Alert archive / Michigan / Mesoscale Discussions in 2012
Mesoscale Discussion 922
The Storm Prediction Center issued this mesoscale discussion at May 27, 2012, 3:38 PM EDT for 8 counties in Michigan. It was in force for 67 min.
The area
The outline as issued.
The facts
- Issued
- May 27, 2012, 3:38 PM EDT (19:38 UTC)
- Expired
- May 27, 2012, 4:45 PM EDT
- In force
- 67 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Barry County, MI, Eaton County, MI, Ingham County, MI, Ionia County, MI, Jackson County, MI, Kent County, MI, Monroe County, MI, Washtenaw County, MI
The radar
The Grand Rapids radar (KGRR), 58 km from the middle of the area, began a volume at 19:41 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, 7.6 hours before the alert went out and 139 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.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1411 m above ground
- 0-6 km bulk shear
- 37 kt
- 0-1 km storm-relative helicity
- 245 m²/s²
- 0-3 km storm-relative helicity
- 205 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.8
The text
As transmitted, in the capitals the NWS used until 2016.
697
ACUS11 KWNS 271939
SWOMCD
SPC MCD 271938
MIZ000-272045-
MESOSCALE DISCUSSION 0922
NWS STORM PREDICTION CENTER NORMAN OK
0238 PM CDT SUN MAY 27 2012
AREAS AFFECTED...SRN MI
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 271938Z - 272045Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...A VERY CONDITIONAL THREAT EXISTS FOR AN ISOLATED SUPERCELL
CAPABLE OF LARGE HAIL...DMGG WINDS...AND PERHAPS A TORNADO. ALTHOUGH
CONVECTIVE INITIATION APPEARS UNLIKELY PER MODEL GUIDANCE...IF
STORMS CAN DEVELOP...A WW WILL BE NECESSARY.
DISCUSSION...19Z VISIBLE AND RADAR IMAGERY SUGGEST A SERIES OF
LOW-LEVEL BOUNDARIES ARE CLOSE TO MERGING...INCLUDING A REMNANT
OUTFLOW EXTENDING FROM NEAR MKG TO BAX...A LAKE BREEZE NEAR ALLEGAN
COUNTY...AND A WARM FRONT EXTENDING ACROSS SRN MI. THE RESULTING
STRENGTHENING IN LOW LEVEL CONVERGENCE COULD BE SUFFICIENT ENOUGH TO
FORCE CONVECTION...OVERCOMING THE REMAINING CONVECTIVE INHIBITION. A
PLUME OF STEEP MID LEVEL LAPSE RATES IS ADVECTING EWD /8-8.5 C/KM
PER MESOANALYSIS/...AND WILL BE SUPPORTIVE OF STRONG SUPERCELLS
GIVEN 50 KT EFFECTIVE BULK SHEAR. FURTHERMORE...VAD WIND PROFILE
DATA INDICATES STRONGER LOW LEVEL WINDS THAN MODEL FORECAST...WITH
NEAR 250 M2/S2 0-3 KM SRH INVOF OF THE WARM FRONT. IF A STORM CAN
INITIATE AND BECOME SUSTAINED...ESPECIALLY INVOF THE WARM FRONT...A
SIGNIFICANT THREAT OF SEVERE WEATHER WILL EXIST. HOWEVER...GIVEN THE
STRENGTH OF THE CAP...INITIATION REMAINS SOMEWHAT UNCERTAIN. THE
AREA WILL CONTINUE TO BE MONITORED.
..HURLBUT/CARBIN.. 05/27/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...DTX...IWX...GRR...
LAT...LON 42728649 43158592 42958497 42518388 42098341 41808341
42078447 42428550 42478641 42728649Nearby
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.