Alert archive / California / Flash Flood Warnings in 2015

Flash Flood Warning 39, NWS Reno, NV

July 8, 2015Nevada County, Sierra County, California

NWS Reno, NV issued this flash flood warning at Jul 8, 2015, 1:51 PM PDT for Nevada County, Sierra County, California. 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 8, 2015, 1:51 PM PDT (20:51 UTC)
Expired
Jul 8, 2015, 4:45 PM PDT
In force
3 hr
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

Counties Nevada County, CA, Sierra County, CA

The radar

The Reno radar (KRGX), 81 km from the middle of the area, began a volume at 20:53 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, 8.9 hours before the alert went out and 185 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 2015-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 12:00Z on 2015-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
6 J/kg
Mixed-layer CIN
-244 J/kg
Mixed-layer LCL
1248 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
107 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.

942 
WGUS55 KREV 082051
FFWREV
CAC057-091-082345-
/O.NEW.KREV.FF.W.0039.150708T2051Z-150708T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RENO NV
151 PM PDT WED JUL 8 2015

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NEVADA COUNTY IN NORTHERN CALIFORNIA...
  SIERRA COUNTY IN NORTHERN CALIFORNIA...

* UNTIL 445 PM PDT
    
* AT 148 PM PDT...DOPPLER RADAR INDICATED CLUSTERS OF THUNDERSTORMS 
  PRODUCING HEAVY RAIN ACROSS EASTERN SIERRA AND EASTERN NEVADA 
  COUNTIES. THESE STORMS ARE EXPECTED TO CONTINUE THROUGH AT LEAST 
  3 PM. FLASH FLOODING IS OCCURRING OR EXPECTED TO BEGIN SHORTLY.

* THESE STORMS ARE IMPACTING MANY AREAS ALONG HIGHWAY 89 FROM NEAR 
  TRUCKEE TO SIERRAVILLE TO CALPINE. FLASH FLOODING IS LIKELY IN LOW 
  SPOTS AND IN STEEP TERRAIN. ROCK SLIDES ARE ALSO POSSIBLE. DO NOT 
  DRIVE THROUGH FLOODED ROADS.

* THESE STORMS ARE PRODUCING LARGE AMOUNTS OF SMALL HAIL AS WELL. 
  THIS MAY RESULT IN SLICK ROADS. 

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE...
  SIERRAVILLE...BOCA RESERVOIR...STAMPEDE RESERVOIR...PROSSER CREEK
  RESERVOIR...INDEPENDENCE LAKE...CALPINE...SATTLEY...
  GLENSHIRE-DEVONSHIRE CDP...TRUCKEE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

MOVE TO HIGHER GROUND NOW. ACT QUICKLY TO PROTECT YOUR LIFE.

&&

LAT...LON 3970 12040 3950 12011 3932 12007 3932 12031
      3939 12036 3945 12038 3949 12044 3953 12043
      3961 12047 3966 12055

$$

CS
4 follow-up statements
631 
WGUS75 KREV 082119
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
219 PM PDT WED JUL 8 2015

CAC057-091-082345-
/O.CON.KREV.FF.W.0039.000000T0000Z-150708T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-SIERRA CA-
219 PM PDT WED JUL 8 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM PDT FOR
NEVADA AND SIERRA COUNTIES...

* AT 216 PM PDT...DOPPLER RADAR INDICATED CLUSTERS OF THUNDERSTORMS 
  PRODUCING HEAVY RAIN FROM NEAR BOCA AND STAMPEDE TO SIERRAVILLE. 
  THESE STORMS WERE MOVING SLOWLY TO THE NORTHWEST AT 10-15 MPH. 
  FLASH FLOODING IS OCCURRING OR EXPECTED TO BEGIN SHORTLY.

* THESE STORMS ARE ALSO PRODUCING LARGE AMOUNTS OF SMALL HAIL, WHICH 
  CAN COVER ROADWAYS QUICKLY RESULTING IN WINTER-LIKE DRIVING 
  CONDITIONS. THIS COULD IMPACT I-80 EAST OF TRUCKEE TO THE NEVADA 
  STATE LINE, AND HIGHWAY 89 NORTH OF TRUCKEE.

* WE JUST RECEIVED A REPORT OF 2 INCHES OF SMALL HAIL ACCUMULATION 
  ALONG HIGHWAY 89 NORTH OF TRUCKEE. NEAR PROSSER CREEK CROSSING.

* SOME LOCATIONS THAT WILL EXPERIENCE FLOODING INCLUDE... 
  SIERRAVILLE...BOCA RESERVOIR...STAMPEDE RESERVOIR...PROSSER CREEK 
  RESERVOIR...INDEPENDENCE LAKE...CALPINE...SATTLEY... GLENSHIRE-
  DEVONSHIRE CDP...TRUCKEE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3970 12040 3950 12011 3932 12007 3932 12031
      3939 12036 3945 12038 3949 12044 3953 12043
      3961 12047 3966 12055

$$

CS
860 
WGUS75 KREV 082148
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
248 PM PDT WED JUL 8 2015

CAC057-091-082345-
/O.CON.KREV.FF.W.0039.000000T0000Z-150708T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-SIERRA CA-
248 PM PDT WED JUL 8 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM PDT FOR
NEVADA AND SIERRA COUNTIES...

* PRIMARY FLASH FLOOD THREAT MOVING INTO THE LOYALTON AREA OF SIERRA 
  COUNTY.

