textproduct: New Orleans/Baton Rouge

KEY MESSAGES

Updated at 1048 PM CDT Tue Jul 21 2026

- Extreme heat warning has been issued for today as heat indices look to increase to 110-115 degrees over most of the area. A heat avisory has been issued for coastal Mississippi with readings of 105-112 expected today.

- Abnormal impacts are expected as Tropical Storm Bertha moves west over the Louisiana gulf coast today with hot, dry and breezy conditions inland while rainfall, breezy conditions along with coastal flooding at the coast (mainly south of I-10). Tropical Storm Watches and Warnings are in place for coastal areas along and south of I-10.

SHORT TERM

(Now through Saturday) Issued at 1035 PM CDT Tue Jul 21 2026

Abnormal tropical storm conditions is putting it lightly. I for one have never seen a tropical storm warning and a heat advisory/warning for the same time frame in the same area. But here we are. The northern half of the area will only notice the wind speeds rise with a tstorm possibly moving through but for the most part will be very hot and dry. As one moves closer to the coast, this is where the more typical conditions for tropical activity should be found. But even here, it will not be to the degree that one would expect. Rainfall will occur along with some storms but getting more than an inch of rain will be tough to do even right at the coast. Coastal flooding is expected but also not to the degree one would think either. Cloud cover is the biggest question mark at this point as it is unclear how far the low level rotating deck of clouds will get and remain long enough inland. We are sure this deck won't make it to the northern half of the area(maybe a fair wx cu field) but the southern half is questionable. Obviously where this deck is able to persist, the temps and heat index will be lower and this is the reason for the advisory part of the thinking. The deep convective cloud cover will quickly get forced to the SW, so basically, all we will depend on is the low level deck or swirl of clouds as high pressure continues to build from the north. We will be leaving all heat products in place for now since the extent inland of cloud cover is still questionable from this low level deck. Will some areas near the coast not reach heat warning criteria? That is a very likely scenario, but this would most likely be within a few parishes deep of the coast. As we move into Thursday, things will begin to improve as far as any rainfall and winds, but the heat will continue right through the weekend.

LONG TERM

(Saturday night through Tuesday) Issued at 1035 PM CDT Tue Jul 21 2026

Surface and upper-level ridging should expand across the central Gulf Coast during the weekend as the remnants of Bertha move farther west and dissipates. Increasing subsidence and somewhat lower deep- layer moisture should reduce the shower/storm coverage compared with the middle of the week. However, sufficient moisture will remain for isolated to scattered afternoon convection along the sea breeze, lake breeze, and any remnant outflow boundaries. Rain chances should generally remain in the 20-40 percent range into Sunday, with the greatest coverage during peak afternoon heating. With weak steering flow, any storm that develops could produce locally heavy rainfall, frequent lightning, and brief gusty winds, but there is no current signal for organized severe weather or a widespread heavy rainfall event.

Heat will again become the primary concern during the weekend and early next week. High temps should generally reach the low to mid 90s, with locally upper 90s possible across northern and western portions of the area, Persistent dewpoints in the upper 70s could produce afternoon heat indices between 105 and 110, potentially requiring additional heat headlines.

The ridging may strengthen even further on Monday and Tuesday, which would favor slightly lower rain chances and continued above-normal temperatures. Confidence is moderate in the overall hot and mainly diurnal-driven convective pattern, but lower regarding daily thunderstorm coverage and whether the center of the ridge is strong enough to largely suppress convection.

AVIATION

(06Z TAFS) Issued at 1035 PM CDT Tue Jul 21 2026

Terminals over the southern half of the area MVFR cigs are expected. PROB30 groups will time the SHRA and TSRA. Winds will be at 20-25 knots shifting from northerly to southerly as Bertha moves through. HDC, MCB, BTR will remain VFR.

MARINE

Issued at 1035 PM CDT Tue Jul 21 2026

The center of Tropical Storm Bertha will move west along the Louisiana gulf coast today through Thursday. As the system moves over our local waters, expect winds and seas to increase with tropical storm conditions possible for most if not all the local waters. The system will move west of the region Thursday and conditions should improve going into the upcoming weekend.

LIX WATCHES/WARNINGS/ADVISORIES

LA...Tropical Storm Watch for LAZ058-094-096.

Tropical Storm Warning for LAZ064-070-076>078-087-089>093-095- 097>100.

Extreme Heat Warning from 10 AM to 8 PM CDT Wednesday for LAZ034>037-039-046>048-056>058-064-070-071-076>087-089>100.

Coastal Flood Advisory until 4 AM CDT Thursday for LAZ058-077- 080-082-093-095-097-098.

Coastal Flood Warning until 4 AM CDT Thursday for LAZ070-076-078- 091.

GM...Tropical Storm Watch for GMZ529.

Tropical Storm Warning for GMZ531>536-541-543-551-553-554-557- 570-572-575-577.

MS...Tropical Storm Watch for MSZ083>085.

Tropical Storm Warning for MSZ086>088.

Extreme Heat Warning from 10 AM to 8 PM CDT Wednesday for MSZ068>071-077.

Coastal Flood Warning until 4 AM CDT Thursday for MSZ086>088.

Heat Advisory from 10 AM to 8 PM CDT Wednesday for MSZ083>088.

GM... Tropical Storm Warning for GMZ532>536-541-543-551-553-554-557- 570-572-575-577.