Alert archive / Nebraska / Mesoscale Discussions in 2021
Mesoscale Discussion 628
The Storm Prediction Center issued this mesoscale discussion at May 15, 2021, 6:12 PM MDT for 9 counties in Nebraska. It was in force for 63 min.
The area
The outline as issued.
The facts
- Issued
- May 15, 2021, 6:12 PM MDT (00:12 UTC)
- Expired
- May 15, 2021, 7:15 PM MDT
- In force
- 63 min
- Issued by
- the Storm Prediction Center
- Concerning
- Severe potential...watch unlikely
- Chance of a watch
- 20%
Counties Arthur County, NE, Chase County, NE, Deuel County, NE, Garden County, NE, Hayes County, NE, Keith County, NE, Lincoln County, NE, McPherson County, NE, Perkins County, NE
The radar
The North Platte radar (KLNX), 122 km from the middle of the area, began a volume at 00:11 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, 0.2 hours before the alert went out and 80 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
- 266 J/kg
- Mixed-layer CIN
- -6 J/kg
- Mixed-layer LCL
- 1597 m above ground
- 0-6 km bulk shear
- 36 kt
- 0-1 km storm-relative helicity
- -5 m²/s²
- 0-3 km storm-relative helicity
- 90 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.3
The text
As transmitted.
954
ACUS11 KWNS 160013
SWOMCD
SPC MCD 160012
NEZ000-COZ000-160115-
Mesoscale Discussion 0628
NWS Storm Prediction Center Norman OK
0712 PM CDT Sat May 15 2021
Areas affected...southwest Nebraska
Concerning...Severe potential...Watch unlikely
Valid 160012Z - 160115Z
Probability of Watch Issuance...20 percent
SUMMARY...Thunderstorms developing over southwest Nebraska this
evening might become capable of producing isolated large hail and
locally strong wind gusts. Overall threat will probably not warrant
a WW, but trends will continue to be monitored.
DISCUSSION...Storms are currently developing across southwest NE
within a weak warm advection regime, and additional storms are
expected this evening as the southerly low-level jet strengthens.
Widespread clouds have limited surface heating resulting in modest
MLCAPE (500-1000 J/kg). However, vertical wind profiles with up to
40 kt effective bulk shear (as sampled by the 00Z North Platte RAOB)
will be sufficient for a few rotating updrafts which along with
7-7.5 C/km mid-level lapse rates will support the potential for a
few instances of large hail. Activity might eventually evolve into a
small MCS before weakening later this evening.
..Dial/Grams.. 05/16/2021
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LBF...BOU...
LAT...LON 40490208 41430251 41940230 41800109 41370020 40450063
40490208SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 15, 6:41 PM MDT | Mesoscale Discussion | SPC | Banner, Kimball, Scotts Bluff | 2 hr |
| May 16, 4:11 PM MDT | Mesoscale Discussion | SPC | Dundy | 94 min |
Nearby
Mesoscale Discussions in Nebraska, 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.