* AT 250 PM PDT...DOPPLER RADAR INDICATED CLUSTERS OF THUNDERSTORMS 
  PRODUCING HEAVY RAIN FROM NEAR STAMPEDE TO LOYALTON. THESE STORMS 
  WERE MOVING SLOWLY TO THE NORTHWEST AT 10-15 MPH. FLASH FLOODING 
  IS OCCURRING OR EXPECTED TO BEGIN SHORTLY.

* THESE STORMS ARE ALSO PRODUCING STRONG GUSTY WINDS AND LARGE 
  AMOUNTS OF SMALL HAIL, WHICH CAN COVER ROADWAYS QUICKLY RESULTING 
  IN WINTER-LIKE DRIVING CONDITIONS. THIS COULD IMPACT I-80 EAST OF 
  TRUCKEE TO THE NEVADA STATE LINE, HIGHWAY 89 NORTH OF TRUCKEE, AND 
  HIGHWAY 49 NEAR LOYALTON.

* EXPECT PONDING WATER ON ROADWAYS, AND FLASH FLOODING IN LOW SPOTS 
  AND STEEP TERRAIN. DO NOT DRIVE INTO AREAS WHERE WATER COVERS THE 
  ROADWAY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3970 12040 3950 12011 3932 12007 3932 12031
      3939 12036 3945 12038 3949 12044 3953 12043
      3961 12047 3966 12055

$$

CS
053 
WGUS75 KREV 082226
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
326 PM PDT WED JUL 8 2015

CAC057-091-082345-
/O.CON.KREV.FF.W.0039.000000T0000Z-150708T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-SIERRA CA-
326 PM PDT WED JUL 8 2015

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM PDT FOR
NEVADA AND SIERRA COUNTIES...

* AT 324 PM PDT...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING 
  MODERATE TO HEAVY RAIN ACROSS MUCH OF EASTERN SIERRA AND EASTERN 
  NEVADA COUNTIES. FLASH FLOODING IS OCCURRING OR EXPECTED TO BEGIN 
  SHORTLY.

* THESE STORMS WILL PRODUCE ENOUGH RAINFALL TO CONTINUE THE THREAT 
  OF FLASH FLOODING. AREAS ALONG HIGHWAY 89 NORTH OF TRUCKEE TO NEAR 
  SIERRAVILLE, ESPECIALLY IN LOW SPOTS AND NEAR CREEKS, ARE AT 
  HIGHEST RISK OF FLASH FLOODING. DO NOT DRIVE INTO FLOODED AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

REPORT SEVERE WEATHER OR FLOODING BY POSTING ON OUR FACEBOOK OR
TWITTER. SEARCH FOR 'NWS RENO'. PICTURES AND VIDEOS ARE VERY HELPFUL.

&&

LAT...LON 3970 12040 3950 12011 3932 12007 3932 12031
      3939 12036 3945 12038 3949 12044 3953 12043
      3961 12047 3966 12055

$$

CS
297 
WGUS75 KREV 082336
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
436 PM PDT WED JUL 8 2015

CAC057-091-082344-
/O.CAN.KREV.FF.W.0039.000000T0000Z-150708T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NEVADA CA-SIERRA CA-
436 PM PDT WED JUL 8 2015

...THE FLASH FLOOD WARNING FOR NEVADA AND SIERRA COUNTIES IS
CANCELLED...

* HEAVY RAINS ARE LIFTING NORTH OF THE AREA. THE HIGH RISK OF FLASH 
  FLOODING HAS ENDED, HOWEVER SOME PONDING WATER REMAINS POSSIBLE. 
  LIGHT TO MODERATE SHOWERS WILL CONTINUE ON AND OFF THROUGH THE 
  EVENING HOURS.

LAT...LON 3970 12040 3950 12011 3932 12007 3932 12031
      3939 12036 3945 12038 3949 12044 3953 12043
      3961 12047 3966 12055

$$
CS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 5:55 PM PDTAreal Flood AdvisoryREVAlpine3 hr
Jul 7, 10:04 PM PDTFlash Flood WatchREVAlpine, El Dorado, Lassen, Modoc, Mono, Nevada and 3 more23 hr
Jul 8, 11:30 AM PDTSpecial Weather StatementREVAlpine45 min
Jul 8, 12:22 PM PDTSpecial Weather StatementREVAlpine, Mono53 min
Jul 8, 12:38 PM PDTFlash Flood WarningREVAlpine, Mono3 hr
Jul 8, 12:41 PM PDTSevere Thunderstorm WarningREVAlpine, El Dorado, Placer49 min
Jul 8, 1:02 PM PDTSevere Thunderstorm WarningREVPlumas28 min
Jul 8, 1:09 PM PDTSpecial Weather StatementREVSierra51 min
Jul 8, 1:36 PM PDTSpecial Weather StatementREVSierra24 min
Jul 8, 1:37 PM PDTFlash Flood WarningREVAlpine3 hr
Jul 8, 1:48 PM PDTFlash Flood WarningREVMono3 hr
Jul 8, 1:58 PM PDTSevere Thunderstorm WarningREVPlumas47 min
Jul 8, 2:04 PM PDTSpecial Weather StatementREVPlumas26 min
Jul 8, 3:06 PM PDTSevere Thunderstorm WarningREVLassen, Sierra39 min
Jul 8, 3:10 PM PDTSpecial Weather StatementREVLassen50 min
Jul 8, 4:01 PM PDTSpecial Weather StatementREVLassen44 min
Jul 8, 4:24 PM PDTSevere Thunderstorm WarningREVLassen36 min

Nearby

Flash Flood Warnings in California, 2015Every flash flood warning in 2015

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.