Alert archive / Michigan / Mesoscale Discussions in 2016

Mesoscale Discussion 778

May 29, 201611 counties in Michigan; Fulton County, Williams County, Ohio

The Storm Prediction Center issued this mesoscale discussion at May 29, 2016, 2:34 PM EDT for 11 counties in Michigan; Fulton County, Williams County, Ohio. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
May 29, 2016, 2:34 PM EDT (18:34 UTC)
Expired
May 29, 2016, 4:30 PM EDT
In force
116 min
Issued by
the Storm Prediction Center
Chance of a watch
20%

Counties Genesee County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Lapeer County, MI, Lenawee County, MI, Livingston County, MI, Oakland County, MI, Shiawassee County, MI, Tuscola County, MI, Washtenaw County, MI, Fulton County, OH, Williams County, OH

The radar

The Detroit radar (KDTX), 36 km from the middle of the area, began a volume at 18:37 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, 6.6 hours before the alert went out and 40 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 12:00Z on 2016-05-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 643 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, Detroit, MI at 12:00Z on 2016-05-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 78 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
643 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
801 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
78 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.2
Supercell composite
1.1

Open this sounding in Storm Lab

The text

As transmitted.

545 
ACUS11 KWNS 291834
SWOMCD
SPC MCD 291834 
MIZ000-OHZ000-INZ000-292030-

MESOSCALE DISCUSSION 0778
NWS STORM PREDICTION CENTER NORMAN OK
0134 PM CDT SUN MAY 29 2016

AREAS AFFECTED...SERN LWR MICHIGAN AND ADJACENT NERN IND/NWRN OH

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY 

VALID 291834Z - 292030Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...DEVELOPING THUNDERSTORM ACTIVITY MAY BE ACCOMPANIED BY AT
LEAST SOME SEVERE WEATHER POTENTIAL THIS AFTERNOON.  THE NEED FOR A
WATCH IS NOT CURRENTLY ANTICIPATED...BUT TRENDS WILL CONTINUE TO BE
MONITORED.

DISCUSSION...THUNDERSTORM ACTIVITY APPEARS IS IN THE PROCESS OF
INITIATING ALONG AN APPARENT LOW-LEVEL CONFLUENCE ZONE...NORTHEAST
OF FORT WAYNE THROUGH THE MICHIGAN THUMB AREA.  ALTHOUGH LOW-LEVEL
CONVERGENCE DOES NOT APPEAR PARTICULARLY STRONG...INHIBITION FOR A
MOIST BOUNDARY LAYER CHARACTERIZED BY CAPE IN EXCESS OF 1000 J/KG IS
BECOMING INCREASINGLY NEGLIGIBLE.  THE DEGREE OF UNSATURATION WITHIN
THE LOWER/MID TROPOSPHERE EVIDENT IN THE 18Z RAOB FROM DETROIT COULD
INITIALLY SLOW STORM DEVELOPMENT.  HOWEVER...MODELS SUGGEST THAT
MID-LEVEL FORCING FOR ASCENT ASSOCIATED WITH THE SHORT WAVE IMPULSE
NOW PIVOTING THROUGH THE UPPER GREAT LAKES MAY CONTRIBUTE TO
SCATTERED INTENSIFYING THUNDERSTORMS BY 20-22Z.

SHEAR APPEARS MARGINAL FOR ORGANIZED STORM DEVELOPMENT...BUT A  BELT
OF 30-40 KT SOUTHWESTERLY LOWER/MID TROPOSPHERIC FLOW MAY SUPPORT
LOCALLY STRONG SURFACE GUSTS...WHICH COULD IMPACT THE DETROIT
METROPOLITAN AREA...AS DOWNDRAFTS INTENSIFY LATER THIS AFTERNOON. 
UNTIL THEN...STRONGER INITIAL STORMS MAY BE ACCOMPANIED BY A RISK
FOR HAIL THAT COULD APPROACH OR BRIEFLY EXCEED SEVERE LIMITS.

..KERR/CORFIDI.. 05/29/2016

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

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

LAT...LON   43408397 44008295 43158262 41618387 41408458 41718490
            42658441 43408397

Nearby

Mesoscale Discussions in Michigan, 2016Mesoscale Discussions in Ohio, 2016Every mesoscale discussion in 2016

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.