Area Forecast Discussion
Issued by NWS Lake Charles, LA
Issued by NWS Lake Charles, LA
221 FXUS64 KLCH 151738 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 1238 PM CDT Tue Sep 15 2026 ...New DISCUSSION, AVIATION, MARINE, FIRE WEATHER... .KEY MESSAGES... - High pressure centered over the northern Gulf Coast will limit daily thunderstorm potential (20-30%) this week. - Drier air will move into the region Thursday and Friday which will lower heat indices and make conditions feel more comfortable. - Precipitation chances increase Sunday into early next week as an area of low pressure moves into the northeastern Gulf. && .DISCUSSION... (This evening through next Monday) Issued at 1237 PM CDT Tue Sep 15 2026 Scattered fair weather cu and a few thunderstorms have already initialized across the region early this afternoon in what remains a very tropical airmass (observed pwat of 2.2 on the 00Z KLCH ob). Inhibiting substantial convection this afternoon will be a steadily building upper level ridge presently centered over eastern Tennessee and northern Georgia, but retrograding westward toward the northern gulf coast. With that in mind, afternoon PoPs are maintained on the low end at 20-30%. At the surface, a weak pressure gradient will keep winds light and variable at 5 MPH or less through the day. Guidance is again indicating a greater than 50% chance of some patchy, light fog development early Wednesday morning in the calm winds and clear skies. Some patchy fog was observed this morning and with no material change in airmass or forecast philosophy, persistence lends prudence to keeping it in the forecast. A weak upper level impulse is expected to progress across the northern gulf from east to west Wednesday around the southern periphery of the building upper level ridge over the southeastern U.S. carrying even higher moisture (hard to make that statement with pwats already at 2.2). This impulse is expected to offer some thunderstorms across the lower atchafalaya basin to the coast, bu the majority of the precipitation is should remain offshore closer to the trough axis. Behind this impulse, noticeably drier air will advect into the region Thursday through Saturday bringing the apparent temperature and actual temperature differential to within about five degrees of one another. It will certainly still be hot, but noticeably less oppressive after months of dewpoints in the upper 70s. The forecast heading into early next week is still somewhat muddied, by the evolution of a large, nontropical, upper level low that most guidance brings across the Florida peninsula and into the northeast gulf by Sunday. Some guidance brings the center of this low into the northern gulf while others keep it over Florida. The track of this low will have an outsize impact on precipitation chances from Sunday through next Tuesday, but at a minimum, the tropical moisture will push dewpoints back into the low to mid 70s for early next week. Jones && .AVIATION... (18Z TAFS) Issued at 1237 PM CDT Tue Sep 15 2026 VFR conditions will prevail through the period. Fair weather cu will continue to develop through the afternoon and early evening before dissipating after 01Z. Upper level ridging building across the region will keep precipitation chances limited to 20-30% so do not expect significant impacts from these. Winds will calm overnight allowing for some patchy, light fog to develop between 09Z and 12Z Wednesday morning. Any fog that develops will dissipate no later than 13Z with VFR conditions to prevail thereafter. Jones && .MARINE... Issued at 1237 PM CDT Tue Sep 15 2026 High pressure over the northern Gulf will keep winds out of the south to southeast at 5-10 kt through tonight with seas of 1-2 feet. A disturbance moving through the area Wednesday will strengthen easterly winds to 20-25 kt and increase wave heights to near 8 feet. Small craft advisories will likely become necessary for the Wednesday into Thursday time period. && .FIRE WEATHER... Issued at 1237 PM CDT Tue Sep 15 2026 A moist airmass remains in place over the region with winds generally light out of the south to southeast. Most of the area will remain dry through Wednesday, though an isolated afternoon shower or thunderstorm cannot be ruled out. Afternoon MinRH will be 40-50 percent inland and 50-60 percent near the coast. For Thursday into the start of the weekend, drier air will begin to move into the CWA, with afternoon MinRH decreasing to 30-40 percent inland and 40-50 percent near the coast. East winds around 5-10 kt are expected for this period. && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...None. && $$ PUBLIC/FIRE/MARINE...66 AVIATION...66