Alert archive / Tennessee / Areal Flood Warnings in 2021

Areal Flood Warning 28, NWS Morristown, TN

September 19, 2021Hamilton County, Tennessee

NWS Morristown, TN issued this areal flood warning at Sep 19, 2021, 11:18 PM EDT for Hamilton County, Tennessee. It was in force for 10 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Sep 19, 2021, 11:18 PM EDT (03:18 UTC)
Expired: Sep 20, 2021, 9:00 AM EDT
In force: 10 hr
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Flood severity: None

County Hamilton County, TN

The radar

The Northeast Alabama radar (KHTX), 88 km from the middle of the area, began a volume at 03:21 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

Nashville Metro, TN (KBNA), launched 00:00Z, 3.3 hours before the alert went out and 167 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: 199 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 563 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 71 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.4

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this areal flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Morristown, TN wrote its last area forecast discussion before this areal flood warning went out at Sep 19, 7:18 PM EDT, 4 hours earlier.

Area forecast discussion, Sep 19, 7:18 PM EDT, 4 hours before

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Hazardous weather outlook, Sep 19, 3:26 PM EDT, 7 hours 52 minutes before

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      <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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The office that day

Everything else NWS Morristown, TN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 19, 9:28 PM EDT	River Flood Warning	MRX	Bledsoe, Marion, Sequatchie	3 days
Sep 20, 8:55 AM EDT	Areal Flood Warning	MRX	Hamilton	3 hr
Sep 20, 10:27 AM EDT	Wind Advisory	MRX	Blount, Carter, Cocke, Greene, Monroe, Sevier and 1 more	20 hr
Sep 20, 2:53 PM EDT	Flash Flood Warning	MRX	Hamilton, Marion	4 hr

Nearby

Areal Flood Warnings in Tennessee, 2021 Every areal flood warning 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.