textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 712 AM CDT Sat Jun 27 2026

- Strong heat will continue with heat index readings up to 108F this weekend and into the new workweek with heat advisories possibly being issued each day through Tuesday for some or all of the area.

- Ongoing minor river flooding continues to impact parts of the Pearl and Pascagoula River Basins.

- Potential for heavy rainfall and strong/severe storms returns toward the middle of next week as an easterly waves moves over the region.

SHORT TERM

(Now through Tuesday) Issued at 1104 PM CDT Fri Jun 26 2026

Short term discussion will be relatively short due to lack of other potential weather hazards besides heat and its associated impacts. High pressure is building into the deep south and northern Gulf for the weekend with temperatures slightly increasing each day which will result in heat indexes increasing with each day. Heat advisory criteria will last into Tuesday. Rain chances are low but non-zero. This means that there is a non-zero potential for a few storms to form throughout the weekend into the early part of the work week. PW's rise rapidly Tuesday afternoon into the evening as an easterly wave moves into the area. This system will cause strong subsidence ahead of it which will help heat index numbers rise as high as 110F. This sets its own problem though, as the moisture and instability increase and trigger temps are hit, it will release all of this energy rapidly causing a large area of storms to develop across the area. These storms will ingest the dry air ahead of them causing strong downbursts to occur. This is very normal for systems that displace dry stable air ahead of them. Once the initial storms occur, the dry air is replaced with PW values that are 2.25"+ which means heavy rainfall potential with waterspout/tornado activity. The wave moving through looks to be unorganized but that does not mean there will be no convective circulations with this, which is very normal. But the message should be rainfall and severe storms.

TE/DSS

LONG TERM

(Tuesday night through Friday) Issued at 1104 PM CDT Fri Jun 26 2026

Overall, model guidance has come into much better agreement today concerning the passage of an fairly vigorous inverted trough axis sliding through on the back of deep layer easterly flow along the southern periphery of a strong mid to upper level high centered over the Ohio Valley. The GFS, ECMWF, and Canadian all now show this trough axis, and its associated deep moisture and forcing, moving through the area Wednesday into Wednesday night. Model sounding analysis indicates a moisture loaded atmosphere with moist adiabatic lapse rates and precipitable water values of 2.2 to 2.3 inches. Although instability will be lower at 1000 to 1500 J/KG, this will still be more than sufficient to produce numerous showers and thunderstorms across the forecast area Wednesday, and PoP of 60 to 70 percent reflects this risk well. Warm rain processes will be in place, so high rainfall rates of 2 to 3 inches per hour can be expected. The one saving grace will a relatively fast storm motion of around 15 knots that will help to somewhat limit the impacts of these higher rainfall rates. Still, our recent heavy rains and very saturated soils will enhance the flash flooding risk for Wednesday. The other impact of the increased rainfall and cloud cover will a slight cool down in temperatures back to more average levels for this time of year with highs in the upper 80s and lower 90s. Heat indices will also fall back to around 105 degrees, or below any heat advisory levels.

Moving into Thursday and Friday, the influence of the strong 595dm H5 ridge over the Ohio Valley will grow in the wake of the inverted trough axis. However, the region will still be on the southern periphery of the ridge, and this will keep a bit more moisture and a weaker cap over the area. PWATS will fall back to more typical levels of 1.7 to 1.8 inches and MLCAPE will climb to around 1500 to 2000 J/KG each afternoon as temperatures warm into the upper 80s and lower 90s. Some drier air in the mid-levels will lead to a slightly higher potential for wet microbursts both days and this is reflected by DCAPE values of 1000 to 1200 J/KG. An isolated damaging wind event cannot be ruled out given these DCAPE values. In general though, we can expect to see very typical conditions for early July across the region as we close out the week and move into the upcoming holiday weekend.

AVIATION

(12Z TAFS) Issued at 712 AM CDT Sat Jun 27 2026

Mostly VFR conditions through the cycle with mostly light southerly winds expected. (Frye)

MARINE

Issued at 1104 PM CDT Fri Jun 26 2026

Mostly favorable marine conditions through the weekend with generally light southerly onshore flow expected. Rain chances are also on the lower end due to high pressure building into the region. This high will move north of the local waters early next week and be replaced with an easterly wave that is expected to move over the local waters Tuesday through Thursday. With this wave expect an uptick in convection with higher rain chances, mostly during the overnight and morning hours. Locally higher winds and seas will be possible in and around convection along with frequent lightning.

LIX WATCHES/WARNINGS/ADVISORIES

LA...Heat Advisory from 11 AM this morning to 7 PM CDT this evening for LAZ057-058-076>078-080-082-084-086-087-098>100.

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