Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 6, NWS Reno, NV

July 30, 2011Alpine County, California

NWS Reno, NV issued this flash flood warning at Jul 30, 2011, 4:27 PM PDT for Alpine County, California. It was in force for 96 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
Jul 30, 2011, 4:27 PM PDT (23:27 UTC)
Expired
Jul 30, 2011, 6:03 PM PDT
In force
96 min
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

County Alpine County, CA

The radar

The Reno radar (KRGX), 145 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, 11.5 hours before the alert went out and 176 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 2011-07-30Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Reno, NV at 12:00Z on 2011-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 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
2720 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
41 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.

035 
WGUS55 KREV 302327
FFWREV
CAC003-310215-
/O.NEW.KREV.FF.W.0006.110730T2327Z-110731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RENO NV
427 PM PDT SAT JUL 30 2011

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHEASTERN ALPINE COUNTY IN CENTRAL CALIFORNIA...

* UNTIL 715 PM PDT

* AT 413 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A THUNDERSTORM OVER THE WARNED AREA.

* THE STORM PRODUCING FLASH FLOODING WILL OTHERWISE REMAIN OVER
  MAINLY RURAL AREAS OF THE INDICATED COUNTY.

STRONG THUNDERSTORMS OVER THE HIGH COUNTRY OF ALPINE COUNTY NEAR 
SONORA PEAK IS PRODUCING HEAVY RAINFALL AT THE HEAD WATERS OF THE 
EAST FORK CARSON RIVER. THE PACIFIC CREST TRAIL RUNS THROUGH THIS 
AREA...ALONG WITH MANY CANYONS AND STREAMS THAT COULD FLASH FLOOD 
FROM THE HEAVY RAINS. 

FLOOD WATERS COULD COME DOWNSTREAM ALONG THE EAST FORK CARSON RIVER 
INTO MARKLEEVILLE LATER THIS AFTERNOON.

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.

LAT...LON 3854 11979 3854 11978 3855 11959 3847 11954
      3842 11956 3840 11958 3840 11962 3836 11962
      3838 11966 3845 11968

$$

HOON
1 follow-up statement
057 
WGUS75 KREV 310103
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
603 PM PDT SAT JUL 30 2011

CAC003-310113-
/O.CAN.KREV.FF.W.0006.000000T0000Z-110731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ALPINE CA-
603 PM PDT SAT JUL 30 2011

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

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

LAT...LON 3854 11979 3854 11978 3855 11959 3847 11954
      3842 11956 3840 11958 3840 11962 3836 11962
      3838 11966 3845 11968

$$

HOON

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 2:55 AM PDTFlash Flood WatchREVMono38 hr
Jul 30, 1:47 PM PDTSpecial Weather StatementREVMono2 hr

Nearby

Flash Flood Warnings in California, 2011Every flash flood warning in 2011

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.