Alert archive / Tennessee / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 187, NWS Morristown, TN

September 1, 2018Blount County, Loudon County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Sep 1, 2018, 4:00 PM EDT for Blount County, Loudon County, Tennessee. It was in force for 30 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: Sep 1, 2018, 4:00 PM EDT (20:00 UTC)
Expired: Sep 1, 2018, 4:30 PM EDT
In force: 30 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Blount County, TN, Loudon County, TN

The radar

The Knoxville radar (KMRX), 82 km from the middle of the area, began a volume at 20:03 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, 8.0 hours before the alert went out and 228 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: 412 J/kg
Mixed-layer CIN: -62 J/kg
Mixed-layer LCL: 1026 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -34 m²/s²
0-3 km storm-relative helicity: -38 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 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 Sep 1, 3:07 PM EDT, 53 minutes earlier.

Area forecast discussion, Sep 1, 3:07 PM EDT, 53 minutes before

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Hazardous weather outlook, Sep 1, 2:59 AM EDT, 13 hours 1 minute before

Hazardous Weather Outlook
National Weather Service Morristown TN
259 AM EDT Sat Sep 1 2018

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-020700-
Cherokee-Clay-Scott TN-Campbell-Claiborne-Hancock-Hawkins-
Sullivan-Johnson-Morgan-Anderson-Union-Grainger-Hamblen-
Northwest Cocke-Cocke Smoky Mountains-Northwest Greene-
Southeast Greene-Washington TN-Unicoi-Northwest Carter-
Southeast Carter-Roane-Loudon-Knox-Jefferson-NW 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-Scott-Russell-Washington-
259 AM EDT Sat Sep 1 2018 /159 AM CDT Sat Sep 1 2018/

This Hazardous Weather Outlook is for portions of Southwest North
Carolina...East Tennessee and Southwest Virginia.

.DAY ONE...Today and Tonight

Patchy dense fog this morning reducing visibility to one-quarter
mile or less.

Scattered mainly afternoon and early evening thunderstorms can be
expected. Some of these storms could be strong with the main
concern being localized heavy rainfall and flooding, and strong
gusty winds and small hail.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

No hazardous weather is expected.

.SPOTTER INFORMATION STATEMENT...

Spotter activation will not be needed.

In the hours before

Special weather statement, Sep 1, 2:02 PM EDT, 1 hour 58 minutes before

Special Weather Statement
National Weather Service Morristown TN
202 PM EDT SAT SEP 1 2018

TNZ084-085-100-011845-
Bradley TN-Meigs TN-McMinn TN-
202 PM EDT SAT SEP 1 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BRADLEY...
SOUTHWESTERN MEIGS AND SOUTHWESTERN MCMINN COUNTIES UNTIL 245 PM
EDT...

At 201 PM EDT, Doppler radar was tracking a strong thunderstorm near
Charleston, or 9 miles north of Cleveland, moving north at 10 mph.

Half inch hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Decatur, Charleston, Calhoun, Hillsview, Hopewell, Big Spring and
Riceville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3522 8492 3536 8497 3542 8501 3544 8498
      3547 8498 3547 8497 3544 8495 3544 8492
      3545 8491 3548 8490 3550 8486 3552 8486
      3554 8472 3526 8471
TIME...MOT...LOC 1801Z 169DEG 9KT 3532 8484

05/MA

Special weather statement, Sep 1, 3:05 PM EDT, 55 minutes before

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Special weather statement, Sep 1, 3:09 PM EDT, 51 minutes before

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Local storm report, Sep 1, 3:13 PM EDT, 47 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 2:02 PM EDT	Special Weather Statement	MRX	Meigs	43 min
Sep 1, 2:20 PM EDT	Areal Flood Advisory	MRX	Bradley	115 min
Sep 1, 2:23 PM EDT	Severe Thunderstorm Warning	MRX	Bradley, Hamilton, McMinn, Meigs	52 min
Sep 1, 2:48 PM EDT	Areal Flood Advisory	MRX	Meigs	117 min
Sep 1, 3:05 PM EDT	Special Weather Statement	MRX	Monroe	40 min
Sep 1, 3:09 PM EDT	Special Weather Statement	MRX	Roane	51 min
Sep 1, 4:03 PM EDT	Severe Thunderstorm Warning	MRX	Blount, Monroe	27 min
Sep 1, 4:35 PM EDT	Areal Flood Advisory	MRX	Blount, Loudon	115 min
Sep 1, 4:40 PM EDT	Areal Flood Advisory	MRX	Bledsoe, Sequatchie	2 hr
Sep 1, 6:22 PM EDT	Special Weather Statement	MRX	Hamblen, Jefferson	38 min
Sep 1, 7:10 PM EDT	Special Weather Statement	MRX	Hawkins	50 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2018 Every severe thunderstorm warning in 2018

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.