623
FXUS64 KLCH 200530
AFDLCH
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAKE CHARLES LA
1230 AM CDT WED AUG 20 2025
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE, FIRE WEATHER
KEY MESSAGES
- A WEAK UPPER LEVEL RIDGE ALOFT AND NORTHERLY FLOW WILL BRING
ABOUT HOT AND HUMID CONDITIONS TODAY WITH LATE IN THE AFTERNOON
THUNDERSTORMS WHICH MAY BRING LOCALLY HEAVY RAINFALL AND GUSTY
WINDS.
- A TROUGH WILL MOVE INTO THE FORECAST AREA ON THURSDAY AND LINGER
INTO FRIDAY BRINGING A DECENT CHANCE FOR THUNDERSTORMS. WITH THE
EXPECTED HIGH MOISTURE CONTENT OF THE ATMOSPHERE HEAVY RAINFALL
WILL BE POSSIBLE.
- A BUILDING HIGH PRESSURE SYSTEM OVER THE MOUNTAIN WEST IS
EXPECTED TO BRING A DRY NORTHWEST FLOW INTO THE FORECAST AREA
OVER THE WEEKEND WITH LOWER RAIN CHANCES AND LESS HUMID
CONDITIONS.
SHORT TERM
(TODAY THROUGH FRIDAY NIGHT)
ISSUED AT 1226 AM CDT WED AUG 20 2025
WATCHING SOME CONVECTION MOVING DOWN FROM NORTHEAST LOUISIANA AND
NORTHWEST MISSISSIPPI TOWARD CENTRAL LOUISIANA. GUIDANCE SHOWS
ACTIVITY WEAKENING BEFORE REACHING THE FORECAST AREA, AND WILL GO
WITH THIS SCENARIO AS AIRMASS OVER THE FORECAST AREA HAS RELATIVELY
STABILIZED. AGAIN IT IS LIKELY ANY NOCTURNAL ACTIVITY THAT FORMS
TONIGHT WILL BE WITH AN ENHANCED LAND BREEZE OFFSHORE AND ACTIVITY
WILL STAY OFFSHORE.
FOR TODAY SOME WEAK UPPER LEVEL RIDGING IS EXPECTED TO EXTEND INTO
THE FORECAST AREA FROM THE RIDGE CENTERED OVER THE FOUR CORNERS,
WHICH WILL ALLOW FOR NORTHERLY FLOW TO BE IN PLACE. MEANWHILE, A
SURFACE TROUGH WILL BE NOTED NORTH OF THE REGION.
CONVECTION IS EXPECTED TO DEVELOP LATE IN THE DAY AHEAD OF THE
SURFACE TROUGH WITH NORTHERLY FLOW PUSHING IT SOUTH INTO THE
FORECAST AREA. DECENT GULF MOISTURE WILL BE TRAPPED BELOW THE RIDGE
AND AHEAD OF THE TROUGH WITH PWAT EXPECTED ABOVE 2 INCHES AND DEW
POINTS IN THE MID 70S. THEREFORE, A MOIST AND UNSTABLE AIR MASS THAT
WILL ALLOW FOR CONVECTION TO FEED DOWN INTO THE FORECAST AREA. ALSO,
SEABREEZE WILL LIKELY TRY TO PUSH INLAND DURING THE LATE AFTERNOON,
AND ANY POSSIBLE COLLISIONS BETWEEN SEABREEZE AND OUTFLOWS FROM THE
NORTH, LIKELY AFTER 4 PM, MAY SET THE STAGE FOR SOME LOCALIZED
ROBUST STORMS WITH GUSTY WINDS, FREQUENT LIGHTNING, AND TORRENTIAL
DOWNPOURS THE MAIN CONCERN.
LOOKING AT THE HEAT RISK, AIR TEMPERATURES AND DEW POINTS ARE
EXPECTED TO BE SIMILAR AS THEY WERE ON MONDAY AND TUESDAY.
THEREFORE, HEAT INDEX READINGS IN THE AFTERNOON BEFORE CONVECTION
BEGINS WILL RANGE FROM 103F TO 107F AND THUS WILL NOT HAVE A HEAT
ADVISORY OUT.
ON THURSDAY, ENHANCED NORTHERLY FLOW BETWEEN THE UPPER LEVEL RIDGE
OVER THE MOUNTAIN WEST AND THE OUTER CYCLONIC FLOW FROM ERIN OFF THE
MID-ATLANTIC COAST, WILL PUSH A TROUGH INTO THE FORECAST AREA.
HIGH MOISTURE CONTENT IS EXPECTED TO POOL AHEAD AND ALONG THE TROUGH
WITH PWAT AROUND 2.25 INCHES AND OVER THE 90TH PERCENTILE.
THEREFORE, EXPECT A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS ON
THURSDAY AND WITH THE HIGH MOISTURE CONTENT, SOME TORRENTIAL
DOWNPOURS WILL BE POSSIBLE. WITH THE EXPECTED CLOUD COVER AND
CONVECTION, HEAT RISK IS EXPECTED TO BE KEPT IN CHECK.
THIS TROUGH IS EXPECTED TO STALL NEAR THE COAST AND LINGER INTO
FRIDAY WITH ANOTHER DAY WITH A DECENT CHANCE FOR SHOWERS AND
THUNDERSTORMS, ESPECIALLY OVER THE SOUTHERN ZONES WITH INTERACTIONS
BETWEEN THE SURFACE BOUNDARY AND SEA BREEZE.
