Alert archive / Michigan / Mesoscale Discussions in 2011

Mesoscale Discussion 1017

May 29, 20115 counties in Indiana; 17 counties in Michigan; 9 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at May 29, 2011, 4:17 PM EDT for 5 counties in Indiana; 17 counties in Michigan; 9 counties in Ohio. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued: May 29, 2011, 4:17 PM EDT (20:17 UTC)
Expired: May 29, 2011, 5:45 PM EDT
In force: 88 min
Issued by: the Storm Prediction Center

All 31 counties

Allen County, IN, DeKalb County, IN, LaGrange County, IN, Noble County, IN, Steuben County, IN, Branch County, MI, Calhoun County, MI, Eaton County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Kalamazoo County, MI, Lenawee County, MI, Livingston County, MI, Macomb County, MI, Monroe County, MI, Oakland County, MI, Saint Clair County, MI, Saint Joseph County, MI, Shiawassee County, MI, Washtenaw County, MI, Wayne County, MI, Defiance County, OH, Fulton County, OH, Henry County, OH, Lucas County, OH, Ottawa County, OH, Paulding County, OH, Sandusky County, OH, Williams County, OH, Wood County, OH

The radar

The Detroit radar (KDTX), 97 km from the middle of the area, began a volume at 20:19 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 12:00Z, 8.3 hours before the alert went out and 101 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 12 J/kg
Mixed-layer CIN: -294 J/kg
Mixed-layer LCL: 499 m above ground
0-6 km bulk shear: 64 kt
0-1 km storm-relative helicity: 128 m²/s²
0-3 km storm-relative helicity: 298 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

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

655 
ACUS11 KWNS 292017
SWOMCD
SPC MCD 292017 
OHZ000-MIZ000-INZ000-292145-

MESOSCALE DISCUSSION 1017
NWS STORM PREDICTION CENTER NORMAN OK
0317 PM CDT SUN MAY 29 2011

AREAS AFFECTED...SRN LOWER MI...NERN IND...NWRN OH

CONCERNING...TORNADO WATCH 395...

VALID 292017Z - 292145Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 395 CONTINUES.

LONG-LIVED QLCS OVER SWRN LOWER MI TO N-CNTRL IND CONTINUES TO
PROGRESS EWD WITH A FORWARD PROPAGATION SPEED OF 45-50 KT.
EXTRAPOLATING THIS TRACK WILL TAKE THE QLCS TOWARDS THE DETROIT TO
TOLEDO METRO AREAS BETWEEN 22-23Z. OBSERVED WIND GUSTS OF 35-45 KT
WERE COMMON ACROSS NRN IL INTO NWRN IND IN/NEAR THE BOW APEX...WHILE
MESOVORTICES AND NOTCHES IN REFLECTIVITY STRUCTURE HAVE BEEN NOTED
OVER THE PAST HOUR.

THE GREATEST RELATIVE RISK OF A SWATH OF DAMAGING WINDS WITH BRIEF
EMBEDDED TORNADOES SHOULD LIE IN THE IND/MI/OH BORDER REGION AS THE
BOW CONTINUES TO TRAVERSE A SLOW-MOVING WARM FRONT. MODIFIED 18Z DTX
RAOB SUPPORTS A RESERVOIR OF STRONG INSTABILITY ALONG THIS AXIS
CHARACTERIZED BY SURFACE DEW POINTS HOLDING NEAR 70 DEG F AND MLCAPE
OF 2500 TO 3000 J/KG. WITH 30 KT SWLY WINDS AT 1 KM AGL SAMPLED IN
THE DTX VWP...0-1 KM SRH OF 150 TO 200 M2/S2 WILL REMAIN SUPPORTIVE
OF BOTH A DAMAGING WIND/TORNADO THREAT.

ANY SWD DEVELOPMENT OF THE QLCS WILL BE DETERRED BY A STRONG CAPPING
INVERSION WHICH APPEARS TO BE STRENGTHENING ACROSS CNTRL IND/W-CNTRL
OH...EVIDENCED BY SURFACE DEW POINTS HAVING MIXED INTO THE UPPER 50S
TO LOWER 60S.

..GRAMS.. 05/29/2011

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

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

LAT...LON   42238556 42718517 42998415 43008309 42998238 42088234
            41498261 41308316 41168384 41058505 41168553 41448562
            42238556

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 29, 9:39 AM EDT	Mesoscale Discussion	SPC	Lake, LaPorte, Marshall, Porter, Saint Joseph, Starke	66 min
May 29, 9:53 AM EDT	Severe Thunderstorm Watch	SPC	Benton, Jasper, Lake, Newton, Porter	6 hr
May 29, 12:59 PM EDT	Mesoscale Discussion	SPC	Adams, Allen, Benton, Carroll, Cass, DeKalb and 21 more	61 min
May 29, 1:29 PM EDT	Tornado Watch	SPC	Adams, Allen, Blackford, Cass, DeKalb, Elkhart and 18 more	7 hr
May 29, 6:51 PM EDT	Mesoscale Discussion	SPC	Genesee, Lapeer, Lenawee, Livingston, Macomb, Monroe and 8 more	54 min
May 29, 6:05 PM EDT	Mesoscale Discussion	SPC	Ashland, Ashtabula, Cuyahoga, Geauga, Lake, Lorain and 5 more	25 min
May 29, 6:17 PM EDT	Severe Thunderstorm Watch	SPC	Ashtabula, Cuyahoga, Erie, Geauga, Huron, Lake and 5 more	5 hr
May 29, 7:28 PM EDT	Mesoscale Discussion	SPC	Ashtabula, Cuyahoga, Erie, Geauga, Huron, Lake and 5 more	62 min

Nearby

Mesoscale Discussions in Michigan, 2011 Mesoscale Discussions in Ohio, 2011 Mesoscale Discussions in Indiana, 2011 Every 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.