Alert archive / Tennessee / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 99, NWS Morristown, TN

July 5, 2020Claiborne County, Tennessee

NWS Morristown, TN issued this severe thunderstorm warning at Jul 5, 2020, 1:28 PM EDT for Claiborne County, Tennessee. It was in force for 47 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 5, 2020, 1:28 PM EDT (17:28 UTC)
Expired
Jul 5, 2020, 2:15 PM EDT
In force
47 min
Issued by
NWS Morristown, TN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Claiborne County, TN

The radar

The Knoxville radar (KMRX), 42 km from the middle of the area, began a volume at 17:27 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, 5.5 hours before the alert went out and 266 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 2020-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 797 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 2020-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 31 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
797 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
1278 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
31 m²/s²
0-3 km storm-relative helicity
37 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 5, 1:13 PM EDT, 15 minutes earlier.

Area forecast discussion, Jul 5, 1:13 PM EDT, 15 minutes before
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
113 PM EDT Sun Jul 5 2020

.UPDATE...
FOR 18Z AVIATION.

&&

.DISCUSSION...

The forecast is still largely on track with only minor edits made.
Over the past 2 hours, observed temperatures have been running
higher than previously forecasted. Hourly temperatures were
raised for the next few hours with interpolation to afternoon
temperatures from the previous forecast. Overall high
temperatures were kept the same as current and future sky cover
trends look to moderate the rate of temperature increase this
afternoon. Although values remained largely the same, dew points
were also updated with the latest, best performing model guidance.
Sky cover was also increased to more than 50% from the central
Cumberland Plateau into the Central Valley per latest satellite
imagery. Diurnal cumulus development is still anticipated area-
wide this afternoon, so the overall sky cover forecast was kept
the same. Since specific areas of enhanced cumuliform development
have yet to take place across the area, chance PoPs were kept the
same into the afternoon to account for areal uncertainty of
convective initiation/progression.

BW

&&

.AVIATION...
18Z TAF DISCUSSION.

The current expectation is for a seasonally eventful TAF period
with VCTS this afternoon into the early evening, along with
reductions to MVFR and potentially IFR tonight. Currently,
convection has initiated near and along higher terrain in east
Tennessee and southwest Virginia with VCTS already being reported
at TRI. The expectation is for further development by 19Z this
afternoon with diurnal diminishing during the evening. With
limited synoptic-scale features, winds largely remain light and
variable into tonight. Based on occurrences from this morning, a
similar meteorological environment, and more widespread
convection expected today, patchy fog is anticipated with
reduction to at least MVFR included in all 3 TAFs. Reduction to
IFR was included at TRI based on stronger model guidance
indication for calm winds and proximity with Boone Lake. The 11Z
to 13Z timeframe is the most likely window for fog development at
the sites, but future trends could indicate earlier development
and possibly longer presence of fog. However, confidence is still
not too high for extent and duration of impact. By midday
tomorrow, diurnal cumulus development is expected ahead of more
anticipated convection just after the TAF period.

BW

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             71  90  71  86  71 /  20  30  30  80  30
Knoxville McGhee Tyson Airport, TN  71  91  70  88  71 /  20  30  20  60  30
Oak Ridge, TN                       71  92  70  88  71 /  20  30  20  60  20
Tri Cities Airport, TN              68  90  67  88  67 /  20  40  10  50  20

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
Hazardous weather outlook, Jul 5, 3:05 AM EDT, 10 hours 23 minutes before
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In the hours before

Special weather statement, Jul 5, 12:35 PM EDT, 53 minutes before
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Special weather statement, Jul 5, 1:02 PM EDT, 26 minutes before
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Special weather statement, Jul 5, 1:16 PM EDT, 12 minutes before
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Special weather statement, Jul 5, 1:25 PM EDT, 3 minutes before
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The office that day

