Alert archive / Michigan / Mesoscale Discussions in 2012
Mesoscale Discussion 2238
The Storm Prediction Center issued this mesoscale discussion at Dec 26, 2012, 3:29 PM EST for 4 counties in Indiana; 19 counties in Michigan. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Dec 26, 2012, 3:29 PM EST (20:29 UTC)
- Expired
- Dec 26, 2012, 6:30 PM EST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
All 23 counties
Elkhart County, IN, LaGrange County, IN, Saint Joseph County, IN, Steuben County, IN, Barry County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Kalamazoo County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Oakland County, MI, Saint Clair County, MI, Saint Joseph County, MI, Shiawassee County, MI, Washtenaw County, MI
The radar
The Detroit radar (KDTX), 95 km from the middle of the area, began a volume at 20:29 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, 8.5 hours before the alert went out and 99 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
- 660 m above ground
- 0-6 km bulk shear
- 41 kt
- 0-1 km storm-relative helicity
- 79 m²/s²
- 0-3 km storm-relative helicity
- 196 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
256
ACUS11 KWNS 262030
SWOMCD
SPC MCD 262029
MIZ000-OHZ000-INZ000-262330-
MESOSCALE DISCUSSION 2238
NWS STORM PREDICTION CENTER NORMAN OK
0229 PM CST WED DEC 26 2012
AREAS AFFECTED...SRN LOWER MI...FAR NRN INDIANA
CONCERNING...HEAVY SNOW
VALID 262029Z - 262330Z
SUMMARY...BANDS OF SNOW WITH RATES LOCALLY APPROACHING 1 IN/HR WILL
CONTINUE THROUGH AROUND 23Z...WITH SNOW RATES EXPECTED TO DECREASE
THEREAFTER.
DISCUSSION...BANDS OF MODERATE TO LOCALLY HEAVY SNOW ROUGHLY ALIGN
WITH A NE/SW-ORIENTED AXIS OF 850-MB CONFLUENCE...NW OF THE CENTER
OF DEEP LOW PRESSURE OVER THE ERN CONUS. RADAR MOSAIC IMAGERY AS OF
AROUND 2020Z INDICATES ONE BAND CENTERED 30 NE MTC TO 25 SW
JXN...ANOTHER BAND CENTERED 30 NNE LAN TO 10 SW AZO...AND YET
ANOTHER BAND CENTERED 20 SW GRR TO 20 SW SBN. SFC OBSERVATIONS
SUGGEST THE RECENT OCCURRENCE OF HEAVY SNOW AT PTK AND YIP...AND
SNOW RATES LOCALLY APPROACHING 1 IN/HR MAY OCCUR WITH THE SNOW
BANDS. AS THE LOW-LEVEL FLOW GRADUALLY BACKS WHILE THE CYCLONE
SHIFTS NEWD TO THE SE OF THE AREA...SNOW BANDS MAY GRADUALLY PIVOT
AND BECOME ORIENTED MORE NNE/SSW. HOWEVER...AFTER 23Z...FORCING FOR
ASCENT ACCOMPANYING THE CYCLONE WILL BECOME INCREASINGLY REMOVED
FROM THE AREA WITH A DECREASE IN THE INFLUX OF LOW/MID-LEVEL
MOISTURE. AS SUCH...SNOW RATES ARE EXPECTED TO DECREASE AFTER 23Z.
..COHEN.. 12/26/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DTX...IWX...GRR...
LAT...LON 42918254 42578271 42018388 41648472 41458584 41458663
41838667 42538596 43098460 43178353 42918254SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Dec 26, 3:25 AM EST | Mesoscale Discussion | SPC | Bartholomew, Boone, Brown, Clark, Clay, Crawford and 45 more | 6 hr |
| Dec 26, 10:39 AM EST | Mesoscale Discussion | SPC | Adams, Allen, Blackford, Boone, Cass, Clinton and 26 more | 6 hr |
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.