Mesoscale Discussion 1295
NWS Storm Prediction Center Norman OK
0320 PM CDT Wed Jun 24 2026
Areas affected...Southeast Wyoming into northern Colorado and far
western Nebraska
Concerning...Severe potential...Watch likely
Valid 242020Z - 242215Z
Probability of Watch Issuance...80 percent
SUMMARY...Thunderstorm development appears likely by late afternoon
for southeast Wyoming and into the Colorado Front Range. Watch
issuance will likely be needed as convection begins to intensify.
DISCUSSION...Deepening cumulus is noted along the northern CO Front
Range per recent GOES day cloud phase imagery with at least a couple
of early, but transient, attempts a initiation noted near Castle
Rock, CO and Cheyenne, WY. This activity is largely being driven by
orographic ascent on the northeastern fringe of the low/mid-level
thermal ridge in place from northern NM to northern CO where
mid-level lapse rates are fairly steep, but capping is somewhat
weaker. Additional attempts at initiation appear likely over the
next 1-2 hours based on satellite trends, but lingering inhibition
at lower elevation may preclude robust, self-sustained convection in
the near term. However, continued daytime heating of a very moist
air mass (dewpoints in the upper 50s/low 60s) will continue to erode
inhibition and increase the probability for successful initiation
either along the Front Range, off the Laramie Mountains, and/or
along a weak cold frontal boundary draped from western NE into
east-central WY. Latest CAM guidance and a recent ACARs sounding
from Denver, CO suggest temperatures in the upper 70s to low 80s may
be required for this to occur.
Once deep convection can become established, it will mature within
an environment favorable for splitting supercells given very
elongated hodographs characterized by 50-60 knots of effective bulk
shear. Southeasterly low-level flow across WY and into northern
CO/western NE may support some tornado threat with any discrete
right-moving supercell, but the more probable hazard will be severe
gusts and very large hail - possibly as large as 2-4 inches in
diameter. Watch issuance is expected once sustained convection
becomes apparent.
..Moore/Guyer.. 06/24/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...PUB...BOU...CYS...RIW...
LAT...LON 39210538 39980535 40820552 41460599 42580666 42960673
43230660 43360628 43380584 43280526 43120472 42850409
42420376 41910349 40690316 40050308 39630316 39300342
39030387 38980429 38950501 38990527 39210538
MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...2.75-4.25 IN
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