Alert archive / California / Flash Flood Warnings in 2010

Flash Flood Warning 13, NWS Reno, NV

August 7, 2010Sierra County, California

NWS Reno, NV issued this flash flood warning at Aug 7, 2010, 4:21 PM PDT for Sierra County, California. It was in force for 50 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
Aug 7, 2010, 4:21 PM PDT (23:21 UTC)
Expired
Aug 7, 2010, 5:11 PM PDT
In force
50 min
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

County Sierra County, CA

The radar

The Reno radar (KRGX), 59 km from the middle of the area, began a volume at 23:21 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 12:00Z, 11.4 hours before the alert went out and 163 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 12:00Z on 2010-08-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 12:00Z on 2010-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2502 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
135 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

679 
WGUS55 KREV 072321
FFWREV
CAC091-080115-
/O.NEW.KREV.FF.W.0013.100807T2321Z-100808T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RENO NV
421 PM PDT SAT AUG 7 2010

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN SIERRA COUNTY IN NORTHERN CALIFORNIA...THIS INCLUDES
  DOG VALLEY AND STAMPEDE RESERVOIR... 

* UNTIL 615 PM PDT

* AT 408 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  HEAVY...FLASH FLOOD PRODUCING...RAINS FROM A CLUSTER OF 
  THUNDERSTORMS EAST AND NORTHEAST OF STAMPEDE RESERVOIR. THESE 
  THUNDERSTORMS ARE NEARLY STATIONARY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO DOG VALLEY
  STAMPEDE RESERVOIR AND AND INTERSTATE 80 NEAR FARAD.

DOPPLER RADAR INDICATES UP TO ONE INCH OF RAIN HAS FALLEN IN THE 
LAST HOUR IN THE HILLY TERRAIN NORTH OF INTERSTATE 80 IN THE LAST 
WITH ADDITIONAL RAINFALL UP TO ONE HALF INCH POSSIBLE.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

LAT...LON 3965 12019 3958 12000 3944 12000 3945 12012

$$
2 follow-up statements
736 
WGUS55 KREV 072324 CCA
FFWREV
CAC091-080115-
/O.COR.KREV.FF.W.0013.100807T2321Z-100808T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING...CORRECTED
NATIONAL WEATHER SERVICE RENO NV
421 PM PDT SAT AUG 7 2010

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN SIERRA COUNTY IN NORTHERN CALIFORNIA...THIS INCLUDES
  DOG VALLEY AND STAMPEDE RESERVOIR... 

* UNTIL 615 PM PDT

* AT 408 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  HEAVY...FLASH FLOOD PRODUCING...RAINS FROM A CLUSTER OF 
  THUNDERSTORMS EAST AND NORTHEAST OF STAMPEDE RESERVOIR. THESE 
  THUNDERSTORMS ARE NEARLY STATIONARY.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO DOG VALLEY
  STAMPEDE RESERVOIR AND AND INTERSTATE 80 NEAR FARAD.

DOPPLER RADAR INDICATES UP TO ONE INCH OF RAIN HAS FALLEN IN THE 
LAST HOUR IN THE HILLY TERRAIN NORTH OF INTERSTATE 80 WITH  
ADDITIONAL RAINFALL UP TO ONE HALF INCH POSSIBLE.

FLOODING IS OCCURRING OR IS IMMINENT. IT IS IMPORTANT TO KNOW WHERE
YOU ARE RELATIVE TO STREAMS...RIVERS...OR CREEKS WHICH CAN BECOME
KILLERS IN HEAVY RAINS. CAMPERS AND HIKERS SHOULD AVOID STREAMS OR
CREEKS.

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

LAT...LON 3965 12019 3958 12000 3944 12000 3945 12012

$$
899 
WGUS75 KREV 080011
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
511 PM PDT SAT AUG 7 2010

CAC091-080019-
/O.CAN.KREV.FF.W.0013.000000T0000Z-100808T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SIERRA CA-
511 PM PDT SAT AUG 7 2010

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTHEASTERN SIERRA
COUNTY...

THE STORMS THAT EARLIER PROMPTED THE FLASH FLOOD WARNING HAVE 
DISSIPATED AND MOVED WEST...WITH A DIMINISHING FLOOD THREAT. 
REMEMBER THAT THE THREAT OF MINOR FLOODING OF LOW SPOTS MAY CONTINUE 
FOR SEVERAL HOURS.

ADDITIONAL THUNDERSTORMS MAY REDEVELOP OVER THE REGION THROUGH 7 
PM...PRODUCING ADDITIONAL RAINFALL AND SMALL HAIL.

LAT...LON 3965 12019 3958 12000 3944 12000 3945 12012

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 6:57 PM PDTSpecial Weather StatementREVLassen33 min
Aug 7, 3:38 PM PDTSpecial Weather StatementREVSierra37 min
Aug 7, 4:34 PM PDTSpecial Weather StatementREVAlpine26 min
Aug 7, 4:38 PM PDTSpecial Weather StatementREVPlumas37 min

Nearby

Flash Flood Warnings in California, 2010Every flash flood warning in 2010

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.