Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 13, NWS Reno, NV

September 13, 2017Lassen County, California

NWS Reno, NV issued this flash flood warning at Sep 13, 2017, 5:36 PM PDT for Lassen 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
Sep 13, 2017, 5:36 PM PDT (00:36 UTC)
Expired
Sep 13, 2017, 8:30 PM PDT
In force
3 hr
Issued by
NWS Reno, NV
Area
Storm-based polygon
Flood severity
None

County Lassen County, CA

The radar

The Reno radar (KRGX), 50 km from the middle of the area, began a volume at 00:36 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 00:00Z, 0.6 hours before the alert went out and 160 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 2017-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 104 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 2017-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 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
104 J/kg
Mixed-layer CIN
-87 J/kg
Mixed-layer LCL
2448 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.7

Open this sounding in Storm Lab

The text

As transmitted.

880 
WGUS55 KREV 140036
FFWREV
CAC035-140330-
/O.NEW.KREV.FF.W.0013.170914T0036Z-170914T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Reno NV
536 PM PDT WED SEP 13 2017

The National Weather Service in Reno has issued a

* Flash Flood Warning for...
  Southeastern Lassen County in northern California...

* Until 830 PM PDT

* At 534 PM PDT, radar indicated thunderstorms producing heavy rain 
  along Highway 395 north of Hallelujah Junction and south of Doyle. 
  Up to two inches of rain have already fallen. Flash flooding is 
  expected to begin shortly or is already occurring.

* Do not drive into flooded areas! Highway 395 may very well have 
  water crossing over it.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3991 12000 3975 12001 3976 12007 3990 12008

$$

CS
2 follow-up statements
878 
WGUS75 KREV 140122
FFSREV

Flash Flood Statement
National Weather Service Reno NV
622 PM PDT WED SEP 13 2017

CAC035-140330-
/O.CON.KREV.FF.W.0013.000000T0000Z-170914T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lassen CA-
622 PM PDT WED SEP 13 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM PDT FOR
SOUTHEASTERN LASSEN COUNTY...

As of 620 PM, radar is indicating the earlier thunderstorms with 
torrential rains are diminishing in intensity. However high flows 
and flash flooding are likely to continue in the area of Highway 395 
north of Hallelujah Junction and south of Doyle for another couple 
hours.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3991 12000 3975 12001 3976 12007 3990 12008

$$

CS
409 
WGUS75 KREV 140257
FFSREV

Flash Flood Statement
National Weather Service Reno NV
757 PM PDT WED SEP 13 2017

CAC035-140306-
/O.CAN.KREV.FF.W.0013.000000T0000Z-170914T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Lassen CA-
757 PM PDT WED SEP 13 2017

...THE FLASH FLOOD WARNING FOR SOUTHEASTERN LASSEN COUNTY IS
CANCELLED...

The heavy rain has ended. Flash flooding is no longer expected to 
pose a threat. We have not received any reports of flooding on or 
near Highway 395. Radar estimated 2 to 4 inches of rainfall in the 
area north of Hallelujah Junction. Standing water may still be on 
the roadway, which can be harder to see at night.

LAT...LON 3991 12000 3975 12001 3976 12007 3990 12008

$$

CS

Nearby

Flash Flood Warnings in California, 2017Every flash flood warning in 2017

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.