406
FXUS64 KLCH 021928
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
228 PM CDT FRI OCT 2 2026
..NEW DISCUSSION, MARINE, FIRE WEATHER
KEY MESSAGES
-HIGH RAIN CHANCES CAN BE EXPECTED OVER THE WEEKEND AS AN UPPER LEVEL
TROUGH, WEAK SURFACE BOUNDARY, AND TROPICAL WAVE ALL MERGE INTO
A VERY MOIST AIR MASS OVER THE REGION.
-TRENDS SHOW A HIGH PROBABILITY OF A "WETTING" RAIN DURING THE
WEEKEND THAT WOULD HELP WITH FIRE WEATHER AND DROUGHT CONCERNS.
-THERE IS SOME POTENTIAL FOR HEAVY RAINFALL DURING THE WEEKEND ESPECIALLY
OVER LOWER ACADIANA AND THE ATCHAFALAYA BASIN WHERE THE BEST
MOISTURE AND LIFT WILL BE LOCATED.
-A SECONDARY SURFACE FRONT ON MONDAY WILL BRING LOWER RAIN CHANCES AND
SLIGHTLY COOLER TEMPERATURES CLOSER TO THE CLIMO NORM FOR EARLY
NEXT WEEK.
DISCUSSION
(THIS EVENING THROUGH NEXT THURSDAY)
ISSUED AT 221 PM CDT FRI OCT 2 2026
THE SYNOPSIS SHOWS THE OLD UPPER LEVEL LOW HAS NOW SHEARED OUT WITH
AN UPPER LEVEL TROUGH/SHEAR AXIS. THIS SHEAR AXIS HAS A TROPICAL
CONNECTION AS IT EXTENDS FROM HURRICANE RACHEL OFF OF MEXICO UP INTO
THE EASTERN GREAT LAKES. MEANWHILE, AN UPPER LEVEL LOW IS LOCATED
OVER THE SOUTHWEST GULF WITH AN ASSOCIATED INVERTED TROUGH/TROPICAL
WAVE EXTENDING NORTHEAST FROM IT TO THE NORTHEAST GULF. A SURGE OF
RICH MOISTURE ORIGINATING FROM THE NORTHWEST CARIBBEAN IS MOVING UP
WITH THE TROPICAL WAVE.
LATEST UPPER AIR SOUNDING SHOWS A PWAT OVER 2 INCHES WITH A WEAKNESS
ALOFT. THEREFORE, SCATTERED SHOWERS ARE DEVELOPING WITH DAYTIME
HEATING AND MOVING EAST TO WEST ACROSS THE FORECAST AREA. THIS
ACTIVITY WILL DECREASE AFTER SUNSET WITH THE LOSS OF DAYTIME HEATING.
OVER THE WEEKEND RAIN CHANCES WILL BE INCREASING, WHICH WILL BE GOOD
NEWS FOR SOME WHO NEED THE RAIN. THE MOIST SHEAR AXIS WILL CONTINUE
TO MOVE SLOWLY EASTWARD PUSHING A WEAK SURFACE BOUNDARY INTO THE
FORECAST AREA ON SATURDAY. MEANWHILE, THE INVERTED TROUGH/TROPICAL
WAVE AND ASSOCIATED RICH DEEP MOISTURE WILL MOVE TO THE NORTHWEST.
THESE SYSTEMS WILL MERGE OVER THE REGION MAKING A VERY HIGHLY
ANOMALOUS MOIST ATMOSPHERE. WITH THE WEAKNESS ALOFT AND VERY MOIST
AIR MASS, PERIODS OF SHOWERS ARE EXPECTED TO DEVELOP DURING THE DAY
ON SATURDAY.
CONSENSUS OF THE GUIDANCE STILL SHOWS PRECIPITABLE WATER VALUES
BETWEEN 2.3 AND 2.6 INCHES. THESE VALUES ARE WELL ABOVE THE 90TH
PERCENTILE CLIMO VALUE OF 1.94 INCHES AND CLOSER TO THE 99TH
PERCENTILE AT OR ABOVE THE MAX MOVING AVERAGE AND DAILY CLIMO MAX.
THE 100H-50H MEAN LAYER RELATIVE HUMIDITY WILL BE OVER 80 PERCENT,
AND WITH WARM CLOUD LAYERS PROJECTED TO BE AROUND OR ABOVE 15K FEET
DEPICTING GOOD WARM RAIN PROCESSES FOR THE CONVECTION, AND ACTIVITY
THAT DEVELOPS WILL HAVE THE POTENTIAL TO BE HIGHLY EFFICIENT
PRECIPITATION PRODUCERS.
THE BEST PROBABILITY FOR SHOWER ACTIVITY WILL BE FROM SATURDAY
AFTERNOON INTO SUNDAY MORNING AS THE WEAK SURFACE BOUNDARY PUSHES
THROUGH PROVIDING A BIT OF ENHANCED LIFT AND A FOCUS. THE STRONGEST
LIFT ASSOCIATED WITH THE UPPER LEVEL FEATURE AND BEST LOW LEVEL
CONVERGENCE LOOK TO BE ALONG THE INVERTED TROUGH, WHICH IS LOOKING
TO SET UP FROM OFF THE SOUTHWEST LOUISIANA COAST INTO THE LOWER
ATCHAFALAYA BASIN THEN INTO SOUTHEAST LOUISIANA. THAT IS LIKELY
WHERE THE STRONGER CONVECTION CAN GET GOING WITH HIGHER RAINFALL
RATES. ELSEWHERE, THE HEAVIER RAIN MAY BE MORE SPORADIC AND PATCHY
AND LOCATED WHERE THE HIGHER CAPES OF BETWEEN 1500 AND 2000 J/KG
CAN DEVELOP.
