Alert archive / Minnesota / Mesoscale Discussions in 2015

Mesoscale Discussion 1521

July 24, 201515 counties in Minnesota; 13 counties in Wisconsin

The Storm Prediction Center issued this mesoscale discussion at Jul 24, 2015, 5:14 PM CDT for 15 counties in Minnesota; 13 counties in Wisconsin. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued: Jul 24, 2015, 5:14 PM CDT (22:14 UTC)
Expired: Jul 24, 2015, 6:45 PM CDT
In force: 91 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 28 counties

Anoka County, MN, Benton County, MN, Carlton County, MN, Chisago County, MN, Hennepin County, MN, Isanti County, MN, Kanabec County, MN, Meeker County, MN, Mille Lacs County, MN, Morrison County, MN, Pine County, MN, Ramsey County, MN, Sherburne County, MN, Washington County, MN, Wright County, MN, Ashland County, WI, Barron County, WI, Bayfield County, WI, Burnett County, WI, Chippewa County, WI, Douglas County, WI, Iron County, WI, Polk County, WI, Price County, WI, Rusk County, WI, Saint Croix County, WI, Sawyer County, WI, Washburn County, WI

The radar

The Duluth radar (KDLH), 106 km from the middle of the area, began a volume at 22:16 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

International Fa, MN (KINL), launched 12:00Z, 10.2 hours before the alert went out and 312 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 97 J/kg
Mixed-layer CIN: 0 J/kg
Mixed-layer LCL: 477 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: -4 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.

358 
ACUS11 KWNS 242214
SWOMCD
SPC MCD 242214 
WIZ000-MIZ000-MNZ000-242345-

MESOSCALE DISCUSSION 1521
NWS STORM PREDICTION CENTER NORMAN OK
0514 PM CDT FRI JUL 24 2015

AREAS AFFECTED...E-CNTRL MN...NWRN WI

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 242214Z - 242345Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...ISOLATED SEVERE THUNDERSTORMS ARE POSSIBLE INTO THIS
EVENING...WITH A PRIMARY THREAT OF DAMAGING WIND AND LARGE HAIL.
COVERAGE IS EXPECTED TO REMAIN FAIRLY SPARSE...WHICH RENDERS THE
NEED FOR WATCH ISSUANCE UNCERTAIN.

DISCUSSION...TSTMS HAVE RECENTLY INITIATED ALONG A COLD FRONT NEAR
BRD...WITH A STRONG THUNDERSTORM NOW LOCATED OVER MILLE LACS LAKE AT
22Z. RADAR AND VIS IMAGERY SHOW ADDITIONAL ATTEMPTS AT INITIATION ON
THE FRONT BOTH TO THE SOUTH AND NORTHEAST OF THIS STORM. EFFECTIVE
SHEAR OF 35-45 KTS IS MORE THAN SUFFICIENT FOR ORGANIZED STORM
STRUCTURES...GIVEN MODERATE MLCAPE IN PLACE PER RECENT MESOANALYSIS.
HOWEVER...LARGE-SCALE ASCENT IS LIMITED AND CONVERGENCE IS WEAK
ALONG THE BOUNDARY...WHICH WILL LIKELY TEND TO LIMIT STORM COVERAGE
AND POTENTIALLY HINDER THE INTENSITY OF UPDRAFTS THAT DO BECOME
ESTABLISHED. AS A RESULT...THE NEED FOR WW IS UNCERTAIN...BUT
REMAINS POSSIBLE IF MULTIPLE ORGANIZED STORMS APPEAR IMMINENT.

..DEAN/HART.. 07/24/2015

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

ATTN...WFO...MQT...GRB...DLH...ARX...MPX...

LAT...LON   45039461 46139433 46499328 46719240 46749144 46989086
            46759007 46338971 45508951 45139091 44899228 44809350
            45039461

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 23, 10:28 PM CDT	Mesoscale Discussion	SPC	Becker, Beltrami, Clay, Clearwater, Grant, Kittson and 11 more	32 min
Jul 24, 12:41 AM CDT	Mesoscale Discussion	SPC	Becker, Beltrami, Clay, Clearwater, Grant, Kittson and 11 more	2 hr
Jul 24, 2:23 AM CDT	Mesoscale Discussion	SPC	Aitkin, Becker, Benton, Big Stone, Brown, Carver and 36 more	67 min
Jul 24, 5:28 AM CDT	Mesoscale Discussion	SPC	Carver, Dakota, Dodge, Fillmore, Freeborn, Goodhue and 12 more	3 hr

Nearby

Mesoscale Discussions in Minnesota, 2015 Mesoscale Discussions in Wisconsin, 2015 Every mesoscale discussion in 2015

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.