Alert archive / Wyoming / Tornado Watches in 2018
Tornado Watch 319
The Storm Prediction Center issued this tornado watch at Jul 28, 2018, 2:34 PM MDT for 8 counties in Nebraska; 10 counties in Wyoming. It was in force for 7 hr.
The area
The outline as issued.
The facts
- Issued
- Jul 28, 2018, 2:34 PM MDT (20:34 UTC)
- Expired
- Jul 28, 2018, 10:00 PM MDT
- In force
- 7 hr
- Issued by
- the Storm Prediction Center
- Largest hail expected
- 3.5 in
- Strongest gust expected
- 65 kt
Counties Banner County, NE, Box Butte County, NE, Cheyenne County, NE, Dawes County, NE, Kimball County, NE, Morrill County, NE, Scotts Bluff County, NE, Sioux County, NE, Albany County, WY, Campbell County, WY, Converse County, WY, Goshen County, WY, Johnson County, WY, Laramie County, WY, Natrona County, WY, Niobrara County, WY, Platte County, WY, Weston County, WY
The radar
The Rapid City radar (KUDX), 192 km from the middle of the area, began a volume at 20:33 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.
What SPC expected
The probabilities SPC published with the watch, for the watch area over its life.
- Two or more tornadoes
- 60%
- One or more EF2 to EF5 tornadoes
- 20%
- Ten or more severe wind reports
- 40%
- One or more gusts of 65 knots or more
- 40%
- Ten or more severe hail reports
- 60%
- One or more hailstones of 2 inches or more
- 60%
- Six or more combined severe hail and wind reports
- 90%
Warnings issued inside it
25 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 28, 3:02 PM MDT | Severe Thunderstorm Warning | CYS | Converse | 43 min |
| Jul 28, 3:12 PM MDT | Tornado Warning | CYS | Converse | 48 min |
| Jul 28, 3:27 PM MDT | Tornado Warning | CYS | Goshen, Platte | 33 min |
| Jul 28, 3:32 PM MDT | Severe Thunderstorm Warning | CYS | Converse, Niobrara, Platte | 43 min |
| Jul 28, 3:49 PM MDT | Tornado Warning | CYS | Albany, Converse, Platte | 41 min |
| Jul 28, 3:55 PM MDT | Severe Thunderstorm Warning | CYS | Banner | 35 min |
| Jul 28, 4:23 PM MDT | Severe Thunderstorm Warning | RIW | Fremont, Hot Springs, Natrona | 39 min |
| Jul 28, 4:26 PM MDT | Tornado Warning | CYS | Albany, Converse, Platte | 34 min |
| Jul 28, 4:29 PM MDT | Severe Thunderstorm Warning | CYS | Banner, Kimball | 46 min |
| Jul 28, 4:49 PM MDT | Severe Thunderstorm Warning | UNR | Campbell | 40 min |
| Jul 28, 4:51 PM MDT | Severe Thunderstorm Warning | CYS | Dawes, Sioux | 39 min |
| Jul 28, 4:53 PM MDT | Tornado Warning | CYS | Goshen, Platte | 52 min |
| Jul 28, 5:13 PM MDT | Severe Thunderstorm Warning | CYS | Banner, Kimball | 47 min |
| Jul 28, 5:34 PM MDT | Tornado Warning | CYS | Cheyenne, Kimball | 26 min |
| Jul 28, 5:43 PM MDT | Severe Thunderstorm Warning | CYS | Goshen, Platte | 47 min |
| Jul 28, 5:53 PM MDT | Flash Flood Warning | CYS | Cheyenne, Kimball | 4 hr |
| Jul 28, 5:56 PM MDT | Severe Thunderstorm Warning | CYS | Converse | 64 min |
| Jul 28, 6:01 PM MDT | Severe Thunderstorm Warning | CYS | Cheyenne, Kimball | 29 min |
| Jul 28, 6:16 PM MDT | Severe Thunderstorm Warning | RIW | Natrona | 33 min |
| Jul 28, 6:28 PM MDT | Severe Thunderstorm Warning | CYS | Albany, Carbon | 35 min |
| Jul 28, 7:05 PM MDT | Severe Thunderstorm Warning | CYS | Banner, Kimball | 40 min |
| Jul 28, 7:44 PM MDT | Severe Thunderstorm Warning | CYS | Platte | 46 min |
| Jul 28, 9:08 PM MDT | Severe Thunderstorm Warning | RIW | Johnson | 37 min |
| Jul 28, 9:09 PM MDT | Severe Thunderstorm Warning | UNR | Campbell | 66 min |
| Jul 28, 9:36 PM MDT | Severe Thunderstorm Warning | CYS | Cheyenne | 24 min |
Discussions around it
SPC mesoscale discussions over the same counties from four hours before the watch to its end.
The nearest sounding before it
Rapid City, SD (KRAP), launched 12:00Z, 8.6 hours before the alert went out and 185 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1215 m above ground
- 0-6 km bulk shear
- 42 kt
- 0-1 km storm-relative helicity
- -16 m²/s²
- 0-3 km storm-relative helicity
- 63 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
437
WWUS20 KWNS 282032
SEL9
SPC WW 282032
NEZ000-SDZ000-WYZ000-290400-
URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 319
NWS Storm Prediction Center Norman OK
235 PM MDT Sat Jul 28 2018
The NWS Storm Prediction Center has issued a
* Tornado Watch for portions of
Western Nebraska Panhandle
Far southwest South Dakota
Eastern Wyoming
* Effective this Saturday afternoon and evening from 235 PM until
1000 PM MDT.
* Primary threats include...
A few tornadoes likely
Scattered large hail and isolated very large hail events to 3.5
inches in diameter likely
Scattered damaging winds and isolated significant gusts to 75
mph possible
SUMMARY...Multiple splitting supercells are anticipated to develop
east-southeast with a very large hail and tornado risk. This
activity should eventually consolidate into a couple clusters,
especially into the Nebraska Panhandle later this evening.
The tornado watch area is approximately along and 70 statute miles
east and west of a line from 100 miles north of Douglas WY to 35
miles east of Cheyenne WY. For a complete depiction of the watch see
the associated watch outline update (WOUS64 KWNS WOU9).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Tornado Watch means conditions are favorable for
tornadoes and severe thunderstorms in and close to the watch
area. Persons in these areas should be on the lookout for
threatening weather conditions and listen for later statements
and possible warnings.
&&
AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 3.5 inches. Extreme turbulence and surface wind
gusts to 65 knots. A few cumulonimbi with maximum tops to 550. Mean
storm motion vector 28035.
...GramsSPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jul 28, 2:17 PM MDT | Mesoscale Discussion | SPC | Banner, Box Butte, Cheyenne, Dawes, Kimball, Morrill and 2 more | 88 min |
| Jul 28, 5:01 PM MDT | Mesoscale Discussion | SPC | Arthur, Chase, Deuel, Dundy, Frontier, Garden and 8 more | 119 min |
| Jul 28, 5:40 PM MDT | Severe Thunderstorm Watch | SPC | Arthur, Chase, Deuel, Dundy, Frontier, Garden and 9 more | 7 hr |
Nearby
Tornado Watches in Wyoming, 2018Tornado Watches in Nebraska, 2018Every tornado watch in 2018
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.