Mesoscale Discussion 1613

Issued

Aug 28, 2020, 1:50 PM EDT (17:50 UTC)

Expired

Aug 28, 2020, 3:15 PM EDT

In force

85 min

Issued by

the Storm Prediction Center

Concerning

Severe potential...watch possible

Chance of a watch

40%

The Grand Rapids radar (KGRR), 49 km from the middle of the area, began a volume at 17:49 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.

149 
ACUS11 KWNS 281750
SWOMCD
SPC MCD 281750 
MIZ000-281915-

Mesoscale Discussion 1613
NWS Storm Prediction Center Norman OK
1250 PM CDT Fri Aug 28 2020

Areas affected...Western and central Lower Michigan

Concerning...Severe potential...Watch possible 

Valid 281750Z - 281915Z

Probability of Watch Issuance...40 percent

SUMMARY...A few severe storms are possible this afternoon. Damaging
wind and large hail will be the primary threats.

DISCUSSION...The boundary layer has destabilized across southern and
central Michigan with temperatures ranging from the mid 70s to the
mid 80s and dewpoints in the low 70s. This has yielded 1000 to 2000
J/kg MLCAPE across the region. A non-severe MCS is currently
crossing Lake Michigan and will arrive in western Michigan within
the hour. Reintensification of ongoing convection and/or additional
development along the outflow boundary is expected in western
Michigan. Moderate instability and effective shear around 35 to 40
kts per GRR VWP would support organized storm modes including a
squall line and possibly supercell organization, especially on the
southern end of the line. A majority of the convection may stay on
the cool side of the warm front which should limit severe weather
chances. Therefore, despite the expectation for a few severe storms
along and near the warm front, the small area may preclude the need
for a severe thunderstorm watch. Conditions will be monitored
closely and if a more widespread/greater severe weather threat
appears imminent, a watch may be needed.

..Bentley/Grams.. 08/28/2020

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

ATTN...WFO...DTX...APX...GRR...

LAT...LON   43568752 43838711 44158614 44208537 43958441 43518388
            43078366 42478435 42298529 42328610 42428684 42528725
            42658753 42738767 43568752

Mesoscale Discussions in Michigan, 2020Every mesoscale discussion in 2020

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.