Alert archive / Michigan / Mesoscale Discussions in 2012
Mesoscale Discussion 660
The Storm Prediction Center issued this mesoscale discussion at May 2, 2012, 2:57 PM EDT for 19 counties in Michigan. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- May 2, 2012, 2:57 PM EDT (18:57 UTC)
- Expired
- May 2, 2012, 4:30 PM EDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
Counties Clinton County, MI, Eaton County, MI, Genesee County, MI, Gratiot County, MI, Ingham County, MI, Jackson County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Midland County, MI, Monroe County, MI, Oakland County, MI, Saginaw County, MI, Saint Clair County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Wayne County, MI
The radar
The Detroit radar (KDTX), 46 km from the middle of the area, began a volume at 18:55 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, 7.0 hours before the alert went out and 49 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
- 581 m above ground
- 0-6 km bulk shear
- 25 kt
- 0-1 km storm-relative helicity
- 152 m²/s²
- 0-3 km storm-relative helicity
- 246 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
696
ACUS11 KWNS 021857
SWOMCD
SPC MCD 021857
MIZ000-022030-
MESOSCALE DISCUSSION 0660
NWS STORM PREDICTION CENTER NORMAN OK
0157 PM CDT WED MAY 02 2012
AREAS AFFECTED...LOWER MI
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 021857Z - 022030Z
PROBABILITY OF WATCH ISSUANCE...40 PERCENT
SUMMARY...POTENTIAL EXISTS FOR AN INCREASING SEVERE TSTM THREAT THIS
AFTERNOON ACROSS EAST/SOUTHEAST PORTIONS OF LOWER MI...WHICH COULD
INCLUDE A RISK FOR A TORNADO ASIDE FROM SEVERE HAIL/WIND.
DISCUSSION...IT APPEARS THAT THE REGION IS BEING INFLUENCED BY THE
SOUTHERN/TRAILING PORTION OF A NORTHEAST-MOVING SHORTWAVE TROUGH
OVER THE UPPER GREAT LAKES REGION INTO ONTARIO THIS AFTERNOON. A
RECENT INCREASE/DEEPENING OF THE CU FIELD HAS BEEN NOTED IN
EAST-CENTRAL LOWER MI PER VISIBLE SATELLITE IMAGERY...AND THIS
ROUGHLY COINCIDES WITH A CORRIDOR OF MAXIMIZED CONVERGENCE NEAR A
WEAK FRONTAL WAVE/WARM FRONT. THERMODYNAMIC MODIFICATIONS TO THE 12Z
OBSERVED SOUNDING FROM DETROIT...ALONG WITH SHORT-TERM RAP
GUIDANCE/SPC OBJECTIVE ANALYSIS...SUGGEST THAT CINH IS NOW
NEGLIGIBLE WITH A CORRIDOR OF MODERATE INSTABILITY EXTENDING
NORTHEASTWARD INTO SOUTHEAST/EAST-CENTRAL LOWER MI.
AMID RELATIVELY STRONG DEEP LAYER SOUTHWESTERLY
FLOW...ORGANIZED/SUSTAINED STORM MODES INCLUDING SOME SUPERCELLS
WOULD BE POSSIBLE SHOULD DEEP CONVECTIVE INITIATION OCCUR...WITH A
TORNADO AND HAIL/WIND RISK CONDITIONALLY POSSIBLE.
HOWEVER...UNCERTAINTY CURRENTLY EXISTS REGARDING THE
LIKELIHOOD/EXTENT OF SAID SEVERE THREAT...ESPECIALLY GIVEN THAT
MID-LEVEL WAVE WILL BE MOVING AWAY FROM THE REGION AND MASS
CONVERGENCE/DEEP LAYER SHEAR SHOULD SLOWLY ABATE WITH TIME.
SHORT-TERM TRENDS ARE BEING CLOSELY MONITORED FOR A POSSIBLE WATCH.
..GUYER/CARBIN.. 05/02/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DTX...IWX...GRR...
LAT...LON 42908502 43668444 43758281 42818260 41788345 41948473
42908502Nearby
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.