729
FXUS64 KLCH 202354
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
554 PM CST THU FEB 20 2020
DISCUSSION
FOR THE 02/21/20 0000 UTC TAF PACKAGE.
AVIATION
MVFR ALL SITES EARLY THIS EVENING, WITH PERIODIC IFR OBSERVED AT
THE ACADIANA TERMINALS AND PATCHES OF LIGHT RAIN CONTINUING TO
STREAM ACROSS THE I-10 TERMINALS. PATCHES OF LIGHT RAIN AND LOW
CLOUDS ARE EXPECTED TO PERSIST THROUGH MID EVENING OR SO, WITH
RAINS ENDING AND LOW CLOUDS CLEARING THE AREA FROM GENERALLY N TO
S BY LATE EVENING OR JUST AFTER MIDNIGHT. BRISK AND GUSTY NORTH
WINDS WILL CONTINUE THROUGH THE EVENING, AND ONLY GRADUALLY
DECREASE FROM N TO S THROUGH THE OVERNIGHT PERIOD INTO FRI.
13
PREV DISCUSSION
/ISSUED 329 PM CST THU FEB 20 2020/
DISCUSSION...
THIS AFTERNOON'S GOES-16 WATER VAPOR IMAGERY INDICATES AN UPPER
LEVEL TROUGH IS CONTINUING TO SLOWLY PROGRESS EASTWARD ACROSS THE
SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. AS THE TROUGH
AXIS APPROACHES AND MOVES EAST OF THE CWA, UPPER LEVEL SUPPORT FOR
OVERRUNNING PRECIPITATION WILL DECREASE AND RESULT IN SHOWERS
COMING TO AN END. THIS DECREASE IN COVERAGE OF SHOWERS CAN ALREADY
BE NOTED IN THE REGIONAL RADAR MOSAIC OVER THE PAST SEVERAL HOURS
AND WILL CONTINUE THROUGH THIS EVENING. THE CONSENSUS OF THE SHORT
TERM GUIDANCE IS THAT THESE SHOWERS SHOULD END BY 9 PM.
HIGH PRESSURE WILL BEGIN BUILDING INTO THE REGION LATE THIS
EVENING AND REMAIN IN PLACE THROUGH SUNDAY. THIS WILL RESULT IN
DRY CONDITIONS AND BELOW NORMAL TEMPERATURES. THE COMBINATION OF
LOW DEWPOINTS, LIGHT WINDS, AND CLEAR SKIES WILL RESULT IN
FAVORABLE CONDITIONS FOR RADIATIONAL COOLING FRIDAY NIGHT INTO
SATURDAY MORNING. THIS WILL RESULT IN THE CHANCE FOR FROST ALONG
WITH SUB-FREEZING TEMPERATURES FOR AREAS NORTH OF INTERSTATE 10.
MODEL AND ENSEMBLE GUIDANCE REMAINS IN GOOD AGREEMENT WITH THE
EVOLUTION OF THE NEXT UPPER LEVEL TROUGH WHICH WILL PROGRESS
EAST-NORTHEASTWARD ACROSS THE CENTRAL PLAINS AND MIDWEST DURING
THE EARLY PART OF NEXT WEEK. THIS TROUGH WILL SUPPORT LEE
CYCLOGENESIS OVER THE CENTRAL PLAINS AND THE COLD FRONT ASSOCIATED
WITH THIS SYSTEM IS FORECAST TO MOVE THROUGH THE CWA LATE MONDAY.
THIS WILL RESULT IN CHANCES FOR SHOWERS FROM LATE SUNDAY NIGHT
THROUGH MONDAY EVENING.
GUIDANCE IS ALSO IN GOOD AGREEMENT THAT A LONGWAVE TROUGH WILL BE
IN PLACE OVER THE EASTERN TWO-THIRDS OF THE CONUS FOR THE SECOND
HALF OF NEXT WEEK. UPPER LEVEL SUBSIDENCE WILL SUPPORT SURFACE
HIGH PRESSURE TO BUILD SOUTHWARD FROM THE NORTHERN PLAINS AND
BECOME CENTERED OVER THE GULF COAST BY FRIDAY. THIS WILL RESULT
IN A PERIOD OF BELOW NORMAL PRECIPITATION CHANCES AND SLIGHTLY
BELOW NORMAL TEMPERATURES DURING THE LATER HALF OF NEXT WEEK.
MARINE...
WINDS WILL CONTINUE TO INCREASE THROUGH THIS EVENING WITH GALE
FORCE GUSTS BECOMING FREQUENT AFTER 6 PM. WINDS WILL REMAIN
ELEVATED THROUGH TONIGHT AND INTO TOMORROW AFTERNOON. THE GALE
WARNING WAS LEFT UNCHANGED WITH THIS FORECAST PACKAGE AS THERE ARE
SOME INDICATIONS THAT GALE FORCE GUSTS MAY END AFTER SUNRISE
FRIDAY. HOWEVER, AT LEAST SMALL CRAFT ADVISORY CONDITIONS WILL
CONTINUE INTO FRIDAY AFTERNOON BEFORE IMPROVING FRIDAY EVENING AS
THE PRESSURE GRADIENT BEGINS TO DECREASE. HIGH PRESSURE WILL
BECOME CENTERED OVER THE NORTHERN GULF COAST THIS WEEKEND AND
RESULT IN MUCH IMPROVED NAVIGATING CONDITIONS THROUGH SUNDAY.
PRELIMINARY POINT TEMPS/POPS
AEX 30 48 28 56 / 0 0 0 0
LCH 35 52 33 58 / 10 0 0 0
LFT 35 51 32 58 / 10 0 0 0
BPT 37 54 36 58 / 10 0 0 0
LCH WATCHES/WARNINGS/ADVISORIES
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ435-450-
452-455-470-472-475.
GALE WARNING UNTIL 6 AM CST FRIDAY FOR GMZ435-450-452-455-470-
472-475.
SMALL CRAFT ADVISORY UNTIL 6 AM CST FRIDAY FOR GMZ430-432.
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