Alert archive / Nevada / Flash Flood Warnings in 2020

Flash Flood Warning 21, NWS Reno, NV

August 26, 20204 counties in Nevada

NWS Reno, NV issued this flash flood warning at Aug 26, 2020, 8:40 PM PDT for 4 counties in Nevada. It was in force for 81 min. 4 reports 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: Aug 26, 2020, 8:40 PM PDT (03:40 UTC)
Expired: Aug 26, 2020, 10:01 PM PDT
In force: 81 min
Issued by: NWS Reno, NV
Area: Storm-based polygon
Flood severity: None

Counties Churchill County, NV, Lyon County, NV, Storey County, NV, Washoe County, NV

The radar

The Reno radar (KRGX), 38 km from the middle of the area, began a volume at 03:44 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
Aug 26, 9:15 PM PDT	HEAVY RAIN 0.57	4 S Fernley, NV	TOTAL RAINFALL REPORTED AT FERNLEY TIGER FIELD. HEAVIEST RAIN (0.49 INCH) FELL IN ABOUT 30 MINUTES BETWEEN 840-910 PM.
Aug 26, 9:38 PM PDT	HEAVY RAIN 0.66	1 Ssw Fernley, NV	HEAVIEST RAIN FELL APPROXIMATELY 845-915 PM.
Aug 26, 9:45 PM PDT	FLASH FLOOD	4 N Silver Springs, NV	LYON SO REPORTED CLOSURE OF HIGHWAY 95A BETWEEN SILVER SPRINGS AND FERNLEY TO CLEAR WATER AND MUD FROM THE ROAD.
Aug 26, 9:51 PM PDT	FLASH FLOOD	Fernley, NV	STREET FLOODING REPORTED IN SEVERAL AREAS OF FERNLEY. FLOOD WATER REACHED ONE HOME AND A FEW OTHER HOMES REPORTED FLOODED YARDS. MOST OF THE HEAVY RAIN FELL IN FERNLEY BETWEEN 840 AND 915 PM.

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

The nearest sounding before it

Reno, NV (KREV), launched 00:00Z, 3.7 hours before the alert went out and 89 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: 228 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 3000 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

251 
WGUS55 KREV 270340
FFWREV
NVC001-019-029-031-270615-
/O.NEW.KREV.FF.W.0021.200827T0340Z-200827T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Reno NV
840 PM PDT Wed Aug 26 2020

The National Weather Service in Reno has issued a

* Flash Flood Warning for...
  West central Churchill County in west central Nevada...
  Storey County in western Nevada...
  Southern Washoe County in western Nevada...
  North central Lyon County in west central Nevada...

* Until 1115 PM PDT.

* At 839 PM PDT, law enforcement reported thunderstorms producing
  heavy rain across the warned area. Up to two inches of rain have
  already fallen. Flash flooding is already occurring.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Law enforcement.

  IMPACT...Flooding of small creeks and streams, urban areas, 
           highways, streets and underpasses as well as other 
           drainage and low lying areas.

* Some locations that will experience flooding include...
  Lahontan Reservoir, Fernley, Fort Churchill Station, Silver
  Springs, Fernley - Tiger Field Airport, Us 50 At Lyon-Churchill Co
  Line, Silver Springs Airport and Wadsworth.

This includes the following streams and drainages...
Churchill Canyon, Carson River and Truckee River.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying
spots.

Please report flooding to your local law enforcement agency when you
can do so safely.

A Flash Flood Warning means that flooding is imminent or occurring.
If you are in the warned area move to higher ground immediately.
Residents living along streams and creeks should take immediate
precautions to protect life and property.

&&

LAT...LON 3960 11909 3927 11902 3922 11925 3926 11935
      3932 11930 3945 11931 3961 11935 3963 11929
      3965 11922

FLASH FLOOD...OBSERVED

$$

CJ

1 follow-up statement

079 
WGUS75 KREV 270501
FFSREV

Flash Flood Statement
National Weather Service Reno NV
1001 PM PDT Wed Aug 26 2020

NVC001-019-029-031-270508-
/O.CAN.KREV.FF.W.0021.000000T0000Z-200827T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Churchill NV-Storey NV-Washoe NV-Lyon NV-
1001 PM PDT Wed Aug 26 2020

...THE FLASH FLOOD WARNING FOR WEST CENTRAL CHURCHILL...STOREY...
SOUTHERN WASHOE AND NORTH CENTRAL LYON COUNTIES IS CANCELLED...

The heavy rain has ended. While flooding is no longer expected to 
pose a threat, standing water and ponding will continue into the 
overnight hours. Some roads may also have been damaged by running 
water. Proceed with caution if heading into more rural areas of 
Lyon County. Please continue to heed any road closures.

LAT...LON 3960 11909 3927 11902 3922 11925 3926 11935
      3932 11930 3945 11931 3961 11935 3963 11929
      3965 11922

$$

CJ

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 26, 5:44 PM PDT	Special Weather Statement	REV	Douglas, Lyon, Storey, Washoe	106 min
Aug 26, 7:43 PM PDT	Special Weather Statement	REV	Lyon	47 min
Aug 26, 8:14 PM PDT	Areal Flood Advisory	REV	Churchill, Lyon	30 min
Aug 26, 9:32 PM PDT	Special Weather Statement	REV	Churchill, Douglas, Lyon, Pershing, Storey, Washoe	118 min

Nearby

Flash Flood Warnings in Nevada, 2020 Every flash flood warning in 2020

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.