803 FXUS64 KLIX 220434 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1134 PM CDT Sat Jun 21 2025 ...New AVIATION... .SHORT TERM... (This evening through Sunday night) Issued at 108 PM CDT Sat Jun 21 2025 Temperatures are once again soaring into the low to mid 90s across the area this afternoon which coupled with dew points in the mid to high 70s is making for a miserably hot and humid day. Heat indices have been ranging between 100 and 110F, but predominantly just below the 108F criteria for a heat advisory. The highest heat indices have been recorded southwest of the lake like yesterday at around 108 to 110F at MSY, APS, and REG though the latter two temperature sensors might be running a tad too warm. As we have reached peak daytime heating this early afternoon, lake and sea breezes are beginning to initiate with showers and weak thunderstorms. Storms will continue to expand in coverage and propagate northwestward around the southwest flank of the surface high pressure system into the late afternoon before gradually dissipating by dusk. In other words, a fairly typical summer day. By Sunday, the axis of the upper-level ridge will lift out to the northeast and amplify over the Appalachians and northeast CONUS leading to a substantial heatwave for that region of the country, but also help to gradually alleviate the suppression of afternoon convection. However, latest guidance has continued to back off on PoPs for Sunday showing more isolated storms than prior indicating the lingering affects of the ridging and lack of lift will continue to limit convective coverage to predominantly the lake and sea breezes and outflow boundaries produced by pop up storms. As such, PoPs were backed down below 50%, and coverage as a whole appears to be more comparable to today instead of more scattered/widespread. Even still, with earlier initiation of convection anticipated tomorrow, temperatures and heat indices will have less time to climb and thus will likely stay below heat advisory criteria (closer to 100-105F heat indices). && .LONG TERM... (Monday through Friday night) Issued at 108 PM CDT Sat Jun 21 2025 As the ridging erodes and southeasterly low-level flow takes hold on the western flank of the Bermuda High early next week, we`ll begin to see more subtle inverted surface troughs/easterly waves follow the periphery of the high and enhance rain chances on certain days. Global guidance tends to favor passage of one of these waves on Monday into Tuesday which will help to enhance rain chances with a more classic convectively active marine area in the morning transitioning to more active afternoon convection inland. As we transition to the back half of the week, we will need to monitor how the massive 597dam ridge over the Mid Atlantic propagates southward and breaks down as to whether we may see a little resurgence in higher temps and lower rain chances to end the week next week or not. No indications this could bring heat indices to heat advisory criteria at this time, but hot and humid is going to be the rule not the exception living along the northern Gulf Coast anyways. && .AVIATION... (06Z TAFS) Issued at 1125 PM CDT Sat Jun 21 2025 Upper high centered over western Kentucky late this evening. Earlier convection has dissipated, but a rather extensive cirrus shield over pretty much all terminals at the midnight hour. Looks like the upper high may now be just far enough north to leave the northern Gulf coast susceptible to easterly waves/inverted troughs. Radar showing a few very small showers over the coastal waters, and wouldn`t entirely rule out some moving onshore prior to sunrise. The cirrus shield could limit any potential lowered visibilities due to fog at sunrise. Main concern for this package will again be the threat of TSRA during the day on Sunday, primarily beyond 18z until about sunset. Model solutions once again range from almost no TSRA development to scattered areal coverage. Forecast soundings don`t have any real limiting factors other than organized forcing. Will carry PROB30 at all terminals during the afternoon hours (18z-24z), but the first few cells of convection could initiate as early as 15-16z. && .MARINE... Issued at 108 PM CDT Sat Jun 21 2025 Easterly to southeasterly winds at 15 knots or less is expected throughout the forecast period while we stay positioned on the southwest flank of the broad Bermuda High over the southwest Atlantic. A few pop up storms could occur tonight, but is more likely on Monday and Tuesday mornings with the passage of a weak easterly wave. A few of these storms could be strong and cause significant wind shifts, high winds and seas, frequently lightning, and waterspouts. && .PRELIMINARY POINT TEMPS/POPS... MCB 73 92 72 91 / 30 30 20 40 BTR 74 93 74 92 / 20 40 20 70 ASD 73 92 74 91 / 10 30 20 60 MSY 78 92 79 92 / 10 40 20 70 GPT 76 90 76 89 / 20 40 20 60 PQL 73 92 74 91 / 30 40 20 60 && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...TJS LONG TERM....TJS AVIATION/UPDATE...RW MARINE...TJS