textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 529 AM CDT Thu Aug 27 2026

- Scattered to numerous showers and thunderstorms are forecast mainly during the afternoon hours today and Friday. A few storms could become strong both days. The main threat from any severe storms will be damaging wind gusts. Frequent lightning and periods of heavy rain will also be possible from these storms. Stay weather aware and remember when thunder roars, go indoors.

- The increase in rain chances and cloud cover will help limit heat threats, however, heat index values may still approach advisory criteria before thunderstorms develop by early afternoon. Those with outdoor plans should continue to take precautions to avoid heat-related illnesses. Stay hydrated and take breaks in the shade or air conditioning if possible.

UPDATE

Issued at 529 AM CDT Thu Aug 27 2026

Have adjusted PoP grids on a couple of occasions this morning. Convective complex moving southeastward across the CWA, and about to reach Lake Pontchartrain. Instantaneous rainfall rates of 4-6 inches per hour have been common, but fortunately in most places it hasn't rained hard for nearly that long. Still enough to cause rush hour issues with the heaviest storms. Mesoscale models aren't quite as bullish on redevelopment this afternoon as earlier runs were, but won't dry things out completely quite yet.

SHORT TERM

(Now through Sunday) Issued at 1255 AM CDT Thu Aug 27 2026

Upper ridging continued to be centered near the Four Corners area during the evening with a deep upper trough to the east of the ridge extending from Lake Huron to Florida. A shortwave moving toward the base of the trough was over Arkansas during the evening.

Locally, there was a small area of thunderstorms between Hattiesburg and Gulfport that was sagging southward, and will reach Interstate 10 in the next 2 hours. A more extensive area of storms was noted near Interstate 20, also sinking southward. The storms near Interstate 20 are likely to make it into southwest Mississippi around 4 AM CDT with heavy rain and brief gusty winds. Ahead of the storms, temperatures were in the upper 70s to mid 80s at midnight CDT.

Main forecast question this morning is how far southward will the convection near Interstate 20 make it? Some of the mesoscale models dissipate this area of convection by mid morning, while others (like the FV3) drive it into the coastal waters. The forecast scenario we'll go with has the early morning convection running out of energy and real estate around mid-morning, with regeneration by mid afternoon. This batch will make it into early evening before dissipating.

Precipitable water values diminish somewhat for the weekend, but still remain near the 75th percentile (1.95). That will be sufficient for at least scattered thunderstorms each day, mainly during the heat of the day, as the troughing retreats far enough west to temporarily get the local area back to what seems to be the prevailing pattern this season, where the local area is stuck in the weakness between 2 ridges.

With the multiple rounds of precipitation expected today, high temperatures probably won't get out of the 80s, although its going to be pretty humid. Saturday will probably be the warmest of the set, as moisture levels will be at a moderate level, getting into the lower 90s. Overnight lows will be 3 to 5 degrees above normal, mainly middle 70s.

LONG TERM

(Sunday night through Wednesday) Issued at 1255 AM CDT Thu Aug 27 2026

As we move into the extended portion of the forecast the pattern will begin to shift. The weak troughing over the southeastern CONUS into the north-central Gulf will get squeezed as ridging to our west and northwest builds east. This will lead to a weak cut-off mid lvl low remaining in place over the northern Gulf late Sunday which will then slowly drift west-southwest into the western Gulf by Tuesday night. There will be ample moisture to work with and thus we will likely see diurnal convection each day.

At the sfc broad and weak high pressure will be centered well off to the east-northeast leaving a rather weak pressure gradient in place. This will also lead to generally weak southeast flow however winds will be somewhat dictated by diurnal shifts as well especially closer to the coast where the southeast winds will likely be a little enhanced from the late morning through the afternoon hours. Winds in the low levels will also be mostly light and out of the southeast or light and variable. With winds becoming more southeasterly from the sfc to at least h85 each day by late morning the seabreeze will not have much of a problem penetrating well inland through the afternoon. Combine that with more than sufficient moisture and broad weak low aloft afternoon showers and thunderstorms look like a pretty good bet. Now at any one point in the afternoon we probably won't have any more than scattered coverage but PoPs especially the southern half of the CWA will be around 60 possibly 70% a few afternoons. These will be more of the typical Summer type afternoon thunderstorm with maybe a few strong storms possible but the biggest issues from any of these storms will be cloud to ground lightning and brief locally heavy rain.

Temperature wise we will end the weekend and begin the new work week with near normal to slightly above normal temps but by mid week it looks like we may start to warm back up. As the low moves farther to the west the ridge will begin to build back in over the area. With that we will see the rain chances start to fall as suppression increases across the region. By Wednesday we may be back into the mid 90s across the northern 3rd/half of the CWA. /CAB/

AVIATION

(12Z TAFS) Issued at 529 AM CDT Thu Aug 27 2026

SHRA/TSRA moving across the terminals at a pretty good clip for now, and may be able to drop TSRA out of at least the KMCB and KBTR forecasts in the near term. Still a question of whether we get redevelopment this afternoon, as we'll need to get some sunshine to destabilize things again. If we do, it'll be mid to late afternoon. Will keep most previous trends going for one more package.

MARINE

Issued at 1255 AM CDT Thu Aug 27 2026

Surface high pressure over the Gulf will maintain a generally weak pressure gradient through much of the period. Weak and variable winds around 5 to 10 knots and varying between southerly and westerly will predominate through the week. Scattered thunderstorms will remain possible every day with winds and waves higher in and near this activity.

LIX WATCHES/WARNINGS/ADVISORIES

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