Alert archive / California / Tornado Warnings in 2023

Tornado Warning 6, NWS Hanford, CA

August 21, 2023Merced County, California

NWS Hanford, CA issued this tornado warning at Aug 21, 2023, 1:12 PM PDT for Merced County, California. It was in force for 33 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 21, 2023, 1:12 PM PDT (20:12 UTC)
Expired: Aug 21, 2023, 1:45 PM PDT
In force: 33 min
Issued by: NWS Hanford, CA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Merced County, CA

The radar

The San Francisco radar (KMUX), 105 km from the middle of the area, began a volume at 20:14 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

Vandenberg AFB, CA (KVBG), launched 12:00Z, 8.2 hours before the alert went out and 274 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 959 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 42 m²/s²
0-3 km storm-relative helicity: 34 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Hanford, CA wrote its last area forecast discussion before this tornado warning went out at Aug 21, 12:54 PM PDT, 18 minutes earlier.

Area forecast discussion, Aug 21, 12:54 PM PDT, 18 minutes before

Area Forecast Discussion
National Weather Service Hanford CA
1254 PM PDT Mon Aug 21 2023

.SYNOPSIS...
Remnants of Tropical Storm Hilary will continue to bring
widespread rainfall to the area through this morning and into
tonight. Thunderstorms are also possible this afternoon. The
system is expected to exit our area Tuesday morning and dry
conditions will begin to prevail Wednesday with some showers
along the Sierra Nevada crest possible on Thursday and Friday.
Flooding will continue to impact the area as the water from
yesterday's excessive rainfall recedes.

&&

.DISCUSSION...
Current satellite imagery shows a broad area of low pressure
spinning off the California coastline. Abundant moisture and
instability from Hilary are present over our CWA with Surface
Based CAPE sitting over 1000 J/kg. The HRRR runs this morning have
been showing quite an active afternoon with thunderstorms firing
off by noon (which are ongoing as we speak) and trekking across
the valley this afternoon into the evening hours. Expect hail of
at least 1/2 inch and strong winds to 50 mph with some of these
storms capable of producing larger hail and stronger winds.
Rotation has been observed on radar already this afternoon and
funnel clouds and/or brief touchdowns of tornadoes is certainly
possible.

With the amount of rainfall some areas received yesterday, any
precipitation with showers or thunderstorms today could help to
exasperate more flooding concerns. Be weary of any standing water
you encounter and always head on the side of caution and avoid
driving through any amount of water in roadways.

After this afternoon, expect conditions to begin to taper back to
seasonal norm for our area with temperatures rebounding back to
near normal and much drier conditions present. Longer range models
are showing a possible heat up by next Tuesday.

&&

.AVIATION...
Widespread MVFR and areas of mountain obscuring IFR conditions in
and near showers and thunderstorms across Kern County mountains
and Sierra Nevada. Showers and thunderstorms will also impact the
remainder of the Central CA interior with areas of MVFR.

&&

.AIR QUALITY ISSUES...
ISSUED:  08/20/2023 13:29
EXPIRES: 08/21/2023 23:59
None.

&&

.CERTAINTY...

The level of certainty for days 1 and 2 is medium.
The level of certainty for days 3 through 7 is medium.

Certainty levels include low...medium...and high. Please visit
www.weather.gov/hnx/certainty.html for additional information
and/or to provide feedback.

&&

.HNX WATCHES/WARNINGS/ADVISORIES...
None.
&&

JMC

weather.gov/hanford

In the hours before

Local storm report, Aug 21, 8:52 AM PDT, 4 hours 20 minutes before

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Special weather statement, Aug 21, 12:16 PM PDT, 56 minutes before

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Special weather statement, Aug 21, 12:38 PM PDT, 34 minutes before

Special Weather Statement
National Weather Service San Joaquin Valley CA
1238 PM PDT Mon Aug 21 2023

CAZ300>302-212015-
Los Banos - Dos Palos CA-Merced - Madera - Mendota CA-
West Side Mountains north of 198 CA-
1238 PM PDT Mon Aug 21 2023

...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL FRESNO COUNTY
THROUGH 115 PM PDT...

