Alert archive / Minnesota / Mesoscale Discussions in 2012
Mesoscale Discussion 1802
The Storm Prediction Center issued this mesoscale discussion at Aug 23, 2012, 6:07 PM CDT for 15 counties in Minnesota. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- Aug 23, 2012, 6:07 PM CDT (23:07 UTC)
- Expired
- Aug 23, 2012, 7:00 PM CDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
Counties Blue Earth County, MN, Brown County, MN, Cottonwood County, MN, Jackson County, MN, Lyon County, MN, Martin County, MN, Murray County, MN, Nicollet County, MN, Nobles County, MN, Pipestone County, MN, Redwood County, MN, Renville County, MN, Rock County, MN, Sibley County, MN, Watonwan County, MN
The radar
The Minneapolis radar (KMPX), 136 km from the middle of the area, began a volume at 23:09 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
Minneapolis, MN (KMPX), launched 12:00Z, 11.1 hours before the alert went out and 134 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
- 2118 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 78 m²/s²
- 0-3 km storm-relative helicity
- 158 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
180
ACUS11 KWNS 232307
SWOMCD
SPC MCD 232307
MNZ000-SDZ000-240000-
MESOSCALE DISCUSSION 1802
NWS STORM PREDICTION CENTER NORMAN OK
0607 PM CDT THU AUG 23 2012
AREAS AFFECTED...SWRN MN...
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 232307Z - 240000Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...AN ISOLATED THREAT FOR HAIL AND PERHAPS A STRONG WIND GUST
IS EXPECTED DURING THE NEXT COUPLE HRS...BUT IS EXPECTED TO REMAIN
TOO MARGINAL/LOCALIZED TO WARRANT A WW. WITH THE LOSS OF DIURNAL
HEATING AND RESULTANT WEAKENING OF INSTABILITY...THE THREAT SHOULD
WANE LATER THIS EVENING.
DISCUSSION...A FOCUSED AREA OF FESTERING TSTMS HAS BEEN ONGOING OVER
THE PAST COUPLE HRS...ALONG/NEAR A WEAK BAROCLINIC ZONE AND SFC LOW.
MORE RECENT DEVELOPMENT HAS BEEN NOTED IN VISIBLE SATELLITE IMAGERY
WITH A TOWERING CU FIELD EXTENDING FARTHER S/SWD ALONG A SFC TROUGH.
SFC OBSERVATIONS INDICATE LOW-LEVEL CONVERGENCE IS RATHER WEAK...BUT
SOME ENHANCEMENT OF VERTICAL MOTION MAY BE OCCURRING IN CONJUNCTION
WITH THE SRN EXTENSION OF A SHORTWAVE UPPER TROUGH TRAVERSING EWD
NEAR THE MN/CANADA BORDER. A NARROW MOISTURE PLUME IS EXTENDING FROM
THE SRN/CNTRL PLAINS...WITH THE AXIS POSITIONED OVER SWRN MN. THIS
SHOULD PROVIDE A FAVORABLE ENVIRONMENT FOR TSTMS TO PERSIST OVER THE
NEXT COUPLE HRS...BUT ANY SUBSTANTIAL ORGANIZATION WILL BE LIMITED
BY MODEST AND WEAKLY VEERING DEEP-LAYER FLOW. AN ACCOMPANYING HAIL
AND PERHAPS ISOLATED STRONG WIND GUST THREAT COULD EXIST WITHIN THE
STRONGEST STORMS...GIVEN ESTIMATED MLCAPE VALUES OF 1500-2000 J/KG.
THE THREAT SHOULD GRADUALLY WANE AFTER SUNSET WITH THE LOSS OF
DIABATIC HEATING.
..ROGERS/WEISS.. 08/23/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...MPX...FSD...
LAT...LON 44379374 43739405 43569502 43589594 43689648 44009647
44579611 44749535 44789443 44729384 44379374Nearby
Mesoscale Discussions in Minnesota, 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.