Mesoscale Discussion 1188
NWS Storm Prediction Center Norman OK
1254 PM CDT Fri Jun 07 2024
Areas affected...north central into central Nebraska
Concerning...Severe potential...Watch possible
Valid 071754Z - 072030Z
Probability of Watch Issuance...60 percent
SUMMARY...Rapid thunderstorm development, including or two
intensifying supercells, appears increasingly probable through 2-4
PM CDT. This activity will pose a risk for producing large hail in
excess of 2 inches in diameter, locally strong surface gusts and
perhaps a tornado or two.
DISCUSSION...Within deepening lee surface troughing, continuing
insolation and northward advection of low-level moisture on
southerly low-level flow are contribute to rapid boundary-layer
destabilization and weakening inhibition across the Nebraska
Sandhills vicinity. This is occurring beneath broadly anticyclonic,
but moderate to strong flow near the northeastern periphery of
large-scale mid/upper ridging. However, forcing for ascent
associated with weak perturbations progressing through this regime
is in the process of spreading eastward across the Nebraska
Panhandle. This lift is likely providing support for the ongoing
high-based convective development approaching the Sandhills.
As surface dew points continue to rise into and through the lower
60s, and temperatures warm into the mid 80s, forecast soundings
suggest that convective temperatures will be approached. It appears
that this will coincide with strengthening deep-layer lift, aided by
lower/mid-tropospheric warm advection initially becoming focused to
northwest and west of the Thedford/Ainsworth vicinities by 19-21Z.
One or two rapidly developing and intensifying supercells appears
possible, in the presence of thermodynamic profiles characterized by
steep mid-level lapse rates with CAPE increasing in excess of 2000
J/kg and strongly sheared deep-layer westerly mean flow increasing
to around 30 kt. As the stronger storms mature, they will tend to
propagate southeastward accompanied by increasing risk for large
hail, and at least some potential for producing a tornado or two.
..Kerr/Guyer.. 06/07/2024
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...GID...LBF...
LAT...LON 42440193 42970083 42229881 41339913 41520055 41890128
42440193