839
FXUS64 KSHV 071005
AFDSHV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
505 AM CDT TUE MAY 7 2024
..NEW AVIATION
SHORT TERM
(TUESDAY THROUGH WEDNESDAY)
ISSUED AT 249 AM CDT TUE MAY 7 2024
EARLY MORNING NT MICROPHYSICS IMAGERY SHOWS LOW CLOUDS STREAMING
NORTH ACROSS THE FA, AS UPPER-LEVEL SHEARED CIRRUS FROM DEEP
CONVECTION ACROSS OK/AR DRIFTS WEST TO EAST, JUST NORTH OF THE
I-30 CORRIDOR. FOR THE MOST PART, TUESDAY WILL REMAIN DRY AND
QUIET, WITH THE MAIN STORY THROUGH THE AFTERNOON BEING THE WARMER
TEMPERATURES AS HIGHS CLIMB INTO THE UPPER 80'S TO NEAR 90 DEG F.
GIVEN THE EXTENT OF THE DIURNALLY DRIVEN SFC HEATING THIS AFTERNOON,
HI-RES GUIDANCE ADVERTISES AN AGGRESSIVE DISPLAY OF SURFACE-BASED
INSTABILITY PARAMETERS ACROSS THE FOUR STATE REGION WITH SBCAPE
VALUES AS HIGH AS 3000-3500 J/KG OR GREATER, WITH 0-6 KM BULK
SHEAR VALUES BETWEEN 40-50 KTS, AND 700-500 LAPSE RATES BETWEEN
7-8 C/KM. THE CATCH HERE IS THAT WHILE THIS MAY BE AVAILABLE,
GUIDANCE LOOKS TO LEAVE IT MOSTLY UNTAPPED AS FORCING REMAINS WELL
DISPLACED FROM THE LOCAL COVERAGE ZONE, PRIMARILY LOCATED IN A
REGION OF BETTER SYNOPTIC FORCING AND ASCENT WELL TO THE NORTH AND
EAST OF THE LOCAL AREA.
MORNING GUIDANCE CONTINUES TO SUGGEST THAT A RESIDUAL SFC
BOUNDARY MAY EXIST CLOSE TO THE I-30 CORRIDOR THIS AFTERNOON FROM
OVERNIGHT CONVECTION ACROSS OKLAHOMA. THIS BOUNDARY SHOULD WASH
OUT AND LOSE IT'S POTENCY DUE TO AFTERNOON MIXING. IT IS WORTH
MENTIONING THAT SOME CAMS DO SUGGEST A SECONDARY INSTABILITY AXIS
TO DRIFT NORTH INTO THE BETTER SFC PARAMETERS, SUPPORTING SOME
LIMITED CONVECTIVE INITIATION BY THE EVENING, BUT BY THIS POINT IT
MAY BE TOO LATE FOR ANY DEEPLY ROOTED CONVECTION TO EVOLVE. MAIN
CONCERNS IF ANY THUNDERSTORMS ARE TO DEVELOP ALONG THE
INSTABILITY AXIS WOULD BE THE THREAT FOR GUSTY WINDS AND HAIL.
THIS WOULD BE LOCATED MAINLY IN THE MARGINAL RISK ZONE (LEVEL 1
OF 5), HIGHLIGHTED IN THE STORM PREDICTION CENTER DAY 1 OUTLOOK.
WEDNESDAY SEVERE THREAT:
BY WEDNESDAY MORNING, BETTER FORCING STARTS TO DIG INTO THE SOUTHERN
PLAINS, WITH A SFC COLD FRONT ADVANCING SOUTHWARD, PROGGED TO ENTER
INTO THE FOUR STATE REGION BY MID TO LATE WEDNESDAY AFTERNOON.
ANOTHER WARM AFTERNOON ACROSS THE FA WILL PROMOTE FURTHER SFC
INSTABILITY AS HIGH TEMPERATURES EASILY CLIMB TO 90 DEG F AND
POSSIBLY A DEGREE OR TWO HIGHER. AS THE BOUNDARY CLASHES WITH THE
LOCAL AIRMASS, DEEPLY ROOTED CONVECTIVE INITIATION WILL LOOK TO
DEVELOP ACROSS A REGION OF HIGH SBCAPE PROFILES APPROACHING, AND
POSSIBLY EVEN EXCEEDING, 3500 J/KG, 0-6 KM BULK SHEAR BETWEEN
40-50 KTS, AND STEEP LAPSE RATES NEARING 8.0 C/KM.
