Alert archive / Tennessee / Special Weather Statements in 2021

Special Weather Statement, NWS Morristown, TN

August 18, 2021Campbell County, Tennessee

NWS Morristown, TN issued this special weather statement at Aug 18, 2021, 7:15 PM EDT for Campbell County, Tennessee. It was in force for 45 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 18, 2021, 7:15 PM EDT (23:15 UTC)
Expired: Aug 18, 2021, 8:00 PM EDT
In force: 45 min
Issued by: NWS Morristown, TN
Hail: 0.50 in
Wind: 40

County Campbell County, TN

The radar

The Knoxville radar (KMRX), 87 km from the middle of the area, began a volume at 23:18 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, 11.3 hours before the alert went out and 212 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: 259 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 919 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 70 m²/s²
0-3 km storm-relative helicity: 72 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 Morristown, TN wrote its last area forecast discussion before this special weather statement went out at Aug 18, 6:25 PM EDT, 50 minutes earlier.

Area forecast discussion, Aug 18, 6:25 PM EDT, 50 minutes before

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      <h1 id="headline">This service is currently unavailable.</h1>
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        The site you requested is temporarily down for maintenance or an unexpected outage.
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Hazardous weather outlook, Aug 18, 3:42 PM EDT, 3 hours 33 minutes before

Hazardous Weather Outlook
National Weather Service Morristown TN
342 PM EDT Wed Aug 18 2021

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-191945-
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-
342 PM EDT Wed Aug 18 2021 /242 PM CDT Wed Aug 18 2021/

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

.DAY ONE...This Afternoon and Tonight

No hazardous weather is expected at this time.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Thursday, a weather system will bring showers and thunderstorms
through the eastern Tennessee Valley. Due to the saturated ground
localized flooding may occur if any areas receive a long period of
heavy rainfall.

With recent rainfall activity keeping soils saturated, any stronger
storms could produce some locally heavy downpours and result in
isolated flooding Friday.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not needed at this time.

TD/KS

In the hours before

Special weather statement, Aug 18, 7:15 PM EDT, 0 minutes before

Special Weather Statement
National Weather Service Morristown TN
715 PM EDT Wed Aug 18 2021

TNZ012-013-190000-
Scott TN-Campbell TN-
715 PM EDT Wed Aug 18 2021

...A strong thunderstorm will impact portions of northwestern
Campbell and northeastern Scott Counties through 800 PM EDT...

At 714 PM EDT, Doppler radar was tracking a strong thunderstorm 8
miles northwest of Jacksboro, or 10 miles west of La Follette, moving
northeast at 10 mph.

HAZARD...Winds in excess of 40 mph and half inch 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...
La Follette, Jacksboro, Jellico, Caryville, Elk Valley, Ketchen,
Fincastle and Royal Blue.

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.

&&

LAT...LON 3659 8430 3659 8419 3638 8402 3629 8433
      3646 8448 3660 8431
TIME...MOT...LOC 2314Z 244DEG 7KT 3642 8430

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 8:35 PM EDT	Areal Flood Advisory	MRX	Carter, Johnson, Sullivan, Unicoi, Washington	4 hr
Aug 17, 10:01 PM EDT	Areal Flood Warning	MRX	Blount, Sevier	3 hr
Aug 18, 12:56 AM EDT	River Flood Warning	MRX	Sevier	3 hr
Aug 18, 6:37 PM EDT	Areal Flood Advisory	MRX	Scott	3 hr
Aug 18, 1:04 AM EDT	Areal Flood Advisory	MRX	Wise	116 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.