Alert archive / Nevada / Flash Flood Warnings in 2011

Flash Flood Warning 7, NWS Reno, NV

September 11, 2011Washoe County, Nevada

NWS Reno, NV issued this flash flood warning at Sep 11, 2011, 3:15 PM PDT for Washoe County, Nevada. 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: Sep 11, 2011, 3:15 PM PDT (22:15 UTC)
Expired: Sep 11, 2011, 5:15 PM PDT
In force: 2 hr
Issued by: NWS Reno, NV
Area: Storm-based polygon
Flood severity: None

County Washoe County, NV

The radar

The Reno radar (KRGX), 55 km from the middle of the area, began a volume at 22:17 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, 10.3 hours before the alert went out and 136 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 23 J/kg
Mixed-layer CIN: -190 J/kg
Mixed-layer LCL: 2101 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -17 m²/s²
0-3 km storm-relative helicity: 20 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.

122 
WGUS55 KREV 112215
FFWREV
NVC031-120015-
/O.NEW.KREV.FF.W.0007.110911T2215Z-110912T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE RENO NV
315 PM PDT SUN SEP 11 2011

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EXTREME SOUTH CENTRAL WASHOE COUNTY IN WESTERN NEVADA...

* UNTIL 515 PM PDT

* AT 312 PM PDT...THUNDERSTORMS WITH HEAVY RAIN CONTINUE TO TRAIN
  ACROSS THE AREA NEAR WASHOE LAKE. A STORM SPOTTER REPORTED 1.18    
  INCHES OF RAIN IN 45 MINUTE.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WASHOE 
  CITY...NEW WASHOE CITY AND THE HILLS EAST OF WASHOE LAKE.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRY
ROADS...FARMLAND...AND RANCHLAND ALONG THE BANKS OF CREEKS...STREAMS 
AND OTHER LOW LYING AREAS ARE SUBJECT TO FLOODING. DO NOT CROSS A 
FAST FLOWING STREAM. IT TAKES ONLY A FEW INCHES OF SWIFTLY FLOWING 
WATER TO CARRY VEHICLES AWAY.

LAT...LON 3937 11980 3938 11968 3934 11965 3933 11968
      3926 11970 3920 11980 3921 11987

$$

HOHMANN

2 follow-up statements

699 
WGUS75 KREV 112304
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
404 PM PDT SUN SEP 11 2011

NVC031-120015-
/O.CON.KREV.FF.W.0007.000000T0000Z-110912T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHOE NV-
404 PM PDT SUN SEP 11 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM PDT FOR
EXTREME SOUTH CENTRAL WASHOE COUNTY...

AT 400 PM PDT...TRAINED WEATHER SPOTTERS AND RADAR CONTINUED TO 
INDICATE THUNDERSTORM PRODUCING MODERATE TO HEAVY RAIN OVER THE 
WARNED AREA. ANOTHER SPOTTER ESTIMATED NEAR 1.5 INCHES OF RAIN SINCE 
THE STORM BEGAN.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WASHOE CITY 
AND NEW WASHOE CITY. WATER FLOWING FROM THE HILLS TO THE EAST OF 
WASHOE LAKE WILL CONTINUE TO FLOW DOWN TOWARD WASHOE LAKE.  

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS AND ROADS IN NEW WASHOE CITY.

LAT...LON 3937 11980 3938 11968 3934 11965 3933 11968
      3926 11970 3920 11980 3921 11987

$$

HOHMANN

878 
WGUS75 KREV 120012
FFSREV

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE RENO NV
512 PM PDT SUN SEP 11 2011

NVC031-120021-
/O.EXP.KREV.FF.W.0007.000000T0000Z-110912T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
WASHOE NV-
512 PM PDT SUN SEP 11 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 515 PM PDT FOR EXTREME
SOUTH CENTRAL WASHOE COUNTY...

THE HEAVY RAIN THAT PROMPTED THE FLASH FLOOD WARNING HAVE MOVED OUT 
OF THE AREA...WITH A DIMINISHING FLOOD THREAT. REMEMBER THAT MINOR 
FLOODING OF LOW SPOTS MAY CONTINUE FOR SEVERAL HOURS.

LAT...LON 3937 11980 3938 11968 3934 11965 3933 11968
      3926 11970 3920 11980 3921 11987

$$

LINDAMAN

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 11, 1:38 PM PDT	Special Weather Statement	REV		22 min
Sep 11, 3:28 PM PDT	Areal Flood Warning	REV	Douglas	3 hr
Sep 11, 4:23 PM PDT	Special Weather Statement	REV		37 min
Sep 11, 4:54 PM PDT	Flash Flood Warning	REV	Washoe	109 min
Sep 11, 4:54 PM PDT	Special Weather Statement	REV		66 min

Nearby

Flash Flood Warnings in Nevada, 2011 Every 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.