534
FXUS64 KLIX 180337
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1037 PM CDT WED JUN 17 2026
..NEW UPDATE
KEY MESSAGES
UPDATED AT 1028 PM CDT WED JUN 17 2026
- POTENTIAL FOR LIFE THREATENING FLASH FLOODING. A FLOOD WATCH IS
IN EFFECT THROUGH FRIDAY MORNING FOR MOST OF SOUTHEAST
LOUISIANA AS WELL AS ALL OF SOUTHWEST AND COASTAL MISSISSIPPI.
- TORNADO WATCH 348 IN EFFECT UNTIL 6 AM CDT FOR MOST OF THE AREA.
- DANGEROUS CONDITIONS FOR MARINERS OF SMALL CRAFT AND MINOR
COASTAL FLOODING ON SOUTH FACING SHORES WEST OF THE MISSISSIPPI
RIVER WILL PERSIST THROUGH TONIGHT AS TROPICAL STORM ARTHUR
MOVES INTO SOUTHWEST LOUISIANA.
- EXTREME HEAT IS EXPECTED THIS WEEKEND. HEAT ADVISORIES WILL
LIKELY BE ISSUED FOR HEAT INDEX VALUES OF AROUND 110 DEGREES.
UPDATE
ISSUED AT 1028 PM CDT WED JUN 17 2026
TORNADO WATCH 348 ISSUED FOR MOST OF SOUTHEAST LOUISIANA AND
COASTAL MISSISSIPPI UNTIL 6 AM CDT. ALSO, ARTHUR HAS BEEN RE-
CLASSIFIED AS POST TROPICAL WITH MAX WIND OF 30 KNOTS.
STILL HIGHLY CONCERNED ABOUT VERY HEAVY RAINFALL THROUGH TOMORROW
MORNING AS WELL, WITH THE INFORMATION IN THE SHORT TERM DISCUSSION
REMAINING VALID. ZFPLIX HAS ALREADY UPDATED FOR THE WATCH. FULL
AFD FOR THE OVERNIGHT PACKAGE SHOULD BE AVAILABLE AROUND 1 AM CDT.
RW
SHORT TERM
(NOW THROUGH SATURDAY NIGHT)
ISSUED AT 135 PM CDT WED JUN 17 2026
TROPICAL STORM ARTHUR WILL MAKE LANDFALL NEAR THE LA/TX BORDER
THIS EVENING. THIS SYSTEM IS HIGHLY SHEARED WITH THE MID-LEVEL LOW
EXPECTED TO TRACK FURTHER TO THE EAST ACROSS THE ATCHAFALAYA BASIN
AND INTO THE FORECAST AREA TONIGHT. A STRONG MESOSCALE CONVECTIVE
COMPLEX WITH HEAVY RAINFALL AND THREAT OF DAMAGING WIND GUSTS AND
A FEW TORNADOES WILL ACCOMPANY THIS MID-LEVEL LOW AS IT PASSES
THROUGH THE REGION. CONDITIONS WILL TURN A BIT BREEZY AS THE LOW
PASSES THROUGH WITH SOUTHERLY WINDS OF 10 TO 20 MPH WITH GUSTS OF
25 MPH DEVELOPING TONIGHT. THIS WILL LEAD TO SOME MINOR COASTAL
FLOODING ISSUES AROUND HIGH TIDE FOR OUR SOUTH FACING SHORELINES,
PARTICULARLY AROUND GRAND ISLE, PORT FOURCHON, AND THE COASTAL
COMMUNITIES OF TERREBONNE PARISH. ABOVE GROUND FLOODING OF 1 TO 2
FEET IS POSSIBLE AROUND HIGH TIDE TONIGHT.
