A 500 MB low pressure trough over the center of the nation brought southwesterly flow to east Tennessee. This ushered a warm frontal boundary well to the north of the area, resulting in a warm and humid airmass.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS MRX wrote it up.
A 500 MB low pressure trough over the center of the nation brought southwesterly flow to east Tennessee. This ushered a warm frontal boundary well to the north of the area, resulting in a warm and humid airmass.
The local office's own words before the first event, 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 the first event at Jul 10, 2:01 PM EST, 3 hours 25 minutes earlier.
AREA FORECAST DISCUSSION National Weather Service Morristown TN 301 PM EDT Sat Jul 10 2021 .SHORT TERM...(Tonight and Sunday)... -Warm and humid with scattered showers and thunderstorms with greatest coverage in the afternoon hours -Isolated damaging winds possible with any stronger storms along with heavy rainfall/isolated flash flooding We remain in a relatively stagnant pattern between an upper low sinking southward over the Mississippi Valley and a building upper ridge to our east. We will continue to be in a rather warm and moist air mass for the short term period. Scattered showers and thunderstorms this afternoon will wane overnight with the loss of heating, before coverage ramps up again on Sunday. The greatest coverage will be during peak heating again on Sunday. Some of the storms may become strong-to-severe this afternoon and again Sunday, with isolated damaging winds and heavy rainfall the main threats. Any area that sees repeated or prolonged heavy rainfall will be at risk for localized flooding. These threats will be highlighted in the HWO. LW .LONG TERM...(Sunday night through Saturday)... Key Messages: 1) Warm and humid with scattered showers and thunderstorms Monday and Tuesday. 2) Lesser chances of showers and thunderstorms late week and through the weekend with increasing temperatures. Discussion... The extended generally remains unchanged from previous forecasts with continued chances of showers and thunderstorms through mid week before chances decrease late week and into the weekend. Sunday night through much of Tuesday, the mid to upper pattern will remain amplified with longwave troughing across much of the central plains and midwest while ridging dominates the western Atlantic. The resulting southerly low level flow will continue to advect moisture poleward with PW values into the 1.5" to 2.0" range. High levels of moisture along with tall skinny cape profiles suggest heavy rain potential and given weak deep layer shear, low chances of organized convection. Well defined forcing will be difficult to come by and as the previous discussions mentioned, the driving force for convection will be from outflow boundaries. The forecast will continue to favor likely PoPs in the afternoon hours with decreasing chances during the overnight periods. Temperatures will remain near average. By midweek, mid to upper flow weakens with slight height rises as the 850 mb ridge axis extends eastward into the southeast. Weaker forcing will limit coverage of showers and thunderstorms and the forecast will reflect this with lower chances of precipitation into the weekend. Temperatures will be a bit warmer during this time period as well as 850mb temps increase. NBM continues to project high temperatures well into the upper 80s to low 90s Thursday through Saturday. Diegan && .AVIATION... 18Z TAF DISCUSSION. There will be scattered showers/storms around at times, mainly this afternoon and again by mid/late morning Sunday. Will try to time the periods of greatest thunder threat with VCTS and tempo groups. The other concern is possible low clouds/fog development again late tonight early Sunday. While confidence is not high, the greatest chance for this to occur looks to be at TYS and TRI. Will include conditions no lower than MVFR, but lower conditions cannot be ruled out at least briefly. Outside of any convection and early morning fog/low cigs, VFR conditions are expected. LW && .PRELIMINARY POINT TEMPS/POPS... Chattanooga Airport, TN 71 87 71 84 69 / 30 60 60 80 60 Knoxville McGhee Tyson Airport, TN 70 88 71 87 69 / 20 60 40 70 50 Oak Ridge, TN 71 85 70 85 68 / 30 60 50 80 50 Tri Cities Airport, TN 67 88 68 88 67 / 40 60 30 60 20 && .MRX WATCHES/WARNINGS/ADVISORIES... NC...NONE. TN...NONE. VA...NONE. &&
Hazardous Weather Outlook National Weather Service Morristown TN 250 PM EDT Sat Jul 10 2021 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-111900- 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- 250 PM EDT Sat Jul 10 2021 /150 PM CDT Sat Jul 10 2021/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...This Afternoon and Tonight An isolated strong-to-severe storm is possible this afternoon along with the possibility of isolated flash flooding. .DAYS TWO THROUGH SEVEN...Sunday through Friday A few isolated strong to severe storms will be possible Sunday, with strong winds the primary threat. In addition, showers and thunderstorms Sunday, Monday, and Tuesday will have the potential to produce heavy rainfall, which may cause localized flooding. .SPOTTER INFORMATION STATEMENT... Spotter activation is not needed at this time.
Special Weather Statement
National Weather Service Morristown TN
104 PM EDT Sat Jul 10 2021
TNZ072-087-101730-
Blount Smoky Mountains TN-Southeast Monroe TN-
104 PM EDT Sat Jul 10 2021
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN BLOUNT AND EAST
CENTRAL MONROE COUNTIES UNTIL 130 PM EDT...
At 103 PM EDT, Doppler radar was tracking a strong thunderstorm near
Smoky Mountains-Twentymile Creek, or 13 miles northwest of
Robbinsville, moving east at 20 mph.
Half inch hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Smoky Mountains-Twentymile Creek, Smoky Mountains-Fontana Area and
Deals Gap.
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.
