Alert archive / Tennessee / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 158, NWS Morristown, TN

July 20, 2015Blount County, Loudon County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Jul 20, 2015, 5:26 PM EDT for Blount County, Loudon County, Tennessee. It was in force for 49 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 20, 2015, 5:26 PM EDT (21:26 UTC)
Expired
Jul 20, 2015, 6:15 PM EDT
In force
49 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 21:30 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, 9.4 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-pSkew-T log-p diagram, Nashville Metro, TN at 12:00Z on 2015-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1312 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Nashville Metro, TN at 12:00Z on 2015-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1312 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
1151 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
-58 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 Jul 20, 3:44 PM EDT, 1 hour 42 minutes earlier.

Area forecast discussion, Jul 20, 3:44 PM EDT, 1 hour 42 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
344 PM EDT MON JUL 20 2015

.SHORT TERM (TONIGHT AND TOMORROW)...SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO DEVELOP AND MOVE THROUGH THE AREA THROUGH THE AFTERNOON
AND EVENING. SHEAR IS WEAK....BUT PLENTY OF DRY AIR IN THE MID
LEVELS AND PW VALUES ARE HIGH. SO MAIN THREATS WITH THIS STORM ARE
DAMAGING WINDS...FROM DOWNBURSTS...AND HEAVY RAINFALL. AS THE
EVENING PROGRESSES...MORE MOISTURE WILL ARRIVE IN THE MID AND UPPER
LEVELS...INCREASING THE PW VALUES AND THE MAIN THREAT WILL BE HEAVY
RAINFALL AND STRONG WINDS. MODELS DIFFER ON ANY SHOWERS OR STORMS
WILL MAKING IT THROUGH THE MORNING HOURS ON TUESDAY...SO HAVE ONLY
INCLUDED CHANCE FOR TOMORROW MORNING. TUESDAY EVENING...A FRONTAL
BOUNDARY MOVES THROUGH THE AREA...WITH SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOPING AGAIN IN THE AFTERNOON. WINDS WILL BE
STRONGER THROUGH THE PROFILE ON TUESDAY AFTENROON...WITH DRY AIR
AGAIN IN THE MID AND UPPER LEVELS. MAIN THREATS WILL BE DAMAGING
WIND AND HAIL. TUESDAY...HEAT INDICES WILL AGAIN BE IN THE MID TO
UPPER 90S...TOPPING OUT IN THE TRIPLE DIGITS FOR SOUTHERN PLATEAU
AND SOUTHERN VALLEY.

.LONG TERM (TUESDAY NIGHT THROUGH MONDAY)...AT THE BEGINNING OF THIS
PERIOD...WE ARE IN A WESTERLY FLOW WITH THE UPPER TROUGH IN EASTERN
CANADA AND THE UPPER RIDGE OVER THE GULF COAST.  THROUGH THE FOLLOW
SEVERAL DAYS THIS PATTERN SHIFTS CLOCKWISE SLOWLY AS THE PATTERN
AMPLIFIES...AND THE TROUGH MOVES EAST INTO THE NW ATLANTIC AND THE
RIDGE INTENSIFIES OVER THE HIGH PLAINS...RESULTING IN A NWLY AND
EVEN NLY FLOW OVER OUR AREA.

WEAK FRONTAL BOUNDARY SAGS INTO THE AREA...AND DEEP MOISTURE IS SLOW
TO FADE SO KEEPING POPS OVER MOST OF THE AREA EARLY IN THIS
PERIOD. BY FRIDAY AND THROUGH SATURDAY THE AIR MASS DRIES OUT
SOMEWHAT AND CUT POPS OVER MUCH OF THE AREA. THEN BY SUNDAY...JUICY
GULF MOISTURE SHOULD BE SPREADING BACK INTO THE AREA...AND STORMS
CHANCES WILL INCREASE AGAIN. HOWEVER...THIS IN CONCERT WITH THE
RIDGE OVER THE PLAINS SWELLING TO THE EAST...SO IT SHOULD BE
DIRUNAL IN NATURE. MONDAY LOOKS DRIER AS RIDGE SWELLS EVEN MORE.
WENT A COUPLE OF DEGREES WARMER THAN GUIDANCE ON MONDAY AS
INFLUENCE FROM RIDGE SEEMS UNDERDONE.

