Alert archive / Wisconsin / Mesoscale Discussions in 2012

Mesoscale Discussion 1580

July 25, 20125 counties in Minnesota; 9 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 25, 2012, 2:05 AM CDT for 5 counties in Minnesota; 9 counties in Wisconsin. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Jul 25, 2012, 2:05 AM CDT (07:05 UTC)
Expired
Jul 25, 2012, 3:00 AM CDT
In force
55 min
Issued by
the Storm Prediction Center
Chance of a watch
80%

Counties Aitkin County, MN, Carlton County, MN, Cass County, MN, Crow Wing County, MN, Pine County, MN, Ashland County, WI, Bayfield County, WI, Burnett County, WI, Douglas County, WI, Iron County, WI, Price County, WI, Rusk County, WI, Sawyer County, WI, Washburn County, WI

The radar

The Duluth radar (KDLH), 65 km from the middle of the area, began a volume at 07:06 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 7.1 hours before the alert went out and 188 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 2012-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1518 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, Minneapolis, MN at 00:00Z on 2012-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 232 square meters per square second.1939Sfc1 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
1518 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
877 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
232 m²/s²
0-3 km storm-relative helicity
392 m²/s²
Significant tornado parameter
1.2
Supercell composite
17.7

Open this sounding in Storm Lab

The text

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

475 
ACUS11 KWNS 250705
SWOMCD
SPC MCD 250705 
WIZ000-MNZ000-250800-

MESOSCALE DISCUSSION 1580
NWS STORM PREDICTION CENTER NORMAN OK
0205 AM CDT WED JUL 25 2012

AREAS AFFECTED...CENTRAL MN TO NW WI

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 250705Z - 250800Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...LINEAR MCS HAS BECOME BETTER ORGANIZED IN THE PAST HOUR
ACROSS CENTRAL MN...AND IS NOW MOVING EWD AT 40 KT.  THE RISK FOR
DAMAGING WINDS WILL LIKELY PERSIST INTO AREAS NEAR AND SW-SE OF
DLH...INTO NW WI THROUGH THE EARLY MORNING HOURS.  A NEW SEVERE
THUNDERSTORM WATCH WILL BE PROPOSED SHORTLY.

DISCUSSION...CONVECTIVE CLUSTER THAT FORMED EARLIER IN SE ND HAS
MOVED EWD AND EVOLVED INTO A MORE N-S ORIENTED LINE...WITH EWD
MOTION AT 40 KT.  THE STORMS ARE MOVE ALONG THE N EDGE OF THE
INSTABILITY GRADIENT...N OF THE SURFACE WARM FRONT AND EMBEDDED
WITHIN A BELT OF 40-45 KT WLY MIDLEVEL FLOW CRESTING THE ERN
PLAINS/MS VALLEY RIDGE.  A FEED OF LOW 70S BOUNDARY LAYER DEWPOINTS
AND MODERATE INSTABILITY WILL CONTINUE FROM THE SW ON A 30-40 KT
LLJ.  THUS...THE ENVIRONMENT WILL REMAIN SUPPORTIVE OF A DAMAGING
WIND RISK THROUGH THE EARLY MORNING HOURS AS THE CONVECTION
APPROACHES AREAS NEAR AND S OF DLH BY 0930Z...AND CONTINUES INTO NW
WI THEREAFTER.

..THOMPSON/PETERS.. 07/25/2012

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

ATTN...WFO...DLH...ARX...MPX...FGF...

LAT...LON   45539019 45359082 45669222 46009321 46319453 46709471
            47089457 47109390 46949196 46649069 46229005 45539019

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 24, 9:08 PM CDTSevere Thunderstorm WatchSPCBecker, Cass, Clay, Crow Wing, Douglas, Grant and 8 more7 hr
Jul 24, 11:24 PM CDTMesoscale DiscussionSPCAitkin, Becker, Benton, Big Stone, Cass, Clay and 20 more96 min
Jul 25, 2:24 AM CDTSevere Thunderstorm WatchSPCAitkin, Benton, Carlton, Cass, Chisago, Crow Wing and 13 more5 hr
Jul 25, 3:41 AM CDTMesoscale DiscussionSPCBecker, Clay, Grant, Hubbard, Mahnomen, Otter Tail and 2 more34 min
Jul 25, 5:24 AM CDTMesoscale DiscussionSPCAitkin, Benton, Big Stone, Carlton, Cass, Chisago and 20 more66 min
Jul 25, 1:56 PM CDTMesoscale DiscussionSPCBecker, Beltrami, Big Stone, Clay, Clearwater, Grant and 14 more2 hr
Jul 25, 5:16 PM CDTSevere Thunderstorm WatchSPCBlue Earth, Dodge, Faribault, Fillmore, Freeborn, Goodhue and 11 more8 hr
Jul 25, 2:57 PM CDTMesoscale DiscussionSPCBrown, Calumet, Clark, Eau Claire, Fond du Lac, Jackson and 17 more2 hr
Jul 25, 6:25 PM CDTMesoscale DiscussionSPCBrown, Calumet, Dodge, Fond du Lac, Green Lake, Kewaunee and 8 more95 min
Jul 25, 6:38 PM CDTSevere Thunderstorm WatchSPCBrown, Calumet, Columbia, Dane, Dodge, Fond du Lac and 23 more7 hr

Nearby

Mesoscale Discussions in Wisconsin, 2012Mesoscale 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.