Alert archive / Minnesota / Mesoscale Discussions in 2007

Mesoscale Discussion 535

April 21, 20076 counties in Minnesota

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2007, 11:26 PM CDT for 6 counties in Minnesota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 21, 2007, 11:26 PM CDT (04:26 UTC)
Expired
Apr 22, 2007, 1:30 AM CDT
In force
2 hr
Issued by
the Storm Prediction Center

Counties Aitkin County, MN, Cass County, MN, Crow Wing County, MN, Itasca County, MN, Mille Lacs County, MN, Saint Louis County, MN

The radar

The Duluth radar (KDLH), 100 km from the middle of the area, began a volume at 04:28 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, 4.4 hours before the alert went out and 250 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 2007-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 16 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 2007-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 146 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
16 J/kg
Mixed-layer CIN
-307 J/kg
Mixed-layer LCL
2804 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
146 m²/s²
0-3 km storm-relative helicity
290 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.4

Open this sounding in Storm Lab

The text

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

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 9:31 PM CDTSevere Thunderstorm WatchSPCBig Stone, Chippewa, Douglas, Kandiyohi, Lac qui Parle, Meeker and 9 more4 hr
Apr 22, 12:07 PM CDTMesoscale DiscussionSPCBlue Earth, Dodge, Faribault, Fillmore, Freeborn, Houston and 6 more113 min

Nearby

Mesoscale Discussions in Minnesota, 2007Every mesoscale discussion in 2007

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.