&&

.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN             74  93  74  89 /  40  50  30  30
KNOXVILLE MCGHEE TYSON AIRPORT, TN  72  89  71  85 /  50  60  20  30
OAK RIDGE, TN                       73  89  72  86 /  50  60  20  30
TRI CITIES AIRPORT, TN              69  88  68  83 /  50  60  30  20

&&

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

JW/GM
Hazardous weather outlook, Jul 20, 3:46 PM EDT, 1 hour 40 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MORRISTOWN TN
346 PM EDT MON JUL 20 2015

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-212000-
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-
346 PM EDT MON JUL 20 2015 /246 PM CDT MON JUL 20 2015/

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST NORTH
CAROLINA...EAST TENNESSEE AND SOUTHWEST VIRGINIA.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

SCATTERED SHOWERS AND THUNDERSTORMS CAN BE EXPECTED. A FEW OF
THESE STORMS MAY BECOME STRONG TO SEVERE...WITH DAMAGING WINDS AND
LOCALIZED FLOODING RAIN THE MAIN THREATS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY...

...SEVERE THUNDERSTORMS ARE POSSIBLE TUESDAY AFTERNOON AND
EVENING...

A FRONTAL BOUNDARY WILL MOVE TOWARD THE AREA TUESDAY. THE AIR-
MASS AHEAD OF THE FRONT WILL BE VERY MOIST AND UNSTABLE PRODUCING
SCATTERED TO WIDESPREAD THUNDERSTORMS...ESPECIALLY DURING THE
AFTERNOON AND EVENING HOURS. SOME OF THESE STORMS COULD BECOME
SEVERE WITH THE MAIN CONCERN BEING DAMAGING DOWNBURST WINDS AND
TORRENTIAL RAINS WHICH MAY PRODUCE LOCALIZED FLASH FLOODING.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY AND TUESDAY MAINLY DURING
THE AFTERNOON AND EVENING HOURS.

In the hours before

Special weather statement, Jul 20, 4:26 PM EDT, 1 hour 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>
Special weather statement, Jul 20, 4:40 PM EDT, 46 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
440 PM EDT MON JUL 20 2015

TNZ071-073-202130-
NORTH SEVIER TN-NW BLOUNT TN-
440 PM EDT MON JUL 20 2015

SIGNIFICANT WEATHER ADVISORY FOR NORTH SEVIER...AND NW BLOUNT
COUNTIES UNTIL 530 PM EDT...

AT 440 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
ROCKFORD...OR 9 MILES NORTHEAST OF ALCOA...MOVING EAST AT 25 MPH.

WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH THIS STORM.

LOCATIONS IMPACTED INCLUDE...
SEVIERVILLE...ALCOA...PIGEON FORGE...ROCKFORD...EAGLETON VILLAGE...
WILDWOOD...SEYMOUR...MCMAHAN...HARRISBURG...KODAK...WEARS VALLEY AND
BIRD CROSSING.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3571 8370 3574 8372 3579 8395 3587 8393
      3585 8391 3584 8385 3591 8376 3594 8368
      3595 8369 3597 8365 3603 8368 3604 8365
      3593 8349 3593 8340 3591 8339 3592 8335
      3591 8332 3587 8331 3583 8327 3569 8365
TIME...MOT...LOC 2040Z 280DEG 21KT 3587 8384

TG
Special weather statement, Jul 20, 4:53 PM EDT, 33 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
453 PM EDT MON JUL 20 2015

TNZ015-016-038-039-070-202145-
HAWKINS TN-JEFFERSON TN-HAMBLEN TN-GRAINGER TN-HANCOCK TN-
453 PM EDT MON JUL 20 2015

SIGNIFICANT WEATHER ADVISORY FOR HAWKINS...JEFFERSON...HAMBLEN...
GRAINGER...AND HANCOCK COUNTIES UNTIL 545 PM EDT...

