299
FXUS64 KSHV 181032
AFDSHV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SHREVEPORT LA
432 AM CST TUE FEB 18 2025
..NEW SHORT TERM, LONG TERM
SHORT TERM
(TUESDAY THROUGH WEDNESDAY NIGHT)
ISSUED AT 432 AM CST TUE FEB 18 2025
COMPLICATED SHORT TERM FORECAST THIS MORNING, WHICH WILL BE LARGELY
DEPENDENT ON HOW FAST THE FREEZING LINE IS ABLE TO SINK SSW THIS
AFTERNOON/TONIGHT AS THE PRECIPITATION RAMPS UP LATE THIS MORNING
THROUGH TONIGHT. THE EARLY MORNING SFC ANALYSIS INDICATES THE
LEADING EDGE OF OUR ARCTIC COLD FRONT EXTENDING FROM THE TX SOUTH
PLAINS NE INTO SW/SCNTRL/NE OK ACROSS NRN AR. MEANWHILE THE
MORNING WATER VAPOR IMAGERY INDICATES UPPER TROUGHING SWINGING
THROUGH ERN CA/SRN NV, WHICH WILL PROGRESS E INTO ERN NM/THE TX
PANHANDLE LATER THIS AFTERNOON. AS IT APPROACHES THE FRONT, THE
SHORT TERM PROGS ARE IN AGREEMENT WITH A DEVELOPING WEAK FRONTAL
WAVE/LOW LEVEL CYCLOGENESIS IN THE H925-850 LYR, THUS ENHANCING
ISENTROPIC FORCING LATER THIS MORNING THROUGH THE AFTERNOON ACROSS
E TX/SE OK, WITH SYNOPTIC FORCING INCREASING AHEAD OF THE
APPROACHING TROUGH YIELDING AN INCREASE IN DEEPER CONVECTION BY
LATE AFTERNOON, PROGRESSING E THROUGH THE EVENING/OVERNIGHT HOURS.
THE ERN EDGE OF THIS ARCTIC AIR MASS OVER NRN AR IS MORE SHALLOW IN
NATURE THAN FARTHER W ACROSS OK, WITH THE HIGHER TERRAIN OF THE OUACHITAS
ALLOWING FOR DAMMING OF THIS AIR MASS LATER TODAY/TONIGHT, WITH THE
SUBFREEZING AIR HAVING TO EVENTUALLY BACKDOOR SW INTO THE NRN ZONES THIS
AFTERNOON, BEFORE EVENTUALLY DEEPENING THIS EVENING AS IT BEGINS
TO DRIFT FARTHER S TONIGHT.
WHILE THE PRECIP ONSET WILL BEGIN AS ALL LIQUID, SOME OF THE
HIGHER TERRAIN OF NRN MCCURTAIN COUNTY OK AND THE NRN SECTIONS OF
SW AR MAY SEE A TRANSITION OVER TO -FZRA AFTER 18Z, BEFORE THE
FREEZING LINE IS ABLE TO BACKDOOR FARTHER SW INTO THE AREA
TONIGHT. FOR THIS REASON, HAVE ISSUED A WINTER WEATHER ADVISORY
FOR THESE AREAS BEGINNING AT 18Z, WITH A 2ND ADVISORY ALSO ISSUED
FOR AREAS FARTHER S INTO EXTREME NE TX/THE REMAINDER OF SRN
AR/PORTIONS OF NW AND NCNTRL LA STARTING AT 00Z, BOTH VALID
THROUGH 12Z WEDNESDAY. -FZRA WILL BE THE MAIN PRECIP TYPE,
ALTHOUGH A BRIEF TRANSITION OVER TO IP WILL BE POSSIBLE MAINLY ON
THE BACK SIDE OF THE DIMINISHING PRECIPITATION LATER THIS
EVENING/OVERNIGHT AS MUCH DRIER AIR BEGINS TO ENTRAIN E AHEAD OF
THE ATTENDANT TROUGH. THIS IS NOT EXPECTED TO BE A MAJOR ICING
EVENT, WITH MOST LOCALES ONLY SEEING A GLAZE UP TO SEVERAL
HUNDRETHS OF AN INCH OF ICE. HOWEVER, PORTIONS OF MCCURTAIN COUNTY
OK AND THE NRN SECTIONS OF SW AR THAT WILL BE IN THE SUBFREEZING
AIR LONGER WILL HAVE THE POTENTIAL FOR UP TO TWO-TENTHS OF AN INCH
OF ICE BEFORE ENDING, WITH AREAS FARTHER S MAINLY FACING IMPACTS
OF A GLAZING ON BRIDGES/OVERPASSES, TREES AND POWER LINES. HAD
DEBATED HOW FAR S TO GO WITH THE ADVISORY, WITH THE HIGH RES PROGS
IN GOOD AGREEMENT BRINGING THE FREEZING LINE INTO NCNTRL LA PRIOR
TO DAYBREAK WEDNESDAY, ON THE BACKSIDE OF THE DIMINISHING PRECIP.
THUS, HAVE ERRED ON THE SIDE OF CAUTION AS IT WON'T TAKE MUCH ICE
FOR MINOR IMPACTS ESPECIALLY ON BRIDGES AND OVERPASSES.
