Mesoscale Discussion 1464

Issued

Aug 10, 2021, 3:43 PM EDT (19:43 UTC)

Expired

Aug 10, 2021, 4:45 PM EDT

In force

62 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch unlikely

Chance of a watch

20%

Counties Alger County, MI, Dickinson County, MI, Marquette County, MI

The Marquette radar (KMQT), 32 km from the middle of the area, began a volume at 19:43 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.

169 
ACUS11 KWNS 101943
SWOMCD
SPC MCD 101943 
MIZ000-102045-

Mesoscale Discussion 1464
NWS Storm Prediction Center Norman OK
0243 PM CDT Tue Aug 10 2021

Areas affected...Portions of the Michigan Upper Peninsula

Concerning...Severe potential...Watch unlikely 

Valid 101943Z - 102045Z

Probability of Watch Issuance...20 percent

SUMMARY...A large supercell has developed on the southern end of a
line of storms with a threat for large hail and damaging winds for
the next 1 to 2 hours.

DISCUSSION...A supercell in Iron County, Michigan has shown a 1.5 to
2.5 inch MESH core for the last hour. This storm continues to show a
strong mid-level mesocyclone and echo tops over 50 kft. There has
been significant sidelobe velocity contamination within the inflow
region of this supercell but close examination of the velocity data
through time and support from an environment with weak flow in the
lowest 2km would suggest a low tornado threat from this supercell.
However, large hail (some greater than 2 inch) and damaging winds
may be possible as this supercell moves east. The airmass near this
storm currently indicates MLCAPE around 1500 J/kg with decreasing
instability with eastern extent. Therefore, expect this supercell to
eventually weaken, but given its strength at present time,
storm-scale dynamic pressure perturbations could allow the storm to
persist further into the less stable airmass than may be otherwise
expected. 

The short duration and relatively isolated threat area will preclude
the need for a watch ahead of this activity.

..Bentley/Thompson.. 08/10/2021

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

ATTN...WFO...MQT...

LAT...LON   45988829 46218851 46608839 46728749 46618640 46278630
            46118671 45968729 45988784 45988829

Mesoscale Discussions in Michigan, 2021Every mesoscale discussion in 2021

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.