AT 452 PM EDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 7 MILES NORTHWEST OF BEAN
STATION TO 7 MILES NORTHWEST OF MORRISTOWN TO NEAR NEW MARKET...AND
MOVING SOUTHEAST AT 15 TO 20 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
MORRISTOWN...JEFFERSON CITY...ROGERSVILLE...DANDRIDGE...RUTLEDGE...
BEAN STATION...WHITE PINE...NEW MARKET...BANEBERRY...RUSSELLVILLE...
STRAWBERRY PLAINS...BLAINE...BULLS GAP...LOWLAND...BUFFALO SPRINGS...
BIRD CROSSING...KLONDIKE...ALPHA...PIEDMONT AND JOPPA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3641 8298 3628 8301 3617 8319 3613 8318
      3615 8322 3613 8324 3608 8323 3609 8324
      3590 8330 3593 8349 3606 8369 3609 8371
      3609 8367 3616 8373 3633 8368 3637 8345
      3640 8346 3643 8337 3652 8338
TIME...MOT...LOC 2052Z 300DEG 13KT 3644 8336 3628 8339 3616 8359

TG
Special weather statement, Jul 20, 4:59 PM EDT, 27 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
459 PM EDT MON JUL 20 2015

TNZ099-100-202145-
BRADLEY TN-HAMILTON TN-
459 PM EDT MON JUL 20 2015

SIGNIFICANT WEATHER ADVISORY FOR BRADLEY...AND HAMILTON COUNTIES
UNTIL 545 PM EDT...

AT 458 PM EDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR
SODDY-DAISY...OR 13 MILES NORTHWEST OF CLEVELAND...MOVING EAST AT 20
MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.

LOCATIONS IMPACTED INCLUDE...
CHATTANOOGA...CLEVELAND...SODDY-DAISY...SIGNAL MOUNTAIN...WALDEN...
LAKESITE...CHARLESTON...RIDGESIDE...HARRISON...EAST CLEVELAND...
WILDWOOD LAKE...FAIRMOUNT...SOUTH CLEVELAND...RED BANK...
COLLEGEDALE...CALHOUN...OOLTEWAH...FLINT SPRINGS...TASSO AND EAST
BRAINERD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THIS STORM.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3498 8548 3507 8536 3511 8539 3515 8539
      3545 8517 3546 8511 3543 8510 3542 8503
      3538 8503 3536 8497 3529 8495 3536 8487
      3530 8474 3529 8472 3528 8475 3525 8473
      3525 8470 3524 8471 3517 8470 3499 8478
TIME...MOT...LOC 2058Z 289DEG 18KT 3528 8507

TG
Special weather statement, Jul 20, 5:07 PM EDT, 19 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
507 PM EDT MON JUL 20 2015

TNZ067>069-071-072-086-202200-
ROANE TN-KNOX TN-BLOUNT SMOKY MOUNTAINS TN-NW BLOUNT TN-LOUDON TN-
NORTHWEST MONROE TN-
507 PM EDT MON JUL 20 2015

SIGNIFICANT WEATHER ADVISORY FOR ROANE...KNOX...BLOUNT SMOKY
MOUNTAINS...NW BLOUNT...LOUDON...AND NORTHWEST MONROE COUNTIES UNTIL
600 PM EDT...

