Alert archive / Nebraska / Mesoscale Discussions in 2023
Mesoscale Discussion 1421
The Storm Prediction Center issued this mesoscale discussion at Jul 4, 2023, 2:17 PM CDT for 15 counties in Kansas; 33 counties in Nebraska. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 4, 2023, 2:17 PM CDT (19:17 UTC)
- Expired
- Jul 4, 2023, 4:45 PM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...severe thunderstorm watch likely
- Chance of a watch
- 80%
All 48 counties
Ellis County, KS, Gove County, KS, Graham County, KS, Jewell County, KS, Lane County, KS, Logan County, KS, Norton County, KS, Osborne County, KS, Phillips County, KS, Rooks County, KS, Scott County, KS, Sheridan County, KS, Smith County, KS, Trego County, KS, Wichita County, KS, Adams County, NE, Antelope County, NE, Boone County, NE, Buffalo County, NE, Butler County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Fillmore County, NE, Franklin County, NE, Furnas County, NE, Gosper County, NE, Greeley County, NE, Hall County, NE, Hamilton County, NE, Harlan County, NE, Howard County, NE, Kearney County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Phelps County, NE, Pierce County, NE, Platte County, NE, Polk County, NE, Sherman County, NE, Stanton County, NE, Valley County, NE, Wayne County, NE, Webster County, NE, Wheeler County, NE, York County, NE
The radar
The Grand Island radar (KUEX), 63 km from the middle of the area, began a volume at 19:18 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
N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 7.3 hours before the alert went out and 155 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.
- Mixed-layer CAPE
- 1345 J/kg
- Mixed-layer CIN
- -204 J/kg
- Mixed-layer LCL
- 1953 m above ground
- 0-6 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- 117 m²/s²
- 0-3 km storm-relative helicity
- 206 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.6
The text
As transmitted.
179
ACUS11 KWNS 041918
SWOMCD
SPC MCD 041917
NEZ000-KSZ000-042145-
Mesoscale Discussion 1421
NWS Storm Prediction Center Norman OK
0217 PM CDT Tue Jul 04 2023
Areas affected...much of central/eastern Nebraska into
northern/western Kansas
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 041917Z - 042145Z
Probability of Watch Issuance...80 percent
SUMMARY...Storms are likely to form later this afternoon from
northeast Nebraska along an outflow boundary southwestward into
Kansas within the surface trough. Both damaging winds and hail will
be likely.
DISCUSSION...Surface map depicts an outflow boundary from northwest
IA into far northeast NE, with a surface trough extending
southwestward into northwest KS. Low-level lapse rates continue to
steepen with strong heating over KS, and this warming air mass will
gradually spread into southern NE. Moisture is plentiful across the
entire area, with dewpoints generally ranging from 65 in the hot air
to around 70 into eastern NE.
Substantial cumulus fields are developing both in the cooler/moist
stationary front/modifying outflow boundary regime over NE, and near
the heated trough into western/northwestern KS. Continued heating
and convergence along the boundaries will likely lead to scattered
storms by late afternoon. Steep lapse rates will favor strong
outflow winds, with veering winds with height and marginal supercell
profiles favor large damaging hail.
..Jewell/Grams.. 07/04/2023
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...OAX...TOP...ICT...GID...LBF...DDC...GLD...
LAT...LON 39820040 40519983 41259944 41969875 42389799 42499760
42389690 42049669 41329691 40399756 39449817 38889887
38639947 38510006 38340123 38530146 38770155 39250102
39820040SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 4, 3:29 PM CDT | Severe Thunderstorm Watch | SPC | Jewell, Mitchell, Osborne, Phillips, Rooks, Smith | 6 hr |
| Jul 4, 3:36 PM CDT | Severe Thunderstorm Watch | SPC | Cheyenne, Decatur, Ellis, Finney, Gove, Graham and 18 more | 8 hr |
| Jul 4, 6:33 PM CDT | Mesoscale Discussion | SPC | Decatur, Gove, Graham, Greeley, Jewell, Lane and 12 more | 87 min |
| Jul 4, 6:55 PM CDT | Severe Thunderstorm Watch | SPC | Atchison, Barton, Brown, Chase, Clay, Cloud and 22 more | 6 hr |
| Jul 3, 7:44 PM CDT | Severe Thunderstorm Watch | SPC | Dawes, Sioux | 4 hr |
| Jul 3, 8:43 PM CDT | Mesoscale Discussion | SPC | Sioux | 92 min |
| Jul 3, 10:23 PM CDT | Severe Thunderstorm Watch | SPC | Boyd, Brown, Cherry, Holt, Keya Paha, Rock and 1 more | 6 hr |
| Jul 3, 10:38 PM CDT | Mesoscale Discussion | SPC | Dawes, Sheridan | 97 min |
| Jul 4, 1:25 AM CDT | Mesoscale Discussion | SPC | Boyd, Cherry, Keya Paha | 95 min |
| Jul 4, 3:05 PM CDT | Severe Thunderstorm Watch | SPC | Banner, Cheyenne, Kimball, Scotts Bluff | 9 hr |
| Jul 4, 6:07 PM CDT | Mesoscale Discussion | SPC | Burt, Butler, Clay, Colfax, Cuming, Dodge and 9 more | 83 min |
| Jul 4, 6:14 PM CDT | Mesoscale Discussion | SPC | Banner, Cheyenne, Kimball | 91 min |
Nearby
Mesoscale Discussions in Nebraska, 2023Mesoscale Discussions in Kansas, 2023Every mesoscale discussion in 2023
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.