Colorado Mesoscale Discussion

Areas affected…southeastern Wyoming and eastern Colorado

Concerning…Severe potential…Severe Thunderstorm Watch likely

Valid 161940Z – 162045Z

Probability of Watch Issuance…80 percent

SUMMARY…Thunderstorms are expected to develop over the high
terrain and along the surface pressure trough this afternoon and
evening, posing a threat for large hail and damaging winds. A
severe thunderstorm watch will likely be needed by 21Z.

DISCUSSION…Low-level stratus clouds finally eroded this morning
over northeastern Colorado and southeastern Wyoming allowing for
full insolation. As a result, destabilization will continue through
the afternoon in the presence of adequate low-level moisture and
very steep midlevel lapse rates (90th percentile value in 12Z DNR
sounding). Weak upslope low-level flow (east of the surface
pressure trough) will contribute to effective deep-layer shear over
40 knots, supportive of supercells capable of producing large hail,
damaging winds, and perhaps a tornado. A severe thunderstorm watch
will likely be needed by 21Z.

Considerable uncertainty remains regarding the eventual convective
evolution from the initial expected supercell mode. Significant
convective inhibition around 700 mb (associated with the stout EML)
exists over the plains, so it is unclear whether storms will be able
to organize and grow upscale with eastward extent. An increasing
low-level jet this evening will provide support for ongoing storms
and encourage new storm development, especially across
western/central Kansas. The threat for organized damaging winds
would increase if this type of convective evolution materializes.

..Jirak/Grams.. 08/16/2019

…Please see www.spc.noaa.gov for graphic product…

ATTN…WFO…LBF…DDC…GLD…PUB…BOU…CYS…

LAT…LON 39610528 40340544 41460560 42330559 42670519 42650446
42430359 41810288 40780213 40010182 39530159 38610154
38200169 37740231 37670279 37770351 38280426 39610528

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