Alert archive / Missouri / Heat Advisories in 2018

Heat Advisory 6, NWS St. Louis, MO

August 24, 201822 counties in Missouri; 17 counties in Illinois

NWS St. Louis, MO issued this heat advisory at Aug 24, 2018, 3:33 PM CDT for 22 counties in Missouri; 17 counties in Illinois. It took effect at Aug 25, 2018, 12:00 PM CDT. It was in force for 3 days.

The area

The counties it named.

The facts

Issued: Aug 24, 2018, 3:33 PM CDT (20:33 UTC)
In effect from: Aug 25, 2018, 12:00 PM CDT
Expired: Aug 28, 2018, 7:00 PM CDT
In force: 3 days
Issued by: NWS St. Louis, MO

All 39 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Clinton County, IL, Fayette County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Monroe County, IL, Montgomery County, IL, Pike County, IL, Randolph County, IL, Saint Clair County, IL, Washington County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, City of Saint Louis, MO, Cole County, MO, Franklin County, MO, Gasconade County, MO, Jefferson County, MO, Knox County, MO, Lewis County, MO, Lincoln County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Saint Charles County, MO, Saint Louis County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 38 km from the middle of the area, began a volume at 20:36 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

Lincoln, IL (KILX), launched 12:00Z, 8.6 hours before the alert went out and 230 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1161 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 163 m²/s²
0-3 km storm-relative helicity: 127 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

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 Aug 24, 12:56 PM CDT, 2 hours 37 minutes earlier.

Area forecast discussion, Aug 24, 12:56 PM CDT, 2 hours 37 minutes before

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Hazardous weather outlook, Aug 24, 4:37 AM CDT, 10 hours 56 minutes before

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In the hours before

Local storm report, Aug 24, 11:52 AM CDT, 3 hours 41 minutes before

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Local storm report, Aug 24, 11:56 AM CDT, 3 hours 37 minutes before

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<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.
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      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
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The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Aug 24, 3:56 AM CDT	Flash Flood Warning	LSX	Knox, Lewis	6 hr
Aug 24, 5:54 AM CDT	Areal Flood Advisory	LSX	Marion, Monroe, Ralls, Shelby	4 hr
Aug 24, 7:08 AM CDT	Areal Flood Advisory	LSX	Pike	3 hr
Aug 24, 8:30 AM CDT	Areal Flood Advisory	LSX	Audrain, Lincoln, Marion, Monroe, Pike, Ralls and 1 more	4 hr
Aug 24, 9:20 AM CDT	River Flood Warning	LSX	Lewis	10 hr
Aug 24, 10:24 AM CDT	Areal Flood Advisory	LSX	Macoupin, Montgomery	4 hr

Nearby

Heat Advisories in Missouri, 2018 Heat Advisories in Illinois, 2018 Every heat advisory in 2018

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.