Alert archive / Mississippi / Heat Advisories in 2026

Heat Advisory 21, NWS Memphis, TN

August 18, 202610 counties in Tennessee; 17 counties in Mississippi; 6 counties in Arkansas

NWS Memphis, TN issued this heat advisory at Aug 18, 2026, 11:41 AM CDT for 10 counties in Tennessee; 17 counties in Mississippi; 6 counties in Arkansas. It took effect at Aug 19, 2026, 11:00 AM CDT. It was in force for .

The area

The counties it named.

The facts

Issued
Aug 18, 2026, 11:41 AM CDT (16:41 UTC)
In effect from
Aug 19, 2026, 11:00 AM CDT
Expired
Aug 18, 2026, 11:31 PM CDT
In force
Issued by
NWS Memphis, TN
All 33 counties

Craighead County, AR, Crittenden County, AR, Cross County, AR, Mississippi County, AR, Poinsett County, AR, St. Francis County, AR, Alcorn County, MS, Benton County, MS, Calhoun County, MS, Chickasaw County, MS, DeSoto County, MS, Itawamba County, MS, Lafayette County, MS, Lee County, MS, Marshall County, MS, Monroe County, MS, Panola County, MS, Pontotoc County, MS, Prentiss County, MS, Tate County, MS, Tippah County, MS, Union County, MS, Yalobusha County, MS, Chester County, TN, Crockett County, TN, Fayette County, TN, Hardeman County, TN, Haywood County, TN, Lauderdale County, TN, Madison County, TN, McNairy County, TN, Shelby County, TN, Tipton County, TN

The radar

The Memphis radar (KNQA), 63 km from the middle of the area, began a volume at 16:43 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Jackson, MS (KJAN), launched 12:00Z, 4.7 hours before the alert went out and 295 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Jackson, MS at 12:00Z on 2026-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 957 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jackson, MS at 12:00Z on 2026-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
957 J/kg
Mixed-layer CIN
-156 J/kg
Mixed-layer LCL
1364 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
50 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The office that day

Everything else NWS Memphis, TN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 18, 11:41 AM CDTExtreme Heat WarningMEGShelby, Tipton32 hr
Aug 17, 7:09 PM CDTSpecial Weather StatementMEGChickasaw21 min
Aug 17, 7:30 PM CDTSpecial Weather StatementMEGMonroe30 min
Aug 18, 4:05 PM CDTSpecial Weather StatementMEGChickasaw25 min

Nearby

Heat Advisories in Mississippi, 2026Heat Advisories in Tennessee, 2026Heat Advisories in Arkansas, 2026Every heat advisory in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.