Alert archive / Michigan / Mesoscale Discussions in 2021
Mesoscale Discussion 1959
The Storm Prediction Center issued this mesoscale discussion at Dec 5, 2021, 1:40 PM EST for 26 counties in Michigan. It was in force for 4 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 5, 2021, 1:40 PM EST (18:40 UTC)
- Expired
- Dec 5, 2021, 5:15 PM EST
- In force
- 4 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Heavy snow
All 26 counties
Alcona County, MI, Alpena County, MI, Antrim County, MI, Arenac County, MI, Benzie County, MI, Clare County, MI, Crawford County, MI, Gladwin County, MI, Grand Traverse County, MI, Iosco County, MI, Isabella County, MI, Kalkaska County, MI, Lake County, MI, Manistee County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montmorency County, MI, Newaygo County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Roscommon County, MI, Wexford County, MI
The radar
The NCL Michigan radar (KAPX), 69 km from the middle of the area, began a volume at 18:43 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.
The nearest sounding before it
Detroit, MI (KDTX), launched 12:00Z, 6.7 hours before the alert went out and 222 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1784 m above ground
- 0-6 km bulk shear
- 93 kt
- 0-1 km storm-relative helicity
- 7 m²/s²
- 0-3 km storm-relative helicity
- 256 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
943
ACUS11 KWNS 051841
SWOMCD
SPC MCD 051840
MIZ000-052215-
Mesoscale Discussion 1959
NWS Storm Prediction Center Norman OK
1240 PM CST Sun Dec 05 2021
Areas affected...Northern Lower Michigan
Concerning...Heavy snow
Valid 051840Z - 052215Z
SUMMARY...Moderate to occasionally heavy snow expected to persist
through the afternoon and into the early evening across northern
Lower Michigan.
DISCUSSION...Regional radar composite shows increasing precipitation
rates across central Michigan in response to frontogenesis and
strengthening isentropic ascent. Moderate to occasionally heavy
snowfall is expected to develop across all of northern Lower
Michigan in the next 1 to 2 hours and persist into the early
evening. Continued low-level warm air advection will eventually
change rain to snow from south to north across the region. However,
the majority of the precipitation is expected to fall as snow with
rates up to 2 inches per hour.
..Bentley.. 12/05/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DTX...APX...GRR...
LAT...LON 43518583 43928655 44968624 45458515 45268349 44548287
43518441 43518583SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 5, 5:22 AM EST | Mesoscale Discussion | SPC | Dickinson, Gogebic, Iron, Menominee, Ontonagon | 6 hr |
Nearby
Mesoscale Discussions in Michigan, 2021Every mesoscale discussion in 2021
Sources
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.