At 1238 PM PDT, Doppler radar was tracking a strong thunderstorm 17
miles southwest of Mendota, or 39 miles southwest of Madera, moving
northeast at 10 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Panoche Road.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 3655 12059 3661 12071 3678 12066 3673 12042
TIME...MOT...LOC 1938Z 204DEG 9KT 3661 12064

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

KM

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 5:00 PM PDT	Flash Flood Warning Considerable damage threat	HNX	Kern	8 hr
Aug 20, 5:19 PM PDT	Flash Flood Warning Considerable damage threat	HNX	Kern	6 hr
Aug 20, 5:26 PM PDT	Flash Flood Warning	HNX	Kern	7 hr
Aug 20, 5:29 PM PDT	Areal Flood Advisory	HNX	Tulare	6 hr
Aug 20, 5:36 PM PDT	Flash Flood Warning	HNX	Kern	6 hr
Aug 20, 5:59 PM PDT	Flash Flood Warning	HNX	Kern	5 hr
Aug 20, 6:02 PM PDT	Flash Flood Warning	HNX	Kern	6 hr
Aug 20, 6:04 PM PDT	Areal Flood Advisory	HNX	Kern	6 hr
Aug 20, 6:50 PM PDT	Flash Flood Warning	HNX	Kern	5 hr
Aug 20, 7:31 PM PDT	Areal Flood Advisory	HNX	Kern	5 hr
Aug 20, 7:53 PM PDT	Areal Flood Advisory	HNX	Tulare	4 hr
Aug 20, 8:01 PM PDT	Areal Flood Advisory	HNX	Fresno, Tulare	5 hr
Aug 20, 8:58 PM PDT	Areal Flood Advisory	HNX	Kern, Tulare	3 hr
Aug 20, 9:12 PM PDT	Flash Flood Warning Considerable damage threat	HNX	Kern	3 hr
Aug 20, 9:17 PM PDT	Areal Flood Advisory	HNX	Kern	3 hr
Aug 21, 12:16 PM PDT	Special Weather Statement	HNX	Merced	29 min
Aug 21, 12:35 PM PDT	Severe Thunderstorm Warning	HNX	Fresno, Merced	25 min
Aug 21, 12:38 PM PDT	Special Weather Statement	HNX	San Benito	37 min
Aug 21, 12:41 PM PDT	Tornado Warning	HNX	Merced	34 min
Aug 21, 12:54 PM PDT	Severe Thunderstorm Warning	HNX	Fresno	36 min
Aug 21, 1:12 PM PDT	Areal Flood Advisory	HNX	Merced	2 hr
Aug 21, 1:22 PM PDT	Special Weather Statement	HNX	Merced	23 min
Aug 21, 1:28 PM PDT	Severe Thunderstorm Warning	HNX	Fresno, Merced	32 min
Aug 21, 1:45 PM PDT	Severe Thunderstorm Warning	HNX	Merced	30 min
Aug 21, 1:59 PM PDT	Severe Thunderstorm Warning	HNX	Fresno, Merced	34 min
Aug 21, 2:20 PM PDT	Special Weather Statement	HNX	San Benito	55 min
Aug 21, 2:23 PM PDT	Special Weather Statement	HNX	Merced	37 min
Aug 21, 2:31 PM PDT	Special Weather Statement	HNX		29 min
Aug 21, 2:33 PM PDT	Areal Flood Advisory	HNX	Fresno, Merced	117 min
Aug 21, 2:53 PM PDT	Severe Thunderstorm Warning	HNX	Kern	67 min
Aug 21, 2:56 PM PDT	Severe Thunderstorm Warning	HNX	Fresno	24 min
Aug 21, 2:57 PM PDT	Areal Flood Advisory	HNX	Kern	2 hr
Aug 21, 3:01 PM PDT	Special Weather Statement	HNX	Mariposa	29 min
Aug 21, 3:17 PM PDT	Severe Thunderstorm Warning	HNX	Kern	28 min
Aug 21, 3:27 PM PDT	Flash Flood Warning	HNX	Kern	109 min
Aug 21, 3:45 PM PDT	Severe Thunderstorm Warning	HNX	Kern	30 min

Nearby

Tornado Warnings in California, 2023 Every tornado warning in 2023 Tornadoes in 2023

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.