197
FXUS64 KLIX 121753
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
1253 PM CDT SUN JUL 12 2026
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE
KEY MESSAGES
UPDATED AT 1252 PM CDT SUN JUL 12 2026
- THE POTENTIAL FOR HEAVY RAINFALL AND LOCALIZED FLASH FLOODING
WILL INCREASE CONTINUES MONDAY INTO POSSIBLY TUESDAY AS A SLOW-
MOVING FRONTAL BOUNDARY APPROACHES FROM THE NORTH.
- A DRIER PATTERN IS EXPECTED LATER HALF OF THE WEEK INTO NEXT
WEEKEND. THE PRIMARY CONCERN WILL THEN SHIFT TOWARD INCREASING
HEAT, WITH HEAT INDICES POTENTIALLY APPROACHING ADVISORY
CRITERIA FRIDAY ONWARD.
SHORT TERM
(NOW THROUGH WEDNESDAY NIGHT)
ISSUED AT 1252 PM CDT SUN JUL 12 2026
THE BROAD UPPER RIDGE THAT COVERED MUCH OF THE SOUTHERN CONUS HAS
SHIFTED WEST/NORTHWEST. THIS IS ALLOWING HEIGHTS TO FALL ACROSS THE
NORTH-CENTRAL GULF COAST AS A WEAKNESS DEVELOPS ON THE EASTERN SIDE
OF THE RIDGE. A TROUGH SETTLING INTO THE SOUTHEAST US THROUGH MONDAY
WILL PROVIDE GREATER LARGE-SCALE SUPPORT FOR CONVECTION.
EARLY OFFSHORE CONVECTION HAS NOT FOLLOWED THE TYPICAL SUMMERTIME
CYCLE, WITH LITTLE IN THE WAY OF STORMS INLAND BUT VERY ACTIVE SOUTH
OF LOUISIANA IN THE OPEN GULF WATERS. A CLOSER INSPECTION OF PW
FIELD ACROSS THE REGION SUGGEST DEEPER MOISTURE PROFILE OFFSHORE IS
SURGING NORTH. CONVERGENCE ALONG THAT GRADIENT HAS BEEN AND WILL
CONTINUE TO SUPPORT THIS ACTIVITY. THE 12Z KLIX SOUNDING SAMPLED A
VERY MOIST AND INCREASINGLY UNSTABLE ENVIRONMENT. PRECIPITABLE WATER
WAS 2.2" INCHES (LIKELY WELL ABOVE THAT OFFSHORE), UP SLIGHTLY FROM
2.15 INCHES AT 00Z AND CONSIDERABLY HIGHER THAN THE 1.83 INCHES
OBSERVED SATURDAY MORNING. CAPE WAS A FAIRLY TYPICAL 1500-2500J/KG.
THE SOUNDING WITH THAT MUCH INSTABILITY ALONG WITH A MOISTURE RICH
COLUMN SUPPORTS EFFICIENT WARM-RAIN PROCESSES, WITH A WET-BULB-ZERO
HEIGHT NEAR 14.8 KFT AND A VERY MOIST BOUNDARY LAYER. WEAK 0-6 KM
SHEAR NEAR 5 KT, MEAN FLOW UNDER 10 KT, AND CORFIDI VECTORS
GENERALLY UNDER 10 KT FAVOR POORLY ORGANIZED, SLOW-MOVING
CONVECTION. THE PRIMARY CONCERN TODAY WILL CONSEQUENTLY BE LOCALLY
HEAVY RAINFALL AND BOUNDARY INTERACTIONS RATHER THAN ORGANIZED
SEVERE WEATHER. THE MODEST DCAPE NEAR 475 J/KG AND RELATIVELY WEAK
LAPSE RATES FURTHER LIMIT THE OVERALL WIND THREAT, ALTHOUGH PRECIP
LOADING AND COLLAPSING STORMS COULD STILL PRODUCE LOCALIZED GUSTY
WINDS.
FORECAST POPS FOR THE REST OF THE DAY GENERALLY RANGE FROM 60 TO 80
PERCENT, BUT THOSE VALUES DO NOT FULLY CONVEY THE UNCERTAINTY
ASSOCIATED WITH THE ONGOING CONVECTIVE SUPPRESSION. CAMS CONTINUE TO
INDICATE POTENTIAL FOR THE SUBSIDENCE TO WEAKEN SUFFICIENTLY FOR
LATE-AFTERNOON DEVELOPMENT ALONG THE INTERSTATE CORRIDORS. IF THAT
OCCURS, STORMS WILL HAVE ACCESS TO A VERY MOIST AND UNSTABLE
ENVIRONMENT, AND SLOW MOVEMENT COULD QUICKLY PRODUCE PONDING OR
LOCALIZED FLASH FLOODING. CONVERSELY, COVERAGE COULD UNDERPERFORM
THE FORECAST IF THE SUBSIDENT INFLUENCE OF THE GULF COMPLEX PERSISTS
LONGER THAN EXPECTED.
