Alert archive / Michigan / Mesoscale Discussions in 2012
Mesoscale Discussion 1890
The Storm Prediction Center issued this mesoscale discussion at Sep 5, 2012, 1:51 PM EDT for 14 counties in Michigan. It was in force for 114 min.
The area
The outline as issued.
The facts
- Issued
- Sep 5, 2012, 1:51 PM EDT (17:51 UTC)
- Expired
- Sep 5, 2012, 3:45 PM EDT
- In force
- 114 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Alcona County, MI, Alpena County, MI, Arenac County, MI, Bay County, MI, Genesee County, MI, Huron County, MI, Iosco County, MI, Lapeer County, MI, Livingston County, MI, Macomb County, MI, Oakland County, MI, Saint Clair County, MI, Sanilac County, MI, Tuscola County, MI
The radar
The Detroit radar (KDTX), 118 km from the middle of the area, began a volume at 17:51 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, 5.9 hours before the alert went out and 115 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
- 761 J/kg
- Mixed-layer CIN
- -15 J/kg
- Mixed-layer LCL
- 636 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km storm-relative helicity
- 19 m²/s²
- 0-3 km storm-relative helicity
- 40 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
415
ACUS11 KWNS 051751
SWOMCD
SPC MCD 051751
MIZ000-051945-
MESOSCALE DISCUSSION 1890
NWS STORM PREDICTION CENTER NORMAN OK
1251 PM CDT WED SEP 05 2012
AREAS AFFECTED...ERN LOWER MI
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 051751Z - 051945Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...A FEW SEVERE STORMS WITH MARGINAL HAIL AND WIND WILL BE
POSSIBLE OVER THE NEXT COUPLE HOURS BEFORE EXITING THE UNITED
STATES.
DISCUSSION...A BROKEN LINE OF STORMS HAS FORMED OVER NERN LOWER
MI...WITH WEAK SURFACE CONVERGENCE AND ALSO IN A ZONE OF THETA-E
ADVECTION WITH SWLY 850 MB FLOW. WHILE MUCH OF FAR SERN LOWER MI WAS
CLOUDY WITH RAIN...THE THUMB AREA WAS RECEIVING ADDITIONAL HEATING
WITH A CU FIELD PRESENT. ISOLATED SEVERE STORMS APPEAR LIKELY ACROSS
THIS REGION OVER THE NEXT 1-3 HOURS BEFORE EXITING THE COUNTRY.
WHILE LAPSE RATES ALOFT ARE FAVORABLE FOR STRONG UPDRAFTS...LOW TO
MIDLEVEL FLOW IS NOT PARTICULARLY STRONG...AND SUGGESTS ONLY
MARGINAL SEVERE STORMS WILL BE POSSIBLE. LOW LEVEL VEERING WITH
HEIGHT MAY RESULT IN SOME ROTATION BUT THE OVERALL TORNADO THREAT IS
LOW.
..JEWELL/CORFIDI.. 09/05/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DTX...APX...
LAT...LON 42538391 43758399 45148340 45368237 45028175 44088148
43198170 42878194 42628225 42428275 42538391SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 4, 9:30 PM EDT | Mesoscale Discussion | SPC | Gogebic, Ontonagon | 60 min |
| Sep 5, 4:45 PM EDT | Mesoscale Discussion | SPC | Alcona, Alpena, Antrim, Arenac, Cheboygan, Chippewa and 14 more | 90 min |
Nearby
Mesoscale Discussions in Michigan, 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.