Alert archive / Nebraska / Mesoscale Discussions in 2020

Mesoscale Discussion 521

May 3, 20204 states

The Storm Prediction Center issued this mesoscale discussion at May 3, 2020, 2:44 PM MDT for 4 states. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued: May 3, 2020, 2:44 PM MDT (20:44 UTC)
Expired: May 3, 2020, 4:45 PM MDT
In force: 2 hr
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 36 counties

Adams County, CO, Arapahoe County, CO, Denver County, CO, Elbert County, CO, Kit Carson County, CO, Lincoln County, CO, Logan County, CO, Morgan County, CO, Phillips County, CO, Sedgwick County, CO, Washington County, CO, Weld County, CO, Yuma County, CO, Cheyenne County, KS, Sherman County, KS, Arthur County, NE, Banner County, NE, Box Butte County, NE, Chase County, NE, Cheyenne County, NE, Dawes County, NE, Deuel County, NE, Dundy County, NE, Garden County, NE, Grant County, NE, Hayes County, NE, Hitchcock County, NE, Keith County, NE, Kimball County, NE, McPherson County, NE, Morrill County, NE, Perkins County, NE, Scotts Bluff County, NE, Sheridan County, NE, Sioux County, NE, Laramie County, WY

The radar

The Cheyenne radar (KCYS), 159 km from the middle of the area, began a volume at 20:44 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 12:00Z, 8.7 hours before the alert went out and 93 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 997 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 68 m²/s²
0-3 km storm-relative helicity: 214 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

477 
ACUS11 KWNS 032044
SWOMCD
SPC MCD 032044 
NEZ000-KSZ000-COZ000-WYZ000-032245-

Mesoscale Discussion 0521
NWS Storm Prediction Center Norman OK
0344 PM CDT Sun May 03 2020

Areas affected...Northeast Colorado...Western Nebraska...far
northwestern Kansas

Concerning...Severe potential...Watch unlikely 

Valid 032044Z - 032245Z

Probability of Watch Issuance...20 percent

SUMMARY...A few supercell thunderstorms will be possible this
afternoon. Large hail and strong/severe wind gusts will be the main
threats. An area of enhanced low-level SRH near an outflow
boundary/surface trough intersection exists in northeast Colorado
and adjacent Nebraska. A brief tornado would be possible in these
areas. Trends will continue to be monitored, but a WW is not
anticipated this evening.

DISCUSSION...A thunderstorm has developed within the Nebraska
Panhandle with increasing cumulus evident on visible satellite
southward into northeastern Colorado. This activity is developing
where a surface trough intersects a subtle outflow boundary in
northern Colorado to near Sidney, NE. A pool of low 50s F dewpoints
has boosted MLCAPE values to over 1000 J/kg. Effective shear of
45-55 kts and steep low/mid-level lapse rates will support supercell
thunderstorms capable of large hail and strong/severe wind gusts.
Weak low-level flow and somewhat large T/Td spreads will limit any
tornado threat; however, northeastern Colorado and adjacent
southwestern Nebraska will see slightly better low-level hodographs
near the outflow/surface trough intersection. A brief tornado is
possible in this area. Buoyancy decreases to the east and activity
is not expected to progress far from the High Plains. Trends will
continue to be monitored, but a WW is not currently expected this
evening.

..Wendt/Hart.. 05/03/2020

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...LBF...GLD...PUB...BOU...CYS...

LAT...LON   41150086 40310083 39240181 38950269 38930385 39470496
            39610490 40290514 40970502 41720428 42800365 42920212
            42160123 41150086

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 3, 5:05 AM MDT	Mesoscale Discussion	SPC	Allen, Anderson, Bourbon, Butler, Chase, Chautauqua and 18 more	2 hr
May 3, 6:58 AM MDT	Mesoscale Discussion	SPC	Allen, Anderson, Bourbon, Butler, Chase, Chautauqua and 18 more	3 hr
May 3, 7:34 AM MDT	Severe Thunderstorm Watch	SPC	Bourbon, Cherokee, Crawford	5 hr
May 3, 2:10 PM MDT	Mesoscale Discussion	SPC	Campbell, Crook, Weston	2 hr

Nearby

Mesoscale Discussions in Nebraska, 2020 Mesoscale Discussions in Colorado, 2020 Mesoscale Discussions in Kansas, 2020 Every mesoscale discussion in 2020

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.