Alert archive / Michigan / Mesoscale Discussions in 2012

Mesoscale Discussion 174

February 29, 201231 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Feb 29, 2012, 12:28 AM EST for 31 counties in Michigan. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Feb 29, 2012, 12:28 AM EST (05:28 UTC)
Expired
Feb 29, 2012, 6:30 AM EST
In force
6 hr
Issued by
the Storm Prediction Center
All 31 counties

Alcona County, MI, Alpena County, MI, Antrim County, MI, Arenac County, MI, Bay County, MI, Benzie County, MI, Charlevoix County, MI, Cheboygan County, MI, Clare County, MI, Crawford County, MI, Emmet County, MI, Gladwin County, MI, Grand Traverse County, MI, Iosco County, MI, Isabella County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Manistee County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montmorency 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), 19 km from the middle of the area, began a volume at 05:27 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 00:00Z, 5.5 hours before the alert went out and 193 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-pSkew-T log-p diagram, Alpena, MI at 00:00Z on 2012-02-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Alpena, MI at 00:00Z on 2012-02-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 184 square meters per square second.1939587897117136156Sfc1 km3 km6 km9 kmRMLM
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
1157 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
184 m²/s²
0-3 km storm-relative helicity
314 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.

100 
ACUS11 KWNS 290528
SWOMCD
SPC MCD 290528 
MIZ000-291130-

MESOSCALE DISCUSSION 0174
NWS STORM PREDICTION CENTER NORMAN OK
1128 PM CST TUE FEB 28 2012

AREAS AFFECTED...NRN LOWER MI

CONCERNING...WINTER MIXED PRECIPITATION 

VALID 290528Z - 291130Z

HEAVY SNOW WILL DEVELOP ACROSS NORTHERN PORTIONS LOWER MICHIGAN OVER
THE NEXT COUPLE OF HOURS AND PERSIST THROUGH EARLY MORNING. SNOWFALL
RATES WILL MAINLY RANGE FROM .5 TO 1 IN/HR. FURTHER SOUTH ACROSS THE
DISCUSSION AREA...MIXED PRECIPITATION TYPES OF FREEZING RAIN AND
SLEET ARE EXPECTED TO PREVAIL.

A SFC LOW CURRENTLY LOCATED OVER NORTHEAST NEBRASKA WILL CONTINUE TO
TRACK NORTHEAST THROUGH THE EARLY MORNING HOURS AS WILL THE
ASSOCIATED UPPER LEVEL TROUGH...NOW SITUATED FROM CENTRAL KANSAS
NORTHWESTWARD TOWARD THE WESTERN DAKOTAS. AS THIS SYSTEM LIFTS
NORTHEAST...A BAND OF FRONTOGENESIS AROUND THE 850-700 MB LAYER WILL
PIVOT EASTWARD FROM MINNESOTA AND WISCONSIN INTO NORTHERN MICHIGAN.
AIDED BY DEEP LAYER ASCENT THROUGH A DEEP SATURATED ENVIRONMENT AND
NEARLY 50 MB DEEP DENDRITIC ZONE...PERIODS OF HEAVY SNOW ARE
EXPECTED. POINT FORECAST SOUNDING INDICATE THAT THE VERTICAL THERMAL
PROFILE WILL REMAIN SUB-FREEZING THROUGHOUT AND THE PRECIPITATION
TYPE WILL REMAIN ALL SNOW THROUGH THE EARLY MORNING HOURS.

FURTHER SOUTH ACROSS THE DISCUSSION AREA...WARMER MIDLEVEL
TEMPERATURES ON THE ORDER OF 1 TO 3 DEG C WILL LEAD TO MAINLY SLEET
AND FREEZING RAIN AT THE SFC. SOME AREAS MAY EVEN TRANSITION TO RAIN
BY 12Z ACROSS FAR SOUTHERN PARTS OF THE MCD AREA.

..LEITMAN.. 02/29/2012

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

ATTN...WFO...DTX...APX...GRR...

LAT...LON   44618635 45248609 45848561 45948504 45938455 45888430
            45468355 45398345 45018315 44378321 43878335 43608366
            43548436 43648580 43768644 44098645 44618635

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 28, 9:41 PM ESTMesoscale DiscussionSPCDelta, Dickinson, Gogebic, Iron, Menominee6 hr

Nearby

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.