Alert archive / Nebraska / Mesoscale Discussions in 2009

Mesoscale Discussion 829

May 15, 20094 states

The Storm Prediction Center issued this mesoscale discussion at May 15, 2009, 7:14 AM CDT for 4 states. It was in force for 91 min.

The area

The outline as issued.

The facts

Issued
May 15, 2009, 7:14 AM CDT (12:14 UTC)
Expired
May 15, 2009, 8:45 AM CDT
In force
91 min
Issued by
the Storm Prediction Center
All 49 counties

Adams County, IA, Fremont County, IA, Mills County, IA, Montgomery County, IA, Page County, IA, Ringgold County, IA, Taylor County, IA, Atchison County, KS, Brown County, KS, Doniphan County, KS, Jackson County, KS, Marshall County, KS, Nemaha County, KS, Pottawatomie County, KS, Republic County, KS, Washington County, KS, Andrew County, MO, Atchison County, MO, Buchanan County, MO, Caldwell County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Grundy County, MO, Harrison County, MO, Holt County, MO, Mercer County, MO, Nodaway County, MO, Platte County, MO, Worth County, MO, Cass County, NE, Clay County, NE, Fillmore County, NE, Gage County, NE, Hamilton County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Nemaha County, NE, Nuckolls County, NE, Otoe County, NE, Pawnee County, NE, Richardson County, NE, Saline County, NE, Sarpy County, NE, Seward County, NE, Thayer County, NE, York County, NE

The radar

The Topeka radar (KTWX), 132 km from the middle of the area, began a volume at 12:14 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

Topeka, KS (KTOP), launched 12:00Z, 0.2 hours before the alert went out and 132 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, Topeka, KS at 12:00Z on 2009-05-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1293 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, Topeka, KS at 12:00Z on 2009-05-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 302 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
1293 J/kg
Mixed-layer CIN
-112 J/kg
Mixed-layer LCL
590 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
302 m²/s²
0-3 km storm-relative helicity
313 m²/s²
Significant tornado parameter
0.0
Supercell composite
13.7

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
May 15, 2:03 AM CDTMesoscale DiscussionSPCFremont, Page, Ringgold, Taylor87 min
May 15, 7:42 AM CDTSevere Thunderstorm WatchSPCFremont, Mills, Montgomery, Page5 hr
May 15, 11:48 AM CDTMesoscale DiscussionSPCFremont, Page57 min
May 15, 1:17 PM CDTMesoscale DiscussionSPCLyon, Osceola58 min
May 15, 12:50 PM CDTTornado WatchSPCAtchison, Doniphan, Johnson, Leavenworth, Linn, Miami and 1 more7 hr
May 15, 2:44 PM CDTMesoscale DiscussionSPCAnderson, Barber, Butler, Chase, Coffey, Comanche and 24 more31 min
May 15, 3:01 PM CDTMesoscale DiscussionSPCJefferson, Leavenworth, Shawnee, Wyandotte59 min
May 15, 3:02 PM CDTTornado WatchSPCAllen, Anderson, Barber, Butler, Chase, Chautauqua and 29 more7 hr
May 15, 3:43 PM CDTMesoscale DiscussionSPCAtchison, Johnson, Leavenworth, Wyandotte62 min
May 15, 5:31 PM CDTMesoscale DiscussionSPCJohnson, Wyandotte119 min
May 15, 5:52 PM CDTMesoscale DiscussionSPCAnderson, Butler, Chase, Coffey, Cowley, Elk and 8 more53 min
May 15, 6:30 PM CDTSevere Thunderstorm WatchSPCBourbon, Cherokee, Crawford, Linn, Miami6 hr
May 15, 2:39 PM CDTTornado WatchSPCFranklin, Jefferson, Saint Charles, Saint Louis, City of Saint Louis7 hr

Nearby

Mesoscale Discussions in Nebraska, 2009Mesoscale Discussions in Missouri, 2009Mesoscale Discussions in Kansas, 2009Every mesoscale discussion in 2009

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.