275
FXUS65 KCYS 280516
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
1116 PM MDT Thu Jun 27 2024

.KEY MESSAGES...

- Scattered showers and thunderstorms are expected across much
  of southeast Wyoming and western Nebraska this afternoon and
  evening. A conditional threat for severe thunderstorms will
  exist across extreme southeast Wyoming and western Nebraska,
  with large hail and damaging winds the primary hazards along
  with the potential for an isolated tornado.

- Another round of strong to severe thunderstorms is expected
  Friday as a cold front sweeps across the CWA. At this time,
  the best chance for convection appears to be in the southern
  Nebraska panhandle.

&&

.MESOSCALE...
Issued at 144 PM MDT Thu Jun 27 2024

Latest GOES WV imagery shows an upper level shortwave moving into
central WY with the latest RAP analysis showing the lee trough
shifting eastwards towards the WY/NE border. Despite morning dew
points east of the I-25 corridor in the upper 50s and low 60s,
daytime mixing and westerly winds off the Laramie Range continue to
push upper 50 dew points farther east in the NE panhandle near the
CWA border with LBF. The placement of this low-level moisture
through this afternoon will be important to watch as the atmosphere
continues to destabilize as it will have significant impacts on the
instability profiles as up to 2000 J/kg of CAPE could be available,
but it appears more likely that storms will only be able to tap into
~500 J/kg across the NE panhandle.

Latest GOES Daytime Microphysics RGB has shown late morning clearing
across the southern NE panhandle and northeast CO with stable low-
level billow clouds across much of Platte/Goshen Co where upper
level clouds have limited daytime heating. Cu fields have begun
developing over the last 30-45 minutes across these areas of
clearing which may be an area of concern for stronger storms to
develop early this afternoon before the more favorable low-level
moisture mixes east. These storms could could produce large hail and
strong winds this afternoon before quickly moving east of the CWA
into central NE. Will need to continue to monitor for additional Cu
development farther north near the Pine Ridge as CAMs have been
initiating storms across a localized moisture pool before quickly
moving east as well. There is a short window for severe
thunderstorms today, potentially ending by 5 PM MDT, with lingering
showers and storms through the evening.

Looking farther west, much of south-central WY has begun to
destabilize as indicated with latest satellite imagery.
However, forecast soundings continue to suggest mid-level
capping could inhibit deeper convection before better lift
arrives from the west. Recent WOFS runs continues to show higher
probabilities (40-60%) of strong winds (gusts >58 mph) entering
southwest Carbon Co by mid-afternoon with the ongoing
convection in the Uintas as it travels east and eventually
increasing in coverage through the early evening near the Sierra
Madre and Snowy Ranges.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1112 PM MDT Thu Jun 27 2024

VFR conditions expected next 24 hours with isolated
thunderstorms during the afternoon Friday. All terminals will
see a breezy Friday, as wind gusts of 30-40 knots are expected
for most areas on Friday afternoon.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.

&&

$$

MESOSCALE...MB
AVIATION...GCC