Alert archive / Colorado / Mesoscale Discussions in 2017
Mesoscale Discussion 660
The Storm Prediction Center issued this mesoscale discussion at May 7, 2017, 4:55 PM MDT for 5 counties in Colorado; Chase County, Deuel County, Dundy County, Nebraska. It was in force for 95 min.
The area
The outline as issued.
The facts
- Issued
- May 7, 2017, 4:55 PM MDT (22:55 UTC)
- Expired
- May 7, 2017, 6:30 PM MDT
- In force
- 95 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
Counties Logan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Yuma County, CO, Chase County, NE, Deuel County, NE, Dundy County, NE
The radar
The Goodland radar (KGLD), 131 km from the middle of the area, began a volume at 22:57 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, 10.9 hours before the alert went out and 50 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
- 2902 m above ground
- 0-6 km bulk shear
- 17 kt
- 0-1 km storm-relative helicity
- -12 m²/s²
- 0-3 km storm-relative helicity
- -4 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
904 ACUS11 KWNS 072255 SWOMCD SPC MCD 072255 NEZ000-KSZ000-COZ000-080030- Mesoscale Discussion 0660 NWS Storm Prediction Center Norman OK 0555 PM CDT Sun May 07 2017 Areas affected...Northeast CO...Northwest KS...Southwest NE Concerning...Severe potential...Watch unlikely Valid 072255Z - 080030Z Probability of Watch Issuance...5 percent SUMMARY...Isolated severe wind gusts, and marginally severe hail, are possible across the northeast CO plains into southwest NE. WW is not warranted for this activity. DISCUSSION...Strong heating across the higher terrain of the central Rockies appears to be primarily responsible for convective generation this afternoon. Over the last hour or so, some of this activity has spread off the Front Range of CO and has loosely organized over the high-plains from Weld to Lincoln to Crowley Counties. While buoyancy is weak, steep lapse rates and an expanding cold pool suggest an arcing band of convection will spread across northeast CO toward southwest NE. Gusty winds appear likely along the leading edge of this convection but hail should remain marginal in severity. Given the expected increase in the LLJ across western KS this evening there may be some longevity with this convection as it spreads northeast. Even so, organized severe threat appears too low to warrant a severe thunderstorm watch. ..Darrow/Edwards.. 05/07/2017 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...BOU...CYS... LAT...LON 40170392 41270258 40680135 39790183 38990323 40170392
Nearby
Mesoscale Discussions in Colorado, 2017Mesoscale Discussions in Nebraska, 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.