Alert archive / Illinois / Dense Fog Advisories in 2016

Dense Fog Advisory 9, NWS St. Louis, MO

July 7, 201616 counties in Missouri; 17 counties in Illinois

NWS St. Louis, MO issued this dense fog advisory at Jul 7, 2016, 3:55 AM CDT for 16 counties in Missouri; 17 counties in Illinois. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jul 7, 2016, 3:55 AM CDT (08:55 UTC)
Expired: Jul 7, 2016, 7:15 AM CDT
In force: 3 hr
Issued by: NWS St. Louis, MO

All 33 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, City of Saint Louis, MO, Franklin County, MO, Iron County, MO, Jefferson County, MO, Lewis County, MO, Lincoln County, MO, Madison County, MO, Marion County, MO, Pike County, MO, Ralls County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 26 km from the middle of the area, began a volume at 08:57 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 00:00Z, 8.9 hours before the alert went out and 218 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: 144 J/kg
Mixed-layer CIN: -255 J/kg
Mixed-layer LCL: 1013 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: -44 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 dense fog 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 dense fog advisory went out at Jul 6, 10:24 PM CDT, 5 hours 31 minutes earlier.

Area forecast discussion, Jul 6, 10:24 PM CDT, 5 hours 31 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>

Hazardous weather outlook, Jul 6, 4:01 PM CDT, 11 hours 54 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
Jul 7, 6:09 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Boone, Callaway, Cole, Moniteau, Monroe and 1 more	66 min
Jul 7, 6:54 AM CDT	Special Weather Statement	LSX	Knox, Lewis, Marion, Shelby	51 min
Jul 7, 7:06 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Callaway, Franklin, Gasconade, Lincoln, Montgomery and 4 more	54 min
Jul 7, 7:11 AM CDT	Severe Thunderstorm Warning	LSX	Knox, Lewis, Marion, Shelby	54 min
Jul 7, 7:18 AM CDT	Severe Thunderstorm Warning	LSX	Audrain, Callaway, Cole, Marion, Monroe	27 min
Jul 7, 7:59 AM CDT	Severe Thunderstorm Warning	LSX	Crawford, Franklin, Gasconade, Jefferson, Lincoln, Montgomery and 6 more	61 min
Jul 7, 9:04 AM CDT	Special Weather Statement	LSX	Jefferson, Saint Francois, Washington	41 min
Jul 7, 7:32 AM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown, Pike	58 min
Jul 7, 8:26 AM CDT	Severe Thunderstorm Warning	LSX	Adams, Brown, Pike	34 min
Jul 7, 11:34 AM CDT	Special Weather Statement	LSX	Marion	26 min

Nearby

Dense Fog Advisories in Illinois, 2016 Dense Fog Advisories in Missouri, 2016 Every dense fog advisory in 2016

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.