Alert archive / Tennessee / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 21, NWS Morristown, TN

May 21, 2001Blount County, Knox County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at May 21, 2001, 7:37 PM EDT for Blount County, Knox County, Tennessee. It was in force for 53 min. 4 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued: May 21, 2001, 7:37 PM EDT (23:37 UTC)
Expired: May 21, 2001, 8:30 PM EDT
In force: 53 min
Issued by: NWS Morristown, TN
Area: Whole counties

Counties Blount County, TN, Knox County, TN

The radar

The Knoxville radar (KMRX), 60 km from the middle of the area, began a volume at 23:40 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.

What was reported inside it

Time	Report	Where	Remark
May 21, 8:01 PM EDT	Thunderstorm Wind	Farragut, TN	Trees down. Also reported by TV meteorologist.
May 21, 8:04 PM EDT	Hail 0.75	Farragut, TN
May 21, 8:15 PM EDT	Thunderstorm Wind	Maryville, TN	Several trees down on Alcoa Highway.
May 21, 8:40 PM EDT	Thunderstorm Wind	Knoxville, TN	Trees down across northern half of county.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

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 21, 7:00 PM EDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

Nashville Metro, TN (KBNA), launched 12:00Z, 11.6 hours before the alert went out and 242 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: 1219 J/kg
Mixed-layer CIN: -36 J/kg
Mixed-layer LCL: 635 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 219 m²/s²
0-3 km storm-relative helicity: 195 m²/s²
Significant tornado parameter: 1.1
Supercell composite: 8.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
WUUS54 KMRX 212338
SVRMRX

TNC009-093-220030-
/NEW.KMRX.SV.W.0072.212337-220030/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MORRISTOWN TN
737 PM EDT MON MAY 21 2001

THE NATIONAL WEATHER SERVICE IN MORRISTOWN HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  BLOUNT COUNTY IN EAST TENNESSEE
  KNOX COUNTY IN EAST TENNESSEE

* UNTIL 830 PM EDT

* AT 735 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM NEAR FRIENDSVILLE...OR 9 MILES SOUTHEAST OF
  LENOIR CITY...MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  MARYVILLE AROUND 755 PM EDT
  ALCOA AROUND 800 PM EDT
  EAGLETON VILLAGE AROUND 805 PM EDT
  BEARDEN AROUND 815 PM EDT
  KNOXVILLE AROUND 825 PM EDT

AT 725 PM EDT LOCAL LAW ENFORCEMENT REPORTED DIME SIZE HAIL AND 
TREES DOWN IN SWEETWATER IN MONROE COUNTY.

THE SEVERE THUNDERSTORM IS CAPABLE OF PRODUCING...
  WINDS UP TO 60 MPH...WHICH COULD PUSH OVER SHALLOW ROOTED TREES AND
  BREAK LIMBS OFF OF TREES ABOUT THE SIZE OF YOUR WRIST.
  HAIL UP TO 1 INCH IN DIAMETER...OR THE SIZE OF QUARTERS.
  FREQUENT AND DEADLY CLOUD-TO-GROUND LIGHTNING.

$$

LAT...LON 3588 8414 3559 8414 3573 8376 3611 8401

The office that day

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

Issued	Product	Office	Counties	Lasted
May 21, 5:42 PM EDT	Severe Thunderstorm Warning	MRX	Claiborne, Union	48 min
May 21, 7:08 PM EDT	Severe Thunderstorm Warning	MRX	McMinn, Meigs	37 min
May 21, 7:11 PM EDT	Severe Thunderstorm Warning	MRX	Monroe	49 min
May 21, 7:23 PM EDT	Severe Thunderstorm Warning	MRX	Loudon	37 min
May 21, 7:25 PM EDT	Severe Thunderstorm Warning	MRX	Hancock	50 min
May 21, 7:42 PM EDT	Severe Thunderstorm Warning	MRX	Sullivan	48 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2001 Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.