IN ADDITION, N WINDS WILL INCREASE ON THE BACK SIDE OF THE ARCTIC
FRONT AS MUCH COLDER AIR BEGINS TO SPILL S, AND WHILE PORTIONS OF
THE EXTREME NW ZONES MAY SEE A BRIEF PERIOD OF COLD WEATHER
ADVISORY CRITERIA AROUND DAYBREAK WEDNESDAY, HAVE HELD OFF ON THE
ADVISORY ATTM AS WIND CHILLS WILL BE MARGINAL. OTHERWISE, POST-
FRONTAL STRATOCU MAY BE A LITTLE SLOW TO LIFT WEDNESDAY, WITH
TEMPS REMAINING IN THE 30S AREAWIDE. N WINDS WILL PERSIST AREAWIDE
WEDNESDAY NIGHT AS THE CENTER OF THE ARCTIC RIDGING SLOWLY BUILDS
S THROUGH THE CNTRL/SRN PLAINS INTO THE LOWER MS VALLEY. THIS WILL
RESULT IN DANGEROUSLY COLD WIND CHILLS WEDNESDAY NIGHT, WITH
AMBIENT 2M TEMPS FALLING INTO THE TEENS TO NEAR 20 DEGREES, WITH
RESULTANT WIND CHILLS FALLING INTO THE SINGLE DIGITS ACROSS NE TX
N OF I-20, SE OK/SW AR, AND INTO THE LOWER AND MIDDLE TEENS
ELSEWHERE ACROSS LOWER E TX/N LA. THUS, A COLD WEATHER ADVISORY
WILL BE NEEDED AREAWIDE, ALTHOUGH THIS WILL BE DEFERRED TO LATER
SHIFTS.
THANK YOU WFO'S FWD/LZK/JAN FOR COLLABORATION THIS MORNING.
15
LONG TERM
(THURSDAY THROUGH TUESDAY)
ISSUED AT 432 AM CST TUE FEB 18 2025
OLE MAN WINTER WILL MAINTAIN ITS GRIP ON THE REGION THURSDAY INTO
THE START OF THE UPCOMING WEEKEND, AS THE ARCTIC SFC RIDGING
REMAINS ANCHORED FROM THE MIDWEST INTO THE NRN GULF. THE AIR MASS
WILL BEGIN A SLOW MODERATING TREND BY SATURDAY, EVEN AS LOW LEVEL
MOISTURE/WEAK ISENTROPIC FORCING COMMENCES AS EARLY AS LATE FRIDAY
NIGHT, AHEAD OF THE NEXT UPPER TROUGH THAT WILL SWING INTO THE SRN
PLAINS SATURDAY MORNING AND EVENTUALLY INTO THE LOWER MS VALLEY.
THUS, AREAS OF -RA WILL BE POSSIBLE LATE FRIDAY NIGHT ACROSS
PORTIONS OF E TX/WRN LA, WITH A BRIEF TRANSITION TO -FZRA NOT OUT
OF THE QUESTION AND WILL BE LARGELY DEPENDENT ON HOW LOW TEMPS CAN
FALL AS SOME WARMING OF THE COLUMN SHOULD OCCUR WITHIN THE SW LOW
LEVEL FLOW, WHICH SHOULD EVENTUALLY MIX DOWN TO THE SFC FROM ANY
-RA THAT FALLS. ANY ICING ACCUMS WILL BE MINOR (IF ANY), ALTHOUGH
AREAS OF -RA WILL EXPAND FARTHER N AND E SATURDAY AHEAD OF THE
APPROACHING TROUGH. MUCH WARMER AND DRIER CONDITIONS ARE
EXPECTED BY SUNDAY INTO THE START OF THE NEW WORK WEEK ONCE THE TROUGH
SHIFTS E OF THE REGION, AS A SRLY LOW LEVEL FLOW COMMENCES BY MONDAY,
AND STRONGER INSOLATION IS EXPECTED WITHIN A DRY NW FLOW ALOFT.
15
AVIATION
(06Z TAFS)
ISSUED AT 1047 PM CST MON FEB 17 2025
FOR THE ARKLATEX TERMINALS, COLD AIR MASS MOVG E AS PACIFIC
MOISTURE ASCENDS THE DOME WITH LOW VFR CLOUDS NOW SPREADING OVER
E TX. HRRR SHOWS -RA DVLPG BETWEEN 12-15Z OVER E TX TERMINALS,
AND INTO KTXK/KSHV 16-20Z. THE LATE AFTN OVERRUNS WITH ISOLD TS
AT OUR TX/LA WITH CIGS LOWERING TO IFR/MVFR. FROPA GEARS UP OVER
OK/AR WITH NE WINDS BACK TO N 03-09Z AS THE ARCTIC AIR POURS
ACROSS I-20. -RA/+RA, BUT MIX -FZRA/IP WHILE ENDING. MINOR
IMPACTS TO ELEVATED STRUCTURES, BUT NOT AS LIKELY ON GROUND. /24/
SPOTTER INFORMATION STATEMENT
ISSUED AT 405 AM CST MON FEB 17 2025
SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
PRELIMINARY POINT TEMPS/POPS
SHV 50 29 38 21 / 60 90 0 0
MLU 53 27 36 20 / 20 100 0 0
DEQ 37 21 33 12 / 90 70 0 0
TXK 42 24 36 18 / 80 80 0 0
ELD 44 21 33 16 / 40 90 0 0
TYR 50 26 34 18 / 80 60 0 0
GGG 49 28 36 19 / 80 80 0 0
LFK 57 33 41 23 / 70 90 0 0
SHV WATCHES/WARNINGS/ADVISORIES
AR...WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST WEDNESDAY
FOR ARZ050-051-059>061.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
WEDNESDAY FOR ARZ070>073.
LA...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
WEDNESDAY FOR LAZ001>006-012>014-019-021.
OK...WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST WEDNESDAY
FOR OKZ077.
TX...WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST
WEDNESDAY FOR TXZ096-097-111-112-126.
SHORT TERM...15
LONG TERM....15
AVIATION...24
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