MODEL SOUNDING ANALYSIS INDICATES A HIGHLY FAVORABLE ENVIRONMENT
FOR BOTH TORNADOES AND HEAVY RAINFALL TO OCCUR. PWATS WILL REMAIN
NEAR THE DAILY MAX TONIGHT INTO TOMORROW AND 500MB TEMPERATURES
WILL RANGE NEAR -5C THROUGH TOMORROW. THESE WARM TEMPERATURES
ALOFT WILL SUPPORT VERY WARM AND HIGHLY EFFICIENT RAIN PROCESSES
THAT IN TURN WILL PRODUCE RAINFALL RATES OF 3 TO 4 INCHES PER HOUR
AS THE MESOSCALE CONVECTIVE COMPLEX MOVES THROUGH THE REGION
OVERNIGHT. THIS WILL LEAD TO A CORRIDOR, MOST LIKELY FROM THE
RIVER PARISHES AND BATON ROUGE METRO NORTHEAST INTO THE NORTHSHORE
AND COASTAL MISSISSIPPI, OF VERY HIGH RAINFALL TOTALS THAT COULD
APPROACH 10 INCHES IN A FEW LOCATIONS. THESE HIGH RAINFALL TOTALS
ON TOP OF ALREADY SATURATED SOILS WILL QUICKLY LEAD TO
CONSIDERABLE AND LIFE-THREATENING FLASH FLOODING CONCERNS TONIGHT
INTO TOMORROW MORNING. THE THREAT OF WIDESPREAD FLASH FLOODING
WILL DIMINISH BY THE AFTERNOON AS THE MID-LEVEL LOW PULLS INTO
ALABAMA AND MORE TYPICAL SUMMER AFTERNOON CONVECTION REDEVELOPS
WITH DAYTIME HEATING.
THE TORNADO THREAT WILL PEAK BETWEEN 9PM AND 8 AM AS THE MID-LEVEL
MOVES THROUGH THE AREA AND DIRECTIONAL SHEAR INCREASES
DRAMATICALLY. 0-3KM SRH VALUES WILL RISE TO BETWEEN 250 AND
350M2/S2 CLOSE TO MIDNIGHT, AND SEVERAL MINI-SUPERCELLS SHOULD FORM
ON THE LEADING FLANK OF THE MESOSCALE CONVECTIVE COMPLEX TONIGHT
FROM LATE THIS EVENING INTO THE EARLY MORNING HOURS. AREAS FROM
THE RIVER AND BAYOU PARISHES, METRO NEW ORLEANS, THE NORTHSHORE,
AND COASTAL MISSISSIPPI HAVE THE HIGHEST PROBABILITIES OF TORNADIC
DEVELOPMENT, BUT THE ENTIRE AREA WILL BE UNDER THREAT TONIGHT.
CONDITIONS WILL GREATLY IMPROVE AS WE MOVE INTO TOMORROW NIGHT AND
REST OF THE SHORT TERM PERIOD IN TERMS OF THE HEAVY RAINFALL
THREAT. A BROAD DEEP LAYER RIDGE AXIS WILL EXPAND NORTHWARD ACROSS
THE GULF SOUTH RESULTING IN LOWER OVERALL RAIN CHANCES AS WE MOVE
INTO FRIDAY AND SATURDAY, BUT THE SIDE-EFFECT WILL BE
SIGNIFICANTLY WARMER TEMPERATURES. HIGHS WILL EASILY CLIMB INTO
THE LOW TO MID 90S AND VERY HIGH DEWPOINTS IN THE UPPER 70S AND
LOWER 80S WILL PRODUCE HEAT INDEX READINGS OF AROUND 110 DEGREES
BOTH DAYS. A HEAT ADVISORY WILL LIKELY BE ISSUED FOR MUCH OF THE
AREA BY TOMORROW. AMPLE INSTABILITY WILL ACCOMPANY THESE WARM
TEMPERATURES WITH MLCAPE OF 2000 TO 2500 J/KG BOTH DAYS. AS A
RESULT, DIURNALLY INDUCED CONVECTION WILL FORM EACH DAY WITH THE
HIGHEST PROBABILITIES NORTH OF I-12 WHERE THE INFLUENCE OF THE MID
TO UPPER LEVEL RIDGE WILL BE LOWER. ALTHOUGH PWATS WILL FALL TO
MORE AVERAGE LEVELS BY SATURDAY, THE WET ANTECEDENT CONDITIONS
COULD LEAD TO ISOLATED FLASH FLOODING INCIDENTS AS RAINFALL RATES
STILL AVERAGE 1 TO 2 INCHES PER HOUR.
