Alert archive / North Carolina / Flash Flood Warnings in 2022

Flash Flood Warning 15, NWS Morristown, TN

July 20, 2022Cherokee County, Clay County, North Carolina

NWS Morristown, TN issued this flash flood warning at Jul 20, 2022, 11:54 PM EDT for Cherokee County, Clay County, North Carolina. It was in force for 5 hr. 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, 2022, 11:54 PM EDT (03:54 UTC)
Expired
Jul 21, 2022, 4:28 AM EDT
In force
5 hr
Issued by
NWS Morristown, TN
Area
Storm-based polygon
Flood severity
None

Counties Cherokee County, NC, Clay County, NC

The radar

The Knoxville radar (KMRX), 128 km from the middle of the area, began a volume at 03:54 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

Peachtre/Fal Fld, GA (KFFC), launched 00:00Z, 3.9 hours before the alert went out and 199 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, Peachtre/Fal Fld, GA at 00:00Z on 2022-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1912 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, Peachtre/Fal Fld, GA at 00:00Z on 2022-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -2 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
1912 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
1424 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-2 m²/s²
0-3 km storm-relative helicity
110 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this flash flood 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 flash flood warning went out at Jul 20, 9:54 PM EDT, 2 hours earlier.

Area forecast discussion, Jul 20, 9:54 PM EDT, 2 hours before
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
954 PM EDT Wed Jul 20 2022

.UPDATE...
EVENING UPDATE.

&&

.DISCUSSION...

Showers and thunderstorms are ongoing in central Kentucky ahead of
a weak front located near the Ohio River. These storms continue to
intensify as the environment consists of >3,000 J/kg of MLCAPE and
fairly weak overall shear. Based on the latest high-res model
guidance, a developing complex is forecast to move into the
region around midnight into the early morning hours. This will
continue the concern for damaging winds, in addition to localized
flooding, following heavy rainfall that occurred earlier. As
such, PoPs were updated to encompass these trends with a focus on
northern areas for the highest values. Also, dew points were
increased slightly to reflect the higher values that continued
into this evening. Otherwise, the forecast remains on track with
only minor adjustments made.

BW

&&

.AVIATION...
00Z TAF DISCUSSION.

A few pop up storms are anticipated this evening with one ongoing
near CHA. Otherwise, the main story will be the arrival of storms
from the northwest that are currently located near the Ohio River.
These storms will likely impact all of the terminals between 05Z
and 10Z with potential for strong winds and reduction to MVFR or
lower. Then after these storms, MVFR ceilings may linger at TYS
and TRI into the daytime hours with generally southerly to
southwesterly winds continuing. Additional storms are possible
later in the afternoon but will likely be more limited in
coverage.

BW

&&

.PREV DISCUSSION...
/ISSUED 312 PM EDT Wed Jul 20 2022/
SHORT TERM...(Tonight and Tomorrow)...

Key Messages:

1. Showers and thunderstorms are likely around and after midnight
tonight. Damaging wind gusts and heavy rainfall/localized
flooding will be the main threats.

2. Another round of showers and thunderstorms are expected
tomorrow with the best chance in the afternoon.

Discussion:

Multiple rounds of showers and thunderstorms will be possible this
forecast period as the wet pattern continues. In the upper levels,
a trough is moving through the Ohio Valley tonight. The Tennessee
Valley will be in northwesterly flow aloft with the possibility
of a minor shortwave or two moving through the region. Luckily,
with the overnight timing, instability will be low with CAPE
around 1000 J/kg. However, with dew points in the lower 70s if a
minor wave does move through, a few strong to severe storms will
be possible with the main threat of damaging winds. Some high res
ensemble guidance shows a line of storms weakening as it
approaches and moves through the region around or after midnight.
If storms are able to remain organized, high rain rates are
possible with PWat values around 1.8 to 2 inches across the
Valley. The official forecast calls for 1 inch of rain or less
tonight but if strong storms develop locally higher totals will be
likely and may lead to flooding issues in places prone to flooding
or places that have recently received a lot of rain.

Another round of showers and thunderstorms are likely tomorrow
afternoon as a cold front slowly sags southward. The I-75 to I-81
corridor and eastward will have the best chance for showers and
thunderstorms tomorrow afternoon. With high instability expected
tomorrow afternoon, a few strong to severe storms cannot be ruled
out. A wind shift indicating frontal passage is predicted tomorrow
afternoon for the northern and western parts of the region.
Despite the cloud cover, highs will be warm in the upper 80s and
near 90.

McD

LONG TERM...(Thursday night through Wednesday)...

Key Messages:

1. Hot and humid for the weekend and into next week. Heat indices of
100+ in the central/southern valley over the weekend and into next
week.

