Alert archive / Michigan / Mesoscale Discussions in 2012

Mesoscale Discussion 675

May 3, 201224 counties in Michigan

The Storm Prediction Center issued this mesoscale discussion at May 3, 2012, 2:39 PM EDT for 24 counties in Michigan. It was in force for 66 min.

The area

The outline as issued.

The facts

Issued
May 3, 2012, 2:39 PM EDT (18:39 UTC)
Expired
May 3, 2012, 3:45 PM EDT
In force
66 min
Issued by
the Storm Prediction Center
All 24 counties

Antrim County, MI, Arenac County, MI, Bay County, MI, Benzie County, MI, Clare County, MI, Crawford County, MI, Gladwin County, MI, Grand Traverse County, MI, Isabella County, MI, Kalkaska County, MI, Lake County, MI, Leelanau County, MI, Manistee County, MI, Mecosta County, MI, Midland County, MI, Missaukee County, MI, Montmorency County, MI, Newaygo County, MI, Ogemaw County, MI, Osceola County, MI, Oscoda County, MI, Otsego County, MI, Roscommon County, MI, Wexford County, MI

The radar

The NCL Michigan radar (KAPX), 59 km from the middle of the area, began a volume at 18:40 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 12:00Z, 6.7 hours before the alert went out and 226 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, Green Bay/Straub, WI at 12:00Z on 2012-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 321 joules per kilogram.LCLLFCEL10008507005003002001001 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, Green Bay/Straub, WI at 12:00Z on 2012-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 160 square meters per square second.19395878Sfc1 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
321 J/kg
Mixed-layer CIN
-146 J/kg
Mixed-layer LCL
565 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
160 m²/s²
0-3 km storm-relative helicity
220 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.8

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

583 
ACUS11 KWNS 031839
SWOMCD
SPC MCD 031839 
MIZ000-031945-

MESOSCALE DISCUSSION 0675
NWS STORM PREDICTION CENTER NORMAN OK
0139 PM CDT THU MAY 03 2012

AREAS AFFECTED...NRN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 229...

VALID 031839Z - 031945Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 229
CONTINUES.

SUMMARY...STRONG THUNDERSTORMS WILL CONTINUE PRIMARILY ACROSS THE
SERN HALF OF WW229 OVER THE NEXT FEW HOURS.

DISCUSSION...LEADING EDGE OF LARGER MCS IS PROGRESSING ACROSS NRN
LOWER MI AT ROUGHLY 45KT.  WHILE THE INTENSITY OF THIS LEADING EDGE
HAS WANED SOME OVER THE LAST HOUR STRONG STORMS ARE BECOMING
ORIENTED IN A NE-SW FASHION TRAILING FROM MISSAUKEE COUNTY ACROSS
CNTRL PORTIONS OF LAKE MI.  WITH TIME THIS DEVELOPING BAND OF STRONG
STORMS SHOULD SAG SEWD AT 15-20KT ACROSS THE REMAINDER OF WW229.

..DARROW.. 05/03/2012

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

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

LAT...LON   45238637 45218357 43498356 43518638 45238637

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 3, 12:51 AM EDTMesoscale DiscussionSPCManistee, Mason, Oceana54 min
May 3, 11:34 AM EDTMesoscale DiscussionSPCArenac, Bay, Clare, Clinton, Genesee, Gladwin and 28 more86 min
May 3, 12:41 PM EDTSevere Thunderstorm WatchSPCAlcona, Alpena, Antrim, Arenac, Bay, Benzie and 23 more5 hr
May 3, 2:35 PM EDTSevere Thunderstorm WatchSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 27 more8 hr
May 3, 3:53 PM EDTMesoscale DiscussionSPCBerrien67 min
May 3, 4:33 PM EDTMesoscale DiscussionSPCAllegan, Barry, Bay, Calhoun, Cass, Clinton and 15 more57 min
May 3, 6:57 PM EDTMesoscale DiscussionSPCAllegan, Barry, Berrien, Branch, Calhoun, Cass and 28 more63 min

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.