Alert archive / Nebraska / Mesoscale Discussions in 2020

Mesoscale Discussion 784

June 2, 2020Phillips County, Sedgwick County, Yuma County, Colorado; Cheyenne County, Kansas; 33 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at Jun 2, 2020, 3:58 PM MDT for Phillips County, Sedgwick County, Yuma County, Colorado; Cheyenne County, Kansas; 33 counties in Nebraska. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Jun 2, 2020, 3:58 PM MDT (21:58 UTC)
Expired
Jun 2, 2020, 5:30 PM MDT
In force
92 min
Issued by
the Storm Prediction Center
Concerning
Severe potential...watch unlikely
Chance of a watch
20%
All 37 counties

Phillips County, CO, Sedgwick County, CO, Yuma County, CO, Cheyenne County, KS, Antelope County, NE, Arthur County, NE, Blaine County, NE, Boone County, NE, Brown County, NE, Chase County, NE, Custer County, NE, Dawson County, NE, Deuel County, NE, Dundy County, NE, Frontier County, NE, Garden County, NE, Garfield County, NE, Gosper County, NE, Grant County, NE, Greeley County, NE, Hayes County, NE, Hitchcock County, NE, Holt County, NE, Hooker County, NE, Keith County, NE, Lincoln County, NE, Logan County, NE, Loup County, NE, McPherson County, NE, Perkins County, NE, Pierce County, NE, Red Willow County, NE, Rock County, NE, Sherman County, NE, Thomas County, NE, Valley County, NE, Wheeler County, NE

The radar

The North Platte radar (KLNX), 84 km from the middle of the area, began a volume at 21:58 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

N. Platte/Lee Bi, NE (KLBF), launched 12:00Z, 10.0 hours before the alert went out and 21 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-pSkew-T log-p diagram, N. Platte/Lee Bi, NE at 12:00Z on 2020-06-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, N. Platte/Lee Bi, NE at 12:00Z on 2020-06-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
2920 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
-29 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

558 
ACUS11 KWNS 022158
SWOMCD
SPC MCD 022158 
NEZ000-KSZ000-COZ000-022330-

Mesoscale Discussion 0784
NWS Storm Prediction Center Norman OK
0458 PM CDT Tue Jun 02 2020

Areas affected...northeast CO...central NE...and portions of
southern SD

Concerning...Severe potential...Watch unlikely 

Valid 022158Z - 022330Z

Probability of Watch Issuance...20 percent

SUMMARY...Recent visible satellite imagery shows updrafts deepening
near a frontal zone across portions of Nebraska and Colorado.
Moderate destabilization may support a few storms capable of severe
hail and damaging winds through this afternoon and into the evening.
Trends will be monitored, but storm coverage and intensity are not
expected to be great enough to justify a watch at this time.

DISCUSSION...A few deep updrafts have been noted between a quasi
stationary front and a surface trough. Dewpoints in the upper 50s to
low 60s F along and behind the front are contributing to moderate
destabilization, with 2000-3500 J/kg of MLCAPE. Shear is forecast to
remain relatively weak, at or about 25 kt, and mostly on the cooler
side of the boundary. This suggests a few multicell storms capable
of severe hail and strong downdraft winds may develop this
afternoon/evening. Hi-res guidance suggests some clustering of
stronger cells near the front this evening, but the lack of
appreciable deep layer shear suggests that the threat and coverage
of any severe weather may be relatively brief. A weather watch is
not anticipated.

..Lyons/Thompson.. 06/02/2020

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

ATTN...WFO...OAX...GID...LBF...GLD...BOU...

LAT...LON   39720237 40010245 40390251 40680256 41100256 41280254
            41540242 41790220 42100160 42500076 42799989 42899959
            42879882 42719809 42389754 41909774 41449836 40999903
            40429990 39800118 39500189 39600234 39720237

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 2, 2:23 PM MDTMesoscale DiscussionSPCSioux2 hr

Nearby

Mesoscale Discussions in Nebraska, 2020Mesoscale Discussions in Colorado, 2020Mesoscale Discussions in Kansas, 2020Every 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.