117
FXUS64 KLIX 210559
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1259 AM CDT TUE JUL 21 2026
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1250 AM CDT TUE JUL 21 2026
- HOT AND MOSTLY DRY TODAY, AND ACROSS NORTHERN SECTIONS ON
WEDNESDAY. HIGHS IN THE MID 90S TO NEAR 100 WITH HEAT INDICES
105-112. HEAT HEADLINES FOR WEDNESDAY AND THURSDAY WILL BE
CONTINGENT ON THE PATH OF TROPICAL STORM BERTHA.
- TROPICAL STORM BERTHA IS FORECAST TO MOVE WESTWARD TOWARD OUR
GENERAL AREA THROUGH MIDWEEK. IMPACTS ARE STILL LOW CONFIDENCE,
BUT AN INCREASE IN RAINFALL (MAINLY SOUTH OF I-10) WITH BREEZY
CONDITIONS ALONG WITH POTENTIAL COASTAL FLOODING ARE MORE AND
MORE POSSIBLE WITH TIME. TROPICAL STORM WATCHES AND WARNINGS ARE
IN PLACE FOR COASTAL AREAS.
SHORT TERM
(NOW THROUGH FRIDAY)
ISSUED AT 1250 AM CDT TUE JUL 21 2026
ALL EYES CONTINUE TO BE ON THE GULF WHERE RECENTLY UPGRADED
TROPICAL STORM BERTHA CONTINUES TO REMAIN NEARLY STATIONARY.
BERTHA IS EVENTUALLY EXPECTED TO MOVE SLOWLY WEST-NORTHWEST OR
WEST ACROSS THE NORTHERN GULF OVER THE NEXT FEW DAYS, LIKELY NEAR
OR OVER COASTAL AREAS OF SOUTHEAST LOUISIANA.
AS LONG AS BERTHA REMAINS NEARLY STATIONARY, WEATHER CONDITIONS
WON'T CHANGE MUCH FROM THOSE OF MONDAY AFTERNOON. ESSENTIALLY, HOT
AND WITH ONLY ISOLATED TO WIDELY SCATTERED AFTERNOON STORMS. A
FEW STORMS COULD BE ON THE STRONG SIDE, BUT MANY AREAS ARE LIKELY
TO REMAIN DRY. HIGH TEMPERATURES IN THE MID AND UPPER 90S WILL BE
COMMON, AS WILL HEAT INDICES IN THE 105 TO 112 RANGE. WILL
CONTINUE THE HEAT ADVISORY FOR TODAY, BUT WILL HOLD OFF FOR
ANOTHER FORECAST PACKAGE ON WHETHER TO ISSUE FOR WEDNESDAY. IF
BERTHA MOVES SLOWER THAN EXPECTED, WE MAY NEED ANOTHER ADVISORY
WEDNESDAY.
CURRENT TIMING OF BERTHA'S MOVEMENT HAS THE SYSTEM IN OUR
SOUTHEASTERN COASTAL WATERS AROUND SUNRISE WEDNESDAY, MOVING NEAR
LOWER PLAQUEMINES PARISH WEDNESDAY AFTERNOON AND EVENING, AND
MOVING WEST OF OUR COASTAL WATERS THURSDAY MORNING, WITH IMPROVING
CONDITIONS BY THURSDAY NIGHT INTO FRIDAY. EVEN AFTER BERTHA
DEPARTS, THERE WILL BE SUFFICIENT MOISTURE REMAINING FOR AT LEAST
ISOLATED TO SCATTERED THUNDERSTORM DEVELOPMENT ON FRIDAY. AT
PRESENT, IT APPEARS THAT THE HEAVIEST RAINFALL WILL BE NEAR AND
LEFT(SOUTH) OF THE TRACK OF BERTHA, WHERE MOST OF THE HEAVY
RAINFALL REMAINS OFFSHORE.
HIGH TEMPERATURES LIKELY TO REMAIN IN THE LOWER AND MIDDLE 90S
THROUGH FRIDAY, EXCEPT WHERE THUNDERSTORMS DEVELOP PRIOR TO NOON
ON A GIVEN DAY.
