ACUS11 KWNS 212252
SWOMCD
SPC MCD 212252=20
CAZ000-220045-

Mesoscale Discussion 0495
NWS Storm Prediction Center Norman OK
0552 PM CDT Tue Apr 21 2026

Areas affected...parts of San Joaquin Valley

Concerning...Severe potential...Watch unlikely=20

Valid 212252Z - 220045Z

Probability of Watch Issuance...20 percent

SUMMARY...Intensifying storms to the west through northwest of
Fresno might become supportive of the development of another tornado
or two through 4-6 PM PDT.

DISCUSSION...The low-topped supercell with reported tornado to the west-northwest of Fresno, earlier, appeared to have been supported
by forcing for ascent to the northeast of a cyclonic mid-level
vorticity center now migrating into the southern Sierra, beneath
which low-level convergence and ambient vertical vorticity became
locally enhanced by the strengthening thunderstorm development.

New thunderstorm development is currently intensifying a bit further
to the west, to the southwest of Madera, as the boundary-layer
begins to reach peak afternoon instability, aided by insolation
beneath cold air associated with mid-level troughing overspreading
much the California coast through the Sierra Nevada. This activity
remains just to the north of cyclonic curved 50-70 kt westerly 500
mb jet nosing inland through the southern Great Basin.
Based on latest surface observations and mesoanalysis, it appears
that a corridor of enhanced low-level convergence is being
maintained near and to the northwest through north of Fresno, which
could support the spin-up of another tornado or two with a
strengthening low-level mesocyclone.

..Kerr/Gleason.. 04/21/2026

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!9d-04bmEvQj8PZKhOsrdQXmMhzC7mbONNNIMjWNvhEyYstYFL6hf3dhCxfvQ3qW1YcAQHHW1E= 8Ptibjt_blswSqf0oI$ for graphic product...

ATTN...WFO...HNX...

LAT...LON 37402050 37662000 36991936 36521951 36541999 36642042
37402050=20

MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN


=3D =3D =3D
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