377
FXUS65 KGJT 281115
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
515 AM MDT Sun Sep 28 2025

.KEY MESSAGES...

- Afternoon and evening convection continues again today in many
  areas but looks to favor the eastern mountain on Monday.

- Some storms may be capable of producing strong winds as well
  as heavy rainfall, which could impact the recent burn scars.

- Light snow can`t be ruled out for the highest elevations
  through Monday though little to no impacts are expected on
  mountain roadways.

&&

.SHORT TERM /THROUGH MONDAY/...
Issued at 225 AM MDT Sun Sep 28 2025

Water vapor imagery shows the upper low still spinning over
SoCal this morning. Models suggest this low will begin to be
nudged to the northeast today as Low pressure digs farther into
the EPac. The low makes into it to northern AZ by this
evening then opens to a wave as it crosses the 4 Corners tonight
and finally crosses the CWA on Monday as it continues to shear
apart. Earlier convection continues to dissipate and throw out
some gusty winds as it does so...but overall the radar quieting
down early this morning and we should like start out with just
isolated chances in most areas through most of the morning.
There really isn`t a significant amount of forcing today with
the lagging back to the West. QG ascent actually increases
across the southeast CWA later tonight as the main lobe of
energy rotates around the AZ low and head for the central
Rockies by mid-day tomorrow. However with anomalous moisture in
place expect instability to be released by weaker energy
ejecting through the flow and orographic forcing...that most
areas will have some threat of shower or thunderstorm activity
today. CAPE values remain in the 500-800 j/kg in most area with
the usually robust HIRES NAM showing 1000+ by peak heating
today. Not confident all of this can be utilized but some more
organized storms will be possible today with moderate to heavy
rainfall rates the main threat...small hail and gusty winds both
secondary threats. A lot of the activity should again taper off
overnight with the exception over the southern valleys and
mountains due to the above mentioned vorticity advection. The
eastern mountains and valleys will be favored on Monday as this
wave passes through with residual moisture and isolated
convection possible farther West.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Issued at 225 AM MDT Sun Sep 28 2025

The start of the work week will see unsettled weather
continuing as the open wave remains overhead and the increased
moisture gets worked on as the wave moves through. The best
chances for any convection will be over the higher terrain as
peak heating and the wave provide plenty of lift. Precip is
expected to end late Tuesday night as the next shortwave
approaches from the west. This shortwave will just clip extreme
NW portions of the forecast area, if it does at all. Dry
conditions then setup Wednesday through Thursday. After that, a
longwave trough and surface cold front will be just on our
doorstep though some timing and tracking differences have
creeped into the various solutions. Time will tell. High temps
will run a little warm, mostly, during the long term period as
southwesterly flow advects in warmer temperatures from the
south.

&&

.AVIATION /12Z TAFS THROUGH 12Z MONDAY/...
Issued at 515 AM MDT Sun Sep 28 2025

Scattered showers and thunderstorms will be a constant threat to
many of the TAF sites through the mid evening hours...with
lesser coverage expected during the overnight hours. VFR remains
in control and this remains in the forecast as well however ILS
to low probability MVFR conditions will be possible when
showers move over an airfield. Widespread high terrain
obscuration is likely as this moisture and active weather moves
through into early next week.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...15
LONG TERM...TGR
AVIATION...TGJT