FXUS64 KLCH 160533 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 1233 AM CDT Thu Apr 16 2026 ...New DISCUSSION, AVIATION, MARINE, FIRE WEATHER... .KEY MESSAGES... - Warm, humid conditions will continue through the end of the week with afternoon highs in the mid to upper 80s. - A cold front will move through the region Saturday evening into early Sunday morning accompanied by showers and thunderstorms with the potential for localized heavy rainfall. - Behind the front, cooler, drier air will make its way into the region Sunday through early next week. && .DISCUSSION... (Today through Wednesday) Issued at 1230 AM CDT Thu Apr 16 2026 A surface high pressure system over the Atlantic east of the Florida coast will continue to ridge westward along the northern Gulf coast and into the forecast area through early Saturday. This will keep a warm and muggy air mass in place. Both high and low temperatures will be around 5 degrees above climo norms. The forecast area through the end of the week will also be on the edge of a Gulf upper level ridge that will bring mainly a dry southwest flow in the mid levels keeping a cap in place. Daytime heating will allow some clouds to form, however, the cap will limit any shower activity. In the immediate term for tonight into early Thursday, boundary layer winds are expected to stay up enough that will preclude widespread fog with a low stratus deck preferred. At the end of the week into the weekend, the upper level ridge over the Gulf will flatten and weaken as it shifts to the south. Meanwhile, a significant upper level storm system over the Pacific Northwest will move eastward and deepen into a sharp upper level trough as it moves east of the Rockies. This system will help move a surface cold front across the forecast area Saturday evening into the overnight. Both East Pac and western Gulf moisture will be picked up ahead of the upper level trough and pool ahead of the frontal system. The moistening airmass will help erode the cap and along with frontal lift help initiate showers ahead of the front. Instability is enough during the late afternoon and early evening hours that a few thunderstorms should mix in with the shower activity. Anomalously high moisture values are expected by late Saturday afternoon into Saturday night with PWAT values above the 90th percentile of 1.6 inches and near the max moving value of 1.9 inches. Meanwhile, Mean Layer Relative Humidity values are progged to be above 80 percent. Which means any storms that form could be efficient precipitation producers. As the front moves eastward during the night, instability will decrease and intensity of the shower activity should also decrease as the activity moves toward Acadiana and the Atchafalaya Basin. Forecast rainfall amounts that fall with that scenario have highest rainfall amounts northwest of a Beaumont/Port Arthur to Opelousas line with average rainfall amounts between 1/2 and 1 inch. The probability of a "wetting" rain or amounts greater than 1/4 of an inch is over 50 percent in that area, and probability of over 1 inch is 30 percent in that area. It should be noted that mean wind field decreases and does become parallel to the theta-e ridge along the front in the evening hours, and if any strong convection is ongoing some high rainfall rates may fall for a length of time and the NBM shows highest rainfall amounts between 2 and 3 inches if this occurs. Therefore, WPC does have a Marginal Excessive Rainfall Outlook (level 1 out of 4) during the Saturday night time period. Behind the front, continental air mass from the Canadian Prairies will move in bringing cooler temperatures through Monday with lows and highs some 5 to 10 degrees below climo norms. On Sunday afternoon, low relative humidity values between 25 and 35 percent and some gusty northeast winds may bring about some degree of fire danger, however a lot will depend on how much rain falls on Saturday night. By mid week, temperatures begin to warm up again. A more active southwest flow will also allow for a chance of showers. 07/Rua && .AVIATION... (06Z TAFS) Issued at 1230 AM CDT Thu Apr 16 2026 Southerly flow will continue to bring in moisture under the nocturnal inversion overnight. Surface winds will continue to be very light, however average boundary layer winds are expected to stay up around 10 knots with boundary layer temperatures staying above surface dew points. This situation points to MVFR ceilings from low clouds rather than visibility restrictions. Ceilings will become VFR by mid morning Thursday. 07/Rua && .MARINE... Issued at 1230 AM CDT Thu Apr 16 2026 Surface high pressure will ridge across the northern Gulf from off the Florida coast through Saturday that will allow for a persistent southerly flow. The light to modest onshore flow will increase on Friday into Friday night with building seas as low pressure forms over the Plains. A cold front in forecast to move through on Saturday night with strong and gusty northerly winds along with building seas behind it. && .FIRE WEATHER... Issued at 1230 AM CDT Thu Apr 16 2026 Although fuels remain dry across the region with various degrees of drought continues, persistent southerly flow for the next few days will bring in low level moisture that will allow for minimum afternoon relative humidity values to range from 40 to 60 percent, this will help keep the fire danger somewhat in check through Saturday. A cold front will move across Saturday night that may bring some portions of the area a wetting rain. Strong northerly winds and low relative humidity values are expected behind the front on Sunday. && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...None. && $$ PUBLIC/FIRE/MARINE...07 AVIATION...07