textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 639 PM CDT Mon Jun 15 2026

- Multiple rounds of showers and thunderstorms with very heavy rainfall are anticipated over the next several days. Areas that receive multiple rounds of heavy rainfall could see localized flash flooding.

- A Flood Watch is in effect through Thursday night for most of southeast Louisiana as well as all of southwest and coastal Mississippi.

- River flooding potential exits as well with forecast areal rainfall amounts of 3 to 7 inches with isolated higher amounts.

SHORT TERM

(Now through Thursday night) Issued at 143 PM CDT Mon Jun 15 2026

A broad mid/upper level trough currently encompasses probably 3/4 of the country, with only the southwestern and West Coast states not under this trough. A weak frontal boundary that moved into the local area last night remains draped across or near the forecast area this afternoon and is expected to remain the primary focus for showers and thunderstorms through Tuesday. The boundary has become increasingly diffuse, but continues to reside within a very moist airmass. This mornings sounding data measured a record high PW for the June 15th, 2.41".

For this afternoon, CAMs show scattered to numerous showers and thunderstorms will redevelop near the boundary and along any remnant outflow boundaries. Instability is present, but not overly strong, with forecast soundings showing generally modest CAPE and weak deep- layer shear. As a result, storms should remain poorly organized overall. However, the deep moisture profile and warm cloud depths will support efficient rainfall production. Any storms that train or repeatedly develop over the same locations could produce localized rainfall totals of 2 to 4 inches in a relatively short period of time. As we saw this morning along the MS coast, upwards of 5-10 inches in small areas is certainly a possibility. Previous thoughts were that the higher risk would be focused in western portions of the CWA. While thats still true based on CAMs in general, but this morning proved it can happen pretty much anywhere locally. Therefore, we have extended the Flash Flood Watch to include the entire CWA except for coastal LA parishes south of New Orleans where flash flooding is extremely rare.

Tonight into Tuesday, the stalled boundary will remain near the area and continue to serve as a focus for scattered to numerous showers and thunderstorms. Another weak shortwave rolling through the base of the trough will enhance convection along that boundary in the early morning hours. Unlike today, it doesn't appear that a partially drier slot will move in from the south. So am concerned with morning storms continuing into the afternoon without a lull.

LONG TERM

(Friday through Sunday night) Issued at 143 PM CDT Mon Jun 15 2026

The remainder of the week continues to suggest that the wet pattern in general will continue. The biggest interest peak falls on plume of moisture in the Bay of Campeche. That wave is forecast to track through Texas from Brownsville to the Sabine Pass by the start of this portion of the forecast period. Whatever form of organization this feature is as it tracks across the region late in the week, local impacts will be pretty much the same. Abundant moisture will accompany it thus with height falls from surface pressure lowering, makes sense to see plenty of rainfall which results in localized flash flooding along with river flooding. Obviously highly dependent on where the bulk of moisture moves through the northern Gulf Coast states. As confidence has increased with local impacts from that system, have extended the Flash Flood Watch to account for the flooding potential.

AVIATION

(00Z TAFS) Issued at 639 PM CDT Mon Jun 15 2026

While all forecast terminals were VFR at forecast issuance time, there are several non-forecast airports that are already seeing MVFR ceilings. Much of this afternoon's SHRA/TSRA activity is lifting to the northeast of the area, at least temporarily. Mesoscale modeling indicates SHRA/TSRA spreading back into the area from the west by about 05-06z. Fairly confident that at least KMCB, KBTR and KHDC will be impacted prior to sunrise, with MVFR to IFR conditions likely. Will not rule out TSRA at remaining terminals overnight, but threat is lower than at the first 3. Threat of TSRA likely to continue for the next several days. If there are any windows that are "least" likely to be impacted, it would be for several hours after sunset.

MARINE

Issued at 143 PM CDT Mon Jun 15 2026

A weak surface high pressure centered over the eastern Gulf and will continue to dominate the local coastal waters. As a result, a steady south to southwesterly flow will persist, with winds generally around 10 to 15 knots through Tuesday night. These conditions will keep seas near 2 to 4 feet across the open Gulf waters, while the sounds and tidal lakes remain closer to 1 to 2 feet.

By early Wednesday, a tropical disturbance in the SW Gulf is forecast to track northward along the Texas coast before moving into western and central Louisiana Wednesday night. The interaction between the weak low to the west and the strong high to the east will cause winds to increase from east to west over the entire gulf via tightening pressure gradient. Forecast boundary layer winds well into the mid 20 knot range should be a good proctor for observed winds over the coastal waters. Thus, expect the need for a Small Craft Advisory during this mid/late week timeframe.

LIX WATCHES/WARNINGS/ADVISORIES

LA...Flood Watch through Friday morning for LAZ034>037-039-046>048- 056>058-064-071-076>087-089-090-092-094-096-098>100.

GM...None. MS...Flood Watch through Friday morning for MSZ068>071-077-083>088.

GM...None.