MD 1586 CONCERNING SEVERE POTENTIAL…WATCH UNLIKELY FOR THE NORTHERN/CENTRAL HIGH PLAINS
Mesoscale Discussion 1586
NWS Storm Prediction Center Norman OK
0444 PM CDT Fri Jul 12 2024
Areas affected…the northern/central High Plains
Concerning…Severe potential…Watch unlikely
Valid 122144Z – 122315Z
Probability of Watch Issuance…5 percent
SUMMARY…Sporadic and highly localized severe wind gusts will be
possible within dry microbursts from northeast Wyoming and western
South Dakota into northeast Colorado through sunset.
DISCUSSION…Isolated high-based, low-topped convection is underway
adjacent to the Big Horns, north of the Black Hills, and into
northeast Colorado along a lee thermal trough. Surface-temperature
dew point spreads where convection is initiating are around 50-55 F,
indicative of a deeply mixed boundary layer over the High Plains. As
such, MLCAPE values are largely around the 500-1000 J/kg where
convection is forming, but do increase with eastern extent towards
the lower plains. This initial activity is expected to struggle to
substantially deepen given the airmass, yielded a predominant dry
microburst wind threat across the region for the first few hours of
development. Moderate northwesterly speed shear within the
cloud-bearing layer may promote small hail production in the
strongest cores, which could augment downdrafts as they fall.
..Grams/Gleason.. 07/12/2024
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…LBF…UNR…GLD…BOU…CYS…BYZ…RIW…
LAT…LON 44860624 45350520 45210270 44800166 43000163 40150186
39950224 40010280 40490305 43140425 44080647 44860624
