Alert archive / North Dakota / Mesoscale Discussions in 2004

Mesoscale Discussion 1741

July 20, 20045 counties in Montana; 26 counties in North Dakota; 8 counties in South Dakota

The Storm Prediction Center issued this mesoscale discussion at Jul 20, 2004, 2:28 PM MDT for 5 counties in Montana; 26 counties in North Dakota; 8 counties in South Dakota. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 20, 2004, 2:28 PM MDT (20:28 UTC)
Expired
Jul 20, 2004, 4:30 PM MDT
In force
2 hr
Issued by
the Storm Prediction Center
All 39 counties

Carter County, MT, Fallon County, MT, Richland County, MT, Sheridan County, MT, Wibaux County, MT, Adams County, ND, Billings County, ND, Bottineau County, ND, Bowman County, ND, Burke County, ND, Burleigh County, ND, Divide County, ND, Dunn County, ND, Emmons County, ND, Golden Valley County, ND, Grant County, ND, Hettinger County, ND, McHenry County, ND, McKenzie County, ND, McLean County, ND, Mercer County, ND, Morton County, ND, Mountrail County, ND, Oliver County, ND, Renville County, ND, Sheridan County, ND, Sioux County, ND, Slope County, ND, Stark County, ND, Ward County, ND, Williams County, ND, Campbell County, SD, Corson County, SD, Dewey County, SD, Harding County, SD, Perkins County, SD, Potter County, SD, Walworth County, SD, Ziebach County, SD

The radar

The Bismarck radar (KBIS), 152 km from the middle of the area, began a volume at 20:28 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 watches that followed

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

The nearest sounding before it

Bismarck Municip, ND (KBIS), launched 12:00Z, 8.5 hours before the alert went out and 157 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, Bismarck Municip, ND at 12:00Z on 2004-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 144 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, Bismarck Municip, ND at 12:00Z on 2004-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 96 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
144 J/kg
Mixed-layer CIN
-216 J/kg
Mixed-layer LCL
1089 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
96 m²/s²
0-3 km storm-relative helicity
145 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

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
Jul 19, 6:24 PM MDTMesoscale DiscussionSPCMineral, Sanders96 min
Jul 20, 2:55 PM MDTSevere Thunderstorm WatchSPCAdams, Benson, Billings, Bottineau, Bowman, Burke and 30 more6 hr
Jul 20, 1:16 PM MDTMesoscale DiscussionSPCAurora, Beadle, Bon Homme, Brule, Buffalo, Charles Mix and 19 more119 min
Jul 20, 1:40 PM MDTTornado WatchSPCAurora, Beadle, Bon Homme, Brookings, Brule, Buffalo and 20 more6 hr
Jul 20, 5:30 PM MDTMesoscale DiscussionSPCAurora, Bon Homme, Brookings, Charles Mix, Clay, Davison and 14 more90 min

Nearby

Mesoscale Discussions in North Dakota, 2004Mesoscale Discussions in South Dakota, 2004Mesoscale Discussions in Montana, 2004Every mesoscale discussion in 2004

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.