Alert archive / Missouri / Areal Flood Advisories in 2021

Areal Flood Advisory 18, NWS St. Louis, MO

June 30, 2021Boone County, Callaway County, Missouri

NWS St. Louis, MO issued this areal flood advisory at Jun 30, 2021, 5:59 AM CDT for Boone County, Callaway County, Missouri. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued: Jun 30, 2021, 5:59 AM CDT (10:59 UTC)
Expired: Jun 30, 2021, 9:00 AM CDT
In force: 3 hr
Issued by: NWS St. Louis, MO
Area: Storm-based polygon

Counties Boone County, MO, Callaway County, MO

The radar

The St Louis radar (KLSX), 127 km from the middle of the area, began a volume at 10:58 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

Springfield, MO (KSGF), launched 00:00Z, 11.0 hours before the alert went out and 268 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: 1477 J/kg
Mixed-layer CIN: -13 J/kg
Mixed-layer LCL: 993 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: 58 m²/s²
0-3 km storm-relative helicity: 120 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 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 Jun 30, 5:56 AM CDT, 3 minutes earlier.

Area forecast discussion, Jun 30, 5:56 AM CDT, 3 minutes before

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Hazardous weather outlook, Jun 30, 4:52 AM CDT, 1 hour 7 minutes before

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    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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        Please try again in a few minutes.
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        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
Jun 29, 8:41 PM CDT	River Flood Warning	LSX	Lewis	30 hr
Jun 30, 3:30 AM CDT	Flash Flood Watch	LSX	Audrain, Boone, Callaway, Cole, Crawford, Franklin and 8 more	33 hr
Jun 30, 5:15 AM CDT	Areal Flood Advisory	LSX	Boone, Moniteau	3 hr
Jun 30, 5:44 AM CDT	River Flood Warning	LSX	Lincoln	49 hr
Jun 30, 7:01 AM CDT	Areal Flood Advisory	LSX	Montgomery	3 hr
Jun 30, 7:49 AM CDT	Areal Flood Advisory	LSX	Lincoln, Montgomery, Warren	3 hr
Jun 30, 4:03 PM CDT	Areal Flood Advisory	LSX	Lewis, Marion	3 hr
Jun 30, 4:34 PM CDT	Areal Flood Advisory	LSX	Marion	46 min
Jun 30, 5:20 PM CDT	Flash Flood Warning	LSX	Marion	2 hr
Jun 30, 6:00 PM CDT	River Flood Warning	LSX	Marion	22 hr
Jun 30, 6:00 PM CDT	River Flood Warning	LSX	Marion	19 hr

Nearby

Areal Flood Advisories in Missouri, 2021 Every 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.