THE FORECASTED RAINFALL TOTAL AMOUNTS THROUGH SUNDAY ARE AVERAGING
BETWEEN 0.5 AND 1.50 INCHES, NORTHWEST OF AN ALEXANDRIA TO SABINE
PASS LINE, WHILE FORECAST TOTAL RAINFALL AMOUNTS FROM 1.5 TO 3.0
INCHES SOUTHEAST OF AN ALEXANDRIA TO SABINE PASS LINE. MEANWHILE,
90TH PERCENTILE OR THE REASONABLE HIGHEST AMOUNTS ARE IN THE 2 TO 4
INCH RANGE, WITH SOME 4 TO 8 INCHES SHOWING UP RIGHT ALONG THE
COAST OF LOWER ACADIANA UP INTO THE LOWER ATCHAFALAYA BASIN.
THEREFORE, A SLIGHT RISK (LEVEL 2 OUT OF 4) POTENTIAL OR BETWEEN A
15 AND 25 PERCENT CHANCE OF SEEING EXCESSIVE RAINFALL THAT MAY
LEAD TO FLASH FLOODING FOR THE LOWER ATCHAFALAYA BASIN ON SATURDAY
WITH A MARGINAL RISK FOR THE REMAINDER OF THE FORECAST AREA, WITH
A MARGINAL RISK EXTENDING INTO SUNDAY FOR LOWER ACADIANA AND THE
ATCHAFALAYA BASIN. AT THE VERY LEAST, THERE IS ABOVE AN 80 PERCENT
CHANCE OF SEEING A WETTING RAIN OF OVER 0.25 INCHES THAT IS MUCH
NEEDED AND SHOULD HELP WITH FIRE WEATHER CONCERNS.
HIGH TEMPERATURES OVER THE WEEKEND WILL BE LITTLE COOLER WITH HIGHS
IN THE MID TO UPPER 80S DUE TO THE CLOUD COVER AND RAIN.
AS AN UPPER LEVEL RIDGE BUILDS OVER THE WESTERN US, THE NORTHERN
STREAM WILL TAKE A DIP TO THE SOUTHEAST AND ALLOW A SECONDARY
FRONTAL SYSTEM TO MOVE ACROSS ON MONDAY INTO TUESDAY THAT IS
EXPECTED TO BRING DRIER CONDITIONS ALONG WITH OVERNIGHT LOWS IN THE
LOWER TO MID 60S AND CLOSER TO THE SEASONAL NORM.
07/RUA
AVIATION
(18Z TAFS)
ISSUED AT 1222 PM CDT FRI OCT 2 2026
SCATTERED SHOWERS AND STORMS ARE POSSIBLE AT ALL SITES THIS
AFTERNOON AND EARLY EVENING AND ARE EXPECTED TO DECREASE FOLLOWING
SUNSET. WINDS WILL REMAIN ENE/E AROUND 5KTS WITH WINDS TRENDING
LIGHT AND VARIABLE AFTER THE SUN GOES DOWN. SOME SHOWERS/STORMS MAY
POTENTIALLY BRING CEILINGS DOWN INTO MVFR CATEGORY FOR A BRIEF
PERIOD OF TIME. ASIDE FROM ANY CONVECTION, VFR CONDITIONS WILL
PREVAIL THROUGH MOST OF THE TAF PERIOD.
AFTER SUNRISE TOMORROW MORNING WINDS WILL ESTABLISH FROM THE
NORTHEAST AROUND 8-10KTS THROUGH THE END OF THE PERIOD. SKIES WILL
ALSO START BECOMING MORE OVERCAST WHICH COULD BRING MVFR INTO THE
REGION. RAIN CHANCES ALSO BEGIN TO INCREASE CLOSER TO THE END OF THE
TAF PERIOD. WILL CONTINUE TO MONITOR AND SEND AMENDMENTS AS NEEDED.
/86/
MARINE
ISSUED AT 221 PM CDT FRI OCT 2 2026
THE GRADIENT BETWEEN AN INVERTED TROUGH OVER THE CENTRAL GULF AND
HIGH PRESSURE OVER THE SOUTHEAST US WILL BRING MODERATE EAST TO
NORTHEAST WINDS AND MODERATE SEAS THROUGH THE WEEKEND. WIDESPREAD
RAIN AND STORMS WILL IMPACT COASTAL WATERS, REDUCING VISIBILITY AND
CAUSING LOCALLY HIGHER WINDS AND WAVES AS A FRONTAL BOUNDARY NEARS
THE COAST. THIS FRONT WILL MOVE OUT INTO THE COASTAL WATERS EARLY
NEXT WEEK WITH A PERIOD OF MODERATE TO STRONG OFFSHORE FLOW.
FIRE WEATHER
ISSUED AT 221 PM CDT FRI OCT 2 2026
A VERY MOIST AND TROPICAL LIKE AIR MASS WILL MOVE INTO THE REGION
THROUGH THE WEEKEND. THIS WILL INCREASE RAIN CHANCES AND HUMIDITY
LEVELS. MINIMUM AFTERNOON RELATIVE HUMIDITY VALUES ARE EXPECTED TO
BE OVER 60 PERCENT. ALSO, THE PROBABILITY FOR A WIDESPREAD WETTING
RAIN IS OVER 80 PERCENT THROUGH THE WEEKEND. THIS SHOULD HELP REDUCE
FIRE DANGER AS WE MOVE INTO EARLY OCTOBER. DRIER AND SLIGHTLY COOLER
WEATHER CAN BE EXPECTED BY TUESDAY.
LCH WATCHES/WARNINGS/ADVISORIES
LA...NONE.
TX...NONE.
GM...NONE.
PUBLIC/FIRE/MARINE...07
AVIATION...86
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