textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 611 PM CDT Mon Apr 27 2026

- Well above average high temperatures in the upper 80s and lower 90s will continue through Wednesday. Heat index values will climb into the lower to upper 90s.

- There is a Marginal Risk for heavy rainfall Wednesday afternoon and evening, mainly in southwest Mississippi and adjacent Louisiana parishes.

- The threat for thunderstorms, some possible strong to severe will continue through the weekend.

SHORT TERM

(Now through Tuesday night) Issued at 113 PM CDT Mon Apr 27 2026

An upper level ridge continues to be centered near Mexico City and expanded across the Gulf to the Great Lakes. The resultant anomalously high 500mb heights will support highs in the upper 80s to lower 90s today and tomorrow. Not a lot of spread in guidance, leading to higher confidence in current forecast. For now, subsidence from the high pressure dome over the CWA is keeping convection at bay. That's not to say rain won't be close. Medium range and meso models show scattered showers and storms developing across southwest and central LA, then moving into Mississippi. The line of rain/no rain looks to be pretty close to northwestern portions of the CWA. Similar setup on Tuesday but with activity even farther to the north and near record high temps.

LONG TERM

(Wednesday through Sunday night) Issued at 113 PM CDT Mon Apr 27 2026

That upper-level ridge anchored over Mexico and expanded north across the southern US will begin losing its northern extent mid week. Should really be seeing erosion of that northern ridge periphery Wednesday as upper level trough to the north broadens and amplifies. Still not enough ridge suppression to bring down temps much but could bring in some rain to the northern portions of the forecast area, especially over southwest Mississippi. Flow parallel to the boundary could result in isolated flash flooding situation. Increased cloud cover or rain brought in from the frontal boundary associated with this trough is best chance to keep highs from nearing or exceeding records, which is near 90 for the most part.

As the aforementioned trough axis passes east of the CWA and digs a little farther south, a cold front will be sliding into southeast LA and southern MS early Thursday. While there may be some scattered showers along the boundary, timing will limit instability and should just be looking at showers.

Southwesterly flow increases in the mid and upper levels Friday as an upper level low comes into the southwestern US, reaching the 4 Corners region late in the day. This setup will first lead to a fairly substantial cirrus deck over the CWA Friday. That, combined with east to northeast surface flow will yield even cooler highs. Will be the first time in about a week that highs struggle to reach climatological normal. Remains to be seen if post frontal PW under 1" is sufficiently re-saturated to produce rain by the end of the day Friday with moisture coming in from the west. By Friday night into Saturday though, rain chances come up considerably and upper low/trough moving across TX will provide conditions much more conducive for widespread shower/storm development over the local area.

AVIATION

(00Z TAFS) Issued at 611 PM CDT Mon Apr 27 2026

VFR conditions expected through the evening hours at all terminals. MVFR ceilings likely to develop again at most terminals after about 08z, with a small chance they could fall into IFR range. Cloud bases should lift with surface heating during the morning, likely becoming VFR prior to 17z. South to southeast winds likely to be around 15 knots for a large portion of the daytime hours on Tuesday with a few gusts above 20 knots.

MARINE

Issued at 113 PM CDT Mon Apr 27 2026

Persistent onshore flow of 10 to 15 knots will remain in place through the middle of this week with high pressure generally centered east of the local coastal waters. Seas will remain well below any hazardous limits at 1 to 3 feet through the period. As we move into the back half of the week we will see a weak cold front drift south towards the coast and could even sink into the coastal waters this weekend. Borderline Exercise Caution conditions will likely develop then as the pressure gradient tightens.

LIX WATCHES/WARNINGS/ADVISORIES

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