Alert archive / California / Tornado Warnings in 2021

Tornado Warning 2, NWS Sacramento, CA

January 4, 2021Butte County, Tehama County, California

NWS Sacramento, CA issued this tornado warning at Jan 4, 2021, 3:35 PM PST for Butte County, Tehama County, California. It was in force for 25 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
Jan 4, 2021, 3:35 PM PST (23:35 UTC)
Expired
Jan 4, 2021, 4:00 PM PST
In force
25 min
Issued by
NWS Sacramento, CA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

Counties Butte County, CA, Tehama County, CA

The radar

The Beale AFB radar (KBBX), 66 km from the middle of the area, began a volume at 23:36 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

Oakland, CA (KOAK), launched 12:00Z, 11.6 hours before the alert went out and 267 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, Oakland, CA at 12:00Z on 2021-01-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 12:00Z on 2021-01-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 182 square meters per square second.19395878Sfc1 km3 km6 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
890 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
182 m²/s²
0-3 km storm-relative helicity
243 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

770 
WFUS56 KSTO 042335
TORSTO
CAC007-103-050000-
/O.NEW.KSTO.TO.W.0002.210104T2335Z-210105T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sacramento CA
335 PM PST Mon Jan 4 2021

The National Weather Service in Sacramento has issued a

* Tornado Warning for...
  East central Tehama County in northern California...
  North central Butte County in northern California...

* Until 400 PM PST.
    
* At 334 PM PST, a severe thunderstorm capable of producing a tornado
  was located 7 miles west of Butte Meadows, or 21 miles south of
  Mineral, moving northeast at 20 mph.

  HAZARD...Tornado.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* This dangerous storm will be near...
  Butte Meadows around 350 PM PST.
  Mill Creek around 355 PM PST.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to 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 4002 12170 4011 12178 4021 12159 4009 12148
TIME...MOT...LOC 2334Z 235DEG 18KT 4008 12169 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

EH
1 follow-up statement
899 
WWUS56 KSTO 042353
SVSSTO

Severe Weather Statement
National Weather Service Sacramento CA
353 PM PST Mon Jan 4 2021

CAC007-103-050003-
/O.EXP.KSTO.TO.W.0002.000000T0000Z-210105T0000Z/
Tehama CA-Butte CA-
353 PM PST Mon Jan 4 2021

...THE TORNADO WARNING FOR EAST CENTRAL TEHAMA AND NORTH CENTRAL
BUTTE COUNTIES WILL EXPIRE AT 400 PM PST...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.

LAT...LON 4002 12170 4011 12178 4021 12159 4009 12148
TIME...MOT...LOC 2353Z 235DEG 18KT 4013 12160 

$$

EH

The office that day

Everything else NWS Sacramento, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jan 4, 2:38 AM PSTFlash Flood WatchSTO15 hr
Jan 4, 1:30 PM PSTSpecial Weather StatementSTOTehama45 min
Jan 4, 1:34 PM PSTSpecial Weather StatementSTOShasta41 min
Jan 4, 2:28 PM PSTSpecial Weather StatementSTOTehama47 min
Jan 4, 2:38 PM PSTTornado WarningSTOTehama21 min

Nearby

Tornado Warnings in California, 2021Every tornado warning in 2021Tornadoes in 2021

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.