LONG TERM
(SUNDAY THROUGH TUESDAY NIGHT)
ISSUED AT 135 PM CDT WED JUN 17 2026
THE INFLUENCE OF THE RIDGE WILL GROW AS WE MOVE INTO NEXT WEEK
WITH LOWER OVERALL RAIN CHANCES AND CONTINUED WARM TEMPERATURES.
HIGHS WILL EASILY CONTINUE TO CLIMB INTO THE LOW TO MID 90S EACH
DAY AND OVERNIGHT LOWS WILL ONLY COOL INTO THE UPPER 70S AND LOWER
80S. HEAT INDEX VALUES WILL CONTINUE TO RISE TO BETWEEN 105 AND
110 DEGREES, SO MORE DAYS OF HEAT ADVISORY CONDITIONS CAN BE
EXPECTED. THE GROWING INFLUENCE OF THE RIDGE WILL LEAD TO A STRONG
MID-LEVEL CAPPING INVERSION AND OVERALL LOWER RAIN CHANCES FROM
SUNDAY THROUGH TUESDAY WITH ONLY ISOLATED TO WIDELY SCATTERED
AFTERNOON SHOWERS AND STORMS ANTICIPATED. RAIN CHANCES WILL BE
HIGHEST OVER THE NORTHERN THIRD OF THE FORECAST AREA WHERE THE
CAPPING INVERSION WILL BE SLIGHTLY WEAKER.
AVIATION
(00Z TAFS)
ISSUED AT 618 PM CDT WED JUN 17 2026
CONDITIONS CURRENTLY AT VFR TO MVFR AS SCATTERED SHOWERS AND A FEW
THUNDERSTORMS TRANSIT THE AREA FROM SOUTH TO NORTH. TROPICAL STORM
ARTHUR AND ITS REMNANTS WILL CONTINUE TO BRING IMPACTS TO THE
AREA WITH RAIN AND GUSTY WINDS THROUGH THE NIGHT. THE MOST
IMPACTFUL WEATHER WILL MOVE THROUGH THE AREA GENERALLY FROM 06Z TO
15Z WITH BTR/MSY/HDC/MCB TARGETED FROM 06Z TO 12Z AND
ASD/NEW/GPTFROM 09Z TO 15Z. BRIEF PERIODS OF WIND SHEAR GUSTS TO
20+ KNOTS WILL ACCOMPANY THE STRONGEST WEATHER.
MARINE
ISSUED AT 135 PM CDT WED JUN 17 2026
TROPICAL STORM ARTHUR WILL MAKE LANDFALL NEAR THE BORDER OF
LOUISIANA AND TEXAS TONIGHT. STRONG SOUTHERLY WINDS OF 20 TO 25
KNOTS WITH GUSTS OF 30 KNOTS WILL REMAIN IN PLACE OVER THE COASTAL
WATERS THROUGH TONIGHT AND INTO TOMORROW AND SEAS OF 6 TO 9 FEET CAN
BE EXPECTED IN THE OPEN GULF WATERS. SMALL CRAFT ADVISORIES REMAIN
IN EFFECT DUE TO THESE CONDITIONS. MOVING INTO THE WEEKEND AND
EARLY NEXT WEEK, A BROAD AREA OF HIGH PRESSURE WILL BUILD BACK OVER
THE EASTERN GULF WATERS. PERSISTENT ONSHORE WINDS OF 10 TO 15 KNOTS
AND SEAS OF 2 TO 4 FEET CAN BE EXPECTED FROM FRIDAY THROUGH EARLY
NEXT WEEK.
LIX WATCHES/WARNINGS/ADVISORIES
LA...FLOOD WATCH THROUGH FRIDAY MORNING FOR LAZ034>037-039-046>048-
056>058-064-071-076>087-089-090-092-094-096-098>100.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT CDT TONIGHT FOR LAZ091-093-
095-097.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CDT FRIDAY FOR GMZ529-531>536-
541-543-551-553-554-557-570-572-575-577.
MS...FLOOD WATCH THROUGH FRIDAY MORNING FOR MSZ068>071-077-083>088.
GM...SMALL CRAFT ADVISORY UNTIL 6 AM CDT FRIDAY FOR GMZ531>536-541-
543-551-553-554-557-570-572-575-577.
SHORT TERM...PG
LONG TERM....PG
AVIATION...DS
MARINE...PG
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