Alert archive / Colorado / Mesoscale Discussions in 2017
Mesoscale Discussion 933
The Storm Prediction Center issued this mesoscale discussion at May 31, 2017, 5:39 PM MDT for Yuma County, Colorado; Cheyenne County, Kansas. It was in force for 66 min.
The area
The outline as issued.
The facts
- Issued
- May 31, 2017, 5:39 PM MDT (23:39 UTC)
- Expired
- May 31, 2017, 6:45 PM MDT
- In force
- 66 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
Counties Yuma County, CO, Cheyenne County, KS
The radar
The Goodland radar (KGLD), 46 km from the middle of the area, began a volume at 23:41 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
Denver, CO (KDEN), launched 12:00Z, 11.7 hours before the alert went out and 110 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
- 2092 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 41 m²/s²
- 0-3 km storm-relative helicity
- 99 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
492 ACUS11 KWNS 312340 SWOMCD SPC MCD 312339 KSZ000-NEZ000-COZ000-010045- Mesoscale Discussion 0933 NWS Storm Prediction Center Norman OK 0639 PM CDT Wed May 31 2017 Areas affected...far eastern CO...far southwestern NE...far northwestern KS Concerning...Severe potential...Watch possible Valid 312339Z - 010045Z Probability of Watch Issuance...40 percent SUMMARY...A couple of slow-moving supercells capable of large hail and severe gusts are likely during the early evening. DISCUSSION...Radar mosaic shows a couple of severe supercells near the CO/NE/KS tri-state region early this evening. Upslope surface flow around 20-kt is resulting in effective shear around 40-kt per KGLD VAD data. Steep low to mid-level lapse rates will support strong accelerations in the vertical for both hail growth and precip-laden downdrafts. It seems plausible the strongest storms may yield a localized significant hail risk (2 inches or greater in diameter) but generally severe hail and severe gusts are the main threats with these storms for the next few hours. ..Smith/Thompson.. 05/31/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...BOU... LAT...LON 39400186 40000287 40410207 39480109 39400186
SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 31, 12:40 PM MDT | Severe Thunderstorm Watch | SPC | Bourbon, Cherokee, Crawford, Linn, Miami | 5 hr |
| May 31, 12:45 PM MDT | Mesoscale Discussion | SPC | Bourbon, Cherokee, Crawford, Linn, Miami | 60 min |
| May 31, 1:10 PM MDT | Severe Thunderstorm Watch | SPC | Allen, Butler, Chase, Chautauqua, Cowley, Elk and 15 more | 6 hr |
Nearby
Mesoscale Discussions in Colorado, 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.