&&
LAT...LON 3543 8409 3549 8408 3551 8405 3557 8399
3558 8374 3556 8374 3556 8377 3552 8383
3552 8388 3547 8392 3547 8394 3545 8397
3541 8402
TIME...MOT...LOC 1703Z 273DEG 18KT 3548 8396
BWSpecial Weather Statement National Weather Service Morristown TN 113 PM EDT Sat Jul 10 2021 TNZ012-013-101745- Scott TN-Campbell TN- 113 PM EDT Sat Jul 10 2021 ...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CAMPBELL AND NORTHEASTERN SCOTT COUNTIES UNTIL 145 PM EDT... At 113 PM EDT, Doppler radar was tracking a strong thunderstorm 9 miles east of Huntsville, or 10 miles southeast of Oneida, moving east at 20 mph. Half inch hail and winds in excess of 40 mph will be possible with this storm. Locations impacted include... La Follette, Jacksboro, Huntsville, Jellico, Caryville, Winfield, Elk Valley and Royal Blue. 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. && LAT...LON 3639 8446 3653 8446 3657 8413 3633 8414 TIME...MOT...LOC 1713Z 273DEG 18KT 3644 8434 BW
Special Weather Statement
National Weather Service Morristown TN
142 PM EDT Sat Jul 10 2021
TNZ013-101815-
Campbell TN-
142 PM EDT Sat Jul 10 2021
...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN CAMPBELL COUNTY UNTIL
215 PM EDT...
At 142 PM EDT, Doppler radar was tracking a strong thunderstorm near
Lot, or 10 miles north of La Follette, moving east at 20 mph.
Winds in excess of 40 mph will be possible with this storm.
Locations impacted include...
Jellico, White Oak, Elk Valley, Indian Mountain State Park and
Fincastle.
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.
&&
LAT...LON 3659 8399 3654 8398 3650 8395 3641 8397
3644 8434 3645 8435 3650 8433 3651 8433
3650 8428 3651 8426 3653 8426 3653 8425
3659 8426
TIME...MOT...LOC 1742Z 269DEG 17KT 3653 8412
BWSpecial Weather Statement
National Weather Service Morristown TN
317 PM EDT Sat Jul 10 2021
TNZ014-015-VAZ001-102000-
Claiborne TN-Hancock TN-Lee VA-
317 PM EDT Sat Jul 10 2021
...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN CLAIBORNE...HANCOCK
AND SOUTH CENTRAL LEE COUNTIES UNTIL 400 PM EDT...
At 317 PM EDT, Doppler radar was tracking a strong thunderstorm 9
miles northeast of Tazewell, or 11 miles west of Sneedville, moving
east at 25 mph.
Pea size hail and winds in excess of 40 mph will be possible with
this storm.
Locations impacted include...
Sneedville, Jonesville, Howard Quarter, Ewing and Evanston.
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.
&&
LAT...LON 3653 8308 3652 8311 3650 8313 3648 8316
3646 8316 3645 8319 3645 8349 3662 8354
3672 8313
TIME...MOT...LOC 1917Z 264DEG 21KT 3653 8342
BWSpecial Weather Statement
National Weather Service Morristown TN
357 PM EDT Sat Jul 10 2021
TNZ015-016-VAZ005-102045-
Hancock TN-Hawkins TN-Scott VA-
357 PM EDT Sat Jul 10 2021
...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN HAWKINS...EASTERN
HANCOCK AND SOUTHWESTERN SCOTT COUNTIES UNTIL 445 PM EDT...
At 356 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Sneedville, moving east at 35 mph.
Wind gusts up to 50 mph will be possible with this storm.
Locations impacted include...
Rogersville, Sneedville, Surgoinsville, Church Hill, Clinchport,
Okolona, Kyles Ford, Treadway, Klondike and Kepler.
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.
&&
LAT...LON 3642 8269 3640 8273 3640 8323 3657 8324
3660 8315 3659 8299 3665 8296 3672 8272
TIME...MOT...LOC 1956Z 257DEG 29KT 3651 8308
BWSpecial Weather Statement National Weather Service Morristown TN 516 PM EDT Sat Jul 10 2021 TNZ035-036-067-069-102200- Anderson TN-Roane TN-Knox TN-Morgan TN- 516 PM EDT Sat Jul 10 2021 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN MORGAN... SOUTHWESTERN KNOX...CENTRAL ANDERSON AND NORTHEASTERN ROANE COUNTIES UNTIL 600 PM EDT... At 515 PM EDT, Doppler radar was tracking a strong thunderstorm near Oliver Springs, or 7 miles northwest of Oak Ridge, moving east at 15 mph. Half inch hail and wind gusts up to 50 mph will be possible with this storm. Locations impacted include... Knoxville, Oak Ridge, Clinton, Farragut, Oliver Springs, Coalfield, Petros, Karns and Frozen Head State Park. 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. This storm may intensify, so be certain to monitor local radio stations and available television stations for additional information and possible warnings from the National Weather Service. && LAT...LON 3599 8450 3615 8448 3615 8406 3588 8410 TIME...MOT...LOC 2115Z 276DEG 12KT 3605 8439 Moulton
The Knoxville radar (KMRX), 94 km away, was scanning. The volume nearest the first event began at 22:27 UTC.
1 flash flood. Local standard time, as filed.
The Middle Fork Little Emory River was out of its banks and flooding nearby properties in the Stephens and Corbin Hill communities of Morgan County along HWY 62.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Tennessee in 2021Every state in 2021This day in weather historyWarnings in Tennessee, July 2021
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 976373.