734
FXUS64 KLIX 212344
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
644 PM CDT MON SEP 21 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 642 PM CDT MON SEP 21 2026
- SCATTERED THUNDERSTORMS ARE EXPECTED MAINLY THIS AFTERNOON AND
EVENING, WITH THE GREATEST COVERAGE ACROSS THE NORTHERN HALF OF
THE AREA. A FEW STRONGER STORMS COULD PRODUCE LOCALIZED STRONG
TO DAMAGING WIND GUSTS.
- RAIN CHANCES DECREASE TUESDAY BEFORE A MOSTLY DRY COLD FRONT
MOVES THROUGH WEDNESDAY, BRINGING A SHIFT TO NORTHERLY WINDS AND
NOTICEABLY LOWER HUMIDITY.
- DRIER AIR BEHIND THE FRONT WILL ALLOW FOR COOLER THURSDAY
MORNING TEMPERATURES, ESPECIALLY ALONG AND NORTH OF I-12, WITH
QUIET AND DRY WEATHER CONTINUING LATE IN THE WEEK.
SHORT TERM
(NOW THROUGH WEDNESDAY NIGHT)
ISSUED AT 1208 PM CDT MON SEP 21 2026
TODAY WILL BE THE MOST CONVECTIVELY ACTIVE PERIOD OF THE SHORT
TERM AS THE APPROACHING UPPER TROUGH CONTINUES TO WEAKEN THE MID-
LEVEL CAP THAT HAS BEEN IN PLACE THE LAST FEW DAYS. CONVECTIVE
TEMPERATURES ARE GENERALLY AROUND 91-92 DEGREES THIS AFTERNOON,
WHICH MOST LOCATIONS SHOULD BEGIN REACHING AROUND 21Z. THAT TIMING
LINES UP WELL WITH THE LATEST CAM GUIDANCE, WHICH HAS TRENDED
TOWARDS GREATER COVERAGE COMPARED TO PREVIOUS RUNS, PARTICULARLY
ACROSS THE NORTHERN HALF OF THE AREA. GIVEN THE IMPROVED
AGREEMENT AND HIGHER CONFIDENCE, POPS WERE INCREASED AROUND 21Z IN
THOSE AREAS. CONVECTION SHOULD INITIALLY BE TIED TO DIFFERENTIAL
HEATING AND ANY LINGERING BOUNDARIES BEFORE STORM-SCALE OUTFLOWS
INCREASINGLY TAKE OVER. DEEP-LAYER SHEAR REMAINS VERY WEAK, SO
STORMS SHOULD LARGELY REMAIN PULSE-TYPE OR LOOSELY ORGANIZED
MULTICELLS. EVEN SO, STRONG INSTABILITY AND FAVORABLE
THERMODYNAMIC PROFILES SHOULD SUPPORT EFFICIENT DOWNDRAFT
ACCELERATION WITH THE STRONGER CORES, AND AN ISOLATED STRONG TO
SEVERE DOWNBURST CANNOT BE RULED OUT NEAR PEAK HEATING. DAMAGING
WIND WOULD BE THE MAIN CONCERN, THOUGH THE OVERALL SEVERE THREAT
REMAINS LIMITED BY THE WEAK SHEAR AND THE RELATIVELY SHORT-LIVED
NATURE OF INDIVIDUAL CELLS. THE CAMS ARE ALSO FAIRLY CONSISTENT
IN CONVECTION WINDING DOWN QUICKLY THIS EVENING, WITH COVERAGE
DECREASING AFTER SUNSET THIS EVENING AND MOST ACTIVITY LARGELY
FINISHED AROUND 03Z.
TUESDAY LOOKS NOTICEABLY LESS ACTIVE AS THE UPPER TROUGH PULLS
FARTHER EAST AND NORTHWESTERLY FLOW DEVELOPS ALOFT. ENOUGH LOW-
LEVEL MOISTURE AND INSTABILITY SHOULD REMAIN FOR ISOLATED
AFTERNOON CONVECTION, BUT FORCING WILL BE WEAKER AND OVERALL
COVERAGE SHOULD BE LOWER THAN TODAY. THE BETTER OPPORTUNITY
APPEARS TO FAVOR THE EASTERN AND NORTHEASTERN PORTIONS OF THE AREA
WHERE DEEPER MOISTURE SHOULD LINGER A LITTLE LONGER. FARTHER WEST,
INCREASING SUBSIDENCE AND SLIGHTLY DRIER AIR ALOFT SHOULD MAKE
CONVECTIVE INITIATION MORE DIFFICULT. WITH LESS RAIN AND CLOUD
COVERAGE, TEMPERATURES SHOULD RESPOND ACCORDINGLY AND REMAIN QUITE
WARM THROUGH THE AFTERNOON.
BY WEDNESDAY, ATTENTION TURNS TO A COLD FRONT DROPPING SOUTH
THROUGH THE LOWER MISSISSIPPI VALLEY. THIS DOES NOT LOOK LIKE A
PARTICULARLY ACTIVE FRONTAL PASSAGE LOCALLY, AS SURFACE HIGH
PRESSURE BUILDS QUICKLY BEHIND THE BOUNDARY AND DEEPER MOISTURE IS
STEADILY DISPLACED SOUTHWARD. ANY MEANINGFUL PRECIPITATION SIGNAL
REMAINS WEAK, SO THE FRONTAL PASSAGE WILL LIKELY BE EASIER TO
IDENTIFY THROUGH A WIND SHIFT AND FALLING DEWPOINTS THAN THROUGH
SHOWER ACTIVITY. THE FRONT SHOULD WORK THROUGH MUCH OF THE AREA
DURING THE DAY AND EVENING, WITH NOTICEABLY DRIER AIR BEGINNING
TO FILTER INTO THE NORTHERN HALF OF THE CWA BY WEDNESDAY NIGHT.
