Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 919

May 26, 201218 counties in Minnesota; 5 counties in North Dakota; Marshall County, South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 26, 2012, 11:57 PM CDT for 18 counties in Minnesota; 5 counties in North Dakota; Marshall County, South Dakota. It was in force for 93 min.

The area

The outline as issued.

The facts

Issued
May 26, 2012, 11:57 PM CDT (04:57 UTC)
Expired
May 27, 2012, 1:30 AM CDT
In force
93 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 24 counties

Becker County, MN, Benton County, MN, Clay County, MN, Crow Wing County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Kanabec County, MN, Mille Lacs County, MN, Morrison County, MN, Otter Tail County, MN, Pope County, MN, Sherburne County, MN, Stearns County, MN, Todd County, MN, Traverse County, MN, Wadena County, MN, Wilkin County, MN, Barnes County, ND, Cass County, ND, Ransom County, ND, Richland County, ND, Sargent County, ND, Marshall County, SD

The radar

The Minneapolis radar (KMPX), 202 km from the middle of the area, began a volume at 04:58 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 00:00Z, 5.0 hours before the alert went out and 200 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, Minneapolis, MN at 00:00Z on 2012-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Minneapolis, MN at 00:00Z on 2012-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 442 square meters per square second.193958Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
517 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
442 m²/s²
0-3 km storm-relative helicity
539 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.1

Open this sounding in Storm Lab

The text

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

546 
ACUS11 KWNS 270457
SWOMCD
SPC MCD 270457 
MNZ000-SDZ000-NDZ000-270630-

MESOSCALE DISCUSSION 0919
NWS STORM PREDICTION CENTER NORMAN OK
1157 PM CDT SAT MAY 26 2012

AREAS AFFECTED...NERN SD...SERN ND INTO CNTRL AND NRN MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 270457Z - 270630Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THREAT FOR ISOLATED LARGE HAIL WILL PERSIST ANOTHER COUPLE
HOURS. STORM INTENSITIES MAY HAVE PEAKED...AND OVERALL THREAT MAY
BEGIN A GRADUAL DECREASE AFTER 06Z OR 07Z. GIVEN PEAK INTENSITY OF
THE CONVECTION WILL PROBABLY LAST ONLY A COUPLE HOURS...AND THE
COVERAGE OF HAIL LARGER THAN 1 INCH WILL PROBABLY REMAIN
LIMITED...WW ISSUANCE MAY NOT BE NECESSARY...BUT AREA WILL CONTINUE
TO BE MONITORED.

DISCUSSION...STORMS INTENSITIES HAVE INCREASED WITHIN ZONE OF
ISENTROPIC ASCENT NORTH OF WARM FRONT FROM NERN SD...SERN ND THROUGH
CNTRL MN. STORMS ARE ELEVATED ABOVE A STABLE LAYER WITH MUCAPE FROM
1500-2000 J/KG AND 7.5 C/KM 700-500 MB LAPSE RATES. EFFECTIVE SHEAR
FROM 30-35 KT IS GENERALLY SUPPORTIVE OF MULTICELL MODES...BUT SOME
MARGINAL SUPERCELL STRUCTURES MAY ALSO OCCUR. MELTING LEVELS ARE
RELATIVELY HIGH AND MAY ALSO SERVE AS A LIMITING FACTOR.
HOWEVER...THIS ENVIRONMENT MAY SUPPORT HAIL AT LEAST TO 1 INCH WITH
VERY ISOLATED LARGER STONES POSSIBLE.

..DIAL/HART.. 05/27/2012

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

ATTN...WFO...DLH...MPX...FGF...ABR...BIS...

LAT...LON   45439363 45639632 45689863 46949817 47299517 46209275
            45439363

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 7:56 PM CDTMesoscale DiscussionSPCAitkin, Carlton, Crow Wing, Itasca, Pine2 hr
May 27, 2:58 PM CDTMesoscale DiscussionSPCCottonwood, Jackson, Martin, Murray, Nobles, Rock62 min
May 27, 3:42 PM CDTSevere Thunderstorm WatchSPCBrown, Cottonwood, Jackson, Lincoln, Lyon, Martin and 6 more8 hr
May 27, 3:49 PM CDTMesoscale DiscussionSPCAnoka, Benton, Chisago, Crow Wing, Douglas, Grant and 19 more56 min
May 27, 6:08 PM CDTSevere Thunderstorm WatchSPCAitkin, Anoka, Benton, Blue Earth, Brown, Carver and 40 more7 hr
May 27, 6:55 PM CDTMesoscale DiscussionSPCBlue Earth, Cottonwood, Jackson, Martin, Murray, Nobles and 3 more2 hr
May 26, 9:07 PM CDTMesoscale DiscussionSPCBennett, Brule, Buffalo, Hughes, Jackson, Jerauld and 5 more53 min

Nearby

Mesoscale Discussions in Minnesota, 2012Mesoscale Discussions in North Dakota, 2012Mesoscale Discussions in South Dakota, 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.