000
FXUS64 KLIX 241647
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1147 AM CDT FRI JUL 24 2026
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1146 AM CDT FRI JUL 24 2026
- IMPACTFUL HEAT CONDITIONS ARE LIKELY TO RETURN THIS WEEKEND AND
PERSIST WELL INTO NEXT WEEK.
SHORT TERM
(NOW THROUGH MONDAY)
ISSUED AT 1146 AM CDT FRI JUL 24 2026
THE TRANSITION BACK TO A HOTTER AND SUBSTANTIALLY DRIER PATTERN IS
UNDERWAY ACROSS THE REGION. VISIBLE SATELLITE IMAGERY SHOWS A FAIR
WEATHER CU FIELD SPREAD OVER LA AND MS. RADAR ACTIVITY IS CONFINED
MAINLY WEST OF THE FORECAST AREA OVER SOUTHWEST/CENTRAL LOUISIANA.
THE 12Z KLIX SOUNDING SAMPLED AN UNUSUALLY DRY COLUMN FOR LATE JULY,
WITH PW OF ONLY 1.46 INCHES WHICH IS NEAR THE 10TH PERCENTILE FOR
THIS TIME OF YEAR. THE COMBINATION OF LIMITED COLUMN MOISTURE, DRY
AIR ALOFT, AND WEAK LARGE-SCALE FORCING SHOULD STRONGLY SUPPRESS
CONVECTION TODAY. A VERY ISOLATED SHOWER CANNOT BE COMPLETELY RULED
OUT OVER THE ATCHAFALYA BASIN AND NORTHWESTERN PORTIONS OF THE CWA,
WHERE SOME CAM GUIDANCE CONTINUES TO GENERATE SPOTTY ACTIVITY.
HOWEVER, EVEN THAT MAY BE GENEROUS GIVEN THE OBSERVED SOUNDING.
TEMPERATURES ARE RESPONDING TO ABUNDANT SUNSHINE, WITH HIGHS
GENERALLY HEADED TOWARDS THE MID 90S INLAND AND LOWER TO MIDDLE 90S
NEAR THE IMMEDIATE COAST AND TIDAL LAKES. HEAT INDICES SHOULD REMAIN
MOSTLY BELOW ADVISORY CRITERIA TODAY, ALTHOUGH VALUES AROUND 105
DEGREES WILL BE POSSIBLE WHERE BOUNDARY-LAYER MOISTURE REMAINS
HIGHEST AND POSSIBLY EVEN MORE LOCALIZED TO LOCATIONS THAT MEASURED
RAIN YESTERDAY.
THE BROAD SCALE UPPER RIDGE AXIS CURRENLTY LOCATED NEAR THE 4
CORNERS WILL SLIDE EAST TO JUST EAST OF THE ROCKIES THRU SUNDAY. AT
THE SAME TIME, A SURFACE HIGH SETTLES ACROSS THE NORTHERN GULF
COAST. WARMING THROUGH THE 850-700 MB LAYER AND INCREASING
SUBSIDENCE WILL STRENGTHEN THE CAP AND FURTHER LIMIT THE USUAL
AFTERNOON CONVECTIVE RELIEF. RAIN CHANCES WILL THEREFORE REMAIN
AROUND 10 PERCENT OR LESS BOTH DAYS THIS WEEKEND, WITH ONLY A ROGUE
LATE-AFTERNOON SHOWER OR STORM POSSIBLE ALONG A SEA BREEZE OR OTHER
LOCALIZED BOUNDARY.
A LIGHT WEST OR NORTHWEST LOW-LEVEL FLOW AROUND THAT SURFACE RIDGE
WILL BECOME INCREASINGLY IMPORTANT THIS WEEKEND. THIS LAND-BASED
SURFACE FLOW REGIME SHOULD ALLOW TEMPERATURES TO RISE RAPIDLY EACH
DAY BEFORE THE SEA AND LAKE BREEZES CAN MOVE FAR INLAND. HIGHS WILL
CLIMB INTO THE MIDDLE AND UPPER 90S SATURDAY, WITH UPPER 90S
BECOMING MORE COMMON SUNDAY AS THAT UPPER RIDGE MOVES EVER SO
SLIGHTLY. IF DEWPOINTS REMAIN IN THE MIDDLE OR UPPER 70S DURING
PEAK HEATING, HEAT INDICES WILL RISE CONSIDERABLY DESPITE THE
RELATIVELY DRY AIR ALOFT. THATS PROBABLY THE BIGGEST LIMIT OF UPPER
BOUND HEAT INDICIES ON SATURDAY. SIMILAR DEWPOINTS ON SUNDAY BUT
WITH AN INCRIMENTAL INCREASE IN AIR TEMPS WILL BEGIN TO BRING MORE
WIDESPREAD 108+ HEAT INDEX VALUES ACROSS THE CWA AND SEE THIS AS THE
FIRST DAY OF THIS FORECAST PERIOD THAT NEEDS A HEAT ADVISORY.
