ZCZC SPCSWOMCD ALL
ACUS11 KWNS 132241 
SPC MCD 132241 
NDZ000-MTZ000-140045-

Mesoscale Discussion 1600
NWS Storm Prediction Center Norman OK
0541 PM CDT Sat Jul 13 2024

Areas affected...Northern to eastern Montana

Concerning...Severe Thunderstorm Watch 522...

Valid 132241Z - 140045Z

The severe weather threat for Severe Thunderstorm Watch 522
continues.

SUMMARY...Large hail remains the primary severe threat for the
short-term across north-central Montana, but a transition into a
more organized cluster/linear segment may occur within the next 1-2
hours. This would support an increasing wind threat downstream
across eastern Montana.

DISCUSSION...Over the past hour, a leading supercell across
north-central MT continues to show strong deviant motion to the
south/southeast and has a history of producing severe hail (1.0 to
1.75 inch) per recent storm reports. For the next 30-60 minutes,
this cell should continue to pose a risk for large to very large
hail given a very favorable supercell environment. Radar and
satellite trends over the past 30 minutes show increasing cumulus
congestus and new cell development in the vicinity of the supercell
- likely a result of strengthening ascent in close proximity to the
supercell and its robust pressure perturbation responsible for the
strong deviant motion. As new cells develop, cold pools will
amalgamate leading to gradual upscale growth, likely within the next
1-2 hours. Evolution into an organized line appears probable given
strong (nearly 50 knots) deep-layer wind shear nearly parallel to
the diffuse frontal boundary. Consequently, the threat for severe
wind should increase in the coming hours downstream. Based on the
current position of the frontal boundary, the severe threat should
mostly remain in WW 522, but additional watch issuance may be needed
across southeast MT in the coming hours if it becomes apparent
convection will maintain a more southeasterly track.

..Moore.. 07/13/2024

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

ATTN...WFO...BIS...BYZ...GGW...TFX...

LAT...LON   47270869 47990950 48350973 48670981 48950966 48990944
            48750863 48570771 48080476 47610416 47180401 46310404
            46130419 46000443 45910468 45870500 45880530 46010583
            46270675 46600754 47270869 

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