Alert archive / Nebraska / Mesoscale Discussions in 2021

Mesoscale Discussion 758

May 26, 202114 counties in Kansas; 19 counties in Nebraska

The Storm Prediction Center issued this mesoscale discussion at May 26, 2021, 9:04 PM CDT for 14 counties in Kansas; 19 counties in Nebraska. It was in force for 116 min.

The area

The outline as issued.

The facts

Issued
May 26, 2021, 9:04 PM CDT (02:04 UTC)
Expired
May 26, 2021, 11:00 PM CDT
In force
116 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 212
All 33 counties

Clay County, KS, Cloud County, KS, Decatur County, KS, Jewell County, KS, Lincoln County, KS, Mitchell County, KS, Norton County, KS, Osborne County, KS, Ottawa County, KS, Phillips County, KS, Republic County, KS, Rooks County, KS, Smith County, KS, Washington County, KS, Adams County, NE, Buffalo County, NE, Clay County, NE, Dawson County, NE, Franklin County, NE, Frontier County, NE, Furnas County, NE, Gosper County, NE, Harlan County, NE, Hayes County, NE, Hitchcock County, NE, Jefferson County, NE, Kearney County, NE, Lincoln County, NE, Nuckolls County, NE, Phelps County, NE, Red Willow County, NE, Thayer County, NE, Webster County, NE

The radar

The Grand Island radar (KUEX), 85 km from the middle of the area, began a volume at 02:05 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 00:00Z, 2.1 hours before the alert went out and 148 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 00:00Z on 2021-05-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 124 joules per kilogram.LCLLFCEL10008507005003002001001 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 00:00Z on 2021-05-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 149 square meters per square second.19395878Sfc1 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
124 J/kg
Mixed-layer CIN
-115 J/kg
Mixed-layer LCL
1622 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
363 m²/s²
Significant tornado parameter
0.1
Supercell composite
9.7

Open this sounding in Storm Lab

The text

As transmitted.

563 
ACUS11 KWNS 270205
SWOMCD
SPC MCD 270204 
KSZ000-NEZ000-270400-

Mesoscale Discussion 0758
NWS Storm Prediction Center Norman OK
0904 PM CDT Wed May 26 2021

Areas affected...Parts of southern Nebraska and northern Kansas

Concerning...Severe Thunderstorm Watch 212...

Valid 270204Z - 270400Z

The severe weather threat for Severe Thunderstorm Watch 212
continues.

SUMMARY...Thunderstorm activity may gradually consolidate and
organize while developing eastward across the region through 10
PM-Midnight CDT.  Eventually, this may be accompanied by increasing
risk for strong surface gusts, in addition to a continuing risk for
large hail.

DISCUSSION...As a southerly low-level jet strengthens this evening,
thunderstorm development continues to increase within stronger
lower/mid tropospheric warm advection.  This is generally focused
along the northeastern periphery of the plume of warmer elevated
mixed-layer air emanating from the southern Rockies (which appears
roughly delineated by 8-10 C around 700 mb), as mid-level troughing
continues to slowly progress east of the northern Rockies. 

A gradual consolidation of convection appears possible through
03-05Z, roughly centered near the Kansas/Nebraska border area, where
inflow of moist air characterized by moderate to large CAPE
(1500-3000 J/kg) probably will maintain vigorous intensities. 
Although this may be mostly rooted above a drier/more stable
boundary layer, in the presence of strong shear within the
convective layer, potential exists for convection to gradually
organize, and eventually pose increasing risk for strong surface
gusts.

..Kerr.. 05/27/2021

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

ATTN...WFO...OAX...TOP...ICT...GID...LBF...GLD...

LAT...LON   41110125 41099954 40189653 39329691 38979773 39229933
            39670043 40640174 41110125

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 26, 7:32 PM CDTMesoscale DiscussionSPCClark, Comanche, Kiowa88 min
May 26, 11:26 PM CDTMesoscale DiscussionSPCButler, Chautauqua, Cowley, Elk, Harper, Montgomery and 2 more64 min
May 27, 12:51 AM CDTMesoscale DiscussionSPCAllen, Anderson, Atchison, Bourbon, Butler, Chase and 39 more84 min
May 27, 1:05 AM CDTSevere Thunderstorm WatchSPCAllen, Anderson, Atchison, Bourbon, Brown, Chase and 32 more7 hr
May 27, 2:17 AM CDTMesoscale DiscussionSPCAtchison, Clay, Cloud, Geary, Jackson, Marshall and 7 more58 min
May 27, 5:28 AM CDTMesoscale DiscussionSPCAnderson, Douglas, Franklin, Jefferson, Johnson, Leavenworth and 7 more92 min
May 27, 11:04 AM CDTMesoscale DiscussionSPCCherokee, Crawford, Labette, Montgomery86 min
May 27, 1:36 PM CDTMesoscale DiscussionSPCAnderson, Atchison, Butler, Chase, Coffey, Douglas and 18 more54 min
May 27, 6:03 PM CDTMesoscale DiscussionSPCDouglas, Franklin, Johnson, Leavenworth, Miami, Wyandotte87 min

Nearby

Mesoscale Discussions in Nebraska, 2021Mesoscale Discussions in Kansas, 2021Every mesoscale discussion in 2021

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.