textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1227 PM CDT Fri Jun 12 2026

- High temperatures are expected to climb into the mid 90s today through Sunday with heat index values approaching 105 degrees. This is our first heat spell of the summer, so please use caution if outdoors for an extended period of time.

- A weak cold front will slowly move into the area during the first half of next week leading to higher shower and thunderstorm chances. This has correlated to a higher Flash Flood risk starting Monday with a Slight Risk (Level 2 out of 5) for Flash Flooding.

SHORT TERM

(Now through Monday night) Issued at 1227 PM CDT Fri Jun 12 2026

Very similar conditions to this afternoon are anticipated for Saturday and Sunday as a broad and deep ridge axis remains centered over the Gulf South. This will lead to fairly typical weather conditions for mid-June with highs climbing into the low to mid 90s over inland areas and the upper 80s and lower 90s along the coast. Heat index values will climb to between 100 and 105 each day, and much of the area will be in moderate to major HeatRisk criteria. Although the heat index will remain below official advisory criteria levels, this first big heatwave of the Summer season and the lack of acclimation to the heat could lead to increased heat illnesses in the area. Stay hydrated and take frequent breaks in an air conditioned or shaded area if you are participating in any outdoor activities or work this weekend. Beyond the heat, PWATS will be near average at around 1.7 to 1.8 inches and this will support scattered to broken cumulus development each day. However, the strong ridging aloft will continue to warm the mid-levels leading to weaker mid-level lapse rates of between 5.4 to 5.6 C/km and lower mixed layer CAPE values of 600 to 700 J/KG. This will greatly limit overall convective potential through the weekend. The most likely ares to experience convection will be wear weak boundaries like the seabreeze and lakebreeze or outflow boundaries interact as increased low level forcing may be able to overcome the weak cap aloft.

As we move into Monday and Monday night, conditions will quickly change as a plume of deep tropical moisture feeds into the region from the southwest. PWATS will surge to between the 90th percentile and daily max on Monday with readings of 2.1 to 2.2 inches expected. This increased moisture will correspond with the ridge axis shifting to the south as a broad longwave trough and an associated surface frontal boundary begin to push into the Lower Mississippi Valley. Increasing positive vorticity advection and more favorable jet dynamics aloft will support increasing deep layer lift across the forecast area by Monday afternoon with the greatest forcing occurring closer to the front in southwest Mississippi and parts of metro Baton Rouge. A fairly sharp gradient will be in place for PoPs that will have categorical PoP over the northern third of the forecast area and only scattered PoP along the Louisiana coast. This is entirely due to expected moisture pooling along the approaching frontal boundary as it slowly drifts into southwest Mississippi by Monday afternoon. Given the high PWATS in place and very efficient warm rain processes aloft as noted by a -5C 500mb temperature, heavy rainfall will be a concern as we move into Monday afternoon and Monday night. Rainfall rates of 2 to 3 inches per hour will be possible, and the orientation of the mid-level wind field is supportive of training and back building convective activity along the frontal boundary. Rainfall totals Monday into Monday night could be in the 4 to 6 inch range in a few localized spots. A flood watch will likely be issued for northern portions of the forecast area later this weekend.

LONG TERM

(Tuesday through Thursday night) Issued at 1227 PM CDT Fri Jun 12 2026

Tuesday will see a continuation of the heavy rainfall threat as the frontal boundary slowly sinks southward across the forecast area. 500mb temperatures will remain near -5C indicating that warm rain processes will continue and that rainfall rates of 2 to 3 inches per hour will persist as PWATS stay above the daily max values for this time of year. The wind field will be little changed, so continued training and backbuilding of thunderstorms along the frontal boundary will continue to be concern, and an additional 4 to 6 inches of rain could occur in localized spots. A few locations could see between 10 and 15 inches of rain by Wednesday morning based on the slow moving nature of the front, favorable wind field for training storms, and the very moist airmass in place.

Wednesday itself will be a day of transition as the front begins to dissipate over the area and the greatest forcing aloft starts to shift to the east along with the parent longwave trough axis. However, deep tropical moisture will continue to linger over the area with PWATS still near 2 inches or between the 75th and 90th percentiles for this time of year. Although forcing will be weaker, highly efficient warm rain processes will continue, and that will keep the threat of heavy rainfall in place. Additional rainfall totals of 2 to 4 inches and rainfall rates of 1.5 to 2.5 inches per hour are possible. The threat of backbuilding storms will be lower as the wind field becomes less favorable, but locally heavier rainfall and already saturated soils will keep a flash flooding threat in place through Wednesday evening. Temperatures will be below average from Monday through Wednesday due to the extensive rainfall and cloud cover over the region.

Thursday will finally see a return to more typical Summer conditions as a mid to upper level ridge axis builds over the forecast area in the wake of the departing longwave trough axis. PWATS will fall to between the 50th and 75th percentiles and the lingering front will fully wash out by Thursday. Convective potential will fall back to more seasonal levels of 40 to 50 percent as scattered afternoon showers and storms fire up along weak mesoscale boundaries. There will continue to be a small flash flooding concern due to saturated soils from the prior days of rainfall. Temperatures will also return to more typical levels around 90 degrees with heat index readings rising back to between 100 and 105 degrees.

AVIATION

(18Z TAFS) Issued at 1227 PM CDT Fri Jun 12 2026

Brief pop up showers and thunderstorms could impact NEW, MSY, and HUM with periods of MVFR visibilities and ceilings between 18z and 23z today. Any impacts will be short-lived at 30 minutes or less. Once these showers and storms dissipate by 00z, VFR conditions will be the prevailing condition at all of the terminals through around 09z. A weak inversion could allow for some light fog to form at MCB and BTR between 09z and 13z resulting in another round of MVFR restrictions. The inversion will quickly mix out after 13z with a return to prevailing VFR conditions at all terminals expected through the end of the forecast period.

MARINE

Issued at 1227 PM CDT Fri Jun 12 2026

A broad area of high pressure will remain centered over the eastern Gulf and Florida through the weekend and into early next week, promoting a persistent south-southeast wind of 10 to 15 knots across the coastal waters through early next week. These winds will produce seas of 2 to 4 feet in the open Gulf waters and 1 to 2 feet in the sounds and tidal lakes. Onshore winds are expected to increase by mid-week to near small craft advisory range as the pressure gradient across the Gulf increases due to a strengthening high over the eastern Gulf and Florida.

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...None. MS...None. GM...None.