MEFFER
LONG TERM
(MONDAY NIGHT THROUGH THURSDAY)
ISSUED AT 1146 AM CDT FRI JUL 24 2026
THE BROAD UPPER-LEVEL RIDGE CENTERED TO THE NORTHWEST WILL REMAIN
THE DOMINANT FEATURE ACROSS THE SOUTH-CENTRAL UNITED STATES DURING
AT LEAST THE FIRST HALF OF NEXT WEEK. MID TO UPPER 590DM HEIGHTS,
STRONG SUBSIDENCE, AND A WARM 850-700 MB LAYER WILL EXTEND ACROSS
SOUTHEAST LOUISIANA AND SOUTHERN MISSISSIPPI. THE PRIMARY DRIVER OF
THE HEAT WILL THEREFORE BE THE COMBINATION OF DEEP-LAYER WARMING,
ABUNDANT SUNSHINE, SUPPRESSED CONVECTION, AND A PERSISTENT WEST TO
NORTHWEST LOW-LEVEL FLOW THAT DELAYS MEANINGFUL MARINE INFLUENCE
DURING THE HOTTEST PART OF THE DAY.
MONDAY THROUGH WEDNESDAY CONTINUE TO APPEAR TO BE THE HOTTEST
PORTION OF THE FORECAST PERIOD. INLAND HIGHS WILL COMMONLY REACH THE
UPPER 90S, WITH SOME LOCATIONS NEAR 100 DEGREES. DID GLANCE AT
RECORD HIGHS FOR EARLY NEXT WEEK AND FORECAST TEMPS ARE RIGHT AT TO
JUST BELOW DEPENDING ON LOCATION.
LOOKING AT MODEL SOUNDINGS FOR SAY NEW ORLEANS MONDAY, COMPARED TO
THIS WEEKEND, MID LEVEL WINDS SHIFT TO SOUTHEAST. THIS HELPS IN
INCREASE MOISTURE IN THE SURFACE TO 700MB LAYER. WHAT THAT DOES IS
INSTEAD OF MIXING DRIER AIR ALOFT TO THE SURFACE, THE HIGHER SURFACE
DEWPOINTS HOLD STEADY EVEN DURING THE AFTERNOON HOURS. THAT'S HOW
THE PATTERN IN PLACE WILL POTENTIALLY PRODUCE DANGEROUS APPARENT
TEMPERATURES. PEAK HEAT INDICES OF 110 TO 115 DEGREES APPEAR
POSSIBLE MONDAY THROUGH WEDNESDAY. HEAT ADVISORY CRITERIA APPEARS TO
BE A GIVEN, BASED ON PERSISTENT DAY-TO-DAY MODEL RUNS, WITH
INCREASINGLY LIKELIHOOD FOR PORTIONS OF THE I-10/12 CORRIDORS TO
APPROACH EXTREME HEAT WARNING CRITERIA ON ONE OR MORE AFTERNOONS.
CONFIDENCE IS HIGHER IN A PROLONGED PERIOD OF IMPACTFUL HEAT THAN IN
THE EXACT MAGNITUDE OR PLACEMENT OF THE HIGHEST HEAT INDICES.
THE DURATION OF THE EVENT WILL BECOME INCREASINGLY IMPORTANT.
OVERNIGHT LOWS WILL REMAIN IN THE UPPER 70S ACROSS MUCH OF THE AREA
AND NEAR OR ABOVE 80 DEGREES AROUND NEW ORLEANS, THE TIDAL LAKES,
AND THE IMMEDIATE COAST. LOOKING AT PREVIOUS SIMILAR EVENTS,
LOCATIONS AROUND THE TIDAL LAKES SOMETIMES GET SUCH LITTLE RELIEF
OVERNIGHT. HAVE SEEN PERIODS WHERE KNEW'S LOWEST HEAT INDEX DOESN'T
EVEN DROP BELOW 100! THE POOR NIGHTTIME RECOVERY ACROSS THE CWA WILL
ALLOW HEAT STRESS TO ACCUMULATE AS THIS EVENT PROGRESSES. WE SEE
THIS IN THE HEATRISK GUIDANCE WHICH SHOWS EXTREME FOR ABOUT 25% OF
THE CWA MONDAY, ~70% OF THE CWA TUESDAY, AND 80-90% WEDNESDAY. THIS
IS CONSISTENT WITH THE COMBINATION OF HOT AFTERNOONS, WARM NIGHTS,
AND VERY LIMITED CONVECTIVE RELIEF. AND SPEAKING OF CONVECTION,
STRONG SUBSIDENCE FROM UPPER RIDGING ALOFT SHOULD HOLD RAIN CHANCES
TO NEAR 10% MONDAY THROUGH WEDNESDAY. A ROGUE STORM COULD STILL
BRIEFLY DEVELOP ALONG A SEA BREEZE, LAKE BREEZE, OR REMNANT BOUNDARY
LATE IN THE AFTERNOON, BUT MEANINGFUL OR WIDESPREAD RELIEF IS NOT
EXPECTED. MOST LOCATIONS WILL REMAIN DRY EACH DAY.
