Alert archive / Missouri / Heat Advisories in 2026
Heat Advisory 9, NWS St. Louis, MO
NWS St. Louis, MO issued this heat advisory at Sep 5, 2026, 12:29 PM CDT for 8 counties in Missouri. It took effect at Sep 5, 2026, 8:00 PM CDT. It was in force for 23 hr.
The area
The counties it named.
The facts
- Issued
- Sep 5, 2026, 12:29 PM CDT (17:29 UTC)
- In effect from
- Sep 5, 2026, 8:00 PM CDT
- Expired
- Sep 6, 2026, 7:00 PM CDT
- In force
- 23 hr
- Issued by
- NWS St. Louis, MO
Counties Boone County, MO, Callaway County, MO, Cole County, MO, Crawford County, MO, Gasconade County, MO, Moniteau County, MO, Osage County, MO, Reynolds County, MO
The nearest sounding before it
Lincoln, IL (KILX), launched 12:00Z, 5.5 hours before the alert went out and 340 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
- 2092 J/kg
- Mixed-layer CIN
- -69 J/kg
- Mixed-layer LCL
- 1467 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 55 m²/s²
- 0-3 km storm-relative helicity
- 50 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 St. Louis, MO wrote its last area forecast discussion before this heat advisory went out at Sep 5, 12:13 PM CDT, 16 minutes earlier.
Area forecast discussion, Sep 5, 12:13 PM CDT, 16 minutes before
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Service Notice</title>
<link rel="stylesheet" href="index.css">
</head>
<body>
<main class="wrap">
<section class="card" role="status" aria-live="polite">
<div class="status" id="status">Temporary Notice</div>
<h1 id="headline">This service is currently unavailable.</h1>
<p id="message1">
The site you requested is temporarily down for maintenance or an unexpected outage.
</p>
<p id="message2">
Please try again in a few minutes.
</p>
<p class="small" id="detail">
If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
</p>
</section>
</main>
<script src="index.js"></script>
</body>
</html>The office that day
Everything else NWS St. Louis, MO issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 5, 5:10 PM CDT | Severe Thunderstorm Warning | LSX | Saint Francois | 35 min |
Nearby
Heat Advisories in Missouri, 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.