Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 878

May 23, 201220 counties in Minnesota; 9 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at May 23, 2012, 2:04 PM CDT for 20 counties in Minnesota; 9 counties in South Dakota. It was in force for 86 min.

The area

The outline as issued.

The facts

Issued
May 23, 2012, 2:04 PM CDT (19:04 UTC)
Expired
May 23, 2012, 3:30 PM CDT
In force
86 min
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 29 counties

Aitkin County, MN, Becker County, MN, Big Stone County, MN, Cass County, MN, Chippewa County, MN, Crow Wing County, MN, Douglas County, MN, Grant County, MN, Hubbard County, MN, Lac qui Parle County, MN, Lincoln County, MN, Morrison County, MN, Otter Tail County, MN, Pope County, MN, Stevens County, MN, Swift County, MN, Todd County, MN, Traverse County, MN, Wadena County, MN, Yellow Medicine County, MN, Brookings County, SD, Deuel County, SD, Grant County, SD, Hamlin County, SD, Lake County, SD, McCook County, SD, Minnehaha County, SD, Moody County, SD, Turner County, SD

The radar

The Minneapolis radar (KMPX), 188 km from the middle of the area, began a volume at 19:05 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, 7.1 hours before the alert went out and 185 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 12:00Z on 2012-05-23Temperature 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 12:00Z on 2012-05-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 354 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
1960 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
354 m²/s²
0-3 km storm-relative helicity
362 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

738 
ACUS11 KWNS 231904
SWOMCD
SPC MCD 231904 
MNZ000-SDZ000-NDZ000-232030-

MESOSCALE DISCUSSION 0878
NWS STORM PREDICTION CENTER NORMAN OK
0204 PM CDT WED MAY 23 2012

AREAS AFFECTED...PORTIONS OF ERN SD AND WRN/CNTRL MN

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 231904Z - 232030Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...A MIXTURE OF ELEVATED AND NEAR-SURFACE BASED THUNDERSTORMS
WILL LIFT NWD ACROSS PORTIONS OF ERN SD AND WRN/CNTRL MN THIS
AFTERNOON. STORMS WILL INITIALLY POSE A THREAT FOR LARGE HAIL...BUT
MAY BECOME SURFACE BASED LATER IN THE DAY WITH INCREASING THREAT FOR
DAMAGING WIND GUSTS. TRENDS WILL BE MONITORED FOR A WW.

DISCUSSION...SURFACE OBSERVATIONS AT 18Z SHOW A COLD FRONT EXTENDING
NWD ACROSS ERN SD INTO NRN MN...WITH A WARM FRONT LIFTING NWD TOWARD
CNTRL MN. TEMPERATURES ACROSS THE WARM SECTOR ARE IN THE 70S TO NEAR
80F...WITH DEWPOINTS IN THE MID TO UPR 50S. COMPOSITE RADAR IMAGERY
SHOWS STORM CLUSTERS AND LINE SEGMENTS DEVELOPING ON THE COLD FRONT
OVER ERN SD...AND N OF THE WARM FRONT OVER CNTRL MN. THIS ACTIVITY
IS MAINLY ELEVATED BASED ON RAP FORECAST SOUNDINGS...BUT COULD
BECOME SURFACE BASED WITH TIME OVER ERN SD AND WRN MN AS BOUNDARY
LAYER CONTINUES TO WARM. OBJECTIVE ANALYSIS GUIDANCE INDICATES
MUCAPE VALUES RANGE FROM 500-1000 J/KG...AND AREA VWP/S SHOW STRONG
DEEP-LAYER WIND PROFILES ARE PRESENT ACROSS THE REGION. THIS
ENVIRONMENT WILL SUPPORT A THREAT FOR ISOLATED LARGE HAIL DURING THE
NEXT FEW HRS...WITH DAMAGING WIND THREAT INCREASING IF STORMS CAN
BECOME SURFACE BASED.

..GARNER/WEISS.. 05/23/2012

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

ATTN...WFO...DLH...MPX...FGF...FSD...ABR...

LAT...LON   45549692 47089567 47369277 46379311 45429527 43259686
            43369759 43779770 45549692

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 22, 8:41 PM CDTMesoscale DiscussionSPCBecker, Clay, Mahnomen, Marshall, Norman, Polk and 3 more64 min
May 23, 5:27 PM CDTMesoscale DiscussionSPCAnoka, Blue Earth, Carver, Chisago, Dakota, Dodge and 20 more93 min
May 22, 7:30 PM CDTMesoscale DiscussionSPCBeadle, Brown, Brule, Buffalo, Campbell, Edmunds and 16 more90 min
May 23, 2:56 PM CDTMesoscale DiscussionSPCUnion94 min
May 23, 4:07 PM CDTSevere Thunderstorm WatchSPCUnion7 hr

Nearby

Mesoscale Discussions in Minnesota, 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.