Alert archive / Michigan / Mesoscale Discussions in 2012
Mesoscale Discussion 250
The Storm Prediction Center issued this mesoscale discussion at Mar 12, 2012, 6:29 PM EDT for LaGrange County, Steuben County, Indiana; 24 counties in Michigan; Fulton County, Williams County, Ohio. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Mar 12, 2012, 6:29 PM EDT (22:29 UTC)
- Expired
- Mar 12, 2012, 8:00 PM EDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
All 28 counties
LaGrange County, IN, Steuben County, IN, Arenac County, MI, Bay County, MI, Branch County, MI, Calhoun County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Gladwin County, MI, Gratiot County, MI, Hillsdale County, MI, Huron County, MI, Ingham County, MI, Jackson County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Midland County, MI, Oakland County, MI, Saginaw County, MI, Saint Joseph County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Fulton County, OH, Williams County, OH
The radar
The Detroit radar (KDTX), 65 km from the middle of the area, began a volume at 22:30 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 12:00Z, 10.5 hours before the alert went out and 68 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
- 1981 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- 124 m²/s²
- 0-3 km storm-relative helicity
- 86 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
449
ACUS11 KWNS 122230
SWOMCD
SPC MCD 122229
MIZ000-OHZ000-INZ000-130000-
MESOSCALE DISCUSSION 0250
NWS STORM PREDICTION CENTER NORMAN OK
0529 PM CDT MON MAR 12 2012
AREAS AFFECTED...LOWER MICHIGAN
CONCERNING...TORNADO WATCH 73...
VALID 122229Z - 130000Z
THE SEVERE WEATHER THREAT FOR TORNADO WATCH 73 CONTINUES.
AN ADDITIONAL WW MAY BE NEEDED ACROSS THE REMAINDER OF SOUTHEASTERN
LOWER MICHIGAN WITHIN THE NEXT HOUR OR TWO.
MOST SIGNIFICANT DISCRETE STORM DEVELOPMENT...INCLUDING SUPERCELLS
...NOW APPEARS UNDERWAY ACROSS PARTS OF SOUTHWESTERN LOWER MICHIGAN.
THIS IS OCCURRING WITHIN AN AREA OF ENHANCED LOW-LEVEL WARM
ADVECTION...WHERE THE AXIS OF STRONGEST PRE-FRONTAL SURFACE HEATING
NOSES INTO THE AXIS OF BOUNDARY LAYER MOISTURE RETURN /WITH SURFACE
DEW POINTS RISING THROUGH THE LOWER/MID 50S. ONE OR TWO ADDITIONAL
SUPERCELLS COULD FORM IN ASSOCIATION WITH THIS FORCING...AND RAPIDLY
SPREAD ACROSS CENTRAL INTO SOUTHEASTERN LOWER MICHIGAN DURING THE
NEXT FEW HOURS...WITHIN 45-50+ KT SOUTHWESTERLY DEEP LAYER MEAN
FLOW. RUC GUIDANCE SUGGESTS THAT THE 850 MB JET WILL CONTINUE TO
INTENSIFY IN EXCESS OF 50 KT THROUGH EARLY EVENING...CONTRIBUTING TO
FURTHER ENLARGEMENT OF ALREADY SIZABLE CLOCKWISE-CURVED LOW-LEVEL
HODOGRAPHS. AND IT APPEARS THAT TORNADIC POTENTIAL COULD PEAK
ACROSS THE LANSING...JACKSON AND FLINT AREAS BETWEEN NOW AND 00-01Z.
..KERR.. 03/12/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DTX...APX...IWX...GRR...
LAT...LON 43968465 44408383 44148287 43258252 41968354 41558413
41438509 41578583 42448524 43968465SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Mar 12, 12:03 PM EDT | Mesoscale Discussion | SPC | Lake, LaPorte, Porter, Saint Joseph | 57 min |
| Mar 12, 4:22 PM EDT | Tornado Watch | SPC | DeKalb, Elkhart, Kosciusko, LaGrange, LaPorte, Marshall and 4 more | 7 hr |
| Mar 12, 7:36 PM EDT | Tornado Watch | SPC | Genesee, Huron, Lapeer, Lenawee, Livingston, Macomb and 7 more | 7 hr |
Nearby
Mesoscale Discussions in Michigan, 2012Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Ohio, 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.