Alert archive / Tennessee / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 53, NWS Morristown, TN

May 4, 2021Cocke County, Jefferson County, Sevier County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at May 4, 2021, 11:10 AM EDT for Cocke County, Jefferson County, Sevier County, Tennessee. It was in force for 22 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: May 4, 2021, 11:10 AM EDT (15:10 UTC)
Expired: May 4, 2021, 11:32 AM EDT
In force: 22 min
Issued by: NWS Morristown, TN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Cocke County, TN, Jefferson County, TN, Sevier County, TN

The radar

The Knoxville radar (KMRX), 54 km from the middle of the area, began a volume at 15:13 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
May 4, 9:37 AM EDT	Severe Thunderstorm Watch	SPC	3 hr

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 3.2 hours before the alert went out and 276 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: 590 J/kg
Mixed-layer CIN: -114 J/kg
Mixed-layer LCL: 753 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 207 m²/s²
0-3 km storm-relative helicity: 213 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

755 
WUUS54 KMRX 041510
SVRMRX
TNC029-089-155-041545-
/O.NEW.KMRX.SV.W.0053.210504T1510Z-210504T1545Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Morristown TN
1110 AM EDT Tue May 4 2021

The National Weather Service in Morristown has issued a

* Severe Thunderstorm Warning for...
  Southeastern Jefferson County in east Tennessee...
  Southwestern Cocke County in east Tennessee...
  Eastern Sevier County in east Tennessee...

* Until 1145 AM EDT.

* At 1110 AM EDT, severe thunderstorms were located along a line
  extending from near Dandridge to near Pigeon Forge to near
  Gatlinburg to near Smoky Mountains-Fontana Area, moving east at 40
  mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Sevierville, Newport, Gatlinburg, Dandridge, Pigeon Forge,
  Parrottsville, Smoky Mountains-Newfound Gap, Smoky
  Mountains-Fontana Area, Smoky Mountains-Balsam Mountain and Pittman
  Center.

This includes Interstate 40 in Tennessee between mile markers 429 and
451.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3558 8360 3557 8363 3557 8366 3559 8366
      3566 8358 3600 8350 3602 8309 3578 8308
      3577 8316 3573 8320 3572 8325 3569 8326
      3566 8330 3566 8335 3562 8340 3561 8344
      3557 8349 3556 8359
TIME...MOT...LOC 1510Z 271DEG 35KT 3597 8347 3580 8346 3568 8352 3557
8366

HAIL...<.75IN
WIND...60MPH
 
$$

BW

1 follow-up statement

519 
WWUS54 KMRX 041532
SVSMRX

Severe Weather Statement
National Weather Service Morristown TN
1132 AM EDT Tue May 4 2021

TNC029-089-155-041542-
/O.CAN.KMRX.SV.W.0053.000000T0000Z-210504T1545Z/
Jefferson TN-Cocke TN-Sevier TN-
1132 AM EDT Tue May 4 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN JEFFERSON...
SOUTHWESTERN COCKE AND EASTERN SEVIER COUNTIES IS CANCELLED...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning has
been cancelled.  However gusty winds are still possible with these
thunderstorms.

A Severe Thunderstorm Watch remains in effect until 100 PM EDT for
east Tennessee.

LAT...LON 3558 8360 3557 8363 3557 8366 3559 8366
      3566 8358 3600 8350 3602 8309 3578 8308
      3577 8316 3573 8320 3572 8325 3569 8326
      3566 8330 3566 8335 3562 8340 3561 8344
      3557 8349 3556 8359
TIME...MOT...LOC 1530Z 271DEG 35KT 3597 8323 3580 8322 3568 8328 3557
8342

$$

BW

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 May 4, 11:04 AM EDT, 6 minutes earlier.

Area forecast discussion, May 4, 11:04 AM EDT, 6 minutes before

AREA FORECAST DISCUSSION
National Weather Service Morristown TN
1104 AM EDT Tue May 4 2021

.UPDATE...
MORNING UPDATE.

&&

.DISCUSSION...

Severe threat remains this morning as a line of showers and
thunderstorms are moving through the area. Surface based
instability continues to wane, however, plenty of elevated
instability continues to support these thunderstorms. Damaging
winds should be the main threat for the remainder of the late
morning and early afternoon. A substantial cold pool behind the
convection will keep conditions quiet this afternoon but much
drier air aloft will promote increased lapse rates and airmass
recovery to the west. How much recovery takes place across the
Tennessee Valley remains in question. CAMs continue to lead to
uncertainty regarding severe potential this afternoon/evening.
Will continue to monitor. Updated grids have been published.

