Alert archive / Nebraska / Mesoscale Discussions in 2004

Mesoscale Discussion 1635

July 12, 200422 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jul 12, 2004, 5:41 PM CDT for 22 counties in Nebraska. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: Jul 12, 2004, 5:41 PM CDT (22:41 UTC)
Expired: Jul 12, 2004, 7:45 PM CDT
In force: 2 hr
Issued by: the Storm Prediction Center

All 22 counties

Antelope County, NE, Boone County, NE, Boyd County, NE, Cedar County, NE, Colfax County, NE, Cuming County, NE, Custer County, NE, Dakota County, NE, Dixon County, NE, Garfield County, NE, Greeley County, NE, Holt County, NE, Knox County, NE, Loup County, NE, Madison County, NE, Pierce County, NE, Platte County, NE, Stanton County, NE, Thurston County, NE, Valley County, NE, Wayne County, NE, Wheeler County, NE

The radar

The North Platte radar (KLNX), 160 km from the middle of the area, began a volume at 22:42 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.

Tornado Watch 613Jul 12, 6:20 PM CDT

The nearest sounding before it

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 10.7 hours before the alert went out and 179 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: 1268 J/kg
Mixed-layer CIN: -335 J/kg
Mixed-layer LCL: 2128 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 29 m²/s²
0-3 km storm-relative helicity: 84 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.

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SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 12, 2:04 PM CDT	Mesoscale Discussion	SPC	Boyd, Keya Paha	116 min
Jul 12, 3:25 PM CDT	Tornado Watch	SPC	Boyd, Cedar, Dixon, Holt, Knox	6 hr
Jul 12, 6:20 PM CDT	Tornado Watch	SPC	Antelope, Boone, Burt, Cedar, Colfax, Cuming and 14 more	7 hr

Nearby

Mesoscale Discussions in Nebraska, 2004 Every 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.