105
FXUS65 KCYS 152324
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
524 PM MDT Wed May 15 2024

.KEY MESSAGES...

- A warming trend will occur through the remainder of the work
  week, with 80s possible by Friday especially for areas along
  and east of I-25.

- Elevated wind gusts are expected in the southeast Wyoming wind
  corridors on Friday and Friday night.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 216 PM MDT Wed May 15 2024

The shortwave responsible for the cooler temperatures and shower
activity earlier today will continue to push off to the east this
afternoon and evening. As a result, showers and storms will become
less numerous as the afternoon progresses with precipitation
chances virtually gone later this evening. Could here a few
rumbles of thunder this afternoon as there is some CAPE
present, however, this cooler and moister airmass is more stable
than the previous few days.

Looking at warmer and drier conditions headed into the end of the
work week. Weak ridging and rising mid-level heights will lead to a
speedy warming trend over the next two days. By Friday afternoon,
700 mb temperatures could be up to +12C! This will lead to well
above average temperatures across the CWA. Highs on Thursday will be
about 15 degrees warmer compared to Wednesday`s temperatures. Highs
will mainly be in the 70s for most locations. Highs on Friday jump
another 5 to 10 degrees with the upper 80s potentially making an
appearance in the Nebraska panhandle! Locations east of the Laramie
Range can expect highs in the 80s, with 70s for areas west. The weak
ridging will keep precipitation chances at a minimum both days,
however, an approaching shortwave to our north could lead to a
breezy afternoon on Friday.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 216 PM MDT Wed May 15 2024

Medium Range models are coming into better agreement with the
pattern over the weekend and early next week...showing
progressive west to southwest flow across southeast Wyoming and
western Nebraska. The northern branch of the polar jet stream is
expected to remain north of the forecast area, and models show
it as far north as the Wyoming/Montana border, therefore, there
is higher confidence in temperature and POP forecasts since
ensemble members are in better agreement overall. There is still
some large ensemble spread with temperatures on Saturday, but
believe this is due to the questionable speed of the
progressive upper level trough Friday night rather than the
trough/cold front digging south along the Front Range.
Otherwise, Models, notably the GFS, has backed off on the windy
conditions for Friday night and Saturday with 700mb winds about
10 knots lower compared to yesterday. This makes sense since the
position of the upper level trough and associated cold front
are located further north and move through the area earlier and
quicker compared to what models showed a few days ago. Overall,
should be a pleasant weekend with warm temperatures in the 70s
across most of southeast Wyoming, and in the low to mid 80s
across western Nebraska. Potential for showers and Tstorms will
be minimal on Saturday, with widely scattered coverage on Sunday
as the southern branch of the jet stream becomes more active.

Expect a slow cool down next week, mainly due to increasing
precipitation chances and a slow moving Pacific upper level
trough. A strong midlevel shortwave is forecast to lift
northeast out of the four corners region Monday and Monday
night, with better forcing and more favorable moisture profiles
in the low to midlevels. Models seem to be in good agreement
with this portion of the forecast. Continued to increase POP
for Monday through Wednesday next week for a daily chance of
showers and thunderstorms...peaking in the afternoon and evening
hours. Due to cloud cover and cooler temperatures, the
probability of strong or severe thunderstorms looks rather low
early next week. Monday and Monday evening looks like the most
favorable time(s) for some strong Tstorms as the trough axis
moves into central Wyoming and Colorado.

&&

.AVIATION /00Z TAFS THROUGH 00Z FRIDAY/...
Issued at 520 PM MDT Wed May 15 2024

Northwest flow aloft will continue. Scattered to broken clouds
from 4000 to 6000 feet will occur through early evening, then
skies will become clear. Rain showers will be in the vicinity of
Laramie and Cheyenne until 02Z. Winds will gust to 24 knots at
the Wyoming terminals until 03Z, and to 23 knots after 15Z
Thursday.

&&

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

&&

$$

SHORT TERM...SF
LONG TERM...TJT
AVIATION...RUBIN