THE GREATEST FLASH FLOODING CONCERN OF THIS FORECAST PERIOD
CONTINUES TO BE MONDAY AS THE UPPER WEAKNESS AND SURFACE BOUNDARY
SETTLE CLOSER TO OR ON TOP OF THE CWA. A DEEPLY MOIST AIRMASS, WITH
PRECIPITABLE WATER VALUES EXPECTED TO BE NEAR DAILY CLIMATOLOGICAL
MAX OF ~2.4 INCHES, WILL COMBINE WITH WEAK STEERING FLOW AND
MULTIPLE LOW-LEVEL CONVERGENCE BOUNDARIES. THIS SETUP WILL FAVOR
SLOW-MOVING STORMS, BACKBUILDING AND LOCALIZED TRAINING. WIDESPREAD
RAINFALL TOTALS OF 1 TO 3 INCHES ARE FORECAST THROUGH THE TUESDAY,
BUT LOCALIZED AMOUNTS OVER 5 INCHES ARE POSSIBLE WHERE REPEATED
CONVECTION OCCURS. CONFIDENCE IS HIGH THAT NUMEROUS THUNDERSTORMS
WILL PRODUCE POCKETS OF HEAVY RAIN MONDAY, BUT REMAINS CONSIDERABLY
LOWER REGARDING THE PRECISE LOCATION OF THE HEAVIEST AXIS. CURRENT
INDICATIONS FAVOR PORTIONS OF THE COASTAL PARISHES/COUNTIES
ALONG/SOUTH OF I-10, BUT MEANINGFUL SHIFTS REMAIN POSSIBLE.
NUMEROUS SHOWERS AND THUNDERSTORMS MAY CONTINUE INTO AT LEAST PART
OF TUESDAY WHILE THE UPPER WEAKNESS REMAINS NEARBY. THE HEAVY-RAIN
THREAT WILL INCREASINGLY DEPEND ON MONDAY'S RAINFALL FOOTPRINT AND
THE LOCATION OF ANY LINGERING BOUNDARIES. AREAS RECEIVING
SUBSTANTIAL RAIN MONDAY WOULD BE MORE SUSCEPTIBLE TO ADDITIONAL
FLOODING TUESDAY EVEN IF RAINFALL RATES OR OVERALL COVERAGE BEGIN TO
DECREASE. GREATER CLOUD COVER AND MORE FREQUENT CONVECTION SHOULD
HOLD DAYTIME TEMPERATURES BELOW RECENT LEVELS MONDAY AND TUESDAY
WITH HIGHS UNLIKELY TO REACH 90.
MEFFER
LONG TERM
(THURSDAY THROUGH SATURDAY NIGHT)
ISSUED AT 1252 PM CDT SUN JUL 12 2026
THE MID-LEVEL WEAKNESS SHOULD BEGIN MOVING AWAY FROM THE CENTRAL
GULF COAST TUESDAY NIGHT INTO WEDNESDAY AS RIDGING GRADUALLY
REBUILDS FROM THE NORTHWEST. SURFACE HIGH PRESSURE IS ALSO EXPECTED
TO BECOME MORE ESTABLISHED ACROSS THE REGION. THIS EVOLUTION SHOULD
BRING DECREASING DEEP-LAYER MOISTURE AND A TRANSITION FROM NUMEROUS
THUNDERSTORMS TO MORE ISOLATED OR SCATTERED, PRIMARILY DIURNAL
CONVECTION WEDNESDAY AND THURSDAY. THE HEAVY-RAIN THREAT SHOULD THEN
DIMINISH CONSIDERABLY, ALTHOUGH ANY SLOW-MOVING STORM COULD STILL
PRODUCE A LOCALIZED DOWNPOUR.
