Alert archive / Colorado / Mesoscale Discussions in 2017
Mesoscale Discussion 964
The Storm Prediction Center issued this mesoscale discussion at Jun 7, 2017, 2:12 PM MDT for 25 counties in Colorado; 12 counties in Nebraska; Goshen County, Laramie County, Platte County, Wyoming. It was in force for 2 hr.
The area
The outline as issued.
The facts
- Issued
- Jun 7, 2017, 2:12 PM MDT (20:12 UTC)
- Expired
- Jun 7, 2017, 4:15 PM MDT
- In force
- 2 hr
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 20%
All 40 counties
Adams County, CO, Arapahoe County, CO, Boulder County, CO, Broomfield County, CO, Crowley County, CO, Custer County, CO, Denver County, CO, Douglas County, CO, El Paso County, CO, Elbert County, CO, Fremont County, CO, Huerfano County, CO, Jefferson County, CO, Las Animas County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Otero County, CO, Phillips County, CO, Pueblo County, CO, Sedgwick County, CO, Teller County, CO, Washington County, CO, Weld County, CO, Yuma County, CO, Arthur County, NE, Banner County, NE, Chase County, NE, Cheyenne County, NE, Deuel County, NE, Garden County, NE, Keith County, NE, Kimball County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE, Goshen County, WY, Laramie County, WY, Platte County, WY
The radar
The Denver radar (KFTG), 109 km from the middle of the area, began a volume at 20:13 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, 8.2 hours before the alert went out and 47 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
- 1579 m above ground
- 0-6 km bulk shear
- 12 kt
- 0-1 km storm-relative helicity
- -6 m²/s²
- 0-3 km storm-relative helicity
- 82 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
099
ACUS11 KWNS 072012
SWOMCD
SPC MCD 072012
NEZ000-COZ000-WYZ000-072215-
Mesoscale Discussion 0964
NWS Storm Prediction Center Norman OK
0312 PM CDT Wed Jun 07 2017
Areas affected...Portions of eastern CO...southeastern WY...and
western NE
Concerning...Severe potential...Watch unlikely
Valid 072012Z - 072215Z
Probability of Watch Issuance...20 percent
SUMMARY...An isolated threat for large hail and strong to damaging
winds will exist through the early evening. Watch issuance is
unlikely.
DISCUSSION...Recent visible satellite imagery depicts an uptick in
convective coverage and intensity across parts of eastern CO,
southeastern WY, and western NE. A minor impulse noted on water
vapor satellite crossing the central Rockies and weak low-level
upslope flow are likely contributing to the increase in thunderstorm
coverage. Low-level moisture remains generally limited per area 12Z
soundings and 20Z surface observations showing dewpoints remaining
in the upper 40s to mid 50s. But, ample diurnal heating along with
steep mid-level lapse rates are contributing to MLCAPE ranging from
500 J/kg along the Front Range of CO to 1000-1500 J/kg farther east
across the central High Plains.
A large-scale upper ridge remains centered over much of the western
CONUS and Rockies, with modest (generally 25 kt or less) mid-level
northwesterly flow present over the discussion area. Still, a
veering wind profile from the surface to around 6 km should support
enough effective bulk shear to have semi-organized updrafts.
Convection developing along the Front Range and what appears to be a
weak surface boundary in western NE will be capable of isolated
instances of large hail and strong to locally damaging winds through
this evening. There may be some potential for one or more small
clusters of thunderstorms to develop and move east-southeastward
with time, which could increase the damaging wind threat some if
they develop. Regardless, current expectations are for the overall
severe risk to remain isolated/marginal, and watch issuance appears
unlikely.
..Gleason/Guyer.. 06/07/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...GLD...PUB...BOU...CYS...
LAT...LON 41290047 40000212 38470323 37030367 37040518 38700551
40060548 41340537 42230537 42280421 42060261 41680096
41290047Nearby
Mesoscale Discussions in Colorado, 2017Mesoscale Discussions in Nebraska, 2017Mesoscale Discussions in Wyoming, 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.