textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 617 PM CDT Sun Jul 26 2026

- Impactful heat conditions will persist well into the new week. Mid week will be the most intense days with heat indices 110-115 degrees.

- Rain chances will remain very low through Wednesday. Scattered thunderstorms should return Thursday through Saturday as the upper ridge weakens and a frontal boundary settles toward the northern Gulf Coast.

SHORT TERM

(Now through Wednesday) Issued at 1142 AM CDT Sun Jul 26 2026

A broad mid/upper-level ridge is currently draped across the Rockies, extending northward into Canada, southward into Mexico, and eastward into the Lower Mississippi Valley. A weak shortwave moving southeastward across Alabama and the Florida Panhandle, but associated showers remain far east of the local area. At the surface, high pressure remains centered over the north-central Gulf. The column remains sufficiently dry and capped to prevent meaningful convective development today. Continued warming through the 850-700 mb layer beneath the upper ridge will strengthen subsidence and inhibition. High temperatures this afternoon will generally reach the mid 90s, with some upper 90s possible. Most locations should see maximum heat indices between 103 and 107 degrees, although isolated values of 108 to 110 degrees remain possible, just not widespread enough to justify an advisory for today.

The upper ridge and surface high over the Gulf will move very little Monday and Tuesday. West to northwest low-level flow will continue to favor strong daytime heating and delay marine influence. At the same time, gradual low-level and column moistening should allow afternoon dewpoints to remain somewhat higher than today. Since a difference of only a couple degrees in the afternoon dewpoint can have a large effect on the heat index, this combo of slightly higher dewpoints with near to slightly higher temps will increase heat indices into Heat Advisory territory beginning Monday. Highs Monday will generally range from the middle to upper 90s. Heat indices should commonly reach 105 to 110 degrees. Tuesday will be hotter as the thermal ridge strengthens and the 850-700 mb layer continues warming. Highs will commonly reach the upper 90s, with localized readings around 100 degrees. Heat indices of 110 to 115 degrees appear increasingly likely. Thus, have issued a heat advisory for Tuesday as well along with an Extreme Heat Watch for areas around tidal lakes as well as the MS Coast. Rain chances will remain around 10 percent or less, and any rogue boundary-driven storm would provide only brief and very localized relief.

Wednesday continues to appear to be the hottest and most impactful day as mid 590dm heights, strong subsidence, abundant sunshine, and persistent west to northwest low-level flow will favor efficient heating. Greater low-level moisture beneath the cap will also make it more difficult for afternoon dewpoints to mix down enough to offset the higher temperatures. Highs Wednesday should again reach the upper 90s, with some locations near 100 degrees. Heat indices of 110 to 115 degrees are possible and an Extreme Heat Warning may be needed again. Overnight temperatures are more climatologically noteworthy than highs, which mostly appear to be just below records. Lows will remain in the upper 70s across much of the area and low 80s across New Orleans metro, the tidal lakes, and the immediate coast. Several forecast lows are near daily warm-minimum records. This limited nighttime recovery will allow heat stress to accumulate through the middle of the week and is an important part of the increasing HeatRisk despite most daytime highs remaining below records.

LONG TERM

(Wednesday night through Saturday) Issued at 1142 AM CDT Sun Jul 26 2026

The upper-level pattern will begin changing Thursday as the ridge retrogrades farther west and a trough amplifies across the eastern United States. Shortwaves moving through the eastern trough should drive a frontal boundary southward toward the central Gulf Coast. The boundary will likely slow or stall near the forecast area as it becomes increasingly parallel to the mid-level flow. Thursday will be the transition day. Falling heights and weakening inhibition should allow scattered convection to redevelop, initially favoring coastal Mississippi and eastern portions of SELA. Rain chances around 30 to 50 percent appear reasonable over the eastern half of the CWA, with lower coverage initially for areas west of I55. The timing of convection certainly play into heat impacts potential. Locations that remain dry through early or middle afternoon could still reach the middle or upper 90s with heat indices near 108 to 112 degrees. Earlier cloud and storm development would substantially limit temperatures, while a slower erosion of the ridge could extend dangerous heat across a larger portion of the area.

By Friday and Saturday, the front should become increasingly diffuse but remain close enough to provide a focus for convection. Deeper moisture, weaker capping, and the combination of the front, sea breeze, and remnant outflow boundaries should support scattered to numerous showers and storms in the afternoon hours. High temperatures should gradually fall into the lower and middle 90s. Humidity will remain high, but increased clouds and convection should reduce both the magnitude and duration of dangerous heat indices. Storms late in the week will be capable of producing locally heavy downpours as deeper moisture returns. Weak steering flow near the stalled boundary could allow brief slow movement or repeated storms. This favors localized urban or poor-drainage issues rather than an organized or widespread flash-flood threat.

AVIATION

(00Z TAFS) Issued at 617 PM CDT Sun Jul 26 2026

Outside of a few small showers over the marshy areas, not much going on across the region. VFR conditions are expected through the cycle along with weak southwesterly winds at or less than 10 knots through the period. (Frye)

MARINE

Issued at 1142 AM CDT Sun Jul 26 2026

Surface high pressure is gradually settling south near the central Gulf. It will eventually become positioned near the Florida Keys by the middle of the week. This will establish a predominantly westerly flow regime across the local coastal waters. A typical summertime diurnal cycle already began last night and will carry on through the forecast period. West to southwest winds will increase to around 10 to 15 knots during the evening and overnight hours, especially over the outer waters, then relaxing to 5 to 10 knots during the day. Seas will respond similarly, occasionally building to 2 to 4 feet offshore overnight and subsiding to around 1 to 2 feet during the afternoon. Strong subsidence will keep thunderstorms very limited through Tuesday. Storm coverage should begin increasing Wednesday near the Mississippi coastal waters and become more noticeable across the marine area Thursday and Friday as the upper ridge aloft weakens. Locally higher winds and seas will be possible near any late-week thunderstorms.

LIX WATCHES/WARNINGS/ADVISORIES

LA...Heat Advisory from 11 AM to 8 PM CDT Monday for LAZ034>037-039- 046>048-056>058-064-070-071-076>087-089>100.

Heat Advisory from 11 AM to 8 PM CDT Tuesday for LAZ034>037-039- 046>048-056-071-091-093>097.

Extreme Heat Watch from Tuesday morning through Tuesday evening for LAZ057-058-064-070-076>087-089-090-092-098>100.

GM...None. MS...Heat Advisory from 11 AM to 8 PM CDT Monday for MSZ068>071-077- 083>088.

Heat Advisory from 11 AM to 8 PM CDT Tuesday for MSZ068>071-077- 083>085.

Extreme Heat Watch from Tuesday morning through Tuesday evening for MSZ086>088.

GM...None.