Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA
Issued by NWS New Orleans/Baton Rouge, LA
511 FXUS64 KLIX 281727 AFDLIX Area Forecast Discussion National Weather Service New Orleans LA 1227 PM CDT Fri Aug 28 2026 ...New SHORT TERM, LONG TERM, AVIATION, MARINE... .KEY MESSAGES... Updated at 1220 PM CDT Fri Aug 28 2026 - Minimal rain chances today and Saturday. Increasing convection Sunday onward. - Main threat from any severe storms will be damaging wind gusts, frequent lightning and periods of heavy rain will. - Heat index values may still approach advisory criteria before thunderstorms develop each afternoon next week. && .SHORT TERM... (Now through Monday night) Issued at 1220 PM CDT Fri Aug 28 2026 A comparatively quiet afternoon is shaping up across most of the area as drier mid and upper level air continues to work southward. Shallow cumulus has been developing with daytime heating, but radar remains quiet over land late this morning with convection confined to the coastal waters. The upper ridge currently centered over New Mexico will gradually shift east toward the Texas Panhandle through Saturday. While the ridge axis remains northwest of the CWA, enough subsidence and midlevel drying will extend into the area to suppress the typical late-August convective cycle. This should be especially true through much of the inland Louisiana parishes west of I-55 and north of I-10/12 corridors. Cannot completely eliminate convection given strong daytime heating and eventual development of the sea/lake breeze, but coverage should remain isolated this afternoon. The somewhat better moisture over far southeastern Louisiana and coastal Mississippi provides the best opportunity for a few storms, with the Mississippi coast favored relative to most inland locations. Saturday looks quite similar. Continued dry air aloft and subsidence on the southeastern flank of the ridge should again keep most inland locations dry, with isolated convection primarily tied to the sea breeze and areas closer to the coast. Better coverage should remain over the coastal waters. With less convection and cloud cover, highs will climb into the lower to middle 90s. Peak heat indices should generally remain below advisory criteria through the weekend but still well into the 100s. Would probably be higher if not for some mixing down of dry air aloft. The pattern begins to change more noticeably Sunday as the upper ridge shifts farther north and east. This allows easterly flow to become better established across the northern Gulf while a weak inverted trough or other perturbation develops over the northeastern Gulf. The resulting moisture return should initially be most pronounced across the eastern and coastal portions of the CWA. Expect a meaningful increase in thunderstorm coverage Sunday from coastal Mississippi through southeast Louisiana, including the New Orleans metro, while the Baton Rouge area may remain on the western edge of the deeper moisture and see a somewhat smaller increase. Increasing cloud cover and convection should hold temperatures down a couple degrees where storms become more numerous Sunday. Locally heavy rainfall and gusty winds will be possible with the stronger storms, but widespread heavy rainfall or severe weather is not currently anticipated. MEFFER && .LONG TERM... (Tuesday through Thursday night) Issued at 1220 PM CDT Fri Aug 28 2026 The primary story during the extended period will be the continued eastward tracking of the upper ridge and a corresponding increase in deep-layer moisture across the north-central Gulf Coast. Monday into Tuesday, the ridge center should be shifting toward the southern Appalachians, placing the local area firmly along its southern periphery. This favors persistent easterly to southeasterly flow from the Gulf and western Atlantic into the region. At the same time, the weak inverted trough moving west across the northern Gulf may provide an additional focus for convection. Rain chances should therefore remain elevated Monday and Tuesday, with the greatest coverage initially across coastal areas before better moisture spreads farther west and north. Wednesday through Friday, the broad-scale pattern remains favorable for a progressively deeper tropical moisture profile. Guidance brings precipitable water values well above 2 inches, with some solutions approaching 2.5 inches late in the week. If that degree of moisture becomes established, convection should become increasingly efficient at producing heavy rainfall. At this point there is not enough confidence in the location or persistence of convection to highlight a widespread flooding threat. However, the combination of deep tropical moisture, weak steering flow and repeated daily convection could eventually support localized heavy rainfall concerns, particularly during the latter half of the week if the wetter guidance verifies. This trend will need to be monitored as the moisture plume and any embedded Gulf circulations become better resolved. Temperatures should remain close to late-August normals overall. Highs will generally reach the lower 90s, with upper 80s possible where convection develops earlier in the day and middle 90s possible where storms are delayed. There remains some potential for heat indices to approach advisory criteria, especially during the early to middle portion of the week in areas that remain dry through peak heating. However, the increasingly moist pattern does not automatically translate into a greater heat threat. While higher dewpoints favor larger heat indices, increasing cloud cover and thunderstorm coverage should increasingly limit afternoon temperatures. If the deeper tropical moisture arrives as currently expected late in the week, the duration and areal coverage of 108+ heat indices may actually decrease. The largest uncertainty during the extended period remains the exact position of the upper ridge. A ridge axis displaced farther south or west would provide greater subsidence, reduce convective coverage and allow hotter temperatures. Conversely, a farther northeast ridge and stronger easterly moisture transport would favor greater thunderstorm coverage, heavier rainfall potential and somewhat cooler daytime temperatures. MEFFER && .AVIATION... (18Z TAFS) Issued at 1220 PM CDT Fri Aug 28 2026 VFR conditions should prevail through the period. Convection will be very limited this afternoon, with KGPT having the greatest chance of being affected by a SHRA/TSRA given the somewhat deeper moisture across coastal Mississippi. Probability is considerably lower at the remaining terminals and does not warrant any TEMPO or PROB30 groups. Otherwise, winds will remain generally light with a northerly component inland, becoming more easterly near the coast with development of the afternoon sea breeze. MEFFER && .MARINE... Issued at 1220 PM CDT Fri Aug 28 2026 Benign marine conditions will continue outside of thunderstorms. A weak pressure gradient will maintain winds generally 10 knots or less through the weekend with seas around 1 to 2 feet. Winds will initially have a northerly to northeasterly component before becoming increasingly easterly Saturday to southeasterly Sunday onward as the upper ridge shifts east and the low-level flow off the Gulf becomes better established. Scattered convection over the open Gulf will remain the primary concern today and Saturday, with thunderstorm coverage increasing across more of the coastal waters Sunday and into next week. MEFFER && .LIX WATCHES/WARNINGS/ADVISORIES... LA...None. GM...None. MS...None. GM...None. && $$ SHORT TERM...ME LONG TERM....ME AVIATION...ME MARINE...ME