SOUTH OF INTERSTATE 20 SATURDAY AND SUNDAY,
ESPECIALLY FOR DEEP EAST TEXAS AND THE TOLEDO BEND COUNTRY OF
WESTERN LOUISIANA. MEDIUM RANGE MODEL GUIDANCE SHOWS GOOD AGREEMENT
IN THE DEVELOPMENT OF A STRONG SURFACE LOW OVER KANSAS THAT WILL
EJECT NORTHEAST TOWARDS THE MIDWEST LATE SUNDAY AND INTO MONDAY,
WITH A COLD FRONT TRAILING SOUTHWARD ACROSS THE SOUTHERN PLAINS,
WHICH SHOULD ALSO RAPIDLY MOVE ACROSS THE AREA MONDAY. THE MODELS
DISAGREE WITH THE ASSOCIATED UPPER TROUGH, BOTH IN TERMS OF STRENGTH
AND TRACK, AND THIS LEADS A GREAT DEAL OF UNCERTAINTY TO THE
FORECAST.
THE GFS KEEPS THE UPPER TROUGH WILL NORTH INTO THE DAKOTAS AND GIVES
US VERY LITTLE IN THE WAY OF QPF. THE ECMWF IS AT THE OTHER EXTREME
AND BRING THE UPPER TROUGH WELL SOUTH INTO KANSAS BEFORE EJECTING IT
NORTHEAST SUNDAY EVENING. THE ECMWF SETS THE STAGE FOR SEVERE
CONVECTION ACROSS MUCH OF THE AREA LATE SUNDAY INTO EARLY MONDAY.
THE CANADIAN IS SOMEWHERE MORE IN THE MIDDLE AND FORECASTS LESS
PRECIP THAN THE ECMWF, BUT STILL SUGGESTS THERE WILL BE SCATTERED
STRONG TO SEVERE STORMS IN ADVANCE OF THE COLD FRONT. GIVEN THE VERY
WARM AND UNSTABLE AIR AND THE DEEP SOUTHERLY FLOW IN PLACE ALONG
WITH THE DEEP LAYER SHEAR, THIS WOULD PROVIDE A FAVORABLE
ENVIRONMENT FOR CONVECTION TO OCCUR BEFORE ADDING LARGE SCALE ASCENT
FROM A NEARBY UPPER TROUGH, SO I'M INCLINED TO TREND THE FORECAST
MORE TOWARDS A BLEND OF THE ECMWF AND CANADIAN REGARDING
THUNDERSTORM CHANCES SUNDAY AND INTO MONDAY. THE KEY REGARDING
SEVERE WEATHER CHANCES WILL BE THE EVENTUAL TRACK AND STRENGTH OF
THE UPPER TROUGH. IF SEVERE STORMS DO DEVELOP, ALL SEVERE HAZARDS
WILL BE A THREAT, AND THE GREATEST CHANCES FOR SEVERE WEATHER SHOULD
BE IN SOUTHEAST OKLAHOMA, NORTHEAST TEXAS, SOUTHWEST ARKANSAS, AND
POSSIBLY EXTREME NORTHWEST LOUISIANA.
DRY WEATHER WILL RETURN MONDAY AFTERNOON AND TUESDAY AS THE FRONT
QUICKLY MOVES EAST. HOWEVER, ANOTHER STRONG UPPER TROUGH AND COLD
FRONT ARE PROGGED TO BRING THE POSSIBILITY OF ANOTHER ROUND OF
SEVERE WEATHER TO THE ENTIRE AREA DURING THE DAY WEDNESDAY.
CN
PRELIMINARY POINT TEMPS/POPS
SHV 56 83 64 86 / 0 0 0 10
MLU 54 80 56 86 / 0 0 0 10
DEQ 48 78 55 84 / 0 0 0 10
TXK 51 80 61 85 / 0 0 0 10
ELD 48 77 56 83 / 0 0 0 10
TYR 56 84 65 84 / 0 0 0 10
GGG 54 84 63 86 / 0 0 0 10
LFK 62 87 65 85 / 10 10 0 20
SHV WATCHES/WARNINGS/ADVISORIES
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
19/09/33
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