THOUGH SOME LOW LEVEL DIRECTIONAL SHEAR WILL BE PRESENT, SUPPORTING
THE CHANCE FOR A TORNADO OR TWO, THE MAIN CONCERN FROM THE
ADVERTISED CAMS AND HREF SOLUTION WILL BE THE THREAT FOR LARGE HAIL
WITHIN THE ENHANCED RISK (LEVEL 3 OF 5). BASED ON LATEST GUIDANCE,
CONVECTION SHOULD DIMINISH AHEAD OF SUNRISE THURSDAY.
RK
LONG TERM
(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 249 AM CDT TUE MAY 7 2024
BY THURSDAY MORNING, THE FORWARD SPEED OF THE ADVANCING SFC BOUNDARY
WILL DICTATE THE COVERAGE OF THE DAY 3 SEVERE THREAT LOCALLY.
GENERAL THINKING FOR NOW IS THAT THE BOUNDARY WILL BE LOCATED
SOMEWHERE BETWEEN I-30 AND I-20, AND IS PROGGED TO SLIDE SOUTH
THROUGH THE AFTERNOON. AFTERNOON MAXT'S SOUTH OF THE BOUNDARY WILL
CLIMB INTO THE UPPER 80'S AND LOW 90'S, WITH INSTABILITY
PARAMETERS STRONGEST IN THIS REGION. FRONTAL BASED FORCING WILL
SUPPORT CONVECTIVE INITIATION ALONG AND AHEAD OF THE BOUNDARY BY
THE AFTERNOON, AND CONTINUE INTO THE EVENING IN THE FORM OF A
POSSIBLE MCS. PRIMARY CONCERNS WITH THE DEVELOPING CONVECTION IS
THE THREAT FOR DAMAGING WIND, AND LARGE HAIL. THE CHANCE FOR AN
EMBEDDED TORNADO SHOULD NOT RULED OUT.
THE FRONT WILL SAG SOUTH OF THE FA BY FRIDAY AM, WITH HIGH PRESSURE
INFLUENCING THE REGION FOR MUCH OF FRIDAY AND INTO WEEKEND. GUIDANCE
OVERNIGHT NOW KEEPS MUCH OF THE AREA RAIN FREE TILL ABOUT EARLY TO
MID NEXT WEEK. POST FRONTAL PASSAGE AIRMASS WILL HELP RETURN TEMPS
TO NEAR NORMAL THROUGH THE REMAINDER OF THE FORECAST PERIOD.
RK
AVIATION
(12Z TAFS)
ISSUED AT 503 AM CDT TUE MAY 7 2024
LITTLE CHANGE FROM THE 06Z TAF PACKAGE. WIDESPREAD MVFR
CONDITIONS CURRENTLY PREVAILING ACROSS OUR AIRSPACE. SHOULD SEE
THESE CEILINGS LIFT ABOVE MVFR CATEGORIES, BECOMING LOW VFR BY MID
TO LATE MORNING WITH LOW VFR CEILINGS SCATTERING OUT DURING THE
AFTERNOON. WHILE CANNOT RULE OUT ISOLATED SHOWERS LATER TODAY, POP
COVERAGE DOES NOT WARRANT A MENTION IN THIS 12Z TAF PACKAGE. LOOK
FOR RETURNING MVFR CEILINGS LATER THIS EVENING INTO THE OVERNIGHT
HOURS.
13
PRELIMINARY POINT TEMPS/POPS
SHV 89 74 90 72 / 10 10 20 40
MLU 88 73 91 71 / 10 0 10 40
DEQ 86 66 85 63 / 20 20 30 50
TXK 89 72 90 68 / 10 20 30 60
ELD 88 70 90 67 / 20 20 20 60
TYR 88 71 89 71 / 10 10 30 30
GGG 88 72 90 70 / 10 10 30 30
LFK 89 72 91 73 / 10 0 10 10
SHV WATCHES/WARNINGS/ADVISORIES
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
SHORT TERM...53
LONG TERM....53
AVIATION...13
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