ZCZC SPCSWOMCD ALL
ACUS11 KWNS 092240 
SPC MCD 092240 
ILZ000-IAZ000-100015-

Mesoscale Discussion 1217
NWS Storm Prediction Center Norman OK
0540 PM CDT Fri Jul 09 2021

Areas affected...portions of eastern Iowa

Concerning...Severe potential...Watch possible 

Valid 092240Z - 100015Z

Probability of Watch Issuance...40 percent

SUMMARY...Some severe hail may accompany the stronger, elevated
updrafts over the next few hours. How widespread the severe hail
threat will be is uncertain given lack of stronger, deep-layer lift.
Conditions will continue to be monitored for the need of a WW
issuance should more robust updrafts become relatively widespread.

DISCUSSION...Multicellular thunderstorms, rooted at/above 850 mb
(per latest RAP forecast soundings) have been intensifying along an
elevated moist-frontal boundary in the 850-700 mb layer given the
passage of a small, embedded impulse at 700 mb. Latest mesoanalysis
suggests that 1000-2000 J/kg MUCAPE parcels are advecting into this
region, supporting updraft intensification and subsequent severe
hail potential. While 40+ kts of effective bulk shear suggest that
some storm organization is possible over the next few hours, the
storms will likely quickly propagate into a relatively more stable
elevated airmass, suggesting that the severe hail threat may also be
short-lived. Given the potentially limited spatial/temporal coverage
of the severe hail threat, the need for a WW issuance is uncertain.
Nonetheless, conditions will continue to be monitored should more
widespread, robust updraft development becomes more prevalent.

..Squitieri/Thompson.. 07/09/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...DVN...ARX...DMX...

LAT...LON   41049208 41719261 42259315 42679333 42929299 43049229
            42979184 42669144 42159100 41679087 41259089 40979108
            40759161 41049208 

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