135
FXUS65 KGJT 281210
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
610 AM MDT Fri Mar 28 2025

.KEY MESSAGES...

- Isolated to scattered showers with isolated thunderstorms
  develop late this afternoon, with showers becoming widespread
  this evening through Saturday morning. The first disturbance
  moves through this evening through Saturday morning, with snow
  favoring the northern and central mountains above 9000 feet.

- After a break Saturday afternoon, another disturbance moves
  through Saturday evening through Sunday morning, bringing
  additional mountain snow and valley rain.

- Snow will be confined to the mountains with amounts of 4-10
  inches generally above 8 kft by the end of the weekend,
  particularly favoring the northern and central mountains.

- Additional storms are possible next week that will bring more
  mountain snow and valley rain to the region.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 356 AM MDT Fri Mar 28 2025

Mid and high cloud cover is overspreading eastern Utah and
portions of western Colorado early this morning as moisture from
the Pacific moves through SoCal across the Great Basin and into
our CWA. This moisture is ahead of a leading shortwave ejecting
out of a low pressure system off the coast of British Columbia
and the Pacific NW. The abundant cloud cover is helping keep our
overnight low temperatures mild with current temperatures in the
mid to upper 50s across eastern Utah and far western Colorado
valleys. This cloud cover could result in a later start to
convection and will also result in a bit cooler temperatures
this afternoon. While not the record highs we saw yesterday,
highs will be 5 to 10 degrees cooler but still 5 to 10 degrees
above normal. Much of the precipitation looks to hold off until
this evening as the shortwave trough and associated cold front
pass overhead, keeping more widespread showers in the picture
this evening through Saturday morning. Some instability and
steep lapse rates is present, but cloud cover may inhibit
thunderstorm activity so kept just an isolated thunder mention
at some higher elevations.

As this trough lifts from southwest to northeast this evening
through Saturday morning, the northern and central Colorado
mountains appear favored for the better snowfall accumulations.
PWAT anomalies peak at 200+ percent of normal this evening
through Saturday morning with this wave but the better QPF
amounts appear to favor the higher elevations. Snow levels will
be quite high to start, at about 9000 to 9500 feet this
afternoon, lowering to around 7500 to 8000 feet by Saturday
morning. It looks like the better snowfall accumulations favor
elevations above 9000 feet, with around 4 to 8 inches over the
Park Range with lesser amounts across higher peaks of the
central mountains and Flat Tops. Due to the milder air
associated with this system and not much in the way of CAA aloft
with the passage of this shortwave and cold front, impacts
appear limited to areas above timberline with roads mostly
remaining wet as temperatures will be quite warm today despite
cloud cover. Some slushy spots are possible at the higher passes
but better accumulations appear to be above pass level, so
decided to hold off on issuing any Winter Weather Advisories for
this next disturbance. Something for the day shift to reassess
based on latest model guidance trends.

Hi res CAMs indicate a bit of a break in precipitation late
Saturday morning into the afternoon before the next disturbance
moves in for Saturday evening, with showers increasing once
again. Temperatures on Saturday will be quite a bit cooler than
today though following tonight`s cold front, with highs near
normal.

&&

.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 356 AM MDT Fri Mar 28 2025

On Saturday night, precipitation will be ongoing, particularly
in the terrain north of I-70, where PWAT anomalies look to be
the greatest. This precipitation is associated with a trough
propagating across our CWA Saturday into Sunday. The highest
PWAT anomalies during this trough passage look to be moderate at
around 140-170% of normal. Regardless, the dynamics will
support precipitation through Sunday morning. Temperatures fall
to near normal on Saturday as colder air moves into our CWA,
dropping snow levels to 5-7kft during this system. The current
forecast for snow totals from this storm is generally
unimpressive, especially in the southern and central mountains.
The greatest snowfall looks to be in the northern mountains,
which benefit from favorable orographics as flow shifts to
west/northwesterly behind the trough.

After the passing trough moves east of the Continental Divide on
Sunday morning, a lull in precipitation is expected through Monday
night as forcing and the elevated atmospheric moisture leave our
area. Light mountain snow is possible during this period as a result
of orographics and a weak passing disturbance. The next chance for
synoptically driven, widespread precipitation looks to come on
Tuesday as a trough moves inland from the Pacific Northwest. At
this point in time, there are significant differences between
models on the details of this system, but it is worth watching
how things trend. High temperatures remain near normal through
early next week, but depending on how Tuesday`s system develops,
temperatures could fall to below normal during the mid-week
period.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 600 AM MDT Fri Mar 28 2025

Broken mid to high level cloud cover will start off the morning
as moisture moves in ahead of the next disturbance.
Precipitation chances increase after 00Z with prevailing valley
rain and mountain snow/rain mix after 04Z/06Z so included a
PROB30 group from 00Z to 04Z/06Z depending on location to
account for this. Breezy conditions will be seen ahead of this
precipitation this afternoon but VFR should prevail until this
evening and overnight when CIGS and VSBY lower due to showers to
MVFR/IFR at times and near ILS breakpoints.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...MDA
LONG TERM...GF
AVIATION...TGJT