ACUS11 KWNS 152257
SWOMCD
SPC MCD 152256=20
NEZ000-COZ000-SDZ000-WYZ000-160100-

Mesoscale Discussion 2148
NWS Storm Prediction Center Norman OK
0556 PM CDT Wed Oct 15 2025

Areas affected...Northeast CO...southeast WY...western NE
Panhandle...and far southwest SD

Concerning...Severe potential...Watch unlikely=20

Valid 152256Z - 160100Z

Probability of Watch Issuance...20 percent

SUMMARY...The area is being monitored for an increase in
severe-storm potential into tonight. The primary concern will be
large hail, though locally severe gusts will also be possible with
southward extent. The need for a watch is uncertain.

DISCUSSION...The latest surface observations and visible satellite
imagery indicate an east/west-oriented quasi-stationary surface
boundary draped across the southwestern NE Panhandle into
southeastern WY, with widespread/persistent boundary-layer stratus
socked in to the north of the boundary. To the south, a mesoscale
surface cyclone is evident in the Denver vicinity, with a northeastward-extending convergence zone across northeastern CO.=20

Convection has been attempting to form along the convergence zone,
though weak large-scale forcing for ascent has limited convective
initiation thus far. If a couple storms can evolve along the
convergence zone, upper 70s to lower 80s temperatures and
middle/upper 50s dewpoints will support surface-based inflow (around
1000 J/kg MLCAPE). This buoyancy and around 50 kt of effective shear
will conditionally support a surface-based supercell or two, with a
risk of large hail, locally severe wind gusts, and a low risk of a
brief tornado (given around 200 m2/s2 effective SRH). However,
overall confidence in the development of sustained surface-based
storms in this corridor remains low, especially given gradually
increasing nocturnal inhibition.

Farther north/northwest, convection is gradually increasing along
the higher terrain from north-central CO into central WY -- as
midlevel heights continue falling ahead of a substantial midlevel
trough moving across the Great Basin. While these storms will be
moving atop a cool/stable boundary layer, around 60 kt of effective
shear and steepening midlevel lapse rates will support elevated
supercell structures with a risk of large hail into tonight.=20

It is unclear if the severe risk will warrant a watch issuance,
though convective and environmental trends are being monitored.

..Weinman/Guyer.. 10/15/2025

...Please see https://urldefense.com/v3/__http://www.spc.noaa.gov__;!!DZ3fj= g!_DMt-oXjb6K-Chi8h0uC9Krl_iSUPfAfs31_Doh2CtvTndjQSt7OnhHqN8UKB7LZFICsp10wR= Tp35mZSb78Rcbpn18w$ for graphic product...

ATTN...WFO...UNR...BOU...CYS...

LAT...LON 39670395 39870441 40580467 41090529 41580553 42030553
42630537 43060504 43320450 43350388 43190325 42740298
41720266 40920266 40450292 39680348 39670395=20

MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 95 MPH
MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN


=3D =3D =3D
To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM.

--- SBBSecho 3.28-Linux
* Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105)