LONG TERM
(FRIDAY NIGHT THROUGH MONDAY)
ISSUED AT 1250 AM CDT TUE JUL 21 2026
HIGH PRESSURE IS EXPECTED TO BUILD BACK OVER THE AREA SURFACE AND
ALOFT OVER THE WEEKEND. MOISTURE WON'T BE QUITE AS ABUNDANT AS THE
LAST SEVERAL DAYS, BUT STILL ENOUGH TO PRODUCE AT LEAST ISOLATED
THUNDERSTORMS EACH DAY. HOT WEATHER WON'T BE GOING ANYWHERE,
EITHER, AS HIGHS WILL REMAIN IN THE LOWER AND MIDDLE 90S THROUGH
EARLY NEXT WEEK. THE GFS SOLUTIONS OVER THE LAST FEW RUNS WOULD
INDICATE THAT THE CURRENT NBM POPS WILL GRADUALLY COME DOWN OVER
THE NEXT FEW DAYS FOR SATURDAY AND SUNDAY.
AVIATION
(06Z TAFS)
ISSUED AT 1250 AM CDT TUE JUL 21 2026
THERE WERE SOME MID LEVEL CLOUDS MOVING WESTWARD ACROSS THE AREA
AT FORECAST ISSUANCE TIME, BUT NOTHING LOW ENOUGH TO INCUR FLIGHT
RESTRICTIONS. VFR CONDITIONS TO CONTINUE OVERNIGHT. THE ONLY
FORECAST ISSUE FOR AVIATION CONCERNS WILL BE FOR THE DEVELOPMENT
OF ISOLATED TO SCATTERED THUNDERSTORMS, PRIMARILY DURING THE
AFTERNOON HOURS. THE BEST POTENTIAL WOULD BE AT KHUM, CLOSEST TO
THE COAST, AND HAVE USED TEMPO THERE, WITH PROB30 ELSEWHERE. MOST
CONVECTION SHOULD DISSIPATE OR MOVE INTO THE GULF BY SUNSET.
MARINE
ISSUED AT 1250 AM CDT TUE JUL 21 2026
OBVIOUSLY, THE MAIN CONCERN FOR MARINERS OVER THE NEXT FEW DAYS
WILL BE THE TRACK OF TROPICAL STORM BERTHA, WHICH IS LIKELY TO
PASS THROUGH A LARGE PORTION OF OUR OPEN WATERS WEDNESDAY AND
THURSDAY. SEAS WILL LIKELY EXCEED 7 FEET IN OUR EASTERN WATERS
LATER TODAY, IF THEY AREN'T ALREADY, AND LIKELY EXCEEDING 10 FEET
FOR MUCH OF THE WATERS WEDNESDAY AND WEDNESDAY NIGHT. SHOULD BEGIN
TO SEE IMPROVEMENT FROM EAST TO WEST THURSDAY INTO FRIDAY, WITH
MUCH MORE TOLERABLE CONDITIONS FOR MARINE OPERATIONS OVER THE
WEEKEND.
LIX WATCHES/WARNINGS/ADVISORIES
LA...TROPICAL STORM WATCH FOR LAZ058-064-070-076>078-087-089>100.
TROPICAL STORM WARNING FOR LAZ070-076-078-091.
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
LAZ034>037-039-046>048-056>058-064-070-071-076>087-089>100.
STORM SURGE WATCH FOR LAZ070-076-078-091.
GM...TROPICAL STORM WATCH FOR GMZ529-531-533-541-543-551-553-570-572.
TROPICAL STORM WARNING FOR GMZ532-534>536-554-557-575-577.
MS...TROPICAL STORM WATCH FOR MSZ083>088.
TROPICAL STORM WARNING FOR MSZ086>088.
HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
MSZ068>071-077-083>088.
STORM SURGE WATCH FOR MSZ086>088.
GM...TROPICAL STORM WATCH FOR GMZ531-533-541-543-551-553-570-572.
TROPICAL STORM WARNING FOR GMZ534>536-554-557-575-577.
SHORT TERM...RW
LONG TERM....RW
AVIATION...RW
MARINE...RW
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