Alert archive / Nebraska / Mesoscale Discussions in 2009

Mesoscale Discussion 577

April 26, 20098 counties in Iowa; 5 counties in Kansas; 30 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2009, 9:18 AM CDT for 8 counties in Iowa; 5 counties in Kansas; 30 counties in Nebraska. It was in force for 27 min.

The area

The outline as issued.

The facts

Issued
Apr 26, 2009, 9:18 AM CDT (14:18 UTC)
Expired
Apr 26, 2009, 9:45 AM CDT
In force
27 min
Issued by
the Storm Prediction Center
All 43 counties

Audubon County, IA, Crawford County, IA, Harrison County, IA, Mills County, IA, Monona County, IA, Pottawattamie County, IA, Shelby County, IA, Woodbury County, IA, Cloud County, KS, Jewell County, KS, Mitchell County, KS, Republic County, KS, Washington County, KS, Adams County, NE, Burt County, NE, Butler County, NE, Cass County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Douglas County, NE, Fillmore County, NE, Gage County, NE, Hall County, NE, Hamilton County, NE, Jefferson County, NE, Johnson County, NE, Lancaster County, NE, Merrick County, NE, Nuckolls County, NE, Otoe County, NE, Platte County, NE, Polk County, NE, Saline County, NE, Sarpy County, NE, Saunders County, NE, Seward County, NE, Thayer County, NE, Thurston County, NE, Washington County, NE, Webster County, NE, York County, NE

The radar

The Omaha radar (KOAX), 98 km from the middle of the area, began a volume at 14:19 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

Omaha, NE (KOAX), launched 12:00Z, 2.3 hours before the alert went out and 98 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, Omaha, NE at 12:00Z on 2009-04-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Omaha, NE at 12:00Z on 2009-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 457 square meters per square second.19395878Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
538 m above ground
0-6 km bulk shear
51 kt
0-1 km storm-relative helicity
457 m²/s²
0-3 km storm-relative helicity
572 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.0

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 261419
SWOMCD
SPC MCD 261418 
IAZ000-NEZ000-KSZ000-261445-

MESOSCALE DISCUSSION 0577
NWS STORM PREDICTION CENTER NORMAN OK
0918 AM CDT SUN APR 26 2009

AREAS AFFECTED...FAR NCNTRL/NERN KS...ERN NEB AND WRN IA

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY 

VALID 261418Z - 261445Z

LARGE HAIL MAY OCCUR WITH STRONGER TSTMS DEVELOPING NWD OUT OF NRN
KS ACROSS ERN NEB INTO WRN SECTIONS OF IA.

CONSIDERABLE LOW-LEVEL WARM ADVECTION WAS OCCURRING ACROSS THE
REGION THIS MORNING...POSSIBLY AIDED BY THE LEFT-EXIT REGION OF AN
EJECTING WAVE OVER MO.  12Z TOP/OAX SOUNDINGS SHOW MID-LVL LAPSE
RATES IN EXCESS 6.8 C/KM AND EFFECTIVE SHEAR AOA 35 KTS...
SUFFICIENT FOR A FEW STORMS TO PRODUCE LARGE HAIL.  AS A RESULT A WW
WILL BE ISSUED SHORTLY.

..RACY.. 04/26/2009

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

ATTN...WFO...DMX...FSD...OAX...TOP...GID...

LAT...LON   40849879 42629588 41829476 40759577 40169621 39749688
            39329807 39509856 40849879

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 25, 7:17 PM CDTMesoscale DiscussionSPCAppanoose, Davis, Wapello, Wayne58 min
Apr 25, 9:23 PM CDTMesoscale DiscussionSPCDavis, Des Moines, Henry, Lee, Van Buren67 min
Apr 25, 10:09 PM CDTSevere Thunderstorm WatchSPCFremont, Page6 hr
Apr 26, 9:34 AM CDTSevere Thunderstorm WatchSPCAudubon, Buena Vista, Calhoun, Carroll, Cass, Cherokee and 29 more6 hr
Apr 26, 12:30 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Cass, Dallas and 13 more60 min
Apr 26, 12:48 PM CDTTornado WatchSPCAdair, Adams, Audubon, Boone, Butler, Calhoun and 33 more4 hr
Apr 26, 2:41 PM CDTMesoscale DiscussionSPCAdair, Adams, Audubon, Boone, Buena Vista, Calhoun and 35 more3 hr
Apr 26, 5:02 PM CDTTornado WatchSPCAdair, Adams, Allamakee, Appanoose, Benton, Black Hawk and 41 more6 hr
Apr 26, 5:14 PM CDTMesoscale DiscussionSPCClayton, Delaware, Dubuque, Jackson61 min
Apr 26, 6:14 PM CDTMesoscale DiscussionSPCAdams, Appanoose, Benton, Black Hawk, Bremer, Buchanan and 40 more61 min
Apr 25, 9:58 PM CDTMesoscale DiscussionSPCAllen, Anderson, Butler, Chase, Chautauqua, Clay and 40 more92 min
Apr 25, 10:39 PM CDTTornado WatchSPCAllen, Chautauqua, Cowley, Elk, Harper, Labette and 5 more4 hr
Apr 26, 1:28 AM CDTMesoscale DiscussionSPCAllen, Barber, Chautauqua, Cowley, Elk, Greenwood and 7 more92 min
Apr 26, 2:10 AM CDTMesoscale DiscussionSPCAnderson, Atchison, Brown, Clay, Coffey, Dickinson and 20 more95 min
Apr 26, 2:39 AM CDTTornado WatchSPCAllen, Chautauqua, Cowley, Elk, Harper, Labette and 5 more3 hr
Apr 26, 5:47 AM CDTMesoscale DiscussionSPCBarton, Dickinson, Edwards, Ellsworth, Ford, Lincoln and 8 more58 min
Apr 26, 5:58 AM CDTTornado WatchSPCBarton, Chase, Clark, Clay, Comanche, Dickinson and 24 more7 hr
Apr 26, 10:19 AM CDTMesoscale DiscussionSPCBarber, Butler, Comanche, Cowley, Dickinson, Ellsworth and 14 more56 min
Apr 26, 10:54 AM CDTMesoscale DiscussionSPCAtchison, Barber, Barton, Butler, Chase, Chautauqua and 42 more66 min
Apr 26, 11:07 AM CDTTornado Watch PDSSPCBarber, Barton, Brown, Butler, Chase, Clark and 40 more7 hr
Apr 26, 12:27 PM CDTMesoscale DiscussionSPCBarton, Clark, Clay, Cloud, Edwards, Ellsworth and 12 more2 hr
Apr 26, 5:44 PM CDTMesoscale DiscussionSPCBarber, Butler, Cowley, Harper, Harvey, Kingman and 5 more61 min
Apr 26, 6:16 PM CDTTornado Watch PDSSPCAllen, Barber, Butler, Chase, Chautauqua, Comanche and 16 more8 hr

Nearby

Mesoscale Discussions in Nebraska, 2009Mesoscale Discussions in Iowa, 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.