517
FXUS64 KLIX 051000
AFDLIX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW ORLEANS LA
400 AM CST WED FEB 5 2025
..NEW SHORT TERM, LONG TERM, AVIATION, MARINE
SHORT TERM
(TODAY THROUGH THURSDAY)
ISSUED AT 355 AM CST WED FEB 5 2025
FOG IS THE ONLY ISSUE IN THE SHORT TERM. THIS IS A GOOD MORNING TO
DICIPHER BETWEEN FOG SUPPORT AND PRODUCTION. THE CURRENT AND FCAST
SOUNDING PROFILES SHOW AN ADVECTIVE FOG REGIME BUT THERE ARE
VARIABLES THAT DON'T SUPPORT THIS. SFC THETAE VALUES ARE LESS THAN
330 AND WINDS WITHIN THE SFC TO 850MB LAYER ARE BACKING AND NOT
VEERING OR AT LEAST UNIDIRECTIONAL. SFC WIND SPEEDS ARE VERY LOW TO
CALM. THE WET BULB TEMP ALSO DOES NOT COOL STRONG ENOUGH ONCE
ENTERING THE DRY LAYER AT 850MB. BUT FCAST PROFILES DO SHOW A
STRONGER 3C LOWERING OF THE WET BULB IN THIS LAYER BY 12Z THIS
MORNING. THIS IS THE MODEL TRYING TO SAY THE DRYING OF THE AIR AT
THIS LEVEL WILL BECOME STRONGER ALLOWING FOR MORE EFFICIENT UPWARD
HEAT TRANSPORT INTO THE SUBSIDENCE INVERSION. CLOUD COVER IS NOT AN
ISSUE WITH ADVECTIVE PROFILES. SO, UPWARD HEAT TRASPORT IS NOT VERY
EFFICIENT THIS MORNING UNTIL AROUND SUNRISE. WHAT ABOUT DOWNWARD
TRANSPORT? DEW PT TEMPS MOVING IN FROM THE GULF ARE IN THE MID 60S
WHILE SST ARE IN THE MID 60S AS WELL. THIS DOES NOT ALLOW ANY HEAT
SINK DOWNWARD BUT DOES NOT WARM THE AIR MASS EITHER, SO THIS IS A
SCENARIO THAT WOULD SUPPORT, NOT PRODUCE. SO, IF FOG CAN BE
PRODUCED UPWIND, IT WOULD NOT DISSIPATE AS IT MOVES OVER THESE
WATERS. SST ARE IN THE MID 50S TO AROUND 60 IN THE MISS SOUND AREA
THOUGH, AND THIS WOULD PRODUCE FOG, ALBEIT SLOWLY AS THE
DEL(DEWT-SST) IS NOT HUGE. THIS IS NOT THE CASE IN THE MISS RIVER
AND THIS IS WHERE WE SHOULD FIND THE THICKEST FOG THIS MORNING.
ALL OF THE VARIABLES THAT DON'T SUPPORT ADVECTIVE, DO SUPPORT
RADIATIVE FOG FORMATION THOUGH. AREAS THAT DO NOT HAVE CLOUD COVER
WOULD DEFINITELY BE ABLE TO PRODUCE WITH AN UPWARD HEAT SINK AS
THE SFC COOLS IN THESE AREAS. THE ONLY AREA THAT THIS IS OCCURRING
IS THE MISS GULF COAST COUNTIES AND AROUND THE PEARL RIVER AREA.
SINCE THE FOG IS PATCHY AND QUITE DENSE AT TIMES, THIS CAN BE EVEN
MORE HAZARDOUS THAN WIDESPREAD DENSE FOG, SO WE WILL BE PLACING
THESE AREAS UNDER A DENSE FOG ADVISORY THIS MORNING. BASICALLY, WE
COULD HAVE SUMMED THIS UP BY SAYING A LOT OF BOUNCING VIS AT ALL
LOCATIONS WITH A FEW MAYBE STAYING DOWN AROUND SUNRISE FOR A FEW
HOURS. THIS SAME SCENARIO LOOKS TO BE THE CASE AGAIN TONIGHT AND
THU NIGHT.
