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266 FXUS64 KLIX 021816AFDLIXArea Forecast DiscussionNational Weather Service New Orleans LA116 PM CDT Tue Sep 2 2025...New SHORT TERM, LONG TERM, AVIATION, MARINE....SHORT TERM...(Tonight through Thursday night) Issued at 1220 PM CDT Tue Sep 2 2025The models remain in good agreement on the timing of a strongerupper trough embedded within deep layer northwest flow aloft. Thislends to higher confidence that a much drier and more stableairmass will be in place by Wednesday night in the wake of thispassing system. In advance of this trough, moisture will remainvery limited with PWATS running between the 25th percentile andmedian values for this time of year. This will keep rain chancessuppressed at 20 percent or less for locations north of coastalLouisiana through tomorrow afternoon. However, along the immediatecoast of Louisiana , a weak stationary boundary will continue to serve as a focus for widely scattered convective activity and lowend chance PoP of around 30 percent through this evening. Once thetrough and associated front passes by, very low PWATS in the 25thpercentile range will be in place through Thursday night acrossthe entire area as deep layer subsidence and negative vorticityadvection takes hold. The front will also sweep far enough offshore to suppress convection even across the coastal waters.Although conditions will be mainly clear and dry, the coolerairmass to the north will not feed down into the Gulf South. Asa result, temperatures will actually warm a few degrees abovenormal in the mid 90s on Thursday as the drier air quickly heatsbeneath strong solar insolation. Fortunately, low dewpoints andhumidity will keep maximum heat index values in the upper 90s.&&.LONG TERM...(Friday through Monday night)Issued at 1220 PM CDT Tue Sep 2 2025The pattern aloft will begin to transition from the persistenttrough that has dominated the eastern half of the CONUS for thepast couple of weeks to a more zonal flow regime as the troughweakens and lifts to the north and east. Initially, the regionwill still be under of the trough on Friday, but over the weekendthe zonal flow pattern will become predominant. Heading into earlynext week, the remnant energy from a Pacific based tropicalfeature that is projected to move through the Baja Californiaregion will move into the Southern Plains. Both the GFS and theECMWF have come into somewhat better agreement on this occurring,bu the GFS has a much stronger and deeper feature forming over thePlains on Monday. Given these disparities in strength, a blended solution using the national blend of models was used for theMonday and Monday night forecast. In the low levels, a surfaceridge will be parked over the area on Friday, but will begin toshift to the east over the weekend and early next week. This willallow the wind field to shift from offshore to onshore by theweekend. These persistent onshore winds will gradually usher in more moisture and PWATS will climb from below the 25th percentile on Friday and Saturday to as high as the 90th percentile or 2.1 inches by Monday. In terms of the sensible weather impacts from these shiftingpatterns, will keep conditions warm and dry on Friday and Saturdaywith largely clear skies, very low PoP of less than 20 percent,and warmer than average temperatures in the mid 90s. Fortunately,the dry air will continue to mitigate heat indices with max valuespeaking near 100 degrees both days. As the moisture deepens onSunday and Monday, cloud development and overall rain chances willstart to increase. PoP on Sunday will see a decent moisturegradient over the area, with scattered convection south of I-10and more isolated activity further inland. The increased inmoisture,convection, and cloud cover will also allow temperaturesto fall back to near average in the upper 80s and lower 90s.Similar conditions are expected on Monday, but rain coverage should be slightly higher as forcing aloft increases with the deepening trough to the west and PWATS climb to somewhere between the 75th and 90th percentile.&&.AVIATION...(18Z TAFS)Issued at 1220 PM CDT Tue Sep 2 2025A dry and fairly stable airmass will keep rain chances limitedthrough tomorrow. As a result, VFR conditions will prevail at allof the terminals. However, a TEMPO group is in place at HUMthrough 22z this afternoon where some scattered thunderstormactivity has a higher probability of formation. If a storm passesover HUM, gusty winds and reduced visibilities will be the primary concerns. PG&&.MARINE...Issued at 1220 PM CDT Tue Sep 2 2025Overall, no major impacts to maritime operations are expectedthrough the weekend. Through tonight, a weak frontal boundary will remain stalled along the coast of Louisiana. Scatteredthunderstorm activity and east winds of 10 to 15 knots areexpected over the offshore waters with this boundary in place.Tomorrow into tomorrow night, a much stronger front will push through the waters and winds will shift to the north. A drier surface high will then settle in for Thursday and Friday with verylow rain chances, light winds, and calm seas. This high will begin to move to the east on Saturday allowing for a light southerly flow to develop. Offshore shower and thunderstorm activity will also increase as moisture feeds back into the area over the weekend.&&.PRELIMINARY POINT TEMPS/POPS...MCB 68 89 69 92 / 10 20 10 0 BTR 71 90 72 93 / 10 20 10 0 ASD 67 90 70 91 / 0 10 0 0 MSY 75 90 75 91 / 10 10 0 0 GPT 70 88 71 88 / 0 0 0 0 PQL 67 89 69 89 / 0 0 0 0 &&.LIX WATCHES/WARNINGS/ADVISORIES...LA...None.GM...None.MS...None.GM...None.&&$$SHORT TERM...PGLONG TERM....PGAVIATION...PGMARINE...PG
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Topic: [Alert]LIX issues Area Forecast Discussion (AFD) at Sep 2, 1:16 PM CDT ...New SHORT TERM, LONG TERM, AVIATION, MARINE... (Read 518 times)
