Alert archive / Tennessee / Areal Flood Warnings in 2021

Areal Flood Warning 34, NWS Huntsville, AL

August 15, 2021Franklin County, Lincoln County, Moore County, Tennessee

NWS Huntsville, AL issued this areal flood warning at Aug 15, 2021, 5:54 PM CDT for Franklin County, Lincoln County, Moore County, Tennessee. 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
Aug 15, 2021, 5:54 PM CDT (22:54 UTC)
Expired
Aug 15, 2021, 9:00 PM CDT
In force
3 hr
Issued by
NWS Huntsville, AL
Area
Storm-based polygon
Flood severity
None

Counties Franklin County, TN, Lincoln County, TN, Moore County, TN

The radar

The Northeast Alabama radar (KHTX), 38 km from the middle of the area, began a volume at 22:53 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 12:00Z, 10.9 hours before the alert went out and 107 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, Nashville Metro, TN at 12:00Z on 2021-08-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 152 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, Nashville Metro, TN at 12:00Z on 2021-08-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 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
152 J/kg
Mixed-layer CIN
-98 J/kg
Mixed-layer LCL
697 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
36 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 Aug 15, 3:55 PM CDT, 1 hour 59 minutes earlier.

Area forecast discussion, Aug 15, 3:55 PM CDT, 1 hour 59 minutes before
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Hazardous weather outlook, Aug 15, 4:26 PM CDT, 1 hour 28 minutes before
Hazardous Weather Outlook...UPDATED
National Weather Service Huntsville AL
426 PM CDT Sun Aug 15 2021

ALZ001>010-016-TNZ076-096-097-161130-
Lauderdale-Colbert-Franklin AL-Lawrence-Limestone-Madison-Morgan-
Marshall-Jackson-DeKalb-Cullman-Moore-Lincoln-Franklin TN-
426 PM CDT Sun Aug 15 2021

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

.DAY ONE...Remainder of today and tonight...

Scattered to numerous thunderstorms will continue to impact the
Tennessee Valley late this afternoon and this evening, before
decreasing in coverage early Monday morning. Frequent cloud to ground
lightning and brief wind gusts of 40-50 MPH will accompany the
strongest storms. However, the greatest threat with this activity
will be locally heavy rainfall and flooding.

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

Scattered to numerous thunderstorms will be possible once again late
Monday morning, before decreasing in coverage during the afternoon
hours.

The remnants of Tropical Storm Fred will lift northward across the
state of Alabama on Monday night and Tuesday, bringing a fair
coverage of light-moderate showers and perhaps a few thunderstorms to
the outlook area during this period. Portions of northeast Alabama
may experience between 1 and 3 inches of additional rainfall, which
could lead to flooding concerns once again.

An active weather pattern will persist for the rest of the week,
with scattered to numerous thunderstorms expected each afternoon from
Wednesday through Saturday.

.SPOTTER CALL TO ACTION STATEMENT...

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

70/DD

In the hours before

Special weather statement, Aug 15, 4:05 PM CDT, 1 hour 49 minutes before
Special Weather Statement
National Weather Service Huntsville AL
405 PM CDT Sun Aug 15 2021

ALZ016-152145-
Cullman AL-
405 PM CDT Sun Aug 15 2021

...A strong thunderstorm will impact portions of southwestern Cullman
County through 445 PM CDT...

At 404 PM CDT, Doppler radar was tracking a strong thunderstorm near
Arkadelphia, or near Sumiton, moving north at 15 mph.

HAZARD...Winds in excess of 30 mph and pea size hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Hanceville, Good Hope, Dodge City, Colony, Wilburn, Logan, Bremen,
Arkadelphia, Black Bottom and Smith Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3389 8701 3390 8710 3391 8708 3393 8710
      3415 8704 3407 8674 3395 8680 3395 8685
      3393 8686 3394 8688 3392 8689 3391 8692
      3387 8692 3386 8696 3386 8699
TIME...MOT...LOC 2104Z 198DEG 15KT 3384 8700

MAX HAIL SIZE...0.25 IN
MAX WIND GUST...30 MPH

MA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 15, 1:59 PM CDTAreal Flood WarningHUNColbert, Lauderdale3 hr
Aug 15, 3:22 PM CDTAreal Flood WarningHUNLauderdale3 hr
Aug 15, 4:05 PM CDTSpecial Weather StatementHUNCullman40 min
Aug 15, 5:56 PM CDTAreal Flood WarningHUNCullman, Limestone, Madison, Morgan3 hr
Aug 15, 6:25 PM CDTAreal Flood WarningHUNJackson, Madison3 hr

Nearby

Areal Flood Warnings in Tennessee, 2021Every 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.