Alert archive / Tennessee / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 152, NWS Morristown, TN

July 31, 20204 counties in Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Jul 31, 2020, 7:52 PM EDT for 4 counties in Tennessee. It was in force for 38 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Jul 31, 2020, 7:52 PM EDT (23:52 UTC)
Expired: Jul 31, 2020, 8:30 PM EDT
In force: 38 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Carter County, TN, Johnson County, TN, Unicoi County, TN, Washington County, TN

The radar

The Knoxville radar (KMRX), 106 km from the middle of the area, began a volume at 23:56 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

Greensboro/Hi Pt, NC (KGSO), launched 12:00Z, 11.9 hours before the alert went out and 210 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: 39 J/kg
Mixed-layer CIN: -111 J/kg
Mixed-layer LCL: 1095 m above ground
0-6 km bulk shear: 29 kt
0-1 km storm-relative helicity: 132 m²/s²
0-3 km storm-relative helicity: 151 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.6

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm 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 severe thunderstorm warning went out at Jul 31, 7:34 PM EDT, 18 minutes earlier.

Area forecast discussion, Jul 31, 7:34 PM EDT, 18 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <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.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Hazardous weather outlook, Jul 31, 2:41 PM EDT, 5 hours 11 minutes before

Hazardous Weather Outlook
National Weather Service Morristown TN
241 PM EDT Fri Jul 31 2020

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-011845-
Cherokee-Clay-Scott-Campbell-Claiborne-Hancock-Hawkins-Sullivan-
Johnson-Morgan-Anderson-Union-Grainger-Hamblen-Northwest Cocke-
Cocke Smoky Mountains-Northwest Greene-Southeast Greene-
Washington-Unicoi-Northwest Carter-Southeast Carter-Roane-Loudon-
Knox-Jefferson-Northwest Blount-Blount Smoky Mountains-
North Sevier-Sevier Smoky Mountains-Sequatchie-Bledsoe-Rhea-Meigs-
McMinn-Northwest Monroe-Southeast Monroe-Marion-Hamilton-Bradley-
West Polk-East Polk-Lee-Wise-Russell-
241 PM EDT Fri Jul 31 2020 /141 PM CDT Fri Jul 31 2020/

This Hazardous Weather Outlook is for portions of southwest North
Carolina...east Tennessee and southwest Virginia.

.DAY ONE...This Afternoon and Tonight

A round of storms is expected this afternoon through this
evening. A moist and unstable airmass will produce scattered
strong to possible severe thunderstorms. Main concern will be
torrential rains and potentially more flash flooding. Isolated
damaging winds are also possible.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Strong to severe storms will be possible late Saturday afternoon
into the evening. Best chances for severe weather will generally
be along and west of Interstate 75. The main threat from these
storms will be isolated damaging wind gusts. Heavy rainfall with
these storms could also lead to the possibility of localized flash
flooding.

A strong to marginally severe storm cannot be ruled out again on
Sunday afternoon across northeast Tennessee and southwest
Virginia with an isolated damaging wind gust being the main
threat.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed this afternoon and again on
Saturday.

In the hours before

Local storm report, Jul 31, 6:11 PM EDT, 1 hour 41 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
611 PM EDT FRI JUL 31 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0530 PM     TSTM WND DMG     5 SW BRICEVILLE         36.12N 84.23W
07/31/2020                   ANDERSON           TN   911 CALL CENTER

            SEVERAL TREES DOWN IN DUTCH VALLEY.

&&

GARUCKAS

Local storm report, Jul 31, 6:26 PM EDT, 1 hour 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
626 PM EDT FRI JUL 31 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0535 PM     TSTM WND DMG     HALLS                   36.09N 83.93W
07/31/2020                   KNOX               TN   BROADCAST MEDIA

            PARTIAL BARN COLLAPSE IN HALLS FROM STRONG
            WINDS.

&&

GARUCKAS

Local storm report, Jul 31, 6:31 PM EDT, 1 hour 21 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
631 PM EDT FRI JUL 31 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0507 PM     TSTM WND DMG     HUNTSVILLE              36.42N 84.49W
07/31/2020                   SCOTT              TN   BROADCAST MEDIA

            SNAPPED TREES AND DOWNED POWER LINES IN
            HUNTSVILLE.

&&

GARUCKAS

Special weather statement, Jul 31, 6:34 PM EDT, 1 hour 18 minutes before

Special Weather Statement
National Weather Service Morristown TN
634 PM EDT Fri Jul 31 2020

TNZ039>043-070-312300-
Cocke Smoky Mountains TN-Jefferson TN-Hamblen TN-Northwest Greene TN-
Northwest Cocke TN-Southeast Greene TN-
634 PM EDT Fri Jul 31 2020

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN JEFFERSON...NORTHERN
COCKE...CENTRAL GREENE AND SOUTHEASTERN HAMBLEN COUNTIES UNTIL 700 PM
EDT...