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

IssuedProductOfficeCountiesLasted
Jul 5, 12:35 PM EDTSpecial Weather StatementMRXCampbell25 min
Jul 5, 1:16 PM EDTSpecial Weather StatementMRXClaiborne29 min
Jul 5, 1:25 PM EDTSpecial Weather StatementMRXCampbell50 min
Jul 5, 1:41 PM EDTSpecial Weather StatementMRXCampbell34 min
Jul 5, 1:43 PM EDTSpecial Weather StatementMRXGrainger32 min
Jul 5, 1:51 PM EDTSpecial Weather StatementMRXSevier39 min
Jul 5, 2:04 PM EDTSpecial Weather StatementMRXJohnson41 min
Jul 5, 2:11 PM EDTSpecial Weather StatementMRXHamblen34 min
Jul 5, 2:12 PM EDTSpecial Weather StatementMRXUnicoi33 min
Jul 5, 2:14 PM EDTSpecial Weather StatementMRXGrainger31 min
Jul 5, 2:17 PM EDTSpecial Weather StatementMRXCampbell43 min
Jul 5, 2:20 PM EDTSpecial Weather StatementMRXClaiborne40 min
Jul 5, 2:24 PM EDTSpecial Weather StatementMRXScott51 min
Jul 5, 2:34 PM EDTAreal Flood AdvisoryMRXJohnson116 min
Jul 5, 2:59 PM EDTSpecial Weather StatementMRXScott46 min
Jul 5, 3:04 PM EDTSpecial Weather StatementMRXCarter26 min
Jul 5, 3:09 PM EDTSpecial Weather StatementMRXBlount36 min
Jul 5, 3:15 PM EDTSpecial Weather StatementMRXBlount45 min
Jul 5, 3:31 PM EDTSpecial Weather StatementMRXHawkins44 min
Jul 5, 3:51 PM EDTSpecial Weather StatementMRXBradley39 min
Jul 5, 3:54 PM EDTSpecial Weather StatementMRXLoudon51 min
Jul 5, 4:06 PM EDTSpecial Weather StatementMRXSullivan, Washington39 min
Jul 5, 4:07 PM EDTSpecial Weather StatementMRXSullivan53 min
Jul 5, 4:10 PM EDTSevere Thunderstorm WarningMRXSullivan, Washington50 min
Jul 5, 4:12 PM EDTSpecial Weather StatementMRXRoane48 min
Jul 5, 4:15 PM EDTSevere Thunderstorm WarningMRXJefferson, Knox, Sevier45 min
Jul 5, 4:20 PM EDTSpecial Weather StatementMRXLoudon, Roane40 min
Jul 5, 4:37 PM EDTSevere Thunderstorm WarningMRXGreene, Sullivan, Washington38 min
Jul 5, 4:42 PM EDTSevere Thunderstorm WarningMRXAnderson, Loudon, Roane48 min
Jul 5, 4:46 PM EDTSevere Thunderstorm WarningMRXHawkins, Sullivan44 min
Jul 5, 5:02 PM EDTSpecial Weather StatementMRXMcMinn43 min
Jul 5, 5:10 PM EDTSevere Thunderstorm WarningMRXMcMinn, Meigs50 min
Jul 5, 5:17 PM EDTSpecial Weather StatementMRXBledsoe43 min
Jul 5, 5:51 PM EDTSevere Thunderstorm WarningMRXBledsoe, Hamilton, Meigs, Rhea24 min
Jul 5, 6:10 PM EDTSpecial Weather StatementMRXBradley50 min
Jul 5, 6:44 PM EDTSpecial Weather StatementMRXHamilton46 min
Jul 5, 7:08 PM EDTSpecial Weather StatementMRXBradley, Hamilton52 min
Jul 5, 1:02 PM EDTSpecial Weather StatementMRXSmyth28 min
Jul 5, 1:38 PM EDTSpecial Weather StatementMRXWise, City of Norton52 min
Jul 5, 2:30 PM EDTSpecial Weather StatementMRXWise30 min
Jul 5, 5:07 PM EDTSevere Thunderstorm WarningMRXRussell, Scott38 min
Jul 5, 5:44 PM EDTSevere Thunderstorm WarningMRXRussell, Scott, Wise46 min
Jul 5, 5:58 PM EDTSpecial Weather StatementMRXRussell47 min
Jul 5, 6:13 PM EDTSevere Thunderstorm WarningMRXRussell33 min
Jul 5, 3:10 PM EDTSpecial Weather StatementMRXGraham35 min

Nearby

Severe Thunderstorm Warnings in Tennessee, 2020Every severe thunderstorm warning in 2020

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.