LONG TERM
(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 355 AM CST WED FEB 5 2025
FOG WILL REMAIN THE BIGGEST ISSUE ON THE TABLE UNTIL WE GET INTO THE
WEEKEND. THIS IS WHEN A COLD FRONT SHOULD BE MOVING TOWARD OR INTO
THE AREA WITH A VERY STRONG THERMAL BOUNDARY SUNDAY OR SUNDAY NIGHT.
RAIN SHOWERS SHOULD BE ABLE TO ACCOMPANY THIS FRONT, BUT INSTABILITY
AT FIRST GLANCE, DOES NOT LOOK VERY HIGH WHICH WOULD KEEP STORMS TO
A MINIMUM. THIS FRONT WILL MOVE VERY SLOWLY AS IT APPROACHES SUNDAY
AND MAY STALL OVER THE NORTHERN PORTION OF THE AREA UNTIL MONDAY
NIGHT WHEN IT GETS A PUSH WHICH COULD BRING IT INTO THE GULF BY TUE
OR WED WHERE IT SHOULD STALL. THE FRONT WILL BE GENTLY SLOPED AND
THE 850MB PORTION WILL STALL OVER OUR AREA AS THE H3 JET WILL REMAIN
ACTIVE OVER IT WITH DISTURBANCES RIPPLING THROUGH WED THROUGH THU OF
NEXT WEEK. THE THERMAL GRADIENT SHOULD BE ORIENTED FROM THE WEST
CENTRAL GULF TO SELA DURING THAT TIME FRAME AND EVENTHOUGH THE GFS
IS THE ONLY MODEL SO FAR THAT SHOWS A SFC LOW DEVELOPING OVER THE
WESTERN GULF, THIS LOOKS LIKE IT WOULD BE THE PREFERRED SCENARIO
SINCE THESE CONDITIONS AND JET SUPPORT WOULD DO EXACTLY THAT. AND
THE FACT THAT THIS HAS BEEN THE COMMON THEME ALL WINTER SO FAR.
AVIATION
(12Z TAFS)
ISSUED AT 355 AM CST WED FEB 5 2025
CIGS AND VIS AT VFR LEVELS THIS MORNING FOR MOST TERMINALS. A FEW,
MAINLY MISS COASTAL TEMINALS WILL REMAIN IN IFR OR LIFR THROUGH MID
MORNING. VIS LEVELS COULD BOUNCE IN AND OUT OF IFR AND VFR FOR
OTHERS BUT ALL TEMINALS SHOULD BE VFR BY LATE MORNING. THESE SAME
CONDITIONS LOOK TO REPLICATE AGAIN TONIGHT.
MARINE
ISSUED AT 355 AM CST WED FEB 5 2025
E THROUGH S WINDS WILL REMAIN THROUGH THE REST OF THIS WEEK AND
SHOULD ALSO REMAIN 15KT OR LESS. FOG IS EXPECTED TO BE AN ISSUE FOR
SOME COASTAL WATERS MAINLY IN THE NEARSHORE WATERS AND ESPECIALLY
THE MISS RIVER NIGHTLY. WINDS OVER THE RIVER ARE WEAK SOUTHERLY SO
THE NORTH END OF N-S ORIENTED RIVER RUNS WILL HAVE FOG DEVELOP IN
THOSE BENDS THIS MORNING. A DENSE FOG ADVISORY WILL BE ISSUED FOR
SOME OF THE PROTECTED WATERS THIS MORNING AND ROADWAYS OVER THESE
AREAS WILL BE IMPACTED AS WELL ESPECIALLY NEAR THE NORTHERN
APPROACHES OF THOSE BRIDGES SUCH AS THE CAUSEWAY.
PRELIMINARY POINT TEMPS/POPS
MCB 79 61 81 60 / 10 0 10 0
BTR 83 65 84 63 / 10 0 10 0
ASD 77 61 80 60 / 0 10 20 10
MSY 77 63 79 62 / 0 0 20 0
GPT 71 59 72 59 / 0 10 20 10
PQL 77 60 78 60 / 0 10 20 10
LIX WATCHES/WARNINGS/ADVISORIES
LA...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR LAZ039-071-
076-079>082.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR GMZ530-532-
534.
MS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ070-071-
077-083>088.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR GMZ532-534.
SHORT TERM...TE
LONG TERM....TE
AVIATION...TE
MARINE...TE
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