Alert archive / Nevada / Flash Flood Warnings in 2021

Flash Flood Warning 7, NWS Reno, NV

July 31, 2021Storey County, Washoe County, Nevada

NWS Reno, NV issued this flash flood warning at Jul 31, 2021, 6:56 PM PDT for Storey County, Washoe County, Nevada. It was in force for 94 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 31, 2021, 6:56 PM PDT (01:56 UTC)
Expired: Jul 31, 2021, 8:30 PM PDT
In force: 94 min
Issued by: NWS Reno, NV
Area: Storm-based polygon
Flood severity: None

Counties Storey County, NV, Washoe County, NV

The radar

The Reno radar (KRGX), 19 km from the middle of the area, began a volume at 01:59 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

Reno, NV (KREV), launched 00:00Z, 1.9 hours before the alert went out and 111 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: 143 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 2759 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: -31 m²/s²
0-3 km storm-relative helicity: -40 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

917 
WGUS55 KREV 010156
FFWREV
NVC029-031-010330-
/O.NEW.KREV.FF.W.0007.210801T0156Z-210801T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Reno NV
656 PM PDT Sat Jul 31 2021

The National Weather Service in Reno has issued a

* Flash Flood Warning for...
  Storey County in western Nevada...
  Southern Washoe County in western Nevada...

* Until 830 PM PDT.

* At 656 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Interstate 80 including the Tahoe-Reno Industrial Center.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3955 11956 3958 11959 3963 11957 3964 11951
      3963 11941 3961 11940 3961 11939 3951 11942
      3951 11953

FLASH FLOOD...RADAR INDICATED

$$

TF

The office that day

Everything else NWS Reno, NV issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 31, 5:29 PM PDT	Special Weather Statement	REV		46 min
Jul 31, 6:39 PM PDT	Areal Flood Advisory	REV	Mineral	3 hr
Jul 31, 8:02 PM PDT	Flash Flood Warning	REV	Churchill, Lyon, Storey, Washoe	118 min
Aug 1, 2:01 PM PDT	Areal Flood Advisory	REV	Washoe	119 min

Nearby

Flash Flood Warnings in Nevada, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.