Alert archive / Tennessee / Flash Flood Watches in 2018

Flash Flood Watch 2, NWS Morristown, TN

May 28, 201828 counties in Tennessee; Cherokee County, Clay County, North Carolina

NWS Morristown, TN issued this flash flood watch at May 28, 2018, 4:20 AM EDT for 28 counties in Tennessee; Cherokee County, Clay County, North Carolina. It took effect at May 29, 2018, 8:00 AM EDT. It was in force for 36 hr.

The area

The counties it named.

The facts

Issued: May 28, 2018, 4:20 AM EDT (08:20 UTC)
In effect from: May 29, 2018, 8:00 AM EDT
Expired: May 30, 2018, 8:00 PM EDT
In force: 36 hr
Issued by: NWS Morristown, TN
Flood severity: None

All 30 counties

Cherokee County, NC, Clay County, NC, Anderson County, TN, Bledsoe County, TN, Blount County, TN, Bradley County, TN, Campbell County, TN, Carter County, TN, Cocke County, TN, Grainger County, TN, Greene County, TN, Hamblen County, TN, Hamilton County, TN, Jefferson County, TN, Knox County, TN, Loudon County, TN, Marion County, TN, McMinn County, TN, Meigs County, TN, Monroe County, TN, Morgan County, TN, Polk County, TN, Rhea County, TN, Roane County, TN, Scott County, TN, Sequatchie County, TN, Sevier County, TN, Unicoi County, TN, Union County, TN, Washington County, TN

The radar

The Knoxville radar (KMRX), 74 km from the middle of the area, began a volume at 08:23 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 00:00Z, 8.3 hours before the alert went out and 231 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 931 J/kg
Mixed-layer CIN: -9 J/kg
Mixed-layer LCL: 1344 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: -22 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 flash flood watch 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 watch went out at May 28, 3:48 AM EDT, 32 minutes earlier.

Area forecast discussion, May 28, 3:48 AM EDT, 32 minutes before

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Hazardous weather outlook, May 27, 9:03 PM EDT, 7 hours 17 minutes before

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The office that day

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

Issued	Product	Office	Counties	Lasted
May 27, 8:21 PM EDT	Flash Flood Warning	MRX	Blount, Knox	80 min
May 27, 9:15 PM EDT	Special Weather Statement	MRX	Sequatchie	45 min
May 27, 9:28 PM EDT	Areal Flood Advisory	MRX	Bledsoe, Hamilton, Rhea, Sequatchie	3 hr
May 27, 10:34 PM EDT	Areal Flood Advisory	MRX	Bradley, McMinn, Meigs, Monroe	116 min
May 28, 12:12 AM EDT	Areal Flood Advisory	MRX	Marion	3 hr
May 27, 9:09 PM EDT	Areal Flood Advisory	MRX	Cherokee	3 hr

Nearby

Flash Flood Watches in Tennessee, 2018 Flash Flood Watches in North Carolina, 2018 Every flash flood watch in 2018

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.