Discussion:

Some lingering showers and thunderstorms may remain in the mountains
and southern valley Thursday night and into the early morning hours
of Friday in wake of the frontal boundary. By mid morning on Friday
the boundary will be south of our area and mid/upper level ridging
will start to build, which leads us into a hot and humid pattern for
the weekend.

Heat indices will likely be in the triple digits in many places
throughout the central and southern Tennessee valley over the
weekend and into next week. Daily high temperatures are expected to
climb into the 90s, which will be exaggerated by dewpoints in the
mid 60s and 70s. It is advised to practice heat safety during the
afternoon and early evening hours when temperatures are expected to
be at their highest. Most areas are likely going to remain dry this
weekend, but a stray diurnal shower cannot be entirely ruled out.

More active weather is likely next week with shortwave energy and a
possible front drifting towards us from the Ohio Valley. This could
bring more significant chances for rain back into the forecast on
Tuesday and into the middle of next week, but there is still
uncertainty about the timing.

Williams

&&

.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN             75  92  72  94  72 /  30  40  30  10   0
Knoxville McGhee Tyson Airport, TN  73  89  71  93  71 /  70  50  10  10   0
Oak Ridge, TN                       73  90  70  93  70 /  70  40   0   0   0
Tri Cities Airport, TN              70  87  67  91  66 /  60  40   0   0   0

&&

.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
Hazardous weather outlook, Jul 20, 9:46 PM EDT, 2 hours 8 minutes before
Hazardous Weather Outlook
National Weather Service Morristown TN
946 PM EDT Wed Jul 20 2022

NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002-
005-006-008-220200-
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-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-Scott VA-Russell-Washington VA-
946 PM EDT Wed Jul 20 2022 /846 PM CDT Wed Jul 20 2022/

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

.DAY ONE...Tonight

Scattered showers and thunderstorms will continue tonight and into
the early morning hours. A few of these storms may be strong to
severe, with the primary threats being damaging wind gusts and
very heavy rainfall that could cause localized flooding.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Showers and thunderstorms will be possible Thursday along an
incoming frontal boundary. A few of these storms could be strong
to severe with gusty winds, and heavy rainfall being the main
threats, with the highest risk being in southeast Tennessee and
southwest North Carolina.

Over the weekend and into next week, temperatures in the central
and southern Tennessee valley will climb into the mid and upper
90s, with heat index values exceeding 100.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not needed at this time.

In the hours before

Special weather statement, Jul 20, 7:35 PM EDT, 4 hours 19 minutes before
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Special weather statement, Jul 20, 8:10 PM EDT, 3 hours 44 minutes before
Special Weather Statement
National Weather Service Morristown TN
810 PM EDT Wed Jul 20 2022

TNZ100-101-210100-
West Polk TN-Bradley TN-
810 PM EDT Wed Jul 20 2022

...A strong thunderstorm will impact portions of southern Bradley and
southwestern Polk Counties through 900 PM EDT...

At 810 PM EDT, Doppler radar was tracking a strong thunderstorm over
South Cleveland, or near Cleveland, moving east at 20 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Cleveland, Benton, South Cleveland, East Cleveland, Wildwood Lake,
Waterville, Conasauga, Parksville, Tasso and Hopewell.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3508 8497 3521 8493 3521 8460 3499 8464
      3499 8472
TIME...MOT...LOC 0010Z 277DEG 17KT 3512 8489

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

CED
Special weather statement, Jul 20, 8:14 PM EDT, 3 hours 40 minutes before
Special Weather Statement
National Weather Service Morristown TN
814 PM EDT Wed Jul 20 2022

TNZ099-210045-
Hamilton TN-
814 PM EDT Wed Jul 20 2022

...A strong thunderstorm will impact portions of south central
Hamilton County through 845 PM EDT...

At 813 PM EDT, Doppler radar was tracking a strong thunderstorm over
Ridgeside, or over Chattanooga, moving east at 10 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Chattanooga, Rossville, Ridgeside, Red Bank, Lookout Mountain, East
Ridge and Ooltewah.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3512 8531 3509 8510 3499 8514 3498 8537
TIME...MOT...LOC 0013Z 285DEG 7KT 3504 8527

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

CED
Special weather statement, Jul 20, 9:18 PM EDT, 2 hours 36 minutes before
Special Weather Statement
National Weather Service Morristown TN
918 PM EDT Wed Jul 20 2022

TNZ036-069-210145-
Anderson TN-Knox TN-
918 PM EDT Wed Jul 20 2022

...A strong thunderstorm will impact portions of south central
Anderson and central Knox Counties through 945 PM EDT...

At 918 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles south of Clinton, moving east at 20 mph.

