085
FXUS65 KCYS 062329
AFDCYS

Area Forecast Discussion
National Weather Service Cheyenne WY
529 PM MDT Sat Jul 6 2024

.KEY MESSAGES...

- Near critical to critical fire weather conditions expected on
  Saturday for parts of Carbon and Albany County. Red Flag
  Warnings are in effect.

- Multiple rounds of scattered showers and thunderstorms are
  expected between now and Sunday evening. Some may produce
  gusty winds or small hail.

- Gradual warming trend next week with little to no
  precipitation chances. Very hot by the weekend.

&&

.SHORT TERM /THROUGH MONDAY NIGHT/...
Issued at 300 PM MDT Sat Jul 6 2024

After dry weather for the last several days, we will have a little
bit more activity over the next 30 hours or so. GOES water vapor
satellite imagery shows a broad trough located along the ND/SD line
at this time, with some mid to high level moisture moving into our
area from the northwest. Visible satellite imagery indicates
some shallow cumulus clouds developing over most of the forecast
area with the exception of a narrow area in the southern NE
panhandle. As moisture aloft increases, more of these shallow
cumulus should be able to deepens and lead to scattered showers
and thunderstorms across the area this afternoon. The
environment is quite limited at this time though, with SBCAPE
only around 500 J/kg at this time mainly due to very limited low
level moisture. However, with fairly steep lapse rates and
decent shear, storms that manage to develop may be able to
produce some isolated hail and gusty to strong winds. This first
round will be roughly now through about 03-04z, mainly
affecting areas along and north of the North Platte River
valley. However, a few storms could creep into the southern NE
panhandle towards the evening hours.

While the first round will clear out this evening, multiple
additional rounds of scattered showers and a few storms are possible
through the night. A shortwave will rotate around the broad longwave
trough over the north central US tonight, and bring with it some
modest synoptic lift and a surface cold front. The front will sweep
through this evening, and the environment behind will be more
moisture rich than the preceding environment. This should keep some
echos on the radar through the night. By Sunday morning, the lower
atmosphere trough axis and frontal boundary will push through the
area. Convergence in the 600 to 700-mb layer will help to kick off
another round of showers and thunderstorms mainly along the I-80
corridor from Cheyenne eastward. This activity will continue through
the afternoon and spread northward. Overall, Sunday will be quite
cool for this time of year with temperatures running 10-20F cooler
than average. Monday looks much drier with warmer temperatures
moving in aloft stabilizing the atmosphere while PW values drop
below average. Temperatures will still be cooler than average
Monday, but we will begin the warming trend that will continue
through the week ahead.

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
Issued at 300 PM MDT Sat Jul 6 2024

A warm and mostly tranquil week is expected for southeast Wyoming
and western Nebraska as an upper-level ridge slowly moves overhead.
Tuesday will be the coolest day in the long term as northwesterly
flow remains aloft due to the upper-level ridge still off to the
west. This cooler flow will turn more northerly Tuesday evening into
early Wednesday morning as the ridge continues to push in from the
west. Despite this cooler flow, 700mb temperatures will increase
into the 12-15C range, leading to a relatively average day. Highs in
southeast Wyoming will range from the low-80s to low-90s near
Torrington with western Nebraska in the upper-80s to low-90s. 700mb
temperatures slowly tick up for Wednesday, ending near the 14-18C
range. Highs on Wednesday will be in the low-80s to low-90s across
southeast Wyoming and upper-80s to low-90s across western Nebraska.
The warming trend continue through the remainder of the week as the
upper-level ridge moves overhead and remains nearly stationary
through the weekend. The warmest day is expected to be Saturday,
with highs in the low-90s to low-100s across southeast Wyoming and
upper-90s to low-100s in western Nebraska. Several days will feature
extremely warm temperatures from Friday onwards, so heat headlines
may make an appearance next week.

As for precipitation chances, this looks to be a very dry and hot
week. The best precipitation chances will remain confined to the
mountains with portions of Laramie County potentially seeing some
light showers. At this time, several vorticity maxima will traverse
around the ridge, leading to some lifting across the region in the
afternoons. These could provide just enough lift to get shower or
thunderstorm development most of the afternoons this week. Kept
precipitation chances low, around the 15-20% range, as dewpoints
will not be supportive of decent precipitation chances across the
region. There is the potential for better precipitation chances over
the weekend, as the ridge is progged to weaken slightly and come
more flat. However, this is still several days out and precipitation
chances remain low at this time.

&&

.AVIATION /00Z TAFS THROUGH 00Z MONDAY/...
Issued at 521 PM MDT Sat Jul 6 2024

Northwest flow aloft will continue as a cold front passes the
terminals tonight, ushering in cooler temperatures for Sunday.

Wyoming TAFS...Scattered to broken clouds from 8000 to
11000 feet will prevail, with showers in the vicinity of
Cheyenne until 15Z, and in the vicinity of Rawlins and Laramie
from 07Z to 15Z. Winds will gust to 32 knots at Laramie until
01Z, to 31 knots at Rawlins until 02Z, and to 23 knots from
04Z to 07Z, and to 35 knots at Cheyenne until 02Z, to 23 knots
from 04Z to 07Z and after 15Z Sunday.

Nebraska TAFS...Ceilings will range from 5000 to 10000 feet,
with occasional thunderstorms at Alliance and Sidney until 01Z,
producing wind gust to 35 knots and visibilities to 5 miles.
Thunderstorms will be in the vicinity at Chadron, Alliance and
Sidney until 03Z, with showers in the vicinity at all terminals
after 03Z. Winds will gust to 25 knots at Chadron and Alliance
until 03Z, and to 22 knots at Sidney until 06Z.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...Red Flag Warning until 8 PM MDT this evening for WYZ425-428.
NE...None.

&&

$$

SHORT TERM...MN
LONG TERM...AM
AVIATION...RUBIN