Areas affected…northeast CO into southeast WY and western NE
Concerning…Severe potential…Watch possible
Valid 011925Z – 012100Z
Probability of Watch Issuance…60 percent
SUMMARY…Thunderstorms are expected to increase in coverage and
intensity this afternoon, posing a threat for large hail and strong
wind gusts. A watch may be needed in the next couple of hours across
parts of northeast CO and perhaps far southeast WY/southwest NE.
DISCUSSION…Convection has developed over higher terrain this
afternoon in moist, upslope flow regime. Cloud cover for much of the
day has limited destabilization across eastern WY into western NE,
but temperatures are beginning to climb into the low 80s as of 19z
across southeast WY into southwest NE where cloud cover has
decreased. Dewpoints across the region range from the mid 50s near
the I-25 corridor to the mid 60s further east, beneath an area of
steep midlevel lapse rates around 7.5-8 C/km. This is leading to
1000-2000 J/kg MLCAPE.
Cells should be surface-based despite some weak MLCIN still
indicated by latest mesoanalysis. CU field across northeast CO into
far southeast WY and southwest NE has been deepening over the last
hour, suggesting capping is weakening. And with continued heating
over the next couple of hours and increased forcing for ascent,
convective coverage should increase as storms move off of higher
terrain. Effective shear will increase over the next few hours and
should support high-based marginal supercells capable of large hail
initially. As storms shift east, steep low level lapse rates will
result in greater strong, locally damaging, wind potential, and
cells may grow upscale into clusters or line segments. A severe
thunderstorm watch may be necessary across portions of the region in
the next couple of hours.
..Leitman/Hart.. 08/01/2019
…Please see www.spc.noaa.gov for graphic product…
ATTN…WFO…LBF…GLD…PUB…BOU…CYS…
LAT…LON 40070237 39340235 38780260 38440317 38550364 38770467
38920481 39300495 39620496 40770489 41350483 41960459
42080457 42440439 42520411 42490353 42280310 41690277
40430242 40070237