Alert archive / Minnesota / Mesoscale Discussions in 2012

Mesoscale Discussion 1387

July 4, 20127 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2012, 12:25 PM CDT for 7 counties in Minnesota. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued: Jul 4, 2012, 12:25 PM CDT (17:25 UTC)
Expired: Jul 4, 2012, 2:00 PM CDT
In force: 95 min
Issued by: the Storm Prediction Center

Counties Aitkin County, MN, Beltrami County, MN, Carlton County, MN, Clearwater County, MN, Itasca County, MN, Koochiching County, MN, Saint Louis County, MN

The radar

The Duluth radar (KDLH), 138 km from the middle of the area, began a volume at 17:24 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.

Severe Thunderstorm Watch 460Jul 4, 12:35 PM CDT

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 5.4 hours before the alert went out and 123 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: 113 J/kg
Mixed-layer CIN: -490 J/kg
Mixed-layer LCL: 1552 m above ground
0-6 km bulk shear: 23 kt
0-1 km storm-relative helicity: 61 m²/s²
0-3 km storm-relative helicity: 101 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.

339 
ACUS11 KWNS 041725
SWOMCD
SPC MCD 041725 
MNZ000-WIZ000-041900-

MESOSCALE DISCUSSION 1387
NWS STORM PREDICTION CENTER NORMAN OK
1225 PM CDT WED JUL 04 2012

AREAS AFFECTED...NRN MN...FAR NRN WI

CONCERNING...SEVERE THUNDERSTORM WATCH 459...

VALID 041725Z - 041900Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 459
CONTINUES.

SUMMARY...A SEVERE THREAT WILL LIKELY CONTINUE TO DEVELOP ESEWD
ACROSS NRN MN THIS AFTERNOON. WIND DAMAGE AND LARGE HAIL WILL BE
POSSIBLE WITH THE STRONGER CORES. WW ISSUANCE WILL BE LIKELY ACROSS
NRN MN AS THE CONVECTION APPROACHES THE ERN EDGE OF WW 459 OVER THE
NEXT HALF HOUR.

DISCUSSION...A CONVECTIVE CLUSTER IS CURRENTLY ONGOING IN NW MN
LOCATED TO THE EAST OF A INVERTED SFC TROUGH AND ON THE NRN EDGE OF
MODERATE INSTABILITY. THE INSTABILITY GRADIENT EXTENDS ESEWD ACROSS
NRN MN INTO NRN WI ALONG WHICH THE CONVECTION WILL LIKELY TRACK THIS
AFTERNOON. REGIONAL WSR-88D VWPS SHOW 40 TO 50 KT OF 0-6 KM SHEAR
ALONG WITH 20 TO 30 KT OF LOW-LEVEL FLOW. AS SFC TEMPS CONTINUE TO
WARM AND LOW-LEVEL LAPSE RATES STEEPEN...THE THREAT FOR DAMAGING
WIND GUSTS MAY INCREASE ESPECIALLY IF THE LINE CAN DEVELOP A COLD
POOL. A LARGE HAIL THREAT WILL LIKELY EXIST WITH THE STRONGER CORES
BUT THE THREAT SHOULD REMAIN ISOLATED.

..BROYLES/THOMPSON.. 07/04/2012

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

ATTN...WFO...DLH...FGF...

LAT...LON   48509375 48549463 48459507 48289536 47909567 47649566
            47319509 46969417 46479323 46299266 46389215 46649178
            47099142 47599176 48509375

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 4, 6:25 AM CDT	Mesoscale Discussion	SPC	Kittson, Lake of the Woods, Marshall, Pennington, Polk, Red Lake and 1 more	95 min
Jul 4, 6:53 AM CDT	Mesoscale Discussion	SPC	Ramsey, Washington	97 min
Jul 4, 8:10 AM CDT	Severe Thunderstorm Watch	SPC	Beltrami, Clearwater, Kittson, Lake of the Woods, Marshall, Pennington and 3 more	6 hr
Jul 4, 12:34 PM CDT	Severe Thunderstorm Watch	SPC	Aitkin, Carlton, Cass, Cook, Crow Wing, Itasca and 4 more	7 hr
Jul 4, 3:57 PM CDT	Mesoscale Discussion	SPC	Cook, Lake	93 min

Nearby

Mesoscale Discussions in Minnesota, 2012 Every 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.