Alert archive / Tennessee / Special Weather Statements in 2021

Special Weather Statement, NWS Nashville, TN

August 29, 2021Williamson County, Tennessee

NWS Nashville, TN issued this special weather statement at Aug 29, 2021, 5:26 PM CDT for Williamson County, Tennessee. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 29, 2021, 5:26 PM CDT (22:26 UTC)
Expired: Aug 29, 2021, 6:00 PM CDT
In force: 34 min
Issued by: NWS Nashville, TN
Hail: 0.00 in
Wind: 30

County Williamson County, TN

The radar

The Nashville radar (KOHX), 37 km from the middle of the area, began a volume at 22:30 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, 10.4 hours before the alert went out and 25 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: 1073 J/kg
Mixed-layer CIN: -30 J/kg
Mixed-layer LCL: 871 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -6 m²/s²
0-3 km storm-relative helicity: 20 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

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

NWS Nashville, TN wrote its last area forecast discussion before this special weather statement went out at Aug 29, 1:45 PM CDT, 3 hours 41 minutes earlier.

Area forecast discussion, Aug 29, 1:45 PM CDT, 3 hours 41 minutes before

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  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
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  <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.
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Hazardous weather outlook, Aug 29, 5:18 AM CDT, 12 hours 8 minutes before

Hazardous Weather Outlook
National Weather Service Nashville TN
518 AM CDT Sun Aug 29 2021

TNZ005>011-023>034-056>066-075-077>080-093>095-301000-
Stewart-Montgomery-Robertson-Sumner-Macon-Clay-Pickett-Houston-
Humphreys-Dickson-Cheatham-Davidson-Wilson-Trousdale-Smith-Jackson-
Putnam-Overton-Fentress-Perry-Hickman-Lewis-Williamson-Maury-
Marshall-Rutherford-Cannon-De Kalb-White-Cumberland-Bedford-Coffee-
Warren-Grundy-Van Buren-Wayne-Lawrence-Giles-
518 AM CDT Sun Aug 29 2021

This Hazardous Weather Outlook is for Middle Tennessee.

.DAY ONE...Today and tonight.

No hazardous weather is expected at this time.

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

Hurricane Ida is forecast to make landfall in Louisiana sometime
this afternoon or early evening, and then turn northeast and weaken
to a Tropical Depression as it moves near or across Middle Tennessee
Tuesday into Wednesday. Actual rainfall amounts across mid state
received will be highly dependent on eventual Ida track, current
indications through are showing that 2 to 4 inches of rainfall, with
locally higher amounts, will be possible. This could lead to flash
flooding on already saturated ground conditions, especially for
locations around and west of I-65 Corridor. In addition, damaging
wind gusts and isolated tornadoes cannot be ruled out as the remnant
low crosses our area.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will likely be needed. Please relay any
information about observed severe weather to the NWS while following
all local, state, and CDC guidelines.

JB Wright

In the hours before

Special weather statement, Aug 29, 5:26 PM CDT, 0 minutes before

Special Weather Statement
National Weather Service Nashville TN
526 PM CDT Sun Aug 29 2021

TNZ059-292300-
Williamson TN-
526 PM CDT Sun Aug 29 2021

...A strong thunderstorm will impact portions of northeastern
Williamson County through 600 PM CDT...

At 526 PM CDT, Doppler radar was tracking a strong thunderstorm over
Franklin, moving north at 15 mph.

HAZARD...Winds in excess of 30 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Franklin, Brentwood, Nolensville and Oak Hill.

This includes Interstate 65 between mile markers 61 and 74.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3604 8682 3604 8679 3601 8673 3601 8671
      3600 8669 3584 8676 3584 8693 3603 8697
      3605 8693
TIME...MOT...LOC 2226Z 180DEG 13KT 3591 8683

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...30 MPH

Schaper

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 29, 4:12 AM CDT	Flash Flood Watch	OHX	Bedford, Cannon, Cheatham, Clay, Coffee, Cumberland and 32 more	62 hr
Aug 29, 6:32 PM CDT	Special Weather Statement	OHX	Lawrence, Wayne	43 min
Aug 29, 6:35 PM CDT	Areal Flood Advisory	OHX	Lawrence, Wayne	55 min

Nearby

Special Weather Statements in Tennessee, 2021 Every special weather statement 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.