RUA
LONG TERM
(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 1228 AM CDT WED AUG 20 2025
THERE CONTINUES TO BE INDICATIONS THAT HIGH PRESSURE SYSTEM OVER
THE MOUNTAIN WEST WITH STRENGTHEN AND EXPAND TO THE EAST WITH A
GENERAL LONG WAVE TROUGH ALONG THE EASTERN U.S. IN THE WAKE OF
ERIN OVER THE WEEKEND. THIS IS EXPECTED TO STRENGTHEN THE
NORTHERLY FLOW OVER THE FORECAST AREA THAT WILL BRING IN DRIER
AIR. THE RESULT WILL BE LOWER RAIN CHANCES AND LESS HUMID
CONDITIONS FOR THE WEEKEND.
EARLY NEXT WEEK THE UPPER LEVEL TROUGH IS EXPECTED TO CONTINUE ALONG
THE U.S EAST COAST. THE UPPER LEVEL RIDGE OVER THE MOUNTAIN WEST IS
EXPECTED TO FLATTEN AND MOVE SOUTH AND BE CENTERED ROUGHLY ACROSS
THE SOUTHWEST U.S. AND TEXAS. THIS WILL ALLOW FOR A RATHER BENIGN
WEST-NORTHWEST FLOW ALOFT OVER THE REGION THAT SHOULD BRING ABOUT
RATHER CLIMO TEMPS AND POPS.
THE DETERMINISTIC NBM IS A LITTLE BIT ON THE "LOWER" SIDE ON THE
SPECTRUM OF TEMPERATURES AS WE GET INTO EARLY NEXT WEEK AND BELOW
THE 25TH PERCENTILE OF THE WHISKER PLOTS. THIS IS LIKELY DUE TO THE
INFLUENCE OF THE GFS WANTING TO BRING A SURFACE FRONT THROUGH THE
FORECAST AREA LATE MONDAY INTO TUESDAY. WILL NOT MAKE ANY CHANGES TO
THE THOSE PERIODS AT THIS TIME, HOWEVER, IT IS PROBABLE THAT THE
SUPPORT FOR A SURFACE FRONT MOVING THROUGH WILL LOWER AS WE GET
CLOSER TO WEEKEND.
RUA
AVIATION
(06Z TAFS)
ISSUED AT 1229 AM CDT WED AUG 20 2025
FAIR CONDITIONS ARE NOTED AT TERMINALS CURRENTLY AND VFR LEVELS ARE
EXPECTED OVERNIGHT. ALTHOUGH WILL BE WATCHING CONVECTION OVER
NORTHERN LOUISIANA AND NORTHWEST MISSISSIPPI TO MAKE SURE IT
DISSIPATES AS EXPECTED BEFORE REACHING CENTRAL LOUISIANA. THERE IS
ALSO AN OUTSIDE CHANCE OF SOME PATCHY FOG TOWARD SUNRISE THAT MAY
BRIEFLY BRING ABOUT VISIBILITY RESTRICTIONS.
ON WEDNESDAY, THERE WILL BE A CHANCE OF SHOWERS AND STORMS LATE IN
THE AFTERNOON AS A TROUGH STARTS TO MOVE DOWN FROM THE NORTH AND THE
SEABREEZE BEGINS TO BECOME ACTIVE. THEREFORE, WILL HAVE VCTS AFTER
20/21Z. AWAY FROM THE CONVECTION, VFR CONDITIONS WITH LIGHT WINDS
ARE EXPECTED.
RUA
MARINE
ISSUED AT 1229 AM CDT WED AUG 20 2025
A WEAK PRESSURE PATTERN WILL BE FOUND OVER THE NORTHWEST GULF
THROUGH THE END OF THE WEEK. THIS WILL ALLOW FOR LIGHT AND VARIABLE
WINDS ALONG WITH LOW SEAS. A TROUGH WILL MOVE TOWARD THE COAST FROM
THE NORTH ON THURSDAY STALLING ALONG THE COAST ON FRIDAY. THIS
TROUGH WILL HELP BRING AN INCREASE IN CHANCES FOR SHOWERS AND
THUNDERSTORMS DURING ANY TIME OF DAY THROUGH FRIDAY. MORE TYPICAL
SCATTERED SHOWERS AND THUNDERSTORMS, MAINLY LATE NIGHT AND EARLY
MORNING, AND AGAIN IN THE AFTERNOON WILL BE IN THE FORECAST OVER THE
WEEKEND.
FIRE WEATHER
ISSUED AT 1229 AM CDT WED AUG 20 2025
A HOT AND HUMID AIR MASS WILL CONTINUE OVER THE REGION ON WEDNESDAY
WITH AFTERNOON HEAT INDEX VALUES AROUND 105 DEGREES AND MINIMUM
RELATIVE HUMIDITY VALUES OVER 50 PERCENT. THERE WILL ALSO BE A
CHANCE FOR LATE AFTERNOON THUNDERSTORMS. MOISTURE WILL INCREASE
FURTHER ON THURSDAY AS A TROUGH MOVES INTO THE REGION WITH MINIMUM
RELATIVE HUMIDITY VALUES OVER 60 PERCENT AND THE POTENTIAL FOR
WIDESPREAD SHOWERS AND THUNDERSTORMS, SOME OF THE STORMS MAY
PRODUCE TORRENTIAL DOWNPOURS.
PRELIMINARY POINT TEMPS/POPS
AEX 97 73 91 71 / 50 40 60 30
LCH 95 75 92 74 / 40 40 80 50
LFT 95 75 92 74 / 40 30 70 40
BPT 95 74 92 73 / 50 50 80 60
LCH WATCHES/WARNINGS/ADVISORIES
LA...NONE.
TX...NONE.
GM...NONE.
SHORT TERM...07
LONG TERM....07
AVIATION...07
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