Alert archive / Nebraska / Mesoscale Discussions in 2017
Mesoscale Discussion 1682
The Storm Prediction Center issued this mesoscale discussion at Oct 1, 2017, 10:54 PM CDT for 11 counties in Kansas; 17 counties in Nebraska. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Oct 1, 2017, 10:54 PM CDT (03:54 UTC)
- Expired
- Oct 2, 2017, 1:00 AM CDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Concerning
- Severe thunderstorm watch 491
All 28 counties
Ellis County, KS, Graham County, KS, Jewell County, KS, Mitchell County, KS, Osborne County, KS, Phillips County, KS, Republic County, KS, Rooks County, KS, Sheridan County, KS, Smith County, KS, Trego County, KS, Adams County, NE, Butler County, NE, Clay County, NE, Colfax County, NE, Fillmore County, NE, Franklin County, NE, Hamilton County, NE, Jefferson County, NE, Merrick County, NE, Nuckolls County, NE, Platte County, NE, Polk County, NE, Saline County, NE, Seward County, NE, Thayer County, NE, Webster County, NE, York County, NE
The radar
The Grand Island radar (KUEX), 6 km from the middle of the area, began a volume at 03:54 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 nearest sounding before it
N. Platte/Lee Bi, NE (KLBF), launched 00:00Z, 3.9 hours before the alert went out and 198 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
- 825 J/kg
- Mixed-layer CIN
- -55 J/kg
- Mixed-layer LCL
- 1777 m above ground
- 0-6 km bulk shear
- 45 kt
- 0-1 km storm-relative helicity
- 70 m²/s²
- 0-3 km storm-relative helicity
- 154 m²/s²
- Significant tornado parameter
- 0.1
- Supercell composite
- 7.1
The text
As transmitted.
269
ACUS11 KWNS 020354
SWOMCD
SPC MCD 020354
NEZ000-KSZ000-020600-
Mesoscale Discussion 1682
NWS Storm Prediction Center Norman OK
1054 PM CDT Sun Oct 01 2017
Areas affected...Kansas...Nebraska
Concerning...Severe Thunderstorm Watch 491...
Valid 020354Z - 020600Z
The severe weather threat for Severe Thunderstorm Watch 491
continues.
SUMMARY...A severe threat will continue for a couple more hours from
eastern Nebraska possibly extending southwestward to near the Kansas
border. Large hail and wind damage will be the primary threats.
Tornado watch 490 will be allowed to expire.
DISCUSSION...The latest radar imagery shows a nearly continuous line
of strong thunderstorms extending from near Norfolk, Nebraska
south-southwestward to north of Hastings and into northwest Kansas.
The line is located along a cold front with an axis of instability
just ahead of the front. RAP analysis suggests that moderate
instability is located across the western third of Kansas with
weaker instability across east-central Nebraska. In addition, the
Hastings WSR-88D VWP shows strong deep-layer shear suggesting that
the severe threat should persist for a few more hours. Although
isolated supercell structures with isolated large hail will still be
possible, a transition to linear has already occurred. This will
favor wind damage as the primary threat. As the line of storms moves
eastward into decreasing instability and as a capping inversion
increases, the severe threat should become more isolated and
marginal.
..Broyles/Thompson.. 10/02/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OAX...TOP...ICT...GID...DDC...GLD...
LAT...LON 40199896 39330053 38940057 38809937 39119841 40109703
41609675 41889709 41869772 41229806 40429870 40199896SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 1, 8:14 PM CDT | Mesoscale Discussion | SPC | Decatur, Graham, Jewell, Norton, Phillips, Rooks and 1 more | 2 hr |
| Oct 2, 3:19 PM CDT | Mesoscale Discussion | SPC | Finney, Grant, Gray, Haskell, Kearny, Lane and 7 more | 116 min |
| Oct 2, 5:25 PM CDT | Tornado Watch | SPC | Finney, Gove, Graham, Greeley, Hamilton, Kearny and 10 more | 6 hr |
| Oct 2, 6:40 PM CDT | Mesoscale Discussion | SPC | Burt, Butler, Clay, Colfax, Cuming, Dakota and 13 more | 3 hr |
Nearby
Mesoscale Discussions in Nebraska, 2017Mesoscale Discussions in Kansas, 2017Every mesoscale discussion in 2017
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.