THE UPPER RIDGE IS FORECAST TO BECOME MORE INFLUENTIAL OVER THE
REGION FRIDAY INTO NEXT WEEKEND AS IT BUILDS ACROSS THE CENTRAL
PLAINS TO THE NORTHERN GULF COAST. INCREASING HEIGHTS FROM THAT AND
GREATER INSOLATION SHOULD ALLOW TEMPERATURES TO CLIMB BACK INTO THE
LOWER AND MIDDLE 90S. WITH HIGHER SURFACE MOISTURE REMAINING IN
PLACE THAT KEEPS DEWPOINTS IN THE MID/UPPER 70S, HEAT INDEX VALUES
WILL ALSO RISE. AT THIS RANGE, CONFIDENCE IS GREATER IN A WARMING
TREND THAN IN TEMPERATURES OR HEAT INDICES REACHING ANY SPECIFIC
HEADLINE THRESHOLD. THE STRENGTH AND PLACEMENT OF THE RIDGE WILL
DETERMINE HOW MUCH CONVECTION IS SUPPRESSED AND HOW QUICKLY HEAT
STRESS INCREASES. A STRONGER RIDGE CENTERED CLOSER TO THE LOWER
MISSISSIPPI VALLEY WOULD SUPPORT HOTTER CONDITIONS, WHILE A RIDGE
REMAINING FARTHER WEST WOULD PERMIT SOMEWHAT GREATER AFTERNOON STORM
COVERAGE AND TEMPER THE HEAT. REGARDLESS, MAY BE LOOKING AT HEAT
ADVISORIES FOR AT LEAST LOCAL URBAN AREAS FRIDAY THRU WEEKEND
MEFFER
AVIATION
(18Z TAFS)
ISSUED AT 1252 PM CDT SUN JUL 12 2026
ANY LINGERING MORNING MVFR CEILINGS SHOULD CONTINUE IMPROVING, WITH
PREVAILING VFR CONDITIONS EXPECTED OUTSIDE CONVECTION. SCATTERED TO
NUMEROUS THUNDERSTORM POTENTIAL EXISTS FOR THIS AFTERNOON BUT GOING
WITH PROB30 GROUPS GIVEN UNCERTAINTY IN IMPACTS AT INDIVIDUAL
TERMINALS. ANY DIRECT THUNDERSTORM IMPACT COULD BRIEFLY PRODUCE IFR
VISIBILITY, GUSTY AND VARIABLE WINDS, AND FREQUENT LIGHTNING.
CONVECTION SHOULD DIMINISH DURING THE EVENING, ALTHOUGH ISOLATED
ACTIVITY MAY PERSIST NEAR THE COAST OVERNIGHT. A GREATER COVERAGE OF
THUNDERSTORMS AND ASSOCIATED FLIGHT RESTRICTIONS IS EXPECTED TO
DEVELOP EARLY MONDAY MORNING AS A FRONT SAGS INTO THE AREA. CAMS
INDICATE POSSIBLE WIDE SWATH OF CONVECTION ALONG A LINE FROM KHUM TO
KGPT BY 10Z.
MEFFER
MARINE
ISSUED AT 1252 PM CDT SUN JUL 12 2026
WEST TO SOUTHWEST WINDS WILL PREVAIL THROUGH TUESDAY AS A WEAK
FRONTAL BOUNDARY APPROACHES AND THEN STALLS NEAR THE COASTAL WATERS.
WINDS TODAY WILL GENERALLY REMAIN 5 TO 10 KNOTS ACROSS THE WESTERN
WATERS, AND TIDAL LAKES WITH 10 TO 15 KNOTS DEVELOPING ACROSS THE
MISSISSIPPI SOUND, CHANDELEUR SOUND, AND ADJACENT EASTERN COASTAL
WATERS AS THE LOCAL PRESSURE GRADIENT TIGHTENS THERE. SEAS WILL
GENERALLY BE 2 TO 3 FEET OVER THE OPEN GULF WATERS AND 2 FEET OR
LESS ACROSS THE PROTECTED WATERS.
THE PRESSURE GRADIENT FURTHER TIGHTENS ACROSS THE EASTERN WATERS
MONDAY AS THE UPPER TROUGH AND SURFACE BOUNDARY APPROACH. WEST WINDS
RESPOND BY INCREASING TO 15 TO 20 KNOTS DURING THE AFTERNOON AND
EVENING HOURS. THAT APPEARS TO BE THE PEAK WINDS SUPPORTED BY THIS
PRESSURE REGIME AS THEY THEN BEGIN FALLING OFF THEREAFTER. WAVES MAY
BUILD TO 3 TO 4 FEET BUT THEN FALL BACK TO AROUND 2 FEET THEREAFTER
AS WEAKER AND MORE VARIABLE FLOW PATTERN RETURNS.
THUNDERSTORMS REMAIN THE PRIMARY SHORT-DURATION HAZARD. TIMING IS A
BIT OUT OF THE NORM AS THAT FRONTAL BOUNDARY MENTIONED ABOVE MOVES
CLOSER INTO THE REGION. STORMS MAY PRODUCE FREQUENT LIGHTNING,
WATERSPOUTS, AND SUDDEN WIND GUSTS WITH LOCALLY HIGHER WAVES.
THUNDERSTORM COVERAGE SHOULD BE GREATEST THROUGH TUESDAY BEFORE
DECREASING LATER IN THE WEEK.
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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