Alert archive / Michigan / Mesoscale Discussions in 2012

Mesoscale Discussion 1401

July 5, 201210 counties in Michigan; 8 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jul 5, 2012, 4:12 AM EDT for 10 counties in Michigan; 8 counties in Ohio. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
Jul 5, 2012, 4:12 AM EDT (08:12 UTC)
Expired
Jul 5, 2012, 5:45 AM EDT
In force
93 min
Issued by
the Storm Prediction Center

Counties Genesee County, MI, Ingham County, MI, Jackson County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Washtenaw County, MI, Wayne County, MI, Cuyahoga County, OH, Erie County, OH, Huron County, OH, Lake County, OH, Lorain County, OH, Lucas County, OH, Ottawa County, OH, Sandusky County, OH

The radar

The Detroit radar (KDTX), 55 km from the middle of the area, began a volume at 08:12 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Detroit, MI (KDTX), launched 00:00Z, 8.2 hours before the alert went out and 56 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 2012-07-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4748 joules per kilogram.LCLEL10008507005003002001001 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 2012-07-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 square meters per square second.1939Sfc1 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
4748 J/kg
Mixed-layer CIN
-23 J/kg
Mixed-layer LCL
1268 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
1.4
Supercell composite
9.5

Open this sounding in Storm Lab

The text

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

756 
ACUS11 KWNS 050813
SWOMCD
SPC MCD 050812
OHZ000-MIZ000-050945-

MESOSCALE DISCUSSION 1401
NWS STORM PREDICTION CENTER NORMAN OK
0312 AM CDT THU JUL 05 2012

AREAS AFFECTED...SOUTHEAST LOWER MI AND NORTHERN OH

CONCERNING...SEVERE THUNDERSTORM WATCH 467...

VALID 050812Z - 050945Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 467
CONTINUES.

SUMMARY...A CORRIDOR OF DAMAGING WIND/SOME HAIL POTENTIAL WILL
CONTINUE TO QUICKLY SPREAD SOUTHEASTWARD ACROSS SOUTHEAST LOWER
MI...POTENTIALLY IMPACTING THE DETROIT METRO AREA BY 0830Z-0900Z
/430AM-5AM LOCAL TIME/. SEVERE TSTM WATCH 467 CONTINUES UNTIL 12Z.
MCS DOWNSTREAM PORTIONS OF NORTHERN OH WILL BE MONITORED FOR AN
ADDITIONAL SEVERE TSTM WATCH EARLY THIS MORNING.

DISCUSSION...A ROUGHLY 50-MILE NORTH-SOUTH EXTENSIVE...AND NOW VERY
WELL-ORGANIZED...QUASI-LINEAR CONVECTIVE CLUSTER/ASSOCIATED BOWING
STRUCTURE CONTINUES TO STEADILY GROW UPSCALE/MATURE AS IT SPREADS
SOUTHEASTWARD ACROSS SOUTHEAST LOWER MI EARLY THIS
MORNING...CENTERED BETWEEN THE LANSING AND FLINT AREAS AS OF 08Z.
FORWARD PROPAGATION/ACCELERATION CONTINUES TO OCCUR WITH SOME
ELEMENTS NOW MOVING EAST-SOUTHEASTWARD AT NEAR 50 KT...WITH A 50 KT
WIND GUST RECENTLY /0728Z/ MEASURED AT LANSING MI. THE DISTINCT
LIKELIHOOD OF COLD POOL EXPANSION AND ADDITIONAL FORWARD
ACCELERATION/PROPAGATION IN THE SHORT-TERM...WITH CONTINUED GUST
FRONT UPLIFT/LEADING ECHOES READILY EVIDENT...WILL LIKELY MAINTAIN
DAMAGING WIND/SOME HAIL POTENTIAL ACROSS THE REMAINDER OF SOUTHEAST
LOWER MI /INCLUDING THE DETROIT METRO AREA/ EVEN WHILE A SHALLOW
NEAR-SURFACE STABLE LAYER EXISTS. IT IS CONCEIVABLE THAT THIS MCS
COULD PERSIST INTO PORTIONS OF NORTHERN OH WITHIN THE NEXT FEW HOURS
/10Z OR AFTER/.

..GUYER.. 07/05/2012

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

ATTN...WFO...CLE...DTX...IWX...GRR...

LAT...LON   42658451 42698409 43358398 42978289 42378226 41748110
            41218136 41078263 41568375 42308461 42658451

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 4, 11:54 PM EDTMesoscale DiscussionSPCClare, Gratiot, Ionia, Isabella, Kent, Lake and 11 more96 min
Jul 5, 2:57 AM EDTMesoscale DiscussionSPCBarry, Branch, Calhoun, Clinton, Eaton, Genesee and 19 more63 min
Jul 5, 3:04 AM EDTSevere Thunderstorm WatchSPCBarry, Calhoun, Eaton, Genesee, Ingham, Ionia and 11 more3 hr
Jul 5, 3:27 PM EDTMesoscale DiscussionSPCBranch, Hillsdale, Jackson, Lenawee, Monroe, Washtenaw and 1 more93 min
Jul 5, 5:58 PM EDTMesoscale DiscussionSPCBerrien, Branch, Cass, Saint Joseph92 min
Jul 4, 9:48 PM EDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Champaign, Clark, Clinton and 35 more87 min
Jul 4, 10:19 PM EDTSevere Thunderstorm WatchSPCAdams, Athens, Auglaize, Belmont, Brown, Butler and 46 more4 hr
Jul 5, 6:16 AM EDTSevere Thunderstorm WatchSPCAshland, Ashtabula, Carroll, Columbiana, Coshocton, Crawford and 21 more3 hr
Jul 5, 8:00 AM EDTMesoscale DiscussionSPCAthens, Belmont, Carroll, Columbiana, Coshocton, Fairfield and 18 more90 min
Jul 5, 11:14 AM EDTMesoscale DiscussionSPCGallia, Lawrence91 min
Jul 5, 11:37 AM EDTSevere Thunderstorm WatchSPCLawrence7 hr

Nearby

Mesoscale Discussions in Michigan, 2012Mesoscale Discussions in Ohio, 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.