MD 1626 CONCERNING SEVERE POTENTIAL…WATCH POSSIBLE FOR MUCH OF CENTRAL AND EASTERN NEBRASKA
Mesoscale Discussion 1626
NWS Storm Prediction Center Norman OK
0346 PM CDT Mon Aug 01 2022
Areas affected...much of central and eastern Nebraska
Concerning...Severe potential...Watch possible
Valid 012046Z - 012315Z
Probability of Watch Issuance...60 percent
SUMMARY...Isolated strong to severe storms including a few
supercells should slowly develop late this afternoon and continue
into this evening. Hail and damaging winds will be possible.
Conditions will be monitored for a possible weather watch.
DISCUSSION...Ahead of a weak mid-level disturbance moving across the
central High Plains, afternoon visible imagery shows alto cumulus
increasing in coverage across portions of central and eastern NE.
Continued heating of the already warm and moist boundary layer
should result in gradual erosion of remaining inhibition late this
afternoon into early this evening. Enhanced mid-level flow
associated with the approaching shortwave is evident on area VAD
VWPs and SPC mesoanalysis, supporting 35 to 45 kt of effective
shear. The combination of subtle forcing for ascent and favorable
shear should support an initial supercellular storm mode with storms
as they gradually develop. The supercell mode and mid-level lapse
rates in excess of 8 C/km should support large hail potential with
the more dominant storms. Damaging winds will also be possible given
relatively large T/TD spreads (greater than 20 F) favoring higher
LCLs. Some upscale growth into a cluster/small MCS is possible later
this evening as outflow from initially supercellular storms
coagulates. This is supported by recent HRRR solutions which some an
increase in storm coverage later this evening as convection
approaches the Missouri River and eastern NE. Should this occur, a
greater risk of damaging winds may develop with any well formed
bowing segments that become established.
Current observational and model trends suggests initial updrafts
will evolve out of the better mixed airmass across western/central
NE in the next couple of hours. There after, storms should become
established as they move farther east into the more moist/unstable
airmass (2500-3000 J/kg MLCAPE). While some uncertainty on storm
development timing and coverage exists given the lack of greater
background forcing, the potential for severe hail and wind suggests
an increasing severe threat this afternoon/evening. Trends will be
monitored for a possible weather watch.
..Lyons/Grams.. 08/01/2022
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...FSD...OAX...GID...LBF...UNR...
LAT...LON 41099991 41310062 41850080 42360085 42820061 43019991
42999940 42999823 42919737 42649667 42439652 42099639
41649615 41349613 41139617 40989629 40939651 40969712
41099991
