Alert archive / Nebraska / Mesoscale Discussions in 2021
Mesoscale Discussion 546
The Storm Prediction Center issued this mesoscale discussion at May 5, 2021, 3:47 PM CDT for 7 counties in Kansas; 24 counties in Nebraska. It was in force for 88 min.
The area
The outline as issued.
The facts
- Issued
- May 5, 2021, 3:47 PM CDT (20:47 UTC)
- Expired
- May 5, 2021, 5:15 PM CDT
- In force
- 88 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 5%
All 31 counties
Cloud County, KS, Jewell County, KS, Mitchell County, KS, Osborne County, KS, Republic County, KS, Smith County, KS, Washington County, KS, Adams County, NE, Butler County, NE, Clay County, NE, Colfax County, NE, Cuming County, NE, Dodge County, NE, Fillmore County, NE, Gage County, NE, Hamilton County, NE, Jefferson County, NE, Lancaster County, NE, Madison County, NE, Merrick County, NE, Nance County, NE, Nuckolls County, NE, Platte County, NE, Polk County, NE, Saline County, NE, Saunders County, NE, Seward County, NE, Stanton County, NE, Thayer County, NE, Webster County, NE, York County, NE
The radar
The Grand Island radar (KUEX), 70 km from the middle of the area, began a volume at 20:50 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
Omaha, NE (KOAX), launched 12:00Z, 8.8 hours before the alert went out and 138 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
- 2603 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 47 m²/s²
- 0-3 km storm-relative helicity
- 75 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
822
ACUS11 KWNS 052048
SWOMCD
SPC MCD 052047
NEZ000-KSZ000-052215-
Mesoscale Discussion 0546
NWS Storm Prediction Center Norman OK
0347 PM CDT Wed May 05 2021
Areas affected...Portions of eastern Nebraska into northern Kansas
Concerning...Severe potential...Watch unlikely
Valid 052047Z - 052215Z
Probability of Watch Issuance...5 percent
SUMMARY...A couple instances of severe hail or a damaging gusts
cannot be ruled out with one of the stronger storms. A WW issuance
is not expected.
DISCUSSION...High-based, low-topped convection continues to
intensify ahead of a slowly east-southeastward advancing cold front
across portions of the Central Plains per latest MRMS mosaic radar
imagery. Immediately along the front, latest Mesoanalysis depicts up
to 500 J/kg MLCAPE driven primarily by ample insolation, mid 40s
surface dewpoints, and 7+ C/km mid-level lapse rates advected
eastward by modest mid-level flow. One of the stronger storms may
briefly support a couple instances of severe hail, though hail is
expected to remain small overall given the very skinny CAPE vertical
profiles. A damaging gust also cannot be ruled out given the
relatively dry boundary layer, as also inferred by near 20F
temperature/dewpoint depressions via the latest METAR observations.
The severe threat area should be confined to a limited area east of
the front given overall scant low-level moisture and slow eastward
advection of the steeper lapse rates. The locally confined, brief
nature of the severe threat precludes a WW issuance.
..Squitieri/Grams.. 05/05/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...OAX...TOP...ICT...GID...
LAT...LON 39089897 39479916 40029890 40799836 41789785 42029771
42149718 41979669 41599641 41489639 41049625 39989655
39319756 39139847 39089897SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 5, 2:29 PM CDT | Mesoscale Discussion | SPC | Clark, Finney, Ford, Grant, Gray, Hamilton and 11 more | 3 hr |
| May 5, 6:39 PM CDT | Mesoscale Discussion | SPC | Barber, Clark, Comanche, Harper, Kiowa | 96 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.