Alert archive / California / Tornado Warnings in 2017

Tornado Warning 2, NWS Sacramento, CA

March 21, 2017Stanislaus County, California

NWS Sacramento, CA issued this tornado warning at Mar 21, 2017, 1:15 PM PDT for Stanislaus County, California. It was in force for 32 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: Mar 21, 2017, 1:15 PM PDT (20:15 UTC)
Expired: Mar 21, 2017, 1:47 PM PDT
In force: 32 min
Issued by: NWS Sacramento, CA
Area: Storm-based polygon

County Stanislaus County, CA

The radar

The San Francisco radar (KMUX), 118 km from the middle of the area, began a volume at 20:15 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, 8.3 hours before the alert went out and 129 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: 22 J/kg
Mixed-layer CIN: -88 J/kg
Mixed-layer LCL: 656 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 136 m²/s²
0-3 km storm-relative helicity: 132 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

908 
WFUS56 KSTO 212015
TORSTO
CAC099-212100-
/O.NEW.KSTO.TO.W.0002.170321T2015Z-170321T2100Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Sacramento CA
115 PM PDT TUE MAR 21 2017

The National Weather Service in Sacramento has issued a

* Tornado Warning for...
  Northeastern Stanislaus County in central California...

* Until 200 PM PDT
    
* At 114 PM PDT, Doppler radar indicated a severe thunderstorm
  capable of producing a tornado. This dangerous storm was located 
  near Oakdale, and moving northeast at 20 mph. Funnel clouds have 
  been reported with this storm.

* Locations impacted include...
  Oakdale, Waterford, East Oakdale, Eugene and Hickman. 

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 in a mobile
home or outdoors, move to the closest substantial shelter and protect
yourself from flying debris.

&&

LAT...LON 3755 12072 3770 12093 3796 12083 3766 12048
TIME...MOT...LOC 2014Z 216DEG 49KT 3773 12079 

$$

cs

1 follow-up statement

598 
WWUS56 KSTO 212047
SVSSTO

Severe Weather Statement
National Weather Service Sacramento CA
147 PM PDT TUE MAR 21 2017

CAC099-212056-
/O.CAN.KSTO.TO.W.0002.000000T0000Z-170321T2100Z/
Stanislaus CA-
147 PM PDT TUE MAR 21 2017

...THE TORNADO WARNING FOR NORTHEASTERN STANISLAUS COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears to be capable of producing a tornado.
Therefore the warning has been cancelled. However small hail is still
possible with this thunderstorm.

LAT...LON 3761 12067 3783 12086 3796 12083 3766 12048
TIME...MOT...LOC 2045Z 216DEG 49KT 3798 12055 

$$

cs

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 21, 10:26 AM PDT	Special Weather Statement	STO	Sacramento	34 min
Mar 21, 11:01 AM PDT	Special Weather Statement	STO	Yuba	44 min
Mar 21, 11:25 AM PDT	Special Weather Statement	STO	Sacramento, San Joaquin	35 min
Mar 21, 12:05 PM PDT	Special Weather Statement	STO	Amador, Nevada, Placer, Sacramento, San Joaquin	40 min
Mar 21, 12:27 PM PDT	Areal Flood Advisory	STO	Amador, Calaveras, El Dorado, Sacramento, San Joaquin, Stanislaus	3 hr
Mar 21, 12:33 PM PDT	Special Weather Statement	STO	Stanislaus	27 min
Mar 21, 12:48 PM PDT	Tornado Warning	STO	Stanislaus	27 min
Mar 21, 1:50 PM PDT	Severe Thunderstorm Warning	STO	Stanislaus, Tuolumne	40 min
Mar 21, 2:29 PM PDT	Severe Thunderstorm Warning	STO	Tuolumne	61 min

Nearby

Tornado Warnings in California, 2017 Every tornado warning in 2017 Tornadoes 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.