Alert archive / Tennessee / Areal Flood Warnings in 2021
Areal Flood Warning 26, NWS Morristown, TN
NWS Morristown, TN issued this areal flood warning at Aug 17, 2021, 10:01 PM EDT for Blount County, Sevier County, Tennessee. It was in force for 3 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
- Aug 17, 2021, 10:01 PM EDT (02:01 UTC)
- Expired
- Aug 18, 2021, 1:00 AM EDT
- In force
- 3 hr
- Issued by
- NWS Morristown, TN
- Area
- Storm-based polygon
- Flood severity
- None
Counties Blount County, TN, Sevier County, TN
The radar
The Knoxville radar (KMRX), 56 km from the middle of the area, began a volume at 02:00 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
Greensboro/Hi Pt, NC (KGSO), launched 00:00Z, 2.0 hours before the alert went out and 347 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.
- Mixed-layer CAPE
- 349 J/kg
- Mixed-layer CIN
- -15 J/kg
- Mixed-layer LCL
- 641 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- 225 m²/s²
- 0-3 km storm-relative helicity
- 278 m²/s²
- Significant tornado parameter
- 0.2
- Supercell composite
- 2.5
What forecasters said that day
The local office's own words before this areal 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 areal flood warning went out at Aug 17, 9:40 PM EDT, 21 minutes earlier.
Area forecast discussion, Aug 17, 9:40 PM EDT, 21 minutes before
AREA FORECAST DISCUSSION
National Weather Service Morristown TN
940 PM EDT Tue Aug 17 2021
.UPDATE...
EVENING UPDATE.
&&
.DISCUSSION...
The remnants of Fred continue to lift out of the area from
southwest to northeast. The southern TN Valley and southwest NC
are dry and the central TN valley only has a few light showers
remaining. Northeast TN and southwest VA sill have pockets of
moderate rain showers which will last another few hours. A
flooding threat still exists across these areas and won't end
until the rain moves out. Any moderate rain should be done around
midnight.
The previous forecast handled the timing of the exiting showers
very well, only had to make a few tweaks to the hourly POP grids.
Through the rest of the night, the biggest concern is patchy fog
developing areawide. Please use caution if traveling overnight as
fog begins to develop. Fog will persist through the night, not
lifting until after daybreak.
Will send out new zones to update Flash Flood Headlines.
SR
&&
.AVIATION...
00Z TAF DISCUSSION.
Rainfall associated with the remnants of Fred are slowly pulling
out of the area from southwest to northeast. CHA is rain-free and
TYS will be within a few hours. Fog will develop overnight as
the rain moves out with MVFR conditions expected at CHA, and IFR
at TYS and TRI due to low CIGs. A return to VFR conditions late
tomorrow morning at all sites.
SR
&&
.PRELIMINARY POINT TEMPS/POPS...
Chattanooga Airport, TN 69 89 72 87 71 / 20 20 40 70 40
Knoxville McGhee Tyson Airport, TN 70 89 71 87 70 / 70 20 40 70 50
Oak Ridge, TN 69 88 70 85 69 / 60 20 40 70 50
Tri Cities Airport, TN 69 85 68 86 68 / 100 20 20 60 40
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...Flash Flood Watch until 2 AM EDT Wednesday for Cocke Smoky
Mountains-Grainger-Hamblen-Hancock-Hawkins-Jefferson-
Johnson-North Sevier-Northwest Carter-Northwest Cocke-
Northwest Greene-Sevier Smoky Mountains-Southeast Carter-
Southeast Greene-Sullivan-Unicoi-Washington.
VA...Flash Flood Watch until 2 AM EDT Wednesday for Lee-Russell-Scott-
Washington-Wise.
&&Hazardous weather outlook, Aug 17, 3:45 PM EDT, 6 hours 16 minutes before
Hazardous Weather Outlook...UPDATED National Weather Service Morristown TN 345 PM EDT Tue Aug 17 2021 NCZ060-061-TNZ012>018-035>047-067>074-081>087-098>102-VAZ001-002- 005-006-008-181200- 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- 345 PM EDT Tue Aug 17 2021 /245 PM CDT Tue Aug 17 2021/ This Hazardous Weather Outlook is for portions of southwest North Carolina...east Tennessee and southwest Virginia. .DAY ONE...This Afternoon and Tonight Rainfall associated with the remnants of Tropical Storm Fred will continue to affect the area through late tonight. Heavy tropical downpours could produce flash flooding, and a potential for mudslides. A Flash Flood Watch remains in effect for portions of the area. .DAYS TWO THROUGH SEVEN...Wednesday through Monday An unsettled pattern will continue Thursday through the weekend with showers and thunderstorms each day. .SPOTTER INFORMATION STATEMENT... Spotter reports of flooding are encouraged.
The office that day
Everything else NWS Morristown, TN issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 17, 8:35 PM EDT | Areal Flood Advisory | MRX | Carter, Johnson, Sullivan, Unicoi, Washington | 4 hr |
| Aug 18, 12:56 AM EDT | River Flood Warning | MRX | Sevier | 3 hr |
| Aug 18, 6:37 PM EDT | Areal Flood Advisory | MRX | Scott | 3 hr |
| Aug 18, 7:15 PM EDT | Special Weather Statement | MRX | Campbell | 45 min |
| Aug 18, 1:04 AM EDT | Areal Flood Advisory | MRX | Wise | 116 min |
Nearby
Areal Flood Warnings in Tennessee, 2021Every areal flood warning in 2021
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.