AT 506 PM EDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM NEAR FARRAGUT TO 8 MILES
NORTHWEST OF SWEETWATER...AND MOVING EAST AT 25 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
KNOXVILLE...OAK RIDGE...MARYVILLE...LENOIR CITY...ALCOA...
SWEETWATER...LOUDON...MADISONVILLE...FARRAGUT...LOUISVILLE...
ROCKFORD...EAGLETON VILLAGE...VONORE...GREENBACK...FRIENDSVILLE...
PHILADELPHIA...WALLAND...CITICO BEACH...HAPPY VALLEY AND CLOVER HILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3544 8414 3562 8454 3562 8452 3564 8454
      3563 8458 3566 8463 3570 8462 3592 8428
      3592 8426 3593 8426 3593 8424 3595 8424
      3594 8422 3599 8418 3600 8411 3592 8375
      3589 8379 3572 8371 3554 8399 3556 8400
TIME...MOT...LOC 2106Z 291DEG 25KT 3595 8417 3571 8454

TG
Special weather statement, Jul 20, 5:13 PM EDT, 13 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MORRISTOWN TN
513 PM EDT MON JUL 20 2015

VAZ001-002-005-202200-
SCOTT VA-LEE VA-WISE VA-
513 PM EDT MON JUL 20 2015

SIGNIFICANT WEATHER ADVISORY FOR SCOTT...LEE...AND WISE COUNTIES
UNTIL 600 PM EDT...

AT 512 PM EDT...DOPPLER RADAR WAS TRACKING A LINE OF STRONG
THUNDERSTORMS ALONG A LINE EXTENDING FROM 23 MILES NORTHWEST OF WISE
TO 6 MILES EAST OF SNEEDVILLE...AND MOVING EAST AT 25 MPH.

HALF INCH HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THESE STORMS.

LOCATIONS IMPACTED INCLUDE...
NORTON...WISE...JONESVILLE...BIG STONE GAP...PENNINGTON GAP...
APPALACHIA...POUND...ST. CHARLES...DUFFIELD...CLINCHPORT...DRYDEN...
PATTONSVILLE...PARDEE AND JASPER.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THESE STORMS...AND MAY
LEAD TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

FREQUENT CLOUD TO GROUND LIGHTNING IS OCCURRING WITH THESE STORMS.
LIGHTNING CAN STRIKE 15 MILES AWAY FROM A THUNDERSTORM. SEEK A SAFE
SHELTER INSIDE A BUILDING OR VEHICLE.

&&

LAT...LON 3713 8255 3707 8252 3660 8264 3659 8314
      3685 8307 3685 8301 3689 8288 3693 8286
      3698 8287 3705 8272 3712 8272 3720 8255
TIME...MOT...LOC 2112Z 247DEG 23KT 3723 8288 3655 8310

TG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 3:14 PM EDTSpecial Weather StatementMRXAnderson, Roane46 min
Jul 20, 3:31 PM EDTSpecial Weather StatementMRXMorgan44 min
Jul 20, 4:26 PM EDTSpecial Weather StatementMRXMcMinn49 min
Jul 20, 4:40 PM EDTSpecial Weather StatementMRXSevier50 min
Jul 20, 4:53 PM EDTSpecial Weather StatementMRXGrainger, Hamblen, Jefferson52 min
Jul 20, 4:59 PM EDTSpecial Weather StatementMRXBradley, Hamilton46 min
Jul 20, 5:07 PM EDTSpecial Weather StatementMRXBlount, Loudon53 min
Jul 20, 5:36 PM EDTSpecial Weather StatementMRXCocke, Greene, Hawkins54 min
Jul 20, 5:43 PM EDTSpecial Weather StatementMRXPolk62 min
Jul 20, 4:21 PM EDTSpecial Weather StatementMRXLee39 min
Jul 20, 5:13 PM EDTSpecial Weather StatementMRXScott, Wise, City of Norton47 min
Jul 20, 6:04 PM EDTSpecial Weather StatementMRXWise, City of Norton41 min
Jul 20, 6:51 PM EDTAreal Flood AdvisoryMRXRussell, Wise, City of Norton114 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2015Every severe thunderstorm warning in 2015

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.