textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1237 PM CDT Thu Jun 11 2026

- Heat index values will climb to between 100 and 105 degrees each day through the middle of next week.

- A weak cold front will slowly move into the area during the first half of next week leading to higher shower and thunderstorm chances. The threat of localized flooding will also increase.

SHORT TERM

(Now through Sunday) Issued at 1135 PM CDT Wed Jun 10 2026

The synoptic picture shows a strong ridge from the Bermuda High reaching well into the gulf. This feature looks to remain there for at least the short term of this fcast. This is key for the pattern that we will see shake out over the coming days. The cold front currently moving through Kansas/Missouri this morning will stall over central Arkansas Fri then move back north and stall again as another round of forcing moves it back SE again starting Sat. This front will stall inland Monday and should be either just north of the area or over the northern tier of counties, convective forcing(cold pooling) should cause the front to move a bit farther south after the weekend. Mid level and sfc flow will provide a deep flow of tropical moisture around the periphery of the ridge from the western gulf up to the front then ENE along the front. That is the short story of what will occur, now for what that causes. We will be literally in the middle ground between this cold front and the system over the SW gulf. This is the area of stronger suppression causing a strong sub inversion to set up trapping moisture in the lowest layers and heating that same layer during that time which includes Fri, Sat and possibly Sun. This will cause our heat index values to move up during this time frame to around 105. There are some hints at a few localized areas getting to around 108, mainly over marsh areas with very little wind. As the front moves close to the area Sun, we should begin to see increasing cloud cover to help keep heat index values in check. The issue then becomes rain. A slow transition to higher PW values will begin to take place Sunday. Synoptically, the ridging from the Bermuda high will be strengthened during the Fri through Sun period by these two systems which would not allow anything from the SW gulf, even if it were to develop, to move due north or NE, but NW around the periphery of this ridge via NE Mexico would absolutely be expected. But we will see the deep tropical moisture flow up through TX and the western gulf around this ridge and join with this cold front possibly starting as early as Sun well to our west, and this will set the stage for the rainfall issues expected next week as this moisture flows along the front.

LONG TERM

(Sunday night through Wednesday) Issued at 1135 PM CDT Wed Jun 10 2026

Upper ridging will continue to be centered over the western Gulf Sunday night, with mainly zonal flow along Interstate 20. At the surface, the Bermuda high will remain in place with a frontal boundary near a Pittsburgh to Memphis to Dallas line. Shortwaves moving through the Great Lakes and Ohio River Valley will gradually deepen across the eastern third of the country by Wednesday, and push the frontal boundary at least into the northern half of our area before it washes out at midweek.

Precipitable water values will already exceed the 90th percentile climatologically (1.92 inches) Sunday evening, and will likely approach daily maxima for Monday through midweek(near 2.2 inches). Monday afternoon is likely to see scattered showers and thunderstorms probably beginning along lake and sea breeze boundaries by midday and propagating on outflow boundaries. A few locally heavy downpours can be expected. For Tuesday and Wednesday, the weakening frontal boundary should serve as a focusing mechanism for thunderstorm development with a potential for training/back- building storms. Areal coverage is likely to be greater than on Monday. With rather warm 500 mb temperatures in place (-5 to -6C), rain processes would be expected to be very efficient. As most areas remain fairly soggy from last weekend, we could end up with one or more rounds of flooding if the heavy rainfall develops in the wrong areas.

As we see higher precipitation chances early next week, that should start to take the edge off of the heat we'll see over the weekend. Cloud cover and storms should hold high temperatures to the middle and upper 80s for the first half of the workweek. Humidity levels and overnight lows will still be uncomfortable, but heat indices should remain below advisory criteria.

AVIATION

(18Z TAFS) Issued at 1237 PM CDT Thu Jun 11 2026

VFR conditions are expected to prevail at most terminals throughout this forecast period. HDC and MCB could see MVFR conditions right around 10-11z tomorrow as moisture pools along the I-55 corridor. Any MVFR conditions should rapidly improve around 12z as the daytime heating mixes out the surface. Only other item of note is expected scattered convection near MSY during the early afternoon. Any convection should dissipate towards the evening as slightly drier air filters into the area.

MARINE

Issued at 1135 PM CDT Wed Jun 10 2026

A broad area of high pressure will remain centered over the eastern Gulf and Florida through the weekend and into early next week. A persistent south-southeast wind of 10 to 15 knots can be expected 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.

LIX WATCHES/WARNINGS/ADVISORIES

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