EF0 tornado, Knowles, California, February 15, 2019

1. EF065 to 85 mphthis tornado

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mph

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF0

Date

February 15, 2019

Touchdown

9:45 AM PST (17:45 UTC)

Lifted

9:50 AM PST (17:50 UTC)

On the ground

5 minutes

Path length

0.6 miles (0.9 km)

Path width

25 yards (23 m)

Deaths

0

Injuries

0

County

Madera County

Touchdown point

37.160, -119.810

Lift-off point

37.166, -119.802

Record number

1902151145-01

A deep moisture plume moved through central California on February 13 and 14 as a strong low pressure system approached the area. Heavy rainfall and strong southerly winds impacted the area as this moisture moved through the area. Several reports of winds gusts exceeding 60 mph were reported and snow levels rose to near 9000 feet which resulted in widespread flooding in the area and several road closures from flooding and debris flows were reported. A strong cold front pushed through the area during the morning of February 15 which resulted in snow levels plummeting to around 5000 feet. Thunderstorms broke out in the colder and unstable post-frontal airmass and several reports of small hail were observed in the San Joaquin Valley. In addition, a small EF 0 tornado briefly touched down n ear Yosemite Lakes and funnel clouds were observed in the San Joaquin Valley. A colder system moved into the area on February 16 and snow levels lowered further down to 1500 feet. Low elevation snowfall on February 16 and 17 resulted in numerous road closures and travel delays and there were several reports of 10 to 20 inches of new snowfall reported in the Southern Sierra Nevada between the evening of February 15 and the evening of February 17. Rainfall totals between February 13 and February 17 were generally between 3 and 7 inches of liquid precipitation in the higher elevations of the Southern Sierra Nevada with 2 to 5 inches in the adjacent foothills. Much of the San Joaquin Valley picked up between a half inch and an inch and a half of rainfall during this period while the Tehachapi Mountains generally picked up between 1 to 2 inches of liquid precipitation during the 5 day period.

An EF 0 tornado near Yosemite Lakes was determined by video and pictures posted on Facebook.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 16:25 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The San Joaquin Valley radar (KHNX), 96 km away, was scanning. The volume nearest the touchdown began at 17:44 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2019 tornado in CaliforniaEvery tornado in California since 1950Warnings in force in California nowThe forecast where you are

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.