Alert archive / Nevada / Flash Flood Warnings in 2021

Flash Flood Warning 1, NWS Reno, NV

July 1, 2021Douglas County, Nevada

NWS Reno, NV issued this flash flood warning at Jul 1, 2021, 5:17 PM PDT for Douglas County, Nevada. 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 outline as issued.

The facts

Issued
Jul 1, 2021, 5:17 PM PDT (00:17 UTC)
Expired
Jul 1, 2021, 8:02 PM PDT
In force
3 hr
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

County Douglas County, NV

The radar

The Reno radar (KRGX), 95 km from the middle of the area, began a volume at 00:17 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, 0.3 hours before the alert went out and 141 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-pSkew-T log-p diagram, Reno, NV at 00:00Z on 2021-07-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 95 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Reno, NV at 00:00Z on 2021-07-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
95 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
3191 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
37 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

922 
WGUS55 KREV 020017
FFWREV
NVC005-020315-
/O.NEW.KREV.FF.W.0001.210702T0017Z-210702T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Reno NV
517 PM PDT Thu Jul 1 2021

The National Weather Service in Reno has issued a

* Flash Flood Warning for...
  Douglas County in western Nevada...

* Until 815 PM PDT.

* At 517 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across portions of Douglas County east of Gardnerville 
  over the Numbers and Monarch Burn scar. Between 1 and 2 inches of 
  rain have fallen based on radar estimates. Flash flooding is 
  ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the in drainages coming off the Numbers and Monarch 
Burn scars. The debris flow can consist of rock, mud, vegetation and 
other loose materials.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Doppler radar.

  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 flash flooding include...
  Portions of Douglas County east of Highway 395 and Gardnerville.

Additional rainfall amounts up to 1 inch are possible in the warned 
area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Move away from recently burned areas. Life-threatening flooding of 
creeks, roads and normally dry stream beds is likely. The heavy 
rains will likely trigger rockslides, mudslides and debris flows in 
steep terrain, especially in and around these areas.

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

&&

LAT...LON 3897 11964 3893 11970 3886 11969 3884 11964
      3882 11959 3881 11952 3886 11950 3892 11949
      3896 11949 3899 11954

FLASH FLOOD...RADAR INDICATED

$$

CS
3 follow-up statements
140 
WGUS75 KREV 020055
FFSREV

Flash Flood Statement
National Weather Service Reno NV
555 PM PDT Thu Jul 1 2021

NVC005-020315-
/O.CON.KREV.FF.W.0001.000000T0000Z-210702T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Douglas NV-
555 PM PDT Thu Jul 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM PDT THIS 
EVENING FOR DOUGLAS COUNTY...

At 555 PM PDT, Radar shows new storm formation in the vicinity of 
the Numbers Fire burn scar, just southeast of Gardnerville, and east 
of Johnson Lane. Flooding is possible in drainages coming off the 
Numbers Fire scar in areas east of Highway 395. Additional spot 
flooding is possible in drainages east and southeast of Johnson Lane 
from new storms in that area.


HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Doppler radar.

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 flash flooding include...
  Areas east of Gardnerville and east of Johnson Lane.

Additional rainfall amounts up to 1 inch are possible in the warned 
area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3897 11964 3893 11970 3886 11969 3884 11964
      3882 11959 3881 11952 3886 11950 3892 11949
      3896 11949 3899 11954

FLASH FLOOD...RADAR INDICATED

$$

CS
567 
WGUS75 KREV 020208
FFSREV

Flash Flood Statement
National Weather Service Reno NV
708 PM PDT Thu Jul 1 2021

NVC005-020315-
/O.CON.KREV.FF.W.0001.000000T0000Z-210702T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Douglas NV-
708 PM PDT Thu Jul 1 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM PDT THIS 
EVENING FOR DOUGLAS COUNTY...

At 708 PM PDT, Radar indicated that most of the heavy thunderstorms 
have dissipated over the Numbers and Monarch burn scars. However a 
few storms remain in the vicinity, including storms near 
Gardnerville. These storms could still result in flooding in 
normally prone low spots near Gardnerville, with flows from earlier 
heavy rains still coming down drainages from the Numbers and Monarch 
burn scar.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Doppler radar.

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 flash flooding include...
  Areas near and east of Highway 395, and Gardnerville

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 3897 11964 3893 11970 3886 11969 3884 11964
      3882 11959 3881 11952 3886 11950 3892 11949
      3896 11949 3899 11954

FLASH FLOOD...RADAR INDICATED

$$

CS
455 
WGUS75 KREV 020302
FFSREV

Flash Flood Statement
National Weather Service Reno NV
802 PM PDT Thu Jul 1 2021

NVC005-020312-
/O.CAN.KREV.FF.W.0001.000000T0000Z-210702T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Douglas NV-
802 PM PDT Thu Jul 1 2021

...FLASH FLOOD WARNING IS CANCELLED FOR DOUGLAS COUNTY...

The heavy rain has ended, however some water will continue to flow 
through channels and normally dry creek beds near and east of 
Gardnerville this evening.

LAT...LON 3897 11964 3893 11970 3886 11969 3884 11964
      3882 11959 3881 11952 3886 11950 3892 11949
      3896 11949 3899 11954

$$

CS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 1, 6:02 PM PDTSpecial Weather StatementREVDouglas28 min
Jul 1, 6:13 PM PDTSpecial Weather StatementREVChurchill92 min
Jul 1, 7:24 PM PDTAreal Flood AdvisoryREVLyon111 min
Jul 1, 7:48 PM PDTSpecial Weather StatementREVStorey57 min
Jul 1, 7:58 PM PDTSevere Thunderstorm WarningREVLyon47 min
Jul 2, 11:13 AM PDTFire Weather WatchREVDouglas, Lyon, Mineral, Storey, Washoe14 hr

Nearby

Flash Flood Warnings in Nevada, 2021Every 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.