Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 82

February 2, 201110 counties in Illinois; 39 counties in Michigan; Kenosha County, Milwaukee County, Racine County, Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Feb 2, 2011, 2:33 AM CST for 10 counties in Illinois; 39 counties in Michigan; Kenosha County, Milwaukee County, Racine County, Wisconsin. It was in force for 4 hr.

The area

The outline as issued.

The facts

Issued
Feb 2, 2011, 2:33 AM CST (08:33 UTC)
Expired
Feb 2, 2011, 6:30 AM CST
In force
4 hr
Issued by
the Storm Prediction Center
All 52 counties

Boone County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Kane County, IL, Kendall County, IL, Lake County, IL, Lee County, IL, McHenry County, IL, Ogle County, IL, Alcona County, MI, Allegan County, MI, Alpena County, MI, Arenac County, MI, Barry County, MI, Bay County, MI, Clare County, MI, Clinton County, MI, Crawford County, MI, Eaton County, MI, Genesee County, MI, Gladwin County, MI, Gratiot County, MI, Huron County, MI, Ionia County, MI, Iosco County, MI, Isabella County, MI, Kent County, MI, Lake County, MI, Lapeer County, MI, Mason County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montcalm County, MI, Muskegon County, MI, Newaygo County, MI, Oceana County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Ottawa County, MI, Presque Isle County, MI, Roscommon County, MI, Saginaw County, MI, Sanilac County, MI, Shiawassee County, MI, Tuscola County, MI, Wexford County, MI, Kenosha County, WI, Milwaukee County, WI, Racine County, WI

The radar

The Grand Rapids radar (KGRR), 50 km from the middle of the area, began a volume at 08:36 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, 8.6 hours before the alert went out and 220 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 2011-02-02Temperature 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 2011-02-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 199 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
593 m above ground
0-6 km bulk shear
60 kt
0-1 km storm-relative helicity
199 m²/s²
0-3 km storm-relative helicity
335 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.

320 
ACUS11 KWNS 020833
SWOMCD
SPC MCD 020833 
MIZ000-INZ000-ILZ000-WIZ000-021230-

MESOSCALE DISCUSSION 0082
NWS STORM PREDICTION CENTER NORMAN OK
0233 AM CST WED FEB 02 2011

AREAS AFFECTED...LOWER MI...NE IL...SERN WI

CONCERNING...BLIZZARD 

VALID 020833Z - 021230Z

MATURE AND IMPRESSIVE MID-LEVEL CYCLONE CONTINUES TO ACCELERATE NEWD
THROUGH NRN IND WITH ATTENDANT LOW/MID-LEVEL DRY SLOT ADVANCING NEWD
INTO SRN/SERN LOWER MI.  ALONG N EDGE OF THIS DRY SLOT...INTENSE
MID-LEVEL FRONTOGENETIC FORCING AND A COUPLE HUNDRED J/KG OF MUCAPE
WERE RESULTING IN MULTIBANDS OF MESOSCALE SNOWFALL /INCLUDING
THUNDER/ OVER CNTRL LOWER MI AND THE THUMB AREA. THIS REGION WILL
EXPERIENCE THE HEAVIEST SNOWFALL RATES BEFORE 12Z...WITH RATES
DIMINISHING THEREAFTER AS STRONGER FORCING SPREADS INTO SWRN
ONTARIO.

MEANWHILE...VIRTUALLY ALL THE MESOSCALE MODELS
/HRRR-NMM-ARW-NSSL-RUC12/ SUGGEST THAT A PERSISTENT MESOSCALE
SNOWBAND...RESULTING FROM A COMBINATION OF RESIDUAL MID-LEVEL
FRONTOGENESIS AND ENHANCED LAKE EFFECT FETCH...WILL EXIST ACROSS
CHICAGOLAND AND EXTREME SERN WI...THROUGH AROUND 15Z.  WHILE THE
WIDESPREAD 1-2 INCH PER HOUR RATES WILL DIMINISH WITH TIME WITHIN
THE DEFORMATION AXIS...NARROW INTENSE SNOWBANDS MAY LINGER FOR A
WHILE LONGER.

INTENSE PRESSURE GRADIENT OBSERVED ACROSS THE REGION WILL MAINTAIN
BLIZZARD CONDITIONS...PARTICULARLY ACROSS THE LAKESHORE AREAS OF SE
WI AND NE IL THROUGH MID-MORNING.

..RACY.. 02/02/2011

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

ATTN...WFO...DTX...APX...GRR...LOT...MKX...DVN...

LAT...LON   42598477 42258659 41598749 41428825 41408907 41938948
            43088796 43688710 45478300 44028156 42938347 42598477

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Feb 1, 6:28 PM CSTMesoscale DiscussionSPCAllegan, Arenac, Barry, Bay, Branch, Calhoun and 45 more5 hr

Nearby

Mesoscale Discussions in Michigan, 2011Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Wisconsin, 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.