461
FXUS65 KGJT 252012
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
212 PM MDT Wed Sep 25 2024

.KEY MESSAGES...

- Dry and unseasonably warm conditions are expected for the
  remainder of the week. Near-record highs are expected from
  Thursday through the weekend.

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 212 PM MDT Wed Sep 25 2024

The string of mainly clear and warm days with cool nights will
continue with this high pressure ridge in control. No big
changes to the forecast in this static pattern and expect
temperatures to continue to warm a few degrees again tomorrow
afternoon and likely pushing record territory in several
locations. There may be just enough moisture and cooling aloft
with a wave passing well to our north to pop a few afternoon
cumulus on the mountain ridges but there will virtually be no
chance of precipitation through Thursday night.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Issued at 212 PM MDT Wed Sep 25 2024

By Friday, the high pressure will have retrograded to the west over
the Desert Southwest with the ridge extending north over the
Intermountain West to southern Idaho and Wyoming. A longwave trough
from the Central Pacific to the Great Lakes over the northern States
and southern Canada is keeping a strong zonal flow with a 140 kt jet
core over these areas that is capping the ridge from extending
farther north and quickly whisking any shortwave disturbances off to
the east before they can dig south into the region. A particularly
strong disturbance tries to disrupt the zonal flow Sunday night into
Monday, but only makes it south to Montana before speeding east out
onto the Northern Plains. The only impact from this system will be a
brief period of northwesterly flow aloft as the high retrogrades to
the west, but then returns to the zonal pattern to the north as the
high pressure swells back to the east over the Rockies. Hence, this
pattern looks to continue through mid next week with little change.

Subsidence under the ridge has warmed the mid layers of the
atmosphere enough to cap any development of cumulus over the
mountains in spite of the nominal moisture that remains in place
over eastern Utah and Western Colorado. This sunny dry weather will
dominate the extended forecast with record or near record high
temperatures 10 to 15 degrees above normal across the region through
Monday with the morning lows running about five degrees above
normal. Note, record highs are in the forecast for the lower valleys
while the high country is forecast to have only near record highs.
The only exception to the clear skies is an upper-level disturbance
rotating around the low over the Mississippi Valley toward the
central and southern Colorado mountains Friday afternoon that
could lead to some cumulus development and a very slight chance
of a shower or thunderstorm forming along the Divide. Stay tuned
over the next 12 hours on this one to see if the high
resolution models pick up on this.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1118 AM MDT Wed Sep 25 2024

Light terrain driven winds and clear skies can be expected over
the next 24 hours...hence solid VFR conditions dominate the
forecast.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...None.
UT...None.

&&

$$

SHORT TERM...15
LONG TERM...DB
AVIATION...GJT