HAZARD...Winds in excess of 40 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Knoxville, Oak Ridge, Clinton, Alcoa, Farragut, Halls, Maloneyville,
Lake Forest, Bearden and Powell.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3585 8391 3586 8391 3588 8395 3586 8398
      3588 8400 3588 8401 3587 8403 3587 8401
      3586 8401 3592 8426 3609 8423 3610 8382
      3584 8386
TIME...MOT...LOC 0118Z 276DEG 17KT 3599 8414

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...40 MPH

CED
Local storm report, Jul 20, 10:53 PM EDT, 1 hour 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
1053 PM EDT WED JUL 20 2022

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

1045 PM     FLASH FLOOD      4 SW CLINTON            36.05N 84.19W
07/20/2022                   ANDERSON           TN   911 CALL CENTER

            MULTIPLE BACKROADS AND MAIN HIGHWAYS
            FLOODED, INCLUDING CLINTON HWY AND OAK RIDGE
            HWY.

&&
Local storm report, Jul 20, 11:07 PM EDT, 47 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MORRISTOWN TN
1107 PM EDT WED JUL 20 2022

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

1030 PM     FLASH FLOOD      3 W POWELL              36.02N 84.09W
07/20/2022                   ANDERSON           TN   PUBLIC

            SOCIAL MEDIA PHOTO OF WATER FLOWING OVER
            ROADWAY BETWEEN CLAXTON AND POWELL.

&&

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 8:10 PM EDTSpecial Weather StatementMRXBradley50 min
Jul 20, 8:14 PM EDTSpecial Weather StatementMRXHamilton31 min
Jul 20, 9:18 PM EDTSpecial Weather StatementMRXKnox27 min
Jul 20, 10:24 PM EDTFlash Flood WarningMRXAnderson, Knox5 hr
Jul 21, 12:05 AM EDTFlash Flood WarningMRXAnderson, Knox3 hr
Jul 21, 1:31 AM EDTSevere Thunderstorm WarningMRXCampbell, Claiborne, Hancock, Hawkins44 min
Jul 21, 1:44 AM EDTSevere Thunderstorm WarningMRXGrainger, Hamblen, Jefferson30 min
Jul 21, 2:15 AM EDTAreal Flood AdvisoryMRXBlount, Cocke, Sevier9 hr
Jul 21, 2:33 AM EDTAreal Flood AdvisoryMRXCampbell, Claiborne, Union5 hr
Jul 21, 2:47 AM EDTFlash Flood WarningMRXAnderson, Knox6 hr
Jul 21, 3:00 AM EDTAreal Flood AdvisoryMRXCampbell, Scott5 hr
Jul 21, 3:03 AM EDTSevere Thunderstorm WarningMRXClaiborne, Grainger, Hamblen, Jefferson, Union42 min
Jul 21, 3:34 AM EDTSevere Thunderstorm WarningMRXAnderson, Campbell, Scott29 min
Jul 21, 4:11 AM EDTAreal Flood AdvisoryMRXCocke, Grainger, Greene, Hamblen, Jefferson3 hr
Jul 21, 4:12 AM EDTSpecial Weather StatementMRXAnderson, Blount, Cocke, Jefferson, Knox, Loudon and 3 more48 min
Jul 21, 4:58 AM EDTAreal Flood AdvisoryMRXCocke, Jefferson, Sevier6 hr
Jul 21, 4:58 AM EDTSpecial Weather StatementMRXBledsoe, Blount, Knox, Loudon, McMinn, Meigs and 4 more62 min
Jul 21, 5:40 AM EDTSpecial Weather StatementMRXBledsoe, McMinn, Meigs, Monroe, Polk, Sequatchie65 min
Jul 21, 6:33 AM EDTSpecial Weather StatementMRXBradley, Hamilton, Marion, Polk, Sequatchie57 min
Jul 21, 6:48 AM EDTSpecial Weather StatementMRXBledsoe, Meigs, Rhea, Sequatchie42 min
Jul 21, 6:51 AM EDTAreal Flood AdvisoryMRXMcMinn, Meigs, Rhea3 hr
Jul 21, 7:27 AM EDTSpecial Weather StatementMRXBradley, Hamilton, Sequatchie48 min
Jul 21, 8:37 AM EDTAreal Flood WarningMRXAnderson, Knox6 hr
Jul 21, 2:32 AM EDTSevere Thunderstorm WarningMRXRussell, Scott, Washington, Wise, City of Norton43 min
Jul 21, 3:08 AM EDTAreal Flood AdvisoryMRXWise, City of Norton3 hr
Jul 21, 4:28 AM EDTAreal Flood WarningMRXCherokee, Clay11 hr

Nearby

Flash Flood Warnings in North Carolina, 2022Every flash flood warning in 2022

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.