LONG TERM
(THURSDAY THROUGH SUNDAY)
ISSUED AT 1208 PM CDT MON SEP 21 2026
THE BIGGEST CHANGE THURSDAY WILL BE THE ARRIVAL OF A NOTICEABLY
DRIER AIR MASS BEHIND WEDNESDAY'S FRONT RATHER THAN ANY
SUBSTANTIAL COOLDOWN. NORTHERLY TO NORTHEASTERLY FLOW WILL
CONTINUE ADVECTING LOWER DEWPOINTS INTO THE AREA, AND GUIDANCE HAS
BECOME MORE CONVINCING THAT THE DRIER AIR WILL REACH FURTHER SOUTH
BY THURSDAY MORNING. WITH THAT IN MIND, OVERNIGHT LOWS WERE NUDGED
DOWNWARD ALONG AND NORTH OF I-12 WHERE LOWER DEWPOINTS AND BETTER
RADIATIONAL COOLING SHOULD ALLOW TEMPERATURES TO FALL MORE
EFFICIENTLY. THE NEW ORLEANS METRO AND IMMEDIATE COASTAL AREAS
SHOULD REMAIN SOMEWHAT WARMER GIVEN THE USUAL URBAN AND MARINE
INFLUENCES. UPPER RIDGING BUILDING OVERHEAD WILL OTHERWISE KEEP
CONDITIONS DRY, WITH WARM AFTERNOON TEMPERATURES BUT NOTICEABLY
LOWER HUMIDITY.
THE RIDGE SHOULD REMAIN THE DOMINANT FEATURE THROUGH THE REMAINDER
OF THE LONG-TERM PERIOD, KEEPING CONVECTION LARGELY SUPPRESSED AND
RESULTING IN A FAIRLY QUIET LATE-WEEK FORECAST. SURFACE HIGH
PRESSURE WILL GRADUALLY SHIFT EAST FRIDAY AND INTO THE WEEKEND,
ALLOWING EASTERLY TO SOUTHEASTERLY FLOW AND A SLOW RETURN OF LOW-
LEVEL MOISTURE. HUMIDITY SHOULD THEREFORE BEGIN CREEPING BACK
UPWARD BY SATURDAY AND SUNDAY, BUT MOISTURE RECOVERY APPEARS
GRADUAL ENOUGH THAT ANY CONVECTION SHOULD REMAIN ISOLATED AT BEST
THROUGH THE WEEKEND.
AVIATION
(00Z TAFS)
ISSUED AT 642 PM CDT MON SEP 21 2026
PREVAILING VFR AT ALL TERMINALS RIGHT NOW, THOUGH SOME
THUNDERSTORMS REMAIN IN THE AREA AND MAY IMPACT HDC, MSY, AND NEW.
BRIEF LOW CEILINGS AND VISIBILITY ISSUES IS POSSIBLE AS CONVECTION
MOVES THROUGH. TUESDAY CAN EXPECT VFR CONDITIONS AS CONVECTION
CHANCES ARE VERY LIMITED. NOT GOING TO RULE OUT A STRAY STORM OR
TWO IMPACTING A TERMINAL, BUT NOT ENOUGH CONFIDENCE TO INCLUDE
PROB30S.
MARINE
ISSUED AT 1208 PM CDT MON SEP 21 2026
GENERALLY BENIGN MARINE CONDITIONS ARE EXPECTED THROUGH THE FIRST
HALF OF THE WEEK, WITH LIGHT WINDS AND RELATIVELY LOW SEAS OUTSIDE
OF SCATTERED THUNDERSTORMS. CONVECTION WILL BE MOST NUMEROUS THIS
AFTERNOON AND EVENING, AND ANY STRONGER STORMS COULD PRODUCE BRIEF
PERIODS OF GUSTY AND ERRATIC ALONG WITH LOCALLY HIGHER WAVES.
WINDS SHOULD REMAIN FAIRLY LIGHT TUESDAY BEFORE A COLD FRONT MOVES
THROUGH THE WATERS WEDNESDAY INTO WEDNESDAY NIGHT. BEHIND THE
FRONT, NORTHERLY TO NORTHEASTERLY FLOW WILL STRENGTHEN AS HIGH
PRESSURE BUILDS ACROSS THE LAND, WITH THE HIGHEST SEAS LIKELY
OCCURRING LATE WEDNESDAY NIGHT INTO THURSDAY, PARTICULARLY THE
OVER THE OPEN GULF WATERS. CONDITIONS SHOULD GRADUALLY IMPROVE
LATE IN THE WEEK AS THE PRESSURE GRADIENT RELAXES AND THE SURFACE
HIGH SHIFTS EAST.
LIX WATCHES/WARNINGS/ADVISORIES
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
SHORT TERM...JZ
LONG TERM....JZ
AVIATION...HL
MARINE...JZ
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