GLOBAL MODELS SUGGEST THAT THURSDAY AND FRIDAY WILL BE THE WEEK'S
DOWNSIDE OF PEAK HEAT IMPACTS LOCALLY AS THE EASTERN SIDE OF THE
RIDGE BEGINS TO WEAKEN WHILE TROUGHING DEVELOPS OVER THE
SOUTHEASTERN CONUS. AN EARLIER BREAKDOWN WOULD ALLOW SLIGHTLY
GREATER AFTERNOON CONVECTIVE COVERAGE AND SHAVE A COUPLE DEGREES
FROM DAYTIME TEMPERATURES. GIVEN THE UNCERTAIN TIMING, ONLY A
GRADUAL EASING OF TEMPS AND A MODEST INCREASE TO SLIGHT CHANCE POPS
ARE WARRANTED LATE IN THE PERIOD WILL POSSIBLY YIELD A MORE GRADUAL
BREAKDOWN OF OPPRESSIVE HEAT.
MEFFER
AVIATION
(18Z TAFS)
ISSUED AT 1146 AM CDT FRI JUL 24 2026
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH ONLY SCATTERED
AFTERNOON CU AND LIGHT WINDS. THE PROBABILITY OF CONVECTION
AFFECTING ANY TERMINAL IS TOO LOW TO HAVE ANY MENTION OF TAFS. SOME
GUIDANCE INDICATES THE POTENTIAL FOR 4-6SM VIS AROUND SUNRISE
SATURDAY AT KMCB. CONFIDENCE IN RESTRICTIONS IS LOW, BUT A BRIEF
PERIOD OF REDUCED VISIBILITY CANNOT BE RULED OUT THERE. OTHERWISE,
NO APPRECIABLE AVIATION IMPACTS ARE EXPECTED.
MEFFER
MARINE
ISSUED AT 1146 AM CDT FRI JUL 24 2026
SURFACE HIGH PRESSURE BUILDING ACROSS THE NORTHERN GULF WILL
MAINTAIN BENIGN MARINE CONDITIONS TODAY AND SATURDAY, WITH WINDS
GENERALLY AROUND 5 TO 10 KNOTS AND SEAS OF 2 FEET OR LESS. THE RIDGE
WILL GRADUALLY SHIFT SOUTHWARD THIS WEEKEND, ESTABLISHING A
PREDOMINANTLY WESTERLY FLOW REGIME FROM SUNDAY THROUGH THE MIDDLE OF
NEXT WEEK.
A TYPICAL SUMMERTIME DIURNAL WIND CYCLE IS EXPECTED, WITH NOCTURNAL
WINDS INCREASING TO AROUND 10 TO 15 KNOTS DURING THE OVERNIGHT
PERIODS AND EARLY MORNING HOURS BEFORE RELAXING CLOSER TO 5 TO 10
KNOTS DURING THE DAYTIMES. SEAS WILL GENERALLY RESPOND SIMILARLY,
WITH 2 TO 4 FEET POSSIBLE OVER THE OUTER WATERS OVERNIGHT AND 1 TO 2
FEET DURING THE DAY. CONDITIONS SHOULD REMAIN BELOW HEADLINE
CRITERIA, ALTHOUGH OCCASIONAL GUSTS APPROACHING 15-20 KNOTS MAY
OCCUR OVER THE OUTER WATERS DURING THE STRONGER NOCTURNAL WIND
PERIODS AND REQUIRE AN EXERCISE CAUTION HEADLINE. STRONG SUBSIDENCE
ALOFT FROM UPPER LEVEL RIDGE INFLUENCE WILL KEEP THUNDERSTORM
COVERAGE VERY LIMITED DURING ALL BUT MAYBE THE END OF THE FORECAST
PERIOD.
MEFFER
LIX WATCHES/WARNINGS/ADVISORIES
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
SHORT TERM...ME
LONG TERM....ME
AVIATION...ME
MARINE...ME
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