textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 119 PM CDT Thu Jul 23 2026

- All Tropical Storm related warnings/advisories have been cancelled - Impactful heat conditions are likely to return this weekend and persist well into next week.

SHORT TERM

(Now through Sunday night) Issued at 119 PM CDT Thu Jul 23 2026

Tropical Storm Bertha continues to move westward along the southwestern Louisiana coast and about to enter Texas. Tropical storm conditions have ended across CWA, although the broad circulation continues to influence local clouds, showers, and winds. Current radar shows bands of light occasionally moderate showers rotating around Bertha and crossing portions of southeast Louisiana and southern Mississippi. Additional scattered development will persist through the afternoon as daytime heating increases buoyancy on the moist boundary layer. Any heavier showers should be brief and poorly organized, but efficient rainfall processes could still produce a quick downpour. Widespread heavy rainfall is not expected, and shower coverage should decrease quickly this evening with the loss of heating and as Bertha moves farther west.

Cloud cover and passing showers have slowed the local temperature rise today compared with recent days. Most locations should remain in the upper 80s to lower 90s this afternoon. This will keep peak heat indices generally below local advisory criteria today. Southerly winds will remain somewhat elevated through the afternoon, with occasional gusts around 15 to 20 knots, before the pressure gradient relaxes this evening.

A rapid transition toward drier and hotter weather begins Friday. The remnants of Bertha will move deeper into Texas while a large upper-level 598dm ridge centered near the Texas Panhandle will migrate towards the Four Corners region. Although the ridge center remains northwest of the CWA, rising heights and increasing subsidence along its southeastern periphery will sharply suppress convection. Rain chances are therefore 10% or less Friday outside of a very low-probability coastal or sea-breeze shower. Abundant sunshine and increasing 500mb heights should allow temps to rebound to back into the middle 90s. Forecast heat indices are generally expected to range from around 105 degrees. Confidence in widespread advisory-level conditions Friday remains lower than for later in the weekend.

MEFFER

LONG TERM

(Monday through Wednesday night) Issued at 119 PM CDT Thu Jul 23 2026

A prolonged period of hot and predominantly dry weather remains the primary forecast concern through the extended period. The large upper high pressure should remain near the Four Corners region Saturday before gradually shifting eastward toward the southern Plains Sunday. It then drifts south to TX/OK Panhandles by midweek. The size of the ridge is notable, with its subsidence influence covering much of the central United States with its northern and southern ends extending both north/south borders of the country. The local forecast area will remain beneath its broad southeastern periphery, supporting persistent midlevel warming, weak large-scale ascent, and limited afternoon convection. Highs Saturday should reach the middle and upper 90s. Daytime highs then increase another degree or two Sunday, followed by widespread upper 90s and localized 100s Monday through Wednesday. The greatest potential for temperatures near 100 will generally be along the I-10/12 corridors.

Deep-layer moisture is forecast to remain relatively limited beneath the ridge, but sufficient boundary-layer moisture will persist to produce dangerous heat indices. Peak heat indices should increasingly reach 108 to 112 degrees Sunday, with values of 110 to 115 degrees possible Monday through Wednesday. Heat Advisory criteria appears increasingly likely across much of the area. The duration of the heat will be as important as any individual afternoon maximum. Overnight lows will trend into the upper 70s across much of the CWA, with lows around or above 80 degrees in the New Orleans metropolitan area, along the immediate coast, and near the tidal lakes. This will provide increasingly poor overnight recovery and support accumulating heat stress through the period. Confidence continues to increase in a prolonged heat event, but near normal regarding the exact magnitude of peak heat indices. Rain chances each day will remain near 10% as strong subsidence should prevent meaningful convective coverage. However, a rogue late- afternoon storm could still develop along a sea-breeze or other localized boundary. Thus, most locations will remain dry each day, and any isolated storm would provide only very localized and temporary relief from the heat.

MEFFER

AVIATION

(18Z TAFS) Issued at 119 PM CDT Thu Jul 23 2026

Bands of light SHRA will continue to pass through the terminals this afternoon, with PROB30 groups to indicate potential for brief reductions in visibility and ceilings. MVFR ceilings should remain prevalent or intermittently redevelop through much of the afternoon before gradually improving toward VFR this evening and overnight as Bertha moves farther west.

Southerly winds will remain gusty at times this afternoon, generally with gusts around 15 to 20 knots, before relaxing this evening. No meaningful precipitation is expected Friday. A scattered to locally broken low-level cumulus field near MVFR bases may develop during the morning, followed by predominantly VFR conditions.

MEFFER

MARINE

Issued at 119 PM CDT Thu Jul 23 2026

The center of Tropical Storm Bertha is near the TX/LA border and still moving west. As such, its influence on local winds/seas will steadily diminish. Recent wind observations in coastal waters clearly depict this and most locations are barely seeing Small Craft speeds. A weak surface ridge will build westward across the northern Gulf Friday, allowing winds and seas to collapse substantially. Winds should generally fall to around 10 knots or less, with seas predominantly 1 to 3 feet.

From Saturday through Wednesday, the surface ridge should drift south of the coastal waters and establish a more typical summertime wind regime. Winds will generally increase overnight to around 10 to 15 knots and relax to near 10 knots during the daytime. Seas should respond similarly, building to around 2 to 4 feet overnight and subsiding to 1 to 3 feet during the day. Any isolated afternoon or evening thunderstorm could briefly produce higher winds, locally rough seas, frequent lightning, and reduced visibility.

MEFFER

LIX WATCHES/WARNINGS/ADVISORIES

LA...None. GM...Small Craft Advisory until 4 PM CDT this afternoon for GMZ533- 535-541-543-551-553-554-570-572-575.

MS...None. GM...Small Craft Advisory until 4 PM CDT this afternoon for GMZ535- 541-543-551-553-554-570-572-575.