Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 162

February 28, 201124 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at Feb 28, 2011, 12:04 AM EST for 24 counties in Michigan. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Feb 28, 2011, 12:04 AM EST (05:04 UTC)
Expired
Feb 28, 2011, 6:00 AM EST
In force
6 hr
Issued by
the Storm Prediction Center
All 24 counties

Allegan County, MI, Barry County, MI, Bay County, MI, Calhoun County, MI, Clinton County, MI, Eaton County, MI, Genesee County, MI, Gratiot County, MI, Huron County, MI, Ingham County, MI, Ionia County, MI, Isabella County, MI, Kalamazoo County, MI, Kent County, MI, Lapeer County, MI, Livingston County, MI, Mecosta County, MI, Midland County, MI, Montcalm County, MI, Newaygo County, MI, Ottawa County, MI, Saginaw County, MI, Shiawassee County, MI, Tuscola County, MI

The radar

The Grand Rapids radar (KGRR), 88 km from the middle of the area, began a volume at 05:03 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

Detroit, MI (KDTX), launched 00:00Z, 5.1 hours before the alert went out and 97 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, Detroit, MI at 00:00Z on 2011-02-28Temperature 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, Detroit, MI at 00:00Z on 2011-02-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 308 square meters per square second.1939587897117136Sfc1 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
593 m above ground
0-6 km bulk shear
87 kt
0-1 km storm-relative helicity
308 m²/s²
0-3 km storm-relative helicity
401 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.

715 
ACUS11 KWNS 280505
SWOMCD
SPC MCD 280504
MIZ000-281100-

MESOSCALE DISCUSSION 0162
NWS STORM PREDICTION CENTER NORMAN OK
1104 PM CST SUN FEB 27 2011

AREAS AFFECTED...CNTRL AND PORTIONS OF SRN LOWER MI

CONCERNING...WINTER MIXED PRECIPITATION

VALID 280504Z - 281100Z

A MIX OF PRECIP TYPES WILL OVERSPREAD CNTRL AND PORTIONS OF SRN
LOWER MI OVERNIGHT TONIGHT. FREEZING RAIN IS EXPECTED TO
OCCUR...MAINLY ACROSS SRN LOWER MI...WITH RATES OF 0.05 INCH PER
HOUR POSSIBLE.

A LARGE SHIELD OF STRATIFORM PRECIP WITH EMBEDDED CONVECTIVE
ELEMENTS WILL OVERSPREAD THE DISCUSSION AREA OVERNIGHT TONIGHT. THIS
ACTIVITY WILL BE SUSTAINED BY INCREASING LOW/MID-LEVEL FRONTOGENESIS
ASSOCIATED WITH A SHORTWAVE TROUGH. AT 04Z...SFC OBSERVATIONS
INDICATE THAT THE FREEZING LINE EXTENDS FROM CNTRL PORTIONS OF THE
THUMB OF LOWER MI TO NEAR MKG. AS SFC LOW PRESSURE ACCELERATES NEWD
ACROSS THE LOWER GREAT LAKES REGION...LOW-LEVEL COLD AIR ADVECTION
WILL INTENSIFY...ALLOW THE SFC FREEZING LINE TO DROP SEWD...MOST
NOTABLY AFTER 07Z ACCORDING TO THE RUC MODEL.

TO THE NORTH OF THE FREEZING LINE...A MIX OF PRECIPITATION TYPES IS
EXPECTED...AS HAS BEEN OBSERVED UPSTREAM ACROSS NERN IL THIS
EVENING. FREEZING RAIN IS MOST LIKELY ACROSS SRN PORTIONS OF THE
DISCUSSION AREA...WITH RATES OF 0.05 INCH PER HOUR POSSIBLE. THIS
WILL OCCUR AS AN ELEVATED WARM NOSE FEATURING TEMPERATURES AOA 3C
ALLOWS FALLING PRECIP TO MELT PRIOR TO FREEZING AT THE SFC...AND
ELEVATED INSTABILITY / MUCAPE VALUES AOA 100 J/KG PER RUC ANALYSIS /
SPREADS NWD. THIS COULD SUPPORT THUNDERSTORMS...WHICH WILL BE
CAPABLE OF PRODUCING LOCALLY HEAVIER FREEZING RAIN. FARTHER
NORTH...COLDER LOW-LEVEL TEMPERATURES WILL BE MORE SUPPORTIVE OF
SLEET AND SNOW...WITH THE POTENTIAL FOR SLEET AND SNOW SPREADING
SEWD AFTER 07Z. MOST OF THE PRECIPITATION IS EXPECTED TO MOVE EAST
OF THE REGION BY 11Z.

..COHEN.. 02/28/2011

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

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

LAT...LON   43028297 42598391 42258492 42058606 42478648 42938666
            43518636 43858488 43978343 43918279 43658253 43028297

Nearby

Mesoscale Discussions in Michigan, 2011Every mesoscale discussion in 2011

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.