612
FXUS64 KLIX 301039
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
539 AM CDT WED SEP 30 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 521 AM CDT WED SEP 30 2026
- SCATTERED TO LOCALLY NUMEROUS SHOWERS AND A FEW STORMS WILL
RETURN TO THE AREA THURSDAY EVENING. ONE OR TWO STORMS COULD
BECOME STRONG, PRODUCING GUSTY WINDS, FREQUENT LIGHTNING AND
BRIEF PERIODS OF HEAVY RAINFALL.
- CONFIDENCE IS INCREASING THAT WIDESPREAD RAIN AND EMBEDDED
THUNDERSTORMS WILL AFFECT THE AREA FRIDAY THROUGH AT LEAST
SUNDAY. WHILE SPECIFIC RAINFALL TOTALS ARE STILL UNCERTAIN,
HEAVY RAIN AND AT LEAST LOCALIZED FLASH FLOODING WILL BE A
THREAT. RESIDENTS SHOULD CONTINUE TO MONITOR THE FORECAST FOR
UPDATES REGARDING THIS THREAT.
SHORT TERM
(NOW THROUGH THURSDAY NIGHT)
ISSUED AT 1125 PM CDT TUE SEP 29 2026
VERY NICE DAY ONCE AGAIN SETTING UP FOR TODAY, BUT THIS WILL START
TO CHANGE SLOWLY LATE WED INTO THU. MOISTENING OF THE LOW LAYERS
OCCURS FIRST WITH THE POSSIBILITY OF A FEW SHOWERS DEVELOPING
LATE TODAY AS WELL AS AGAIN LATE IN THE DAY THU. MOST OF THU
LOOKS GOOD BUT DEEP MOISTURE WILL BEGIN TO MOVE IN FROM THE GULF
POSSIBLY OVERNIGHT THU INTO FRI AND THIS IS WHERE MOST OF OUR
RAINFALL WITH THIS SYSTEM WILL COME FROM. MORE ON THAT IN THE
EXTENDED.
LONG TERM
(FRIDAY THROUGH TUESDAY)
ISSUED AT 1125 PM CDT TUE SEP 29 2026
FRIDAY THROUGH MONDAY WILL BE THE PRIMARY FOCUS FOR ACTIVE
WEATHER MESSAGING. A TROPICAL WAVE WILL BE MOVE NORTHWESTWARD OUT
OF THE CARIBBEAN AND TOWARD THE NORTHERN GULF COAST, BRINGING DEEP
TROPICAL MOISTURE TO THE AREA. AT THE SAME TIME, AN UPPER TROUGH
WILL LIFT INTO THE MID MISSISSIPPI RIVER VALLEY, ERODING THE
WESTERN PERIPHERY OF THE UPPER RIDGE CENTERED OFF THE SE CONUS.
THIS WILL FORCE A SLOW- MOVING COLD FRONT TOWARD THE AREA AS WELL.
THESE TWO SYSTEMS WILL INTERACT RESULTING IN WIDESPREAD RAINFALL
WITH EMBEDDED THUNDERSTORMS ACROSS THE LOCAL AREA MAINLY FROM
FRIDAY THROUGH SUNDAY, WITH THE MOST INTENSE RAIN TAPERING OFF BY
MONDAY.
MOST GUIDANCE INDICATES PRECIPITABLE WATER (PWAT) VALUES WILL BE
BETWEEN 2.3 TO 2.6 INCHES ACROSS MUCH OF THE AREA BY LATE FRIDAY
WITH SIMILAR VALUES SATURDAY AND SUNDAY. PWAT VALUES LIKE THESE ARE
NEAR THE DAILY RECORD MAXIMUM OBSERVED VALUES FOR THE OCT 2-4 TIME
FRAME. THIS WILL RESULT IN PRIME CONDITIONS FOR EFFICIENT RAINFALL
PROCESSES, AND IN FACT THE MODEL FORECAST SOUNDING PROFILES ARE
BASICALLY MOIST ADIABATIC FROM THE SURFACE TO THE TROPOPAUSE. DEEP
TROPICAL MOISTURE OF THIS NATURE IS SYNONYMOUS WITH EXCESSIVE
RAINFALL EVENTS.
