345
FXUS65 KCYS 110314
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
914 PM MDT Fri May 10 2024

.KEY MESSAGES...

- Trending warmer through the weekend, but remaining unsettled
  with daily chances for showers and storms. Severe weather is
  not expected.

- A cold frontal passage is expected on Wednesday, with much of
  the region returning to below-normal temperatures and
  increased chances for rain and high-elevation snow.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 330 PM MDT Fri May 10 2024

A warming trend should persist across southeast WY & the western
NE Panhandle as thermal profiles warm in response to weak upper-
level ridging extending along the northern periphery of a fairly
persistent, slow-moving closed low drifting across the 4 Corners
region through the short term forecast period. Daytime highs may
reach the upper 60s and lower 70s across much of the high plains
by Sunday afternoon as 700-mb temperatures climb to +6 to +8 deg
C by 00z Monday. Despite the warming trend, it should be a some-
what unsettled pattern w/ daily chances for showers and thunder-
storms as multiple pieces of mid-level energy continuously pivot
around the north side of the aforementioned low. Rain amounts do
not look to be anything substantial given the lack of organized/
stronger dynamics. Weak CAPEs under 500 J/kg & modest deep layer
shear will preclude any risk for strong/severe storms.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 330 PM MDT Fri May 10 2024

A transient ridge will position itself across the Rockies for the
early part of next week after this weekend`s cutoff flow finally
ejects off to the east. Multi-model ensemble mean 700-mb
temperatures will climb to around +6 to +8C between Monday afternoon
and Tuesday afternoon, supporting surface temperatures about 10F
warmer than average for Monday afternoon. Lapse rates look fairly
steep, but moisture won`t be particularly abundant with dewpoints in
the 30s to mid 40s and precipitable water near average for this time
of year. The result will be modest instability, but enough to get
some thunderstorms going during the afternoon. A trough over the
Pacific northwest will be approaching early next week, and a leading
shortwave ejecting out will pass through Monday night providing a
boost to lift. Shear looks unimpressive, but we could see some small
hail and gusty winds with inverted-v soundings in place during the
afternoon. The main trough axis approaches late Tuesday or early
Wednesday, setting up lift for another round of showers and
thunderstorms. Expect temperatures to be cooler than Monday for much
of the area, except far SE Wyoming and the southern NE panhandle
which should be similar. Slightly more shear could allow for more
organized convection, but the setup is quite messy with forecast
soundings showing backing wind profiles and muddled lifting
mechanisms. However, this period Tuesday afternoon through Wednesday
morning will probably be the best chance for appreciable
precipitation during the upcoming week.

Expect cooler conditions across the area Wednesday as 700-mb
temperatures get knocked back down to near 0C. Lingering cloud cover
and scattered showers will also be present. Model consistently falls
apart for the end of the week, with some (GEFS members) showing an
amplified ridge over the Pacific northwest, and others (ECMWF
ensemble members) showing a more zonal flow pattern. Regardless,
look for drier air to work in for Thursday and Friday, leading to
temperatures back to near normal and more limited precipitation
chances.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 905 PM MDT Fri May 10 2024

A trough aloft will slowly move from southern Nevada this
evening to southeastern Utah Saturday evening.

Wyoming TAFS...Clear skies will prevail tonight, with scattered
clouds from 6000 to 8000 feet on Saturday. Winds will gust to
20 knots at Cheyenne and Laramie from 14Z to 20Z.

Nebraska TAFS...Clear skies will prevail, with scattered clouds
near 9000 feet at Sidney from 15Z to 01Z.

&&

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

&&

$$

SHORT TERM...CLH
LONG TERM...MN
AVIATION...RUBIN