Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 3, NWS Reno, NV

August 14, 2012Nevada County, Placer County, California

NWS Reno, NV issued this flash flood warning at Aug 14, 2012, 4:26 PM PDT for Nevada County, Placer County, California. It was in force for 2 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
Aug 14, 2012, 4:26 PM PDT (23:26 UTC)
Expired
Aug 14, 2012, 6:30 PM PDT
In force
2 hr
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

Counties Nevada County, CA, Placer County, CA

The radar

The Reno radar (KRGX), 70 km from the middle of the area, began a volume at 23:27 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 164 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 2012-08-14Temperature 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 2012-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -4 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
2794 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
-4 m²/s²
0-3 km storm-relative helicity
12 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.

101 
WGUS55 KREV 142326
FFWREV
CAC057-061-150130-
/O.NEW.KREV.FF.W.0003.120814T2326Z-120815T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RENO NV
426 PM PDT TUE AUG 14 2012

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL NEVADA COUNTY IN CENTRAL CALIFORNIA...
  EXTREME NORTHEASTERN PLACER COUNTY IN CENTRAL CALIFORNIA...

* UNTIL 630 PM PDT

* AT 418 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HIRSCHDALE

A NEARLY STATIONARY THUNDERSTORM OVER THE MARTIS VALLEY IS PRODUCING 
HEAVY RAIN. DOPPLER RADAR IN RENO INDICATES UP TO 1 INCH OF RAIN IN 
THE LAST HOUR. THIS STORM WILL CONTINUE TO PRODUCE HEAVY RAIN 
THROUGH THE NEXT 30 MINUTES...AND THIS ADDITIONAL HEAVY RAIN SHOULD 
PRODUCE EXCESSIVE RUN OFF THROUGH THE MARTIS VALLEY. THIS RUN OFF 
MAY LEAD TO FLASH FLOODING IN LOW LYING AREAS AND ALONG STEEP 
TERRAIN.

A FLASH FLOOD WARNING MEANS FLOODING IS IMMINENT OR OCCURRING. PEOPLE
IN FLOOD PRONE AND LOW LYING AREAS SHOULD MOVE TO HIGHER GROUND. DO
NOT ATTEMPT TO CROSS SWIFT FLOWING WATER BY FOOT OR AUTOMOBILE.

LAT...LON 3936 12015 3939 12007 3941 12001 3932 12002
      3930 12007 3928 12015

$$
2 follow-up statements
543 
WGUS75 KREV 150009
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
509 PM PDT TUE AUG 14 2012

CAC057-061-150130-
/O.CON.KREV.FF.W.0003.000000T0000Z-120815T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-PLACER CA-
509 PM PDT TUE AUG 14 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM PDT FOR
EXTREME NORTHEASTERN PLACER AND EAST CENTRAL NEVADA COUNTIES...

AT 456 PM PDT...THUNDERSTORMS PRODUCING MODERATE TO HEAVY RAIN WAS 
CONTINUING OVER THE SOUTHERN PORTIONS OF THE MARTIS VALLEY. DOPPLER 
RADAR INDICATES RAIN FALL OF UP TO 2 INCHES IN THIS AREA OVER THE 
LAST ONE AND A HALF HOURS. RAIN FALL RATES ARE DECREASING BUT RAPID 
RUN OFF FROM THE PREVIOUS HEAVY RAIN COULD STILL PRODUCE FLASH 
FLOODING IN PORTIONS OF THE MARTIS VALLEY AND ALONG THE STEEPER 
TERRAIN. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO HIRSCHDALE

A FLASH FLOOD WARNING MEANS FLOODING IS IMMINENT OR OCCURRING. PEOPLE
IN FLOOD PRONE AND LOW LYING AREAS SHOULD MOVE TO HIGHER GROUND. DO
NOT ATTEMPT TO CROSS SWIFT WATERS BY FOOT OR AUTOMOBILE.

LAT...LON 3936 12015 3939 12007 3941 12001 3932 12002
      3930 12007 3928 12015

$$
596 
WGUS75 KREV 150124
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
624 PM PDT TUE AUG 14 2012

CAC057-061-150134-
/O.EXP.KREV.FF.W.0003.000000T0000Z-120815T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-PLACER CA-
624 PM PDT TUE AUG 14 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 630 PM PDT FOR EXTREME
NORTHEASTERN PLACER AND EAST CENTRAL NEVADA COUNTIES...

THE THREAT FOR CONTINUED FLASH FLOODING HAS DIMINISHED. LIGHT RAIN 
WILL CONTINUE FOR ANOTHER HOUR OVER PORTIONS OF THE MARTIS VALLEY. 
REMEMBER THAT MINOR FLOODING OR RUNOFF MAY CONTINUE IN LOW SPOTS FOR 
SEVERAL HOURS.

LAT...LON 3936 12015 3939 12007 3941 12001 3932 12002
      3930 12007 3928 12015

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 14, 4:18 PM PDTSevere Thunderstorm WarningREVNevada, Placer42 min

Nearby

Flash Flood Warnings in California, 2012Every flash flood warning in 2012

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.