Alert archive / Michigan / Mesoscale Discussions in 2012
Mesoscale Discussion 1399
The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2012, 2:57 AM EDT for Steuben County, Indiana; 25 counties in Michigan. It was in force for 63 min.
The area
The outline as issued.
The facts
- Issued
- Jul 5, 2012, 2:57 AM EDT (06:57 UTC)
- Expired
- Jul 5, 2012, 4:00 AM EDT
- In force
- 63 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 26 counties
Steuben County, IN, Barry County, MI, Branch County, MI, Calhoun County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Gratiot County, MI, Hillsdale County, MI, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kent County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Midland County, MI, Monroe County, MI, Montcalm County, MI, Oakland County, MI, Saginaw County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI
The radar
The Grand Rapids radar (KGRR), 74 km from the middle of the area, began a volume at 06:58 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Detroit, MI (KDTX), launched 00:00Z, 7.0 hours before the alert went out and 101 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
- 4748 J/kg
- Mixed-layer CIN
- -23 J/kg
- Mixed-layer LCL
- 1268 m above ground
- 0-6 km bulk shear
- 32 kt
- 0-1 km storm-relative helicity
- 75 m²/s²
- 0-3 km storm-relative helicity
- 119 m²/s²
- Significant tornado parameter
- 1.4
- Supercell composite
- 9.5
The text
As transmitted, in the capitals the NWS used until 2016.
714
ACUS11 KWNS 050657
SWOMCD
SPC MCD 050657
MIZ000-OHZ000-INZ000-050800-
MESOSCALE DISCUSSION 1399
NWS STORM PREDICTION CENTER NORMAN OK
0157 AM CDT THU JUL 05 2012
AREAS AFFECTED...LOWER MI
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 050657Z - 050800Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...ISOLATED WIND DAMAGE/SOME HAIL POTENTIAL WILL LIKELY
CONTINUE OVERNIGHT TO SPREAD SOUTHEASTWARD ACROSS
SOUTH-CENTRAL/SOUTHEAST LOWER MI. CLOSELY MONITORING CONVECTIVE
TRENDS...A SEVERE TSTM WATCH COULD BE NEEDED SOON.
DISCUSSION...A SMALL LINEAR CONVECTIVE CLUSTER CONTINUES TO STEADILY
MOVE SOUTHEASTWARD AT AROUND 30-35 KT ACROSS LOWER MI...AROUND 30
MILES NORTHWEST OF THE LANSING AREA AS OF 0650Z. WHILE THE BOUNDARY
LAYER HAS COOLED SLIGHTLY OVER THE PAST FEW HOURS...A MOIST/VERY
UNSTABLE AIRMASS CONTINUES TO FEED THIS COMPLEX FROM THE WEST...WITH
VERY UNSTABLE CONDITIONS NOTED PER REGIONAL 00Z OBSERVED SOUNDINGS.
EXISTING ORGANIZATION OF THE MCS AND LEADING DOWNSTREAM ECHOS
SUGGEST THIS MCS SHOULD CONTINUE TO MAINTAIN ITS ORGANIZATION AND
FORWARD PROPAGATE ACROSS SOUTH-CENTRAL/SOUTHEAST MI OVERNIGHT WITH
AT LEAST AN ISOLATED WIND DAMAGE/HAIL POTENTIAL CONTINUING.
..GUYER/MEAD.. 07/05/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...CLE...DTX...IWX...GRR...
LAT...LON 43568592 43368520 43768451 43498313 42528262 41738367
41518505 42898568 43568592SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 5, 3:27 PM EDT | Mesoscale Discussion | SPC | Adams, Allen, DeKalb, Steuben, Wells | 93 min |
| Jul 5, 5:58 PM EDT | Mesoscale Discussion | SPC | Adams, Allen, Blackford, Boone, Carroll, Cass and 40 more | 92 min |
| Jul 4, 11:54 PM EDT | Mesoscale Discussion | SPC | Clare, Gratiot, Ionia, Isabella, Kent, Lake and 11 more | 96 min |
| Jul 5, 3:04 AM EDT | Severe Thunderstorm Watch | SPC | Barry, Calhoun, Eaton, Genesee, Ingham, Ionia and 11 more | 3 hr |
| Jul 5, 4:12 AM EDT | Mesoscale Discussion | SPC | Genesee, Ingham, Jackson, Lenawee, Livingston, Macomb and 4 more | 93 min |
Nearby
Mesoscale Discussions in Michigan, 2012Mesoscale Discussions in Indiana, 2012Every mesoscale discussion in 2012
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.