Alert archive / North Carolina / Flash Flood Warnings in 2021

Flash Flood Warning 27, NWS Morristown, TN

May 4, 2021Cherokee County, Clay County, North Carolina

NWS Morristown, TN issued this flash flood warning at May 4, 2021, 12:01 PM EDT for Cherokee County, Clay County, North Carolina. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: May 4, 2021, 12:01 PM EDT (16:01 UTC)
Expired: May 4, 2021, 3:00 PM EDT
In force: 3 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), 119 km from the middle of the area, began a volume at 16:01 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.

What was reported inside it

Time	Report	Where	Remark
May 4, 12:53 PM EDT	FLASH FLOOD	Murphy, NC	FLASH FLOOD WATER 12 INCHES ABOVE THE BRIDGE OVER LAURAL BROOK ON LAURAL BROOK WAY. PERSONS IN PRIVATE HOMES TRAPPED IN SUBDIVISION BY RISING WATER, BUT NO RESIDENCES OR PERSONS ARE ENDANGERED AT THIS TIME.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Peachtre/Fal Fld, GA (KFFC), launched 12:00Z, 4.0 hours before the alert went out and 208 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: 590 J/kg
Mixed-layer CIN: -114 J/kg
Mixed-layer LCL: 753 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 207 m²/s²
0-3 km storm-relative helicity: 213 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.3

Open this sounding in Storm Lab

The text

As transmitted.

410 
WGUS54 KMRX 041601
FFWMRX
NCC039-043-041900-
/O.NEW.KMRX.FF.W.0027.210504T1601Z-210504T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Morristown TN
1201 PM EDT Tue May 4 2021

The National Weather Service in Morristown has issued a

* Flash Flood Warning for...
  Cherokee County in southwestern North Carolina...
  Clay County in southwestern North Carolina...

* Until 300 PM EDT.

* At 1201 PM EDT, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 3 inches of rain have fallen over the last 6 hours. 
  Additional rainfall amounts of 1 to 2 inches are possible in the 
  warned area over the next 3 hours. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar and automated gauges.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Andrews, Murphy, Hayesville, Marble, Brasstown, Unaka, Tusquitee, 
  Hiawasse Dam, Culberson, Violet, Hot House, Topton and Shooting 
  Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3499 8432 3523 8429 3527 8423 3524 8419
      3524 8413 3529 8403 3523 8400 3522 8396
      3526 8384 3524 8376 3526 8371 3523 8369
      3520 8373 3520 8372 3516 8374 3516 8366
      3514 8365 3500 8352 3499 8348

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

CDG

The office that day

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

Issued	Product	Office	Counties	Lasted
May 4, 11:52 AM EDT	Special Weather Statement	MRX	Graham	38 min
May 4, 12:06 PM EDT	Special Weather Statement	MRX	Cherokee	24 min

Nearby

Flash Flood Warnings in North Carolina, 2021 Every flash 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.