Alert archive / Wyoming / Mesoscale Discussions in 2019
Mesoscale Discussion 1821
The Storm Prediction Center issued this mesoscale discussion at Aug 20, 2019, 9:05 PM MDT for Morgan County, Weld County, Colorado; Goshen County, Laramie County, Platte County, Wyoming. It was in force for 85 min.
The area
The outline as issued.
The facts
- Issued
- Aug 20, 2019, 9:05 PM MDT (03:05 UTC)
- Expired
- Aug 20, 2019, 10:30 PM MDT
- In force
- 85 min
- Issued by
- the Storm Prediction Center
Counties Morgan County, CO, Weld County, CO, Goshen County, WY, Laramie County, WY, Platte County, WY
The radar
The Cheyenne radar (KCYS), 81 km from the middle of the area, began a volume at 03:07 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 (KDNR), launched 00:00Z, 3.1 hours before the alert went out and 252 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
- 358 J/kg
- Mixed-layer CIN
- -3 J/kg
- Mixed-layer LCL
- 3844 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- -51 m²/s²
- 0-3 km storm-relative helicity
- -24 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.3
The text
As transmitted.
593
ACUS11 KWNS 210306
SWOMCD
SPC MCD 210305
NEZ000-COZ000-WYZ000-210430-
Mesoscale Discussion 1821
NWS Storm Prediction Center Norman OK
1005 PM CDT Tue Aug 20 2019
Areas affected...Portions of southeastern WY...northeastern CO...and
the far western NE Panhandle
Concerning...Severe Thunderstorm Watch 607...
Valid 210305Z - 210430Z
The severe weather threat for Severe Thunderstorm Watch 607
continues.
SUMMARY...An isolated severe threat continues across mainly western
portions of Severe Thunderstorm Watch 607.
DISCUSSION...Storms have generally weakened this evening along and
just east of the higher terrain in southeastern WY and northeastern
CO. Even with continued low-level easterly upslope flow across this
region, convective inhibition has increased. Convective overturning
from storms earlier this afternoon/evening may have also locally
reduced mid-level lapse rates. Even so, weak to moderate instability
coupled with sufficient shear may continue to support an isolated
severe threat across mainly western portions of Severe Thunderstorm
Watch 607 in the short term. Large hail remains the primary threat.
The potential for clustering of storms later tonight into the
western NE Panhandle appears lower due to a general lack of storm
organization and intensity across southeastern WY as of 03Z.
..Gleason.. 08/21/2019
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...BOU...CYS...
LAT...LON 42550523 42910456 42920378 40050380 40090466 42000520
42550523SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 20, 6:00 PM MDT | Mesoscale Discussion | SPC | Morgan, Weld | 90 min |
| Aug 20, 10:34 PM MDT | Mesoscale Discussion | SPC | Logan, Phillips, Sedgwick | 56 min |
| Aug 21, 12:51 PM MDT | Mesoscale Discussion | SPC | Arapahoe, Boulder, Broomfield, Clear Creek, Custer, Denver and 13 more | 114 min |
| Aug 21, 2:47 PM MDT | Severe Thunderstorm Watch | SPC | Adams, Arapahoe, Boulder, Broomfield, Crowley, Denver and 9 more | 6 hr |
| Aug 21, 4:39 PM MDT | Mesoscale Discussion | SPC | Boulder, Broomfield, Denver, Douglas, El Paso, Jefferson and 2 more | 96 min |
Nearby
Mesoscale Discussions in Wyoming, 2019Mesoscale Discussions in Colorado, 2019Every mesoscale discussion in 2019
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.