Riner, Wyoming Weather Forecast Discussion

113
FXUS65 KCYS 240759
AFDCYS
Area Forecast Discussion
National Weather Service Cheyenne WY
159 AM MDT Wed Sep 24 2025
.KEY MESSAGES...
- A Freeze Warning is in effect for the high valleys west of the
  Laramie Range Wednesday morning. Freezing temperatures and
  frost possible.
- A ridge of high pressure aloft will lead to drier and warmer
  weather for Thursday through the weekend.
- Another chilly night is expected Thursday, then overnight lows
  increase through the weekend and into early next week.
&&
.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 157 AM MDT Wed Sep 24 2025
Clouds have cleared out tonight with mostly clear skies ongoing
across much of southeast Wyoming. Across the southern Panhandle,
lower ceilings are beginning to develop as residual moisture from
yesterday`s system remains in the lower atmosphere. GOES 19 imagery
shows these clouds mainly across Morrill, Kimball, and Cheyenne
counties. Some patchy fog is trying to develop across Albany and
Carbon counties, as expected given ample moisture in these
locations. Patchy fog could be dense in some locations, but
widespread dense fog is not anticipated this time as a weak
downslope component remains across these locations. Temperatures are
quite cool tonight, in the 30s and 40s across the entire region.
Mostly quiet weather is expected today as upper-level flow remains
northeasterly throughout the day. An upper-level ridge is slowly
moving eastward, though has a significant positive tilt, leading to
those northeasterly winds aloft. Upper-level winds will remain
northeasterly throughout the day as the eastern branch of the upper-
level ridge remains overhead. A weak Omega Block-like pattern is
expected to take hold by Thursday morning with the ridge axis over
the Intermountain West and a upper-level low across north central
California and a secondary trough over much of the Midwest. Since
the eastern low of this "Omega Block" is a progressive trough, the
Omega Block pattern is not expected to be a true block, as the
system will slowly advect easterly as the upper-level ridge across
the Midwest pushes to the east through the day Thursday and into
Friday. However, an "Omega Block Pattern" is the best way to
describe the upper-level flow today through Friday. A similar
pattern is expected at 500mb, with the cyclonic vorticity advection
fairly clear in the eastern branch of this Omega Block, suggesting
no issues with advecting the eastern trough out of the area and
progressing the system along. Minimal CVA is expected aloft across
the region, leading to minimal mid-level synoptic lift across
southeast Wyoming and western Nebraska. A broad, diffuse ridge is
expected to take hold at 700mb, further suggesting quiet weather
with minimal precipitation chances. Additionally, warm air advection
will increase 700mb temperatures from around 1C to 3C today to 8C to
10C by Thursday morning. As a result, Thursday`s temperatures will
be much warmer than today`s, likely increasing by about 10 degrees
for much of the CWA. Clear skies overnight tonight and Thursday
night will help overnight lows drop back to the low- to mid-40s for
most locations, with low-30s in many of the valleys. Freeze
headlines may be needed for some of the valleys tonight, but
overnight lows will be warmer Thursday night after a warmer day.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
Issued at 104 PM MDT Tue Sep 23 2025
An upper level ridge will keep things rather dry
starting Thursday. Following the trough that pushed through the
Intermountain West, a amplified ridge sets in. The strong subsident
flow is expected to suppress any rising motion to decrease any
rain/snowfall chances. 700mb temperatures look to remain stagnant
between 9 to 11C Thursday through the weekend. So temperatures look
to remain the the 70`s in Wyoming with low to mid 80`s in the
Nebraska Panhandle. Friday into Saturday, an upper level trough
traverses across the Canadian Providences as well and another trough
pushing into the southern California coast. The southern trough will
inject some moisture into the region however will strengthen the
ridge over the intermountain west as the Rex Block sets up. The
northern trough will compress the ridge to give us a dry but gusty
weekend. Our next precipitation chances after the weekend may come
Monday afternoon with another shortwave pushing through the
intermountain west.
&&
.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1109 PM MDT Tue Sep 23 2025
Mostly calm tonight across the region with light winds and
mostly clear skies. Some fog may move into the Wyoming terminals
overnight tonight, though confidence is lower at KCYS. Light
winds tomorrow afternoon with clear skies.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Freeze Warning until 10 AM MDT this morning for WYZ105-109>111-
     113-115.
NE...None.
&&
$$
SHORT TERM...AM
LONG TERM...MM
AVIATION...MN/AM

NWS CYS Office Area Forecast Discussion