Diegan

&&

.AVIATION...
12Z TAF DISCUSSION.

Showers and thunderstorms are anticipated to be in the general
area for most of the day today. Certainty on the exact timing of
the storms is low due to model variances with the extent of
convection late this morning and in the evening. Expect generally
MVFR to VFR conditions outside of storms, but all airports will
likely be impacted by several rounds of thunderstorms today. Fog
looks likely overnight, but left mention out for now to keep TAF
length down.

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             80  62  73  49  72 /  90  80  20   0   0
Knoxville McGhee Tyson Airport, TN  80  61  71  47  67 /  80  60  40   0  10
Oak Ridge, TN                       78  59  70  46  67 /  80  60  40   0  10
Tri Cities Airport, TN              80  60  70  43  65 /  70  60  60   0  10

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&

Hazardous weather outlook, May 4, 2:57 AM EDT, 8 hours 13 minutes before

Hazardous Weather Outlook
National Weather Service Morristown TN
257 AM EDT Tue May 4 2021

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-050700-
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-
257 AM EDT Tue May 4 2021 /157 AM CDT Tue May 4 2021/

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

.DAY ONE...Tonight

Strong to severe thunderstorms will be possible this morning and
again this evening. Damaging wind, large hail are the main
threats, but an isolated tornado cannot be ruled out. In
addition, multiple rounds of moderate to heavy rainfall will
further increase the potential for isolated flash flooding today.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Spotters are encouraged to relay reports of severe weather and
flooding to our office today.

In the hours before

Local storm report, May 4, 10:33 AM EDT, 37 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
1033 AM EDT TUE MAY 4 2021

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

0945 AM     TSTM WND DMG     3 W DEERLODGE           36.20N 84.82W
05/04/2021                   MORGAN             TN   911 CALL CENTER

            SEVERAL TREES DOWN ON HWY 62 IN THE CHESTNUT
            RIDGE COMMUNITY.

&&

Special weather statement, May 4, 10:37 AM EDT, 33 minutes before

Special Weather Statement
National Weather Service Morristown TN
1037 AM EDT Tue May 4 2021

TNZ016-039-040-042-070-041515-
Jefferson TN-Hamblen TN-Northwest Greene TN-Northwest Cocke TN-
Hawkins TN-
1037 AM EDT Tue May 4 2021

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN HAWKINS...
NORTHEASTERN JEFFERSON...NORTHWESTERN COCKE...NORTHWESTERN GREENE AND
HAMBLEN COUNTIES UNTIL 1115 AM EDT...

At 1036 AM EDT, Doppler radar was tracking a strong thunderstorm near
White Pine, or near Morristown, moving northeast at 50 mph.

Penny size hail and winds in excess of 40 mph will be possible with
this storm.

Locations impacted include...
Morristown, Rogersville, White Pine, Baneberry, Russellville,
Mosheim, Bulls Gap, St. Clair, Lowland and Romeo.

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.

&&

A Severe Thunderstorm Watch remains in effect until 200 PM EDT for
east Tennessee.

LAT...LON 3630 8289 3602 8325 3614 8341 3627 8329
      3626 8328 3628 8328 3628 8326 3630 8326
      3646 8311
TIME...MOT...LOC 1436Z 221DEG 41KT 3615 8327

BW

Local storm report, May 4, 10:41 AM EDT, 29 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
NATIONAL WEATHER SERVICE MORRISTOWN TN
1041 AM EDT TUE MAY 4 2021

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

0945 AM     TSTM WND DMG     3 SW DEERLODGE          36.20N 84.82W
05/04/2021                   MORGAN             TN   911 CALL CENTER

            CORRECTS PREVIOUS TSTM WND DMG REPORT FROM 3
            W DEERLODGE. SEVERAL TREES DOWN ON HWY 62 IN
            THE CHESTNUT RIDGE COMMUNITY.

&&

Local storm report, May 4, 10:50 AM EDT, 20 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
1050 AM EDT TUE MAY 4 2021

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

0945 AM     TSTM WND DMG     2 ENE HIGH POINT        36.16N 84.79W
05/04/2021                   MORGAN             TN   911 CALL CENTER

            SEVERAL TREES DOWN ALONG HWY 62 IN THE
            CHESTNUT RIDGE COMMUNITY.

&&

Local storm report, May 4, 11:05 AM EDT, 5 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
1105 AM EDT TUE MAY 4 2021

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

0955 AM     TSTM WND DMG     PIKEVILLE               35.61N 85.20W
05/04/2021                   BLEDSOE            TN   911 CALL CENTER

            NUMEROUS TREES DOWN AND TRAILER BLOWN OVER
            IN THE PIKEVILLE AREA.

