ZCZC SPCSWOMCD ALL
ACUS11 KWNS 231825 
SPC MCD 231825 
MNZ000-NDZ000-232030-

Mesoscale Discussion 1331
NWS Storm Prediction Center Norman OK
0125 PM CDT Fri Jul 23 2021

Areas affected...Northwest Minnesota

Concerning...Severe potential...Watch possible 

Valid 231825Z - 232030Z

Probability of Watch Issuance...40 percent

SUMMARY...Thunderstorms may develop sooner than forecast guidance
has suggested, possibly within the next couple of hours. Large hail
and damaging winds would be the main threats this afternoon/evening.
Trends are being monitored for a possible severe thunderstorm watch.

DISCUSSION...Temperatures in northwestern Minnesota have risen into
the low 90s F. This has occurred quicker than forecast guidance has
suggested. With dewpoints still holding in the low 70s F, MLCAPE is
also increasing to above 1500 J/kg. Within this environment, a field
of cumulus has developed along with a handful of deeper towers in
the vicinity of Thief River Falls. With an upstream shortwave trough
evident on water vapor imagery within western/central North Dakota,
subtle mid-level cooling will occur in northern Minnesota this
afternoon. These factors would suggest that convection initiation is
becoming more probable, perhaps as early as within the next couple
of hours. With all 12Z guidance forecasting initiation during the
late afternoon, timing remains the greatest uncertainty. When storms
develop, long, straight hodographs with 35-40 kts of effective shear
will favor splitting supercells capable of damaging winds and large
hail. A severe thunderstorm watch is possible this afternoon
depending on convective trends over the next few hours.

..Wendt/Hart.. 07/23/2021

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

ATTN...WFO...DLH...FGF...

LAT...LON   47519741 48339689 48949640 49029567 48679464 48199411
            47449404 46989473 46969686 47209732 47519741 

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