HEAVIEST RAIN WILL LIKELY OCCUR LATE FRIDAY INTO SUNDAY WHEN
INSTANTANEOUS RATES OF OVER 4 INCHES PER HOUR WILL BE POSSIBLE IN
THE HEAVIEST STORMS. RAINFALL RATES LIKE THESE, EVEN OVER SHORT
PERIODS CAN EASILY OVERWHELM DRAINAGE CAPACITY IN URBAN AND OTHER
POOR DRAINAGE AREAS. IF FORECAST CONFIDENCE CONTINUES TO INCREASE
REGARDING THE EXCESSIVE RAINFALL RISK, ADDITIONAL UPGRADES AND
EXPANSION OF RISK AREAS WILL BE POSSIBLE WITH THE NEW EXCESSIVE
RAINFALL OUTLOOKS IN THE COMING DAYS.
CURRENT STORM TOTALS FOR THE FRIDAY THROUGH SUNDAY PERIOD ARE
FORECAST IN THE 3-6" RANGE, BUT THIS COMES WITH A BIG CAVEAT THAT
THERE WILL LIKELY BE POCKETS OF HIGHER TOTALS. THE UPPER END
POTENTIAL IS TOUGH TO NAIL DOWN AT THIS POINT GIVEN THE SEVERAL DAYS
LEAD TIME, BUT IT CERTAINLY WOULDN'T BE OUT OF THE QUESTION FOR A
COUPLE PLACES TO SEE WELL OVER 6" THE THREE-DAY PERIOD.
IF THERE'S ANY GOOD NEWS TO GLEAM, IT'S THAT RIVERS ACROSS THE
REGION ARE AT BASE FLOW OR LOWER RIGHT NOW AND THUS STORAGE CAPACITY
IS HIGH. CURRENT ENSEMBLE GUIDANCE IS GENERALLY INDICATING A 10% OR
LOWER CHANCE OF REACHING MINOR FLOOD STAGE AT ANY GIVEN RIVER
FORECAST POINT. WOULDN'T BE SURPRISED TO SEE THOSE PROBABILITIES
COME UP IN A FEW PLACES AS THE FORECAST ITSELF BECOMES CLEARER AND
THE RANGE OF POSSIBILITIES THEREFORE DECREASES. BUT FOR NOW, THIS
APPEARS TO BE MORE OF A FLASH FLOOD CONCERN THAN A SIGNIFICANT RIVER
FLOOD CONCERN.
BEYOND MONDAY, THE NEXT THING THAT WILL NEED TO BE WATCHED WILL BE
THE PROGRESSION OF THE STALLED FRONT OFFSHORE. WHILE SOME GLOBAL
GUIDANCE INDICATES THAT THE BOUNDARY WILL MOVE THE TROPICAL MOISTURE
WITH IT OFFSHORE. HOWEVER, IT'S POSSIBLE THAT THE FRONT NEVER CLEARS
OUT FULLY AND ADDITIONAL DAYS OF ELEVATED POPS AND PWATS LINGER EVEN
INTO NEXT WEEK.
AVIATION
(12Z TAFS)
ISSUED AT 521 AM CDT WED SEP 30 2026
VFR THROUGH THIS CYCLE.
MARINE
ISSUED AT 1125 PM CDT TUE SEP 29 2026
AS THE WEEK PROGRESSES, WINDS WILL BEGIN TO STRENGTHENING TO 15
TO 20 KNOTS BY THURSDAY OR THURSDAY NIGHT. SHOWERS AND SOME
THUNDERSTORMS WILL BEGIN TO INCREASE IN COVERAGE TOWARD THE END OF
THE WEEK AS WELL AS A TROPICAL WAVE MOVES THROUGH THE NORTHERN
GULF AND INTERACTS WITH AN APPROACHING WEAK COLD FRONT.
LIX WATCHES/WARNINGS/ADVISORIES
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
SHORT TERM...TE
LONG TERM....TJS
AVIATION...TE
MARINE...TE
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page