Alert archive / Alabama / Heat Advisories in 2021
Heat Advisory 4, NWS Huntsville, AL
NWS Huntsville, AL issued this heat advisory at Jul 28, 2021, 2:26 PM CDT for 8 counties in Alabama; Lincoln County, Tennessee. It took effect at Jul 29, 2021, 10:00 AM CDT. It was in force for 9 hr.
The area
The counties it named.
The facts
- Issued
- Jul 28, 2021, 2:26 PM CDT (19:26 UTC)
- In effect from
- Jul 29, 2021, 10:00 AM CDT
- Expired
- Jul 29, 2021, 7:00 PM CDT
- In force
- 9 hr
- Issued by
- NWS Huntsville, AL
Counties Colbert County, AL, Cullman County, AL, Franklin County, AL, Lauderdale County, AL, Lawrence County, AL, Limestone County, AL, Madison County, AL, Morgan County, AL, Lincoln County, TN
The radar
The Northeast Alabama radar (KHTX), 103 km from the middle of the area, began a volume at 19:29 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
Birmingham, AL (KBMX), launched 12:00Z, 7.4 hours before the alert went out and 167 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.
- Mixed-layer CAPE
- 230 J/kg
- Mixed-layer CIN
- -173 J/kg
- Mixed-layer LCL
- 1062 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- 22 m²/s²
- 0-3 km storm-relative helicity
- 24 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
What forecasters said that day
The local office's own words before this heat advisory went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Huntsville, AL wrote its last area forecast discussion before this heat advisory went out at Jul 28, 12:00 PM CDT, 2 hours 26 minutes earlier.
Area forecast discussion, Jul 28, 12:00 PM CDT, 2 hours 26 minutes before
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</html>Hazardous weather outlook, Jul 28, 9:21 AM CDT, 5 hours 5 minutes before
Hazardous Weather Outlook National Weather Service Huntsville AL 921 AM CDT Wed Jul 28 2021 ALZ001>010-016-TNZ076-096-097-290530- Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan- Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN- 921 AM CDT Wed Jul 28 2021 This Hazardous Weather Outlook is for north Alabama and portions of southern middle Tennessee. .DAY ONE...This Afternoon and Tonight... Hot and humid conditions are forecast across the Tennessee Valley this afternoon. A Heat Advisory is in effect for northwest and north central Alabama until 7 PM this evening. Heat Index values should remain just below advisory criteria of 105 degrees across northeast Alabama and southern middle Tennessee. Regardless, caution is urged and residents of the Tennessee Valley are urged to drink plenty of water, stay in an air-conditioned room, stay out of the sun, and check up on relatives and neighbors. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday... A short-lived heat wave is expected across the Tennessee Valley later this week, with dangerously high heat indices in the 105-110 degree range for much of northern Alabama and southern middle Tennessee, Thursday through Saturday. Isolated to scattered thunderstorm chances return on Saturday, as a cold front approaches the region from the north. The front will stall across the region early next week, resulting in several rounds of thunderstorms from Saturday through Monday. Conditions do appear favorable for strong to severe thunderstorms, especially on Sunday and Sunday night. .SPOTTER CALL TO ACTION STATEMENT... Activation of storm spotters and emergency management personnel is not anticipated at this time.
The office that day
Everything else NWS Huntsville, AL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 28, 4:09 AM CDT | Dense Fog Advisory | HUN | Cullman, DeKalb, Jackson, Limestone, Madison, Marshall and 1 more | 4 hr |
| Jul 28, 9:15 AM CDT | Heat Advisory | HUN | Colbert, Cullman, Franklin, Lauderdale, Lawrence, Limestone and 2 more | 10 hr |
Nearby
Heat Advisories in Alabama, 2021Heat Advisories in Tennessee, 2021Every heat advisory in 2021
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.