textproduct: Memphis

KEY MESSAGES

Issued at 646 AM CDT Wed Aug 19 2026

- Dangerous heat is expected to persist on Wednesday with Heat Advisories and Extreme Heat Warnings in effect.

- A Slight (level 2 out of 5) Risk for severe weather is in place for portions of northeastern Arkansas, the Missouri Bootheel, and West Tennessee Wednesday night into early Thursday. Damaging winds and localized heavy rainfall are the main threats.

DISCUSSION

(Today through Tuesday) Issued at 1241 AM CDT Wed Aug 19 2026

Surface analysis this evening places a quasi-stationary front from the Central Plains into portions of the Lower Mississippi Valley with the front effectively just to the south of the forecast area. Convection Tuesday afternoon was limited to a single strong thunderstorm over northeast Mississippi. Otherwise, dry conditions have persisted across the Mid-South into the evening with temperatures in the 80s to around 90 degrees with surface dewpoints in the 70s.

The aforementioned quasi-stationary boundary will begin to lift back north as a warm front overnight into Wednesday. Short-term models including CAMs indicate convective development over eastern Kansas and western Missouri overnight gradually spreading southeast and weakening as it approaches the Mid-South by sunrise Wednesday. This activity may leave some remnant outflow boundaries up near the MO/KY border with mainly rain free conditions occurring during the day, especially along and south of I-40.

Temperatures across the Mid-South will rise back into the mid 90s to lower 100s again on Wednesday. These very hot temperatures combined with dewpoints in the lower to middle 70s will produce heat index values between 105 to 112 degrees across the Mid- South. The Extreme Heat Warning was expanded north to Jonesboro and up to portions of the Memphis metro area as short-term guidance indicates the potential for moisture to pool in this region. A Heat Advisory was also expanded up to the Missouri border where heat index values may reach Advisory criteria. Otherwise, no other modifications were made to the Advisory and Warnings in effect.

Latest guidance indicates showers and thunderstorms will develop Wednesday afternoon over southern Missouri and slowly spread southeast into the Mid-South Wednesday night into early Thursday morning. Considerable uncertainty remains between guidance with the latest 00Z NAM keeping most of the activity north of the Mid- South with other model solutions suggesting development after 06Z Thursday. Moderately steep mid-level lapse rates, MLCAPE values between 1500-2500 J/kg, and precipitable water values around 2 inches support the potential for severe thunderstorms. Model soundings show some favorable storm relative helicities with clockwise curved hodographs but also feature parcels becoming elevated throughout the night with a capping inversion below 850 mb. Thus, confidence in any tornado development remains very low at best. Damaging winds will be the primary threat, with a secondary threat of localized heavy rainfall and perhaps some marginally severe hail.

Shower and thunderstorm chances will continue Thursday into Thursday night as a mid-level trough pushes into the eastern U.S., allowing a cold front to push through the Mid-South. This front will bring some relief with cooler temperatures, especially over portions of West Tennessee into the upcoming weekend.

AVIATION

(12Z TAFS) Issued at 646 AM CDT Wed Aug 19 2026

VFR conditions will prevail through the period at all terminals, aside from intermittent TS impacts at JBR/MKL Thursday morning near the end of the period. The most pressing aviation concern at the start of the period will be an area of out flow that will impact each site through today. The expectation is for a window of north-northeasterly flow from late morning into the afternoon, by which winds will recover and prevail out of the south through the remainder of the period. Additional convection will develop over the remains of the outflow overnight tonight and into Thursday morning. Currently, the highest confidence for impacts is at JBR/MKL, but some guidance brings precipitation as far south as MEM. For now, only included PROB30s at JBR/MKL with the potential for one to be added into the MEM TAF in future issuances today.

FIRE WEATHER

Issued at 1241 AM CDT Wed Aug 19 2026

Fire danger potential remains low as 20 ft winds remain light, but minimum relative humidity values could locally drop below 40% Wednesday afternoon across portions of east Arkansas and northwest Mississippi. Fog potential remains low (<10%) due to dry soils. Wetting rain chances increase Wednesday night into Thursday morning as a cold front moves south into the area. Some thunderstorms are possible during this time, which will be accompanied by a chance for damaging winds and heavy rainfall.

MEG WATCHES/WARNINGS/ADVISORIES

AR...Heat Advisory from 11 AM this morning to 8 PM CDT this evening for ARZ009-018.

Extreme Heat Warning from 11 AM this morning to 8 PM CDT this evening for ARZ026>028-035-036-048-049-058.

MO...Heat Advisory from 11 AM this morning to 8 PM CDT this evening for MOZ113-115.

MS...Heat Advisory from 11 AM this morning to 8 PM CDT this evening for MSZ002>005-009-013>017-021>024.

Extreme Heat Warning from 11 AM this morning to 8 PM CDT this evening for MSZ001-007-008-010>012-020.

TN...Heat Advisory from 11 AM this morning to 8 PM CDT this evening for TNZ019-048-050>053-089>091.

Extreme Heat Warning from 11 AM this morning to 8 PM CDT this evening for TNZ049-088.