Alert archive / Michigan / Mesoscale Discussions in 2012

Mesoscale Discussion 5

January 2, 201210 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Jan 2, 2012, 10:46 AM EST for 10 counties in Michigan. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued: Jan 2, 2012, 10:46 AM EST (15:46 UTC)
Expired: Jan 2, 2012, 2:45 PM EST
In force: 4 hr
Issued by: the Storm Prediction Center

Counties Antrim County, MI, Charlevoix County, MI, Grand Traverse County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Missaukee County, MI, Osceola County, MI, Schoolcraft County, MI, Wexford County, MI

The radar

The NCL Michigan radar (KAPX), 94 km from the middle of the area, began a volume at 15:45 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 3.8 hours before the alert went out and 190 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 960 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 148 m²/s²
0-3 km storm-relative helicity: 205 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

340 
ACUS11 KWNS 021546
SWOMCD
SPC MCD 021546 
MIZ000-021945-

MESOSCALE DISCUSSION 0005
NWS STORM PREDICTION CENTER NORMAN OK
0946 AM CST MON JAN 02 2012

AREAS AFFECTED...UPPER MI...NRN LOWER MI

CONCERNING...HEAVY SNOW 

VALID 021546Z - 021945Z

HEAVY SNOWFALL WILL PERSIST ACROSS PARTS OF UPPER MI AND NRN LOWER
MI THIS MORNING INTO THE AFTERNOON. SNOWFALL RATES OF 2 INCHES PER
HOUR WILL BE COMMON WITHIN THE HEAVIER BANDS.

RADAR REFLECTIVITY SHOWS SEVERAL NARROW BUT INTENSE LAKE EFFECT
SNOWBANDS EXTENDING DOWNSTREAM FROM LAKE SUPERIOR ACROSS
ALGER...ANTRIM...KALKASKA AND MISSAUKEE COUNTIES AS OF 1535Z. THE
LATEST HRRR GUIDANCE SHOWS STRONG LOW-LEVEL CONVERGENCE ALONG THIS
CORRIDOR WHICH SHOULD KEEP THE SNOWBANDS INTENSE THROUGH EARLY
AFTERNOON. THE SNOWBANDS SHOULD TAKE ON MORE OF AN NORTH TO SOUTH
ORIENTATION AS SFC WINDS VEER TO A NORTHERLY DIRECTION. THIS WOULD
MOVE THE HEAVY SNOWFALL SWWD WITH TIME AFFECTING AREAS FROM GRAND
TRAVERSE BAY SWD ALONG THE WRN SHORE OF LAKE MICHIGAN. SNOWFALL
RATES OF 2 INCHES PER HOUR SHOULD EXIST WITHIN THE CORE OF THE MOST
INTENSE SNOWBANDS. AS SFC WINDS VEER LATE THIS MORNING AND INCREASE
TO AROUND 20 KT ACROSS A LARGER AREA...LOCALIZED BLIZZARD CONDITIONS
WILL ALSO BE POSSIBLE.

..BROYLES.. 01/02/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...APX...GRR...MQT...

LAT...LON   45618523 46488627 46548692 46378720 45598645 45098610
            44378595 43988582 43888563 43848506 44248460 45618523

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 2, 2:33 AM EST	Mesoscale Discussion	SPC	Alger, Antrim, Charlevoix, Delta, Grand Traverse, Kalkaska and 3 more	6 hr
Jan 2, 6:24 PM EST	Mesoscale Discussion	SPC	Allegan, Cass, Saint Joseph, Van Buren	3 hr

Nearby

Mesoscale Discussions in Michigan, 2012 Every 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.