&&

Local storm report, May 4, 11:07 AM EDT, 3 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
1107 AM EDT TUE MAY 4 2021

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

0430 AM     HAIL             OLIVER SPRINGS          36.04N 84.34W
05/04/2021  E0.88 INCH       ANDERSON           TN   PUBLIC

            CORRECTS PREVIOUS HAIL REPORT FROM OLIVER
            SPRINGS. VIA SOCIAL MEDIA POST.

&&

The office that day

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

Issued	Product	Office	Counties	Lasted
May 3, 8:29 PM EDT	Special Weather Statement	MRX	Greene, Unicoi, Washington	46 min
May 3, 8:47 PM EDT	Special Weather Statement	MRX	Hamblen, Jefferson	43 min
May 4, 3:10 AM EDT	Severe Thunderstorm Warning	MRX	Morgan, Roane	50 min
May 4, 3:53 AM EDT	Severe Thunderstorm Warning	MRX	Anderson, Morgan, Roane	52 min
May 4, 3:56 AM EDT	Special Weather Statement	MRX	Morgan	49 min
May 4, 4:12 AM EDT	Special Weather Statement	MRX	Morgan	48 min
May 4, 4:40 AM EDT	Severe Thunderstorm Warning	MRX	Anderson, Knox	30 min
May 4, 4:45 AM EDT	Special Weather Statement	MRX	Blount	45 min
May 4, 4:57 AM EDT	Areal Flood Advisory	MRX	Anderson, Morgan, Roane	3 hr
May 4, 5:14 AM EDT	Special Weather Statement	MRX	Knox	46 min
May 4, 5:34 AM EDT	Special Weather Statement	MRX	Blount	41 min
May 4, 6:05 AM EDT	Severe Thunderstorm Warning	MRX	Blount, Sevier	30 min
May 4, 6:11 AM EDT	Areal Flood Advisory	MRX	Anderson, Knox	3 hr
May 4, 6:16 AM EDT	Areal Flood Advisory	MRX	Blount	3 hr
May 4, 6:52 AM EDT	Special Weather Statement	MRX	Sevier	53 min
May 4, 7:00 AM EDT	Flash Flood Warning	MRX	Blount, Sevier	3 hr
May 4, 7:24 AM EDT	Areal Flood Advisory	MRX	Scott	3 hr
May 4, 7:58 AM EDT	Special Weather Statement	MRX	Cocke	47 min
May 4, 9:05 AM EDT	Special Weather Statement	MRX	Morgan, Scott	40 min
May 4, 9:18 AM EDT	Special Weather Statement	MRX	Hamilton	27 min
May 4, 9:37 AM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Morgan, Rhea, Roane	38 min
May 4, 9:48 AM EDT	Severe Thunderstorm Warning	MRX	Bledsoe, Rhea	27 min
May 4, 9:50 AM EDT	Special Weather Statement	MRX	Anderson, Campbell, Claiborne, Union	40 min
May 4, 9:53 AM EDT	Special Weather Statement	MRX	Hamilton, Marion, Sequatchie	67 min
May 4, 10:03 AM EDT	Severe Thunderstorm Warning	MRX	Anderson, Blount, Knox, Loudon, Roane	13 min
May 4, 10:18 AM EDT	Special Weather Statement	MRX	McMinn, Meigs	57 min
May 4, 10:24 AM EDT	Special Weather Statement	MRX	Blount, Knox	36 min
May 4, 10:37 AM EDT	Special Weather Statement	MRX	Hamblen	38 min
May 4, 10:41 AM EDT	Severe Thunderstorm Warning	MRX	Blount, Jefferson, Knox, Sevier	34 min
May 4, 10:45 AM EDT	Severe Thunderstorm Warning	MRX	Blount, Monroe	30 min
May 4, 11:11 AM EDT	Flash Flood Warning	MRX	Hamilton, Marion, Sequatchie	3 hr
May 4, 11:29 AM EDT	Areal Flood Warning	MRX	Blount, Sevier	6 hr
May 4, 11:44 AM EDT	Areal Flood Advisory	MRX	Blount, Monroe	2 hr
May 4, 11:47 AM EDT	Areal Flood Advisory	MRX	Blount, Sevier	118 min
May 4, 12:06 PM EDT	Special Weather Statement	MRX	Polk	24 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2021 Every severe thunderstorm 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.