Alert archive / Michigan / Mesoscale Discussions in 2012
Mesoscale Discussion 23
The Storm Prediction Center issued this mesoscale discussion at Jan 17, 2012, 8:44 AM EST for 21 counties in Michigan. It was in force for 3 hr.
The area
The outline as issued.
The facts
- Issued
- Jan 17, 2012, 8:44 AM EST (13:44 UTC)
- Expired
- Jan 17, 2012, 11:15 AM EST
- In force
- 3 hr
- Issued by
- the Storm Prediction Center
All 21 counties
Alcona County, MI, Alpena County, MI, Antrim County, MI, Cheboygan County, MI, Clare County, MI, Crawford County, MI, Gladwin County, MI, Grand Traverse County, MI, Kalkaska County, MI, Lake County, MI, Mecosta County, MI, Missaukee County, MI, Montmorency County, MI, Newaygo County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Presque Isle County, MI, Roscommon County, MI, Wexford County, MI
The radar
The NCL Michigan radar (KAPX), 56 km from the middle of the area, began a volume at 13:44 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
Alpena, MI (KAPX), launched 12:00Z, 1.7 hours before the alert went out and 223 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
- 446 m above ground
- 0-6 km bulk shear
- 67 kt
- 0-1 km storm-relative helicity
- 59 m²/s²
- 0-3 km storm-relative helicity
- 221 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
012
ACUS11 KWNS 171345
SWOMCD
SPC MCD 171344
MIZ000-171615-
MESOSCALE DISCUSSION 0023
NWS STORM PREDICTION CENTER NORMAN OK
0744 AM CST TUE JAN 17 2012
AREAS AFFECTED...NRN LWR MI
CONCERNING...HEAVY SNOW
VALID 171344Z - 171615Z
HEAVY SNOW RATES ON THE ORDER OF 1 INCH PER HOUR ARE EXPECTED TO
DEVELOP ACROSS MUCH OF NORTHERN LOWER MICHIGAN BY LATE MORNING AND
CONTINUE INTO THE AFTERNOON.
STRENGTHENING LIFT AND SATURATION WITHIN THE FAVORABLE MIXED PHASED
LAYER FOR DENDRITIC ICE CRYSTAL GROWTH IS CONTRIBUTING TO A
DEVELOPING BAND OF MODERATE TO HEAVY SNOW...WHICH APPEARS LIKELY TO
BEGIN OVERSPREADING MUCH OF NORTHERN LOWER MICHIGAN BY 16-18Z. THIS
IS GENERALLY OCCURRING WITHIN THE EXIT REGION OF A 90+ KT CYCLONIC
500 MB JET STREAK NOSING NORTHEASTWARD OUT OF THE CENTRAL PLAINS.
MODELS INDICATE FURTHER INTENSIFICATION OF THIS FEATURE THROUGH
MIDDAY...AS IT APPROACHES SOUTHERN PORTIONS OF THE GREAT LAKES
REGION...SUPPORTING CONTINUING SURFACE CYCLOGENESIS ACROSS SOUTHERN
LOWER MICHIGAN INTO SOUTHWESTERN ONTARIO. COINCIDING LOW/ MID-LEVEL
FRONTOGENETIC FORCING ACROSS NORTHERN LOWER MICHIGAN MAY CONTRIBUTE
TO INTENSIFYING LIFT AND PRECIPITATION RATES WITHIN A MOIST /PW
AROUND .50 INCHES/ SUBFREEZING ENVIRONMENT SUPPORTIVE OF HEAVY SNOW
RATES AROUND OR IN EXCESS OF 1 INCH PER HOUR...WHICH LIKELY WILL
PERSIST INTO THE AFTERNOON HOURS.
..KERR.. 01/17/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...APX...GRR...
LAT...LON 44978601 45678447 45308305 44438331 43868457 43428585
43508630 44178633 44978601Nearby
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.