Alert archive / California / Tornado Warnings in 2020
Tornado Warning 1, NWS Reno, NV
NWS Reno, NV issued this tornado warning at Aug 15, 2020, 2:35 PM PDT for Lassen County, California. It was in force for 55 min. 1 report 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, 2020, 2:35 PM PDT (21:35 UTC)
- Expired
- Aug 15, 2020, 3:30 PM PDT
- In force
- 55 min
- Issued by
- NWS Reno, NV
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 0.75 in
County Lassen County, CA
The radar
The Reno radar (KRGX), 57 km from the middle of the area, began a volume at 21:37 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Aug 15, 3:04 PM PDT | TORNADO | 5 S Chilcoot, CA | NWS RENO (REV) STORM SURVEY. A MESOANTICYCLONE EMBEDDED WITHIN A DEEP PYROCUMULONIMBUS UPDRAFT INSIDE THE LOYALTON WILDFIRE PERIMETER GENERATED AN EF1 RATED ANTICYCLONIC TORNADO THAT SNAPPED SEVERAL QUAKING ASPEN TREES (DI 27, DOD 4) ALONG A 0.09-MILE PATH ON |
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 12:00Z, 9.6 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2809 m above ground
- 0-6 km bulk shear
- 16 kt
- 0-1 km storm-relative helicity
- 46 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
917
WFUS55 KREV 152135
TORREV
CAC035-152230-
/O.NEW.KREV.TO.W.0001.200815T2135Z-200815T2230Z/
BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Reno NV
235 PM PDT Sat Aug 15 2020
The National Weather Service in Reno has issued a
* Tornado Warning for...
Southeastern Lassen County in northern California...
* Until 330 PM PDT.
* At 228 PM PDT, a pyrocumulonimbus from the Loyalton Wildfire is
capable of producing a fire induced tornado and outflow winds in
excess of 60 mph was located south of Chilcoot, and is nearly
stationary.
HAZARD...Tornado.
SOURCE...Radar indicated rotation.
IMPACT...Extreme fire behavior with strong outflow winds capable
of downing trees and starting new fires. This is and
extremely dangerous situation for fire fighters.
* This tornadic pyrocumulonimbus will remain over mainly rural areas
of southeastern Lassen County in the vicinity of the fire.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.
&&
LAT...LON 3975 12012 3972 12007 3970 12014 3971 12015
3973 12015
TIME...MOT...LOC 2128Z 240DEG 0KT 3972 12013
TORNADO...RADAR INDICATED
HAIL...<.75IN
$$
WH2 follow-up statements
675
WWUS55 KREV 152153
SVSREV
Severe Weather Statement
National Weather Service Reno NV
253 PM PDT Sat Aug 15 2020
CAC035-152230-
/O.CON.KREV.TO.W.0001.000000T0000Z-200815T2230Z/
Lassen CA-
253 PM PDT Sat Aug 15 2020
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 330 PM PDT FOR
SOUTHEASTERN LASSEN COUNTY...
At 250 PM PDT, a pyrocumulonimbus from the Loyalton Wildfire is
capable of producing a fire induced tornado and outflow winds in
excess of 60 mph was located south of Chilcoot near and to the east
of the fire.
HAZARD...Tornado.
SOURCE...Radar indicated rotation.
IMPACT...Extreme fire behavior with strong outflow winds capable of
downing trees and starting new fires. This is an extremely
dangerous situation for fire fighters.
This tornadic pyrocumulonimbus will remain over mainly rural areas
of southeastern Lassen County in the vicinity of the fire.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Follow any evacuation orders from your local authorities. Do not go
into this area! Life-threatening situation!
&&
LAT...LON 3975 12012 3972 12007 3970 12014 3971 12015
3973 12015
TIME...MOT...LOC 2152Z 240DEG 0KT 3972 12013
TORNADO...RADAR INDICATED
HAIL...0.00IN
$$
WH993
WWUS55 KREV 152227
SVSREV
Severe Weather Statement
National Weather Service Reno NV
327 PM PDT Sat Aug 15 2020
CAC035-152232-
/O.EXP.KREV.TO.W.0001.000000T0000Z-200815T2230Z/
Lassen CA-
327 PM PDT Sat Aug 15 2020
...THE TORNADO WARNING FOR SOUTHEASTERN LASSEN COUNTY WILL EXPIRE AT
330 PM PDT...
The tornadic pyrocumulonimbus from the Loyalton Wildfire which
prompted the warning has weakened. However, extreme fire behavior is
likely to continue into early evening with additional fire tornadoes
and strong outflow winds in excess of 60 mph possible.
Continue to follow evacuation orders from your local authorities. Do
not go into this area!
LAT...LON 3975 12012 3972 12007 3970 12014 3971 12015
3973 12015
TIME...MOT...LOC 2222Z 240DEG 0KT 3972 12013
$$
WHThe office that day
Everything else NWS Reno, NV issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 15, 2:14 AM PDT | Dense Smoke Advisory | REV | Lassen, Plumas, Sierra | 6 hr |
| Aug 15, 2:59 PM PDT | Fire Weather Watch | REV | Lassen, Modoc, Plumas, Sierra | 13 hr |
Nearby
Tornado Warnings in California, 2020Every tornado warning in 2020Tornadoes in 2020
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; radar from the NEXRAD Level II archive.