At 634 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from Russellville to near White Pine to 6 miles
south of Baneberry. Movement was east at 45 mph.

Wind gusts up to 50 mph will be possible with these storms.

Locations impacted include...
Morristown, Greeneville, Newport, White Pine, Baneberry,
Parrottsville, Russellville, Mosheim, Bulls Gap and Baileyton.

LAT...LON 3633 8271 3617 8279 3594 8293 3594 8339
      3613 8328 3627 8324 3628 8312 3624 8307
      3628 8303 3627 8302 3630 8298
TIME...MOT...LOC 2234Z 263DEG 41KT 3626 8318 3614 8323 3596 8332

CED

Local storm report, Jul 31, 6:43 PM EDT, 1 hour 9 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
643 PM EDT FRI JUL 31 2020

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0615 PM     TSTM WND DMG     TAZEWELL                36.46N 83.57W
07/31/2020                   CLAIBORNE          TN   TRAINED SPOTTER

            LOTS OF TREES AND POWER LINES DOWN IN
            TAZEWELL WITH POWER OUTAGES. ONE TREE FELL
            ON A HOUSE NEAR CANE CIRCLE, AND ONE HOUSE
            HAS SIDING BLOWN OFF.

&&

GARUCKAS

Special weather statement, Jul 31, 6:58 PM EDT, 54 minutes before

Special Weather Statement
National Weather Service Morristown TN
658 PM EDT Fri Jul 31 2020

TNZ016-017-042-044-312345-
Sullivan TN-Washington TN-Northwest Greene TN-Hawkins TN-
658 PM EDT Fri Jul 31 2020

...SIGNIFICANT WEATHER ADVISORY FOR WESTERN SULLIVAN...EASTERN
HAWKINS...WASHINGTON AND NORTHERN GREENE COUNTIES UNTIL 745 PM EDT...

At 658 PM EDT, Doppler radar was tracking strong thunderstorms along
a line extending from 13 miles east of Sneedville to near
Surgoinsville to 6 miles southeast of Rogersville to 8 miles
northwest of Greeneville. Movement was east at 35 mph.

Wind gusts up to 50 mph will be possible with these storms.

Locations impacted include...
Johnson City, Kingsport, Bristol Tn, Rogersville, Jonesborough,
Surgoinsville, Spurgeon, Midway, Colonial Heights and Gray.

LAT...LON 3640 8228 3640 8230 3626 8234 3622 8237
      3622 8306 3632 8298 3640 8297 3654 8306
      3655 8305 3656 8299 3655 8298 3655 8296
      3654 8295 3657 8289 3660 8268 3660 8240
      3654 8225
TIME...MOT...LOC 2258Z 257DEG 32KT 3650 8297 3642 8291 3634 8291 3624
8295

CED

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 1:28 AM EDT	Areal Flood Advisory	MRX	Campbell, Scott	3 hr
Jul 31, 5:52 AM EDT	Areal Flood Advisory	MRX	Anderson, Campbell, Cocke, Grainger, Greene, Hamblen and 5 more	3 hr
Jul 31, 4:20 PM EDT	Special Weather Statement	MRX	Roane	25 min
Jul 31, 4:24 PM EDT	Severe Thunderstorm Warning	MRX	Rhea, Roane	21 min
Jul 31, 4:42 PM EDT	Severe Thunderstorm Warning	MRX	Morgan, Scott	48 min
Jul 31, 5:10 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Campbell, Claiborne, Scott, Union	50 min
Jul 31, 5:24 PM EDT	Severe Thunderstorm Warning	MRX	Anderson, Knox, Union	36 min
Jul 31, 5:50 PM EDT	Special Weather Statement	MRX	Blount	25 min
Jul 31, 5:55 PM EDT	Severe Thunderstorm Warning	MRX	Claiborne, Grainger, Hancock, Union	35 min
Jul 31, 6:16 PM EDT	Severe Thunderstorm Warning	MRX	Jefferson, Sevier	29 min
Jul 31, 6:28 PM EDT	Severe Thunderstorm Warning	MRX	Claiborne, Grainger, Greene, Hamblen, Hancock, Hawkins	32 min
Jul 31, 6:34 PM EDT	Special Weather Statement	MRX	Greene	26 min
Jul 31, 6:58 PM EDT	Special Weather Statement	MRX	Hawkins, Sullivan, Washington	47 min
Jul 31, 7:00 PM EDT	Severe Thunderstorm Warning	MRX	Cocke, Greene	30 min
Jul 31, 7:16 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Hawkins, Sullivan, Washington	29 min
Jul 31, 7:26 PM EDT	Severe Thunderstorm Warning	MRX	Greene, Unicoi, Washington	34 min
Jul 31, 3:09 AM EDT	Areal Flood Advisory	MRX	Lee, Russell, Scott, Wise, City of Norton	3 hr

Nearby

Severe Thunderstorm Warnings in Tennessee, 2020 Every severe thunderstorm warning in 2020

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.