Mesoscale Discussion 1368
NWS Storm Prediction Center Norman OK
0335 PM CDT Thu Jul 20 2017
Areas affected...Portions of northeast CO...southeast WY...western
Concerning...Severe potential...Watch unlikely
Valid 202035Z - 202300Z
Probability of Watch Issuance...20 percent
SUMMARY...Some isolated severe risk may accompany convection
spreading off the CO/WY Front Range vicinity and across the High
Plains into the evening hours. Present indications are that Watch
issuance will be unlikely.
DISCUSSION...Convection continues building over the CO/WY Front
Range in response to diurnally enhanced orographic circulations.
Sufficient convective coverage may yield loosely organized, merging
cold pools spreading eastward over the High Plains into the evening
hours -- amid a modestly moist, upslope flow regime. With surface
dewpoints in the 50s over these areas, amid steep low- to mid-level
lapse rates, sufficient buoyancy will exist for a few strong
convective cores. With DCAPE of around 1300-1800 J/kg, a few severe
wind gusts may occur -- especially where local cold-pool
amalgamation takes place. Isolated marginally severe hail could
occur, especially with convection as it initially spreads east of
the higher terrain. While the presence of around 25 kt of effective
shear may be sufficient for loose and smaller-scale convective
organization, the lack of richer moisture, the lack of stronger
buoyancy, and the lack of even stronger deep shear should limit the
overall severe coverage.
...Please see www.spc.noaa.gov for graphic product...
LAT...LON 39110483 40240513 41290517 41570423 41490303 40960228
39600220 39040268 38800384 39110483