textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 529 AM CDT Mon Jun 29 2026

- Hot conditions will continue with heat index readings approaching 110 on Tuesday and Wednesday.

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

SHORT TERM

(Now through Thursday) Issued at 1247 AM CDT Mon Jun 29 2026

The region will continue to feel the influence of a broad and deep high pressure system centered over the Tennessee Valley today into tonight. This will result in mostly sunny skies, hot temperatures, and continued dry conditions. Deep layer subsidence will help to warm the mid and upper levels, leading to very weak lapse rates and limited instability this afternoon. At most, some fair weather cumulus will develop below 10k feet as temperatures climb into the mid to upper 90s this afternoon. As the temperatures climb, the drier air aloft will mix down to the surface helping to push dewpoints down into the lower 70s. This will help to keep heat index values in check at around 105 degrees this afternoon. Thus, a heat advisory will not be issued for the area today. Tonight will see temperatures cool back into the mid to upper 70s resulting in some relief from the hot temperatures this afternoon.

Tuesday will be a transitional day as the high lifts slightly further to the north toward the Ohio Valley. This will place the region more on the southern periphery of the deep layer ridge resulting in a more persistent and deep easterly flow regime taking hold by Tuesday afternoon. This easterly flow will allow moisture to feed back into the area and PWATS should increase from around 1.5 inches in the morning to 1.8 inches, or near average for this time of year, by the afternoon hours. As moisture increases in the mid-levels, lapse rates will steepen to around 6.0C/KM and mixed layer CAPE values will rise to around 1500 J/KG by the late afternoon hours. Although instability will improve, the convective temperature will remain quite high in the mid 90s, so any convective initiation will occur late in the afternoon and into the evening hours when these temperatures are reached. Additionally, lingering dry air in the mid-levels could entrain into some of the deeper updrafts that form late Tuesday leading to an increased risk for wet microbursts and damaging wind gusts. These events will be very isolated, one or two storms at most, with the greatest risk over portions of coastal Mississippi late Tuesday. DCAPE values in coastal Mississippi of around 1100 J/KG and relatively steep lapse rates approaching 7.0C/KM in the lowest 3km of the atmosphere support this wet microburst risk.

A weak area of enhanced vorticity will slide through on the back of the deep layer easterly flow Tuesday night and Wednesday and slightly deeper moisture will accompany this vorticity max. This will help to push PWATS to around the 75th percentile, or near 2 inches, Tuesday night into Wednesday and this increased moisture will tap into a fairly unstable airmass to produce continued scattered convection along the coast Tuesday night. The convection will focus along any landbreeze boundaries that develop overnight. As we move into the daytime hours, the weak forcing aloft from the vort max will combine with the typical diurnally forced seabreeze cycle to produce scattered to numerous showers and thunderstorms. These storms will move from the coast in the morning hours to inland areas in the afternoon hours. The storms will be fairly progressive with storm motion of 15 to 20 mph, so the threat of heavy rainfall and flooding will be somewhat reduced. Still, rainfall rates of 1 to 2 inches per hour are expected and this could lead to some localized street flooding issues in areas with wet antecedent conditions or poor drainage. Temperatures will be near average in the low to mid 90s and heat index values will approach heat advisory range due to higher dewpoints and overall increased humidity before the rains develops.

Thursday will see conditions revert to more typical Summer time weather as the vorticity max moves out of the region and the lingering easterly flow regime dominates. The ridge will gain some influence by drying out the mid-levels and PWATS will fall back to average for this time of year. The end result will be diurnally forced convection firing up along the seabreeze front and then shifting inward along outflow boundaries that form. The convection will be more scattered with some areas not seeing any rainfall through the day. Temperatures will be near average in the low to mid 90s and heat index readings will rise to just below advisory levels as dewpoints drop slightly due to the drier air mixing down from aloft. The atmosphere will also be favorable for additional wet microburst development as the mid-levels dry and steep lapse rates persist below 3km. An isolated damaging wind event could occur with the deepest convective development Thursday afternoon.

LONG TERM

(Thursday night through Sunday) Issued at 1247 AM CDT Mon Jun 29 2026

Deep layer easterly flow will continue through the latter half of the week with strong mid-upper ridging situated over the OH River Valley. By Thursday into Friday, continental dry air will begin to mix into the mid-levels and could temper PWATs some. This could limit the excessive rainfall risk, but could also enhance the potential for downbursts and wet microbursts associated with afternoon storms given the lower atmosphere will still be plenty moist and unstable to support diurnal convection.

Lingering easterly flow will leave us open to additional weak inverted trough passes associated with a decaying frontal system over the southwest Atlantic into the weekend. However, the general eastern CONUS ridging pattern headed into the weekend will favor high temperatures into the mid 90s with heat indices between 100 to 110 degrees each day. The primary uncertainty with the necessity for heat-related headlines will be dependent on confidence of cloud cover and longevity of these elevated heat indices during the afternoon prior to any storm development.

Looking ahead, the longwave pattern within the global ensemble guidance continue to suggest the potential for a larger mid-upper ridge setting up over the west-central CONUS and favoring troughing and northwest flow across the southeastern CONUS headed into next week which could bring temperatures down and potentially bring more convective activity into the area.

AVIATION

(12Z TAFS) Issued at 529 AM CDT Mon Jun 29 2026

VFR conditions will continue to prevail at all of the terminals through tomorrow morning as a dry and stable high pressure system sits over the region. Some widely scattered fair weather cumulus will form this afternoon, but this will have no impact on aviation operations.

MARINE

Issued at 1247 AM CDT Mon Jun 29 2026

High pressure will remain centered over the waters through Tuesday. Winds will remain light and variable over this period with the seabreeze cycle being the primary influence closer to the coast. A weak low pressure system passing through the region on Wednesday will allow winds to turn more easterly at 5 to 10 knots. These easterly winds will persist into Thursday. By Friday, winds will turn more southerly as high pressure over the eastern Gulf builds in. There will be a risk of thunderstorms that could produce locally gusty winds and waterspouts from Wednesday through Friday.

LIX WATCHES/WARNINGS/ADVISORIES

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