Alert archive / Alabama / Areal Flood Warnings in 2021

Areal Flood Warning 47, NWS Huntsville, AL

September 19, 2021Limestone County, Morgan County, Alabama

NWS Huntsville, AL issued this areal flood warning at Sep 19, 2021, 12:49 PM CDT for Limestone County, Morgan County, Alabama. It was in force for 3 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, 12:49 PM CDT (17:49 UTC)
Expired: Sep 19, 2021, 4:00 PM CDT
In force: 3 hr
Issued by: NWS Huntsville, AL
Area: Storm-based polygon
Flood severity: None

Counties Limestone County, AL, Morgan County, AL

The radar

The Northeast Alabama radar (KHTX), 83 km from the middle of the area, began a volume at 17:52 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

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 5.8 hours before the alert went out and 263 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: 896 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 611 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 29 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 warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Huntsville, AL wrote its last area forecast discussion before this areal flood warning went out at Sep 19, 12:48 PM CDT, 1 minute earlier.

Area forecast discussion, Sep 19, 12:48 PM CDT, 1 minute before

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Hazardous weather outlook, Sep 19, 4:08 AM CDT, 8 hours 41 minutes before

Hazardous Weather Outlook
National Weather Service Huntsville AL
408 AM CDT Sun Sep 19 2021

ALZ001>010-016-TNZ076-096-097-200015-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
408 AM CDT Sun Sep 19 2021

This Hazardous Weather Outlook is for north Alabama and portions of
southern middle Tennessee.

.DAY ONE...Today and Tonight...

A significant threat for flash flooding is expected to develop across
the Tennessee Valley today as widespread showers and thunderstorms
will produce multiple rounds of heavy rainfall across the region. A
Flash Flood Watch is in effect until 7 PM Monday.

.DAYS TWO THROUGH SEVEN...Monday through Saturday...

Periods of heavy showers and storms are expected to develop across
the region Monday and Tuesday and a threat for flash flooding will
persist into early this week. Additionally, rises on rivers, creeks,
and streams are expected and minor flooding will be possible. This
activity will become more scattered in nature on Wednesday and taper
off by Wednesday evening as a cold front sweeps through the area.

.SPOTTER CALL TO ACTION STATEMENT...

Activation of storm spotters and emergency management personnel is
not anticipated at this time.

In the hours before

Local storm report, Sep 19, 9:32 AM CDT, 3 hours 17 minutes before

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Local storm report, Sep 19, 9:39 AM CDT, 3 hours 10 minutes before

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Local storm report, Sep 19, 11:44 AM CDT, 1 hour 5 minutes before

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Local storm report, Sep 19, 12:42 PM CDT, 7 minutes before

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Local storm report, Sep 19, 12:45 PM CDT, 4 minutes before

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The office that day

Everything else NWS Huntsville, AL issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 19, 4:21 AM CDT	Flash Flood Warning	HUN	Jackson	3 hr
Sep 19, 7:25 AM CDT	Flash Flood Warning	HUN	Madison, Marshall	3 hr
Sep 19, 7:29 AM CDT	Areal Flood Warning	HUN	Jackson	9 hr
Sep 19, 8:23 AM CDT	River Flood Warning	HUN	Jackson, Madison, Marshall	4 days
Sep 19, 8:27 AM CDT	River Flood Warning	HUN	Madison	41 hr
Sep 19, 10:18 AM CDT	Areal Flood Warning	HUN	Madison, Marshall	6 hr
Sep 19, 10:59 AM CDT	Areal Flood Warning	HUN	Madison, Morgan	5 hr
Sep 19, 1:13 PM CDT	Flash Flood Warning	HUN	Madison, Marshall, Morgan	3 hr
Sep 19, 3:52 PM CDT	Areal Flood Warning	HUN	Jackson, Limestone, Madison, Marshall, Morgan	6 hr
Sep 19, 3:48 PM CDT	River Flood Warning	HUN	Franklin, Lincoln	35 hr

Nearby

Areal Flood Warnings in Alabama, 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.