Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 172

February 28, 20125 states

The Storm Prediction Center issued this mesoscale discussion at Feb 28, 2012, 9:41 PM EST for 5 states. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued: Feb 28, 2012, 9:41 PM EST (02:41 UTC)
Expired: Feb 29, 2012, 3:45 AM EST
In force: 6 hr
Issued by: the Storm Prediction Center

All 77 counties

Delta County, MI, Dickinson County, MI, Gogebic County, MI, Iron County, MI, Menominee County, MI, Aitkin County, MN, Anoka County, MN, Becker County, MN, Benton County, MN, Big Stone County, MN, Carlton County, MN, Cass County, MN, Chippewa County, MN, Chisago County, MN, Clay County, MN, Crow Wing County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Isanti County, MN, Kanabec County, MN, Kandiyohi County, MN, Lac qui Parle County, MN, Meeker County, MN, Mille Lacs County, MN, Morrison County, MN, Otter Tail County, MN, Pine County, MN, Pope County, MN, Sherburne County, MN, Stearns County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Traverse County, MN, Wadena County, MN, Wilkin County, MN, Wright County, MN, Barnes County, ND, Cass County, ND, Dickey County, ND, LaMoure County, ND, McIntosh County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Brown County, SD, Day County, SD, Grant County, SD, Marshall County, SD, McPherson County, SD, Roberts County, SD, Ashland County, WI, Barron County, WI, Bayfield County, WI, Burnett County, WI, Chippewa County, WI, Door County, WI, Douglas County, WI, Florence County, WI, Forest County, WI, Iron County, WI, Langlade County, WI, Lincoln County, WI, Marathon County, WI, Marinette County, WI, Menominee County, WI, Oconto County, WI, Oneida County, WI, Polk County, WI, Price County, WI, Rusk County, WI, Sawyer County, WI, Shawano County, WI, Taylor County, WI, Vilas County, WI, Washburn County, WI

The radar

The Minneapolis radar (KMPX), 130 km from the middle of the area, began a volume at 02:42 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

Minneapolis, MN (KMPX), launched 00:00Z, 2.7 hours before the alert went out and 132 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: 2 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 503 m above ground
0-6 km bulk shear: 44 kt
0-1 km storm-relative helicity: 146 m²/s²
0-3 km storm-relative helicity: 245 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.

783 
ACUS11 KWNS 290242
SWOMCD
SPC MCD 290241
MIZ000-WIZ000-MNZ000-SDZ000-NDZ000-290845-

MESOSCALE DISCUSSION 0172
NWS STORM PREDICTION CENTER NORMAN OK
0841 PM CST TUE FEB 28 2012

AREAS AFFECTED...SERN ND...NERN SD...CNTRL MN...NRN WI AND PORTIONS
OF THE UPPER PENINSULA OF MI

CONCERNING...HEAVY SNOW

VALID 290241Z - 290845Z

PERIODS OF MODERATE TO HEAVY SNOW WILL MOVE NORTHWARD ACROSS THE MCD
AREA THROUGH THE OVERNIGHT AREAS. SNOWFALL RATES WILL MAINLY
APPROACH .5 IN/HR TO 1 IN/HR. HOWEVER...BRIEF HEAVIER BURSTS ARE
POSSIBLE.

A SFC LOW CURRENTLY OVER N CNTRL NEBRASKA WILL CONTINUE TO TRACK
NORTHEASTWARD OVERNIGHT IN CONJUNCTION WITH AN UPPER LEVEL TROUGH
SITUATED FROM THE WESTERN PLAINS OF KS TOWARD EASTERN MONTANA. AS
THIS SYSTEM CONTINUES NORTHEASTWARD OVERNIGHT...A BAND OF LOW AND
MIDLEVEL FRONTOGENESIS WILL STRENGTHEN AND MOVE NORTHWARD ACROSS THE
MCD AREA. DEEP LAYER ASCENT ASSOCIATED WITH THIS BAND OF
FRONTOGENESIS...WAA AND DCVA AHEAD OF THE APPROACHING LOW...WILL
ALLOW FOR AT LEAST PERIODIC BANDS OF HEAVY SNOWFALL. FURTHER SUPPORT
FOR HEAVY BANDED PRECIPITATION IS EVIDENT BY SOME MODEST MUCAPE
VALUES /LESS THAN 100 J/KG/ ACROSS SOUTHERN PORTIONS OF THE MCD
AREA. THEREFORE...A FEW STRIKES OF LIGHTNING MAY ACCOMPANY HEAVIER
SNOW BURSTS. FURTHER NORTH...SLANT-WISE TYPE INSTABILITY IS
ANTICIPATED.

THE HEAVIEST SNOWFALL IS EXPECTED ACROSS WESTERN PORTIONS OF THE MCD
AREA THROUGH ABOUT 06Z TO 09Z BEFORE HIGHER RATES SHIFT EASTWARD
INTO WI AND THE U.P OF MI.

..LEITMAN.. 02/29/2012

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

ATTN...WFO...MQT...GRB...DLH...ARX...MPX...FGF...ABR...BIS...

LAT...LON   44748730 44498764 44518841 44638949 44959088 45109238
            44929481 44929566 45049660 45329831 45609911 46139945
            46709917 47159823 47329626 47289426 47089193 46698929
            46158723 45908674 45548674 45078704 44748730

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Feb 29, 12:28 AM EST	Mesoscale Discussion	SPC	Alcona, Alpena, Antrim, Arenac, Bay, Benzie and 25 more	6 hr

Nearby

Mesoscale Discussions in Minnesota, 2012 Mesoscale Discussions in Wisconsin, 2012 Mesoscale Discussions in North Dakota, 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.