Alert archive / Michigan / Mesoscale Discussions in 2012

Mesoscale Discussion 2

January 2, 20129 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Jan 2, 2012, 2:33 AM EST for 9 counties in Michigan. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Jan 2, 2012, 2:33 AM EST (07:33 UTC)
Expired: Jan 2, 2012, 8:30 AM EST
In force: 6 hr
Issued by: the Storm Prediction Center

Counties Alger County, MI, Antrim County, MI, Charlevoix County, MI, Delta County, MI, Grand Traverse County, MI, Kalkaska County, MI, Leelanau County, MI, Marquette County, MI, Schoolcraft County, MI

The radar

The Marquette radar (KMQT), 103 km from the middle of the area, began a volume at 07:34 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 00:00Z, 7.6 hours before the alert went out and 208 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: 646 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 234 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.

351 
ACUS11 KWNS 020734
SWOMCD
SPC MCD 020733
MIZ000-021330-

MESOSCALE DISCUSSION 0002
NWS STORM PREDICTION CENTER NORMAN OK
0133 AM CST MON JAN 02 2012

AREAS AFFECTED...ERN UPPER MI...NWRN LOWER MI

CONCERNING...HEAVY SNOW

VALID 020733Z - 021330Z

BANDS OF HEAVY LAKE EFFECT SNOW WITH RATES NEAR 2 IN/HR SHOULD
PERSIST THROUGH MUCH OF THE MORNING AND SLOWLY SHIFT FROM A NW-SE TO
NNW-SSE ORIENTATION.

RADAR REFLECTIVITY OVER THE PAST FEW HOURS HAS DEPICTED
CONSOLIDATION INTO A COUPLE OF MORE INTENSE BANDS OFF LK SUPERIOR
INTO ALGER...DELTA AND MARQUETTE COUNTIES...ACROSS NRN LOWER MI TO
CHARLEVOIX COUNTY AS OF 0725Z. RUC/NAM GUIDANCE ARE CONSISTENT IN
MAINTAINING STRONG LOW-LEVEL CONVERGENCE ACROSS THE ERN UP...WITH A
SLOW SHIFT OF MEAN FLOW THROUGH THE CLOUD-BEARING LAYER FROM THE NW
TO THE NNW THROUGH THE MORNING. THIS SCENARIO APPEARS REASONABLY
WELL DEPICTED BY WRF-NMM/NSSL SIMULATED REFLECTIVITY WHICH SUGGESTS
THE HEAVIER SNOW BANDS SHOULD GRADUALLY DEVELOP SWWD TOWARDS THE
TRAVERSE BAY AREA OF NWRN LOWER MI. GIVEN THE PRESENCE OF UPSTREAM
CLOUD TOP COOLING NOTED IN IR IMAGERY...LONG/CROSS-LAKE FETCH AND
ONGOING BASE REFLECTIVITY AROUND 35 DBZ...SNOWFALL RATES NEAR 2
IN/HR WILL REMAIN LIKELY. IN ADDITION...SURFACE WIND GUSTS OF 35 TO
45 KT WILL MAINTAIN LOCALIZED BLIZZARD CONDITIONS ALONG THE LK
SHORES.

..GRAMS.. 01/02/2012

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

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

LAT...LON   46338750 46918794 47468825 47528780 46878639 45698536
            44998459 44698469 44548507 44678584 45598685 46338750

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 2, 10:46 AM EST	Mesoscale Discussion	SPC	Antrim, Charlevoix, Grand Traverse, Kalkaska, Lake, Leelanau and 4 more	4 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.