Alert archive / Missouri / Areal Flood Advisories in 2021

Areal Flood Advisory 29, NWS St. Louis, MO

July 1, 2021Saint Charles County, Missouri

NWS St. Louis, MO issued this areal flood advisory at Jul 1, 2021, 5:51 AM CDT for Saint Charles County, Missouri. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Jul 1, 2021, 5:51 AM CDT (10:51 UTC)
Expired
Jul 1, 2021, 8:54 AM CDT
In force
3 hr
Issued by
NWS St. Louis, MO
Area
Storm-based polygon

County Saint Charles County, MO

The radar

The St Louis radar (KLSX), 9 km from the middle of the area, began a volume at 10:55 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, 10.9 hours before the alert went out and 234 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, Lincoln, IL at 00:00Z on 2021-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 573 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, Lincoln, IL at 00:00Z on 2021-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.19395878Sfc1 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
573 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
892 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.7

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood 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 areal flood advisory went out at Jul 1, 4:34 AM CDT, 1 hour 17 minutes earlier.

Area forecast discussion, Jul 1, 4:34 AM CDT, 1 hour 17 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 1, 5:00 AM CDT, 51 minutes before
Hazardous Weather Outlook
National Weather Service Saint Louis MO
500 AM CDT Thu Jul 1 2021

ILZ058>060-064-065-069-070-074-079-095>102-MOZ018-019-026-027-
034>036-041-042-047>052-059>065-072>075-084-085-099-021000-
Adams IL-Audrain MO-Bond IL-Boone MO-Brown IL-Calhoun IL-Callaway MO-
Clinton IL-Cole MO-Crawford MO-Fayette IL-Franklin MO-Gasconade MO-
Greene IL-Iron MO-Jefferson MO-Jersey IL-Knox MO-Lewis MO-Lincoln MO-
Macoupin IL-Madison IL-Madison MO-Marion IL-Marion MO-Moniteau MO-
Monroe IL-Monroe MO-Montgomery IL-Montgomery MO-Osage MO-Pike IL-
Pike MO-Ralls MO-Randolph IL-Reynolds MO-Saint Charles MO-
Saint Clair-Saint Francois MO-Saint Louis City MO-Saint Louis MO-
Sainte Genevieve MO-Shelby MO-Warren MO-Washington IL-Washington MO-
500 AM CDT Thu Jul 1 2021

This Hazardous Weather Outlook is for portions of eastern and
central Missouri as well as west central and southwest Illinois.

.DAY ONE...Today and tonight.

There is a chance of thunderstorms today and this evening.  A Flash
Flood Watch remains in effect early this morning for parts of
central and eastern Missouri with locally heavy rainfall expected.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

There is a slight chance of thunderstorms for parts of the area
Tuesday through Wednesday.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to report any flooding to the National
Weather Service.

GKS

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 30, 8:41 PM CDTAreal Flood AdvisoryLSXSaint Charles3 hr
Jun 30, 10:44 PM CDTAreal Flood AdvisoryLSXMonroe, Ralls7 hr
Jul 1, 12:12 AM CDTAreal Flood AdvisoryLSXMarion, Shelby23 min
Jul 1, 12:35 AM CDTFlash Flood WarningLSXMarion, Shelby3 hr
Jul 1, 2:57 AM CDTAreal Flood AdvisoryLSXMarion, Monroe, Shelby3 hr
Jul 1, 3:21 AM CDTAreal Flood AdvisoryLSXMarion, Shelby2 hr
Jul 1, 5:16 AM CDTAreal Flood AdvisoryLSXCallaway, Montgomery, Warren3 hr
Jul 1, 6:04 AM CDTAreal Flood AdvisoryLSXBoone, Callaway, Cole, Moniteau28 min
Jul 1, 6:32 AM CDTFlash Flood WarningLSXBoone, Callaway, Cole, Moniteau3 hr
Jul 1, 6:59 AM CDTRiver Flood WarningLSXMonroe37 hr
Jul 1, 8:21 AM CDTRiver Flood WarningLSXCole32 hr
Jul 1, 11:54 AM CDTRiver Flood WarningLSXLincoln27 hr
Jun 30, 8:55 PM CDTRiver Flood WarningLSXBrown21 days
Jul 1, 11:28 AM CDTRiver Flood WarningLSXMorgan, Pike21 days
Jul 1, 11:30 AM CDTRiver Flood WarningLSXCalhoun, Greene, Jersey21 days

Nearby

Areal Flood Advisories in Missouri, 2021Every areal flood 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.