Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 4, NWS Reno, NV

August 15, 2012Nevada County, California

NWS Reno, NV issued this flash flood warning at Aug 15, 2012, 5:04 PM PDT for Nevada County, California. It was in force for 116 min. 2 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 15, 2012, 5:04 PM PDT (00:04 UTC)
Expired
Aug 15, 2012, 7:00 PM PDT
In force
116 min
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

County Nevada County, CA

What was reported inside it

TimeReportWhereRemark
Aug 15, 5:41 PM PDTHEAVY RAIN 0Hirschdale, CACALIFORNIA HIGHWAY PATROL IS REPORTING WATER COVERING THE ROAD AT INTERSTATE 80 AND THE HIRSHDALE OFFRAMP.
Aug 15, 5:47 PM PDTHEAVY RAIN 2.333 S Boca Reservoir, CA2.33 INCHES TOTAL RAINFALL IN 1 HOUR MEASURED IN GLENSHIRE AREA OF TRUCKEE. 2 TO 6 INCHES WATER RUNNING DOWN LOCAL STREETS.

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, 0.1 hours before the alert went out and 166 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 2012-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 44 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 2012-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -17 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
44 J/kg
Mixed-layer CIN
-81 J/kg
Mixed-layer LCL
2543 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-17 m²/s²
0-3 km storm-relative helicity
63 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.

387 
WGUS55 KREV 160004
FFWREV
CAC057-160200-
/O.NEW.KREV.FF.W.0004.120816T0004Z-120816T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RENO NV
504 PM PDT WED AUG 15 2012

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A

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

* UNTIL 700 PM PDT

* AT 458 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            
  GLENSHIRE...HIRSCHDALE AND THE MARTIS VALLEY.

A STATIONARY THUNDERSTORM IS PRODUCING HEAVY RAIN OVER THE TRUCKEE 
GLENSHIRE AREA. A SPOTTER REPORTED TWO-THIRDS OF AN INCH OF RAIN IN 
THE LAST 20 MINUTES...WITH HAIL COVERING ROADS. THIS COMBINED WITH 
OVER 1 INCH OF RAINFALL YESTERDAY WILL LEAD TO FLASH FLOODING. 

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS...AND RANCHLAND ALONG THE BANKS OF CREEKS...STREAMS AND OTHER 
LOW LYING AREAS ARE SUBJECT TO FLOODING. NEVER DRIVE YOUR VEHICLE 
INTO AREAS WHERE THE WATER COVERS THE ROADWAY. 

LAT...LON 3938 12016 3938 12004 3932 12003 3932 12016

$$

BRONG
3 follow-up statements
372 
WGUS75 KREV 160015
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
515 PM PDT WED AUG 15 2012

CAC057-160200-
/O.CON.KREV.FF.W.0004.000000T0000Z-120816T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-
515 PM PDT WED AUG 15 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM PDT FOR EAST
CENTRAL NEVADA COUNTY...

AT 507 PM PDT...TRAINED WEATHER SPOTTERS IN THE TRUCKEE GLENSHIRE 
AREA HAVE REPORTED 1.25 INCHES OF RAIN WITH LARGE HAIL IN THE LAST 
35 MINUTES. AN ADDITIONAL 1 TO 2 INCHES OF RAIN IS LIKELY IN THE 
WARNED AREA THROUGH 6 PM.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  GLENSHIRE...HIRSCHDALE...THE MARTIS VALLEY AND INTERSTATE 80       
  BETWEEN TRUCKEE AND FLORISTON.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL AND SATURATED SOILS WILL CAUSE 
FLOODING OF SMALL CREEKS AND STREAMS...HIGHWAYS...STREETS AND 
UNDERPASSES.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTO
AREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLY
DEEPER THAN THEY APPEAR. A FEW INCHES OF FAST FLOWING WATER IS
POWERFUL ENOUGH TO SWEEP VEHICLES OFF THE ROAD.

LAT...LON 3938 12016 3938 12004 3932 12003 3932 12016

$$

BRONG
936 
WGUS75 KREV 160040
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
540 PM PDT WED AUG 15 2012

CAC057-160200-
/O.CON.KREV.FF.W.0004.000000T0000Z-120816T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-
540 PM PDT WED AUG 15 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 700 PM PDT FOR EAST
CENTRAL NEVADA COUNTY...

AT 536 PM PDT...THE THUNDERSTORM PRODUCING VERY HEAVY RAIN OVER 
INTERSTATE 80 EAST OF TRUCKEE IS SLOWLY MOVING NORTH OVER BOCA AND 
PROSSER CREEK RESERVOIRS. 

JUST AFTER 5 PM...TRAINED WEATHER SPOTTERS IN THE TRUCKEE GLENSHIRE 
AREA REPORTED OVER 1 INCH OF RAIN IN 35 MINUTES.  THE CALIFORNIA 
HIGHWAY PATROL ALSO REPORTED ROCKS AND MUD ARE COVERING A PORTION OF 
INTERSTATE 80 NEAR FARAD.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO            
  GLENSHIRE...HIRSCHDALE...BOCA AND PROSSER CREEK RESERVOIRS AND     
  INTERSTATE 80 BETWEEN TRUCKEE AND FLORISTON.

NEVER DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE 
ROADWAY. A FEW INCHES OF FAST FLOWING WATER IS POWERFUL ENOUGH TO 
SWEEP VEHICLES OFF THE ROAD. CAMPERS AND BOATERS AT BOCA...PROSSER 
AND STAMPEDE RESERVOIRS SHOULD SEEK SHELTER UNTIL THE THUNDERSTORM 
PASSES.

LAT...LON 3938 12016 3938 12004 3932 12003 3932 12016

$$

BRONG
140 
WGUS75 KREV 160153
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
653 PM PDT WED AUG 15 2012

CAC057-160200-
/O.EXP.KREV.FF.W.0004.000000T0000Z-120816T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-
653 PM PDT WED AUG 15 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 700 PM PDT FOR EAST CENTRAL
NEVADA COUNTY...

THE THREAT FOR CONTINUED FLASH FLOODING HAS DIMINISHED. REMEMBER 
THAT MINOR FLOODING OR RUNOFF MAY CONTINUE IN LOW SPOTS FOR SEVERAL 
HOURS. THIS INCLUDES AREAS AROUND...BUT NOT LIMITED TO... 
GLENSHIRE...HIRSCHDALE...AND THE MARTIS VALLEY.

LAT...LON 3938 12016 3938 12004 3932 12003 3932 12016

$$

DF

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.