974
FXUS65 KGJT 162321
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
521 PM MDT Fri May 16 2025

.KEY MESSAGES...

- Warm and dry conditions will continue through Saturday, with
  isolated afternoon showers limited to the higher terrain north
  of I-70.

- Critical fire weather conditions are expected Saturday
  afternoon across east-central and southeast Utah where the
  Fire Weather Watch has been upgraded to a Red Flag Warning.

- The next storm will move in Sunday, bringing cooler and wetter
  conditions through Tuesday, as well as mountain snow.

&&

.SHORT TERM /THROUGH SATURDAY NIGHT/...
Issued at 245 PM MDT Fri May 16 2025

Remnant moisture and a weak shortwave moving across the north
(more a wiggle in the near zonal flow) will keep isolated to
scattered showers with a few thunderstorms in the picture this
afternoon across the northern mountains. So far today, not much
is happening outside of a few virga showers but a lot less than
activity than the last couple days. Temperatures are already
about 5 degrees warmer than yesterday and highs are expected to
be closer to normal today and about 5 degrees above normal on
Saturday as southwest flow increases ahead of an incoming low
pressure trough dropping into the Great Basin from the Pacific
Northwest. Enough mixing and warm air advection will allow
highs to push towards 80 degrees in the Grand Valley with some
lower desert valleys in eastern Utah pushing low to mid 80s,
while the remaining lower valleys look to see highs well into
the 70s. This warm bump is all before the much cooler airmass
arrives on Sunday with the incoming low pressure trough.

Southwest winds will gust 25 to 35 mph across east-central to
southeast Utah and southwest Colorado on Saturday, with
relative humidity also dropping into the teens and single
digits, resulting in critical fire weather conditions. Decided
to upgrade the Fire Weather Watch to a Red Flag Warning on
Saturday for the zones where fuels are considered critical at
this time, which includes east-central and southeast Utah (Utah
Fire Zones 490 and 491). Regardless of fuel status, caution is
urged and outdoor burning is not recommended given the drier and
breezy to windy conditions. Precipitation may increase across
eastern Utah Saturday night but the latest model guidance seems
to be coming around to holding off on the majority of widespread
precipitation until Sunday.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
Issued at 245 PM MDT Fri May 16 2025

A deep upper-level trough will move overhead on Sunday,
bringing widespread precipitation across the CWA along with
another bout of strong wind gusts upwards of 35 mph.
Temperatures behind the associated slow-moving cold front will
drop high temperatures on Sunday 10-15 degrees below normal,
though there is little clarity on how much this will bolster
snow accumulations considering the uncertainty on how quick the
front will move. Should frontal passage occur late morning/early
afternoon, cooler temperatures may yield lower snow levels and
higher accumulations as opposed to a mid-afternoon frontal
passage during peak heating. Deterministic models are siding
with the latter at the moment, resulting in modest snow
accumulations of 2-4" over the San Juans, central Colorado
mountains, and the Grand Mesa, and higher accumulations of 6-10"
over the eastern Uintas. Uncertainty grows on Monday as a
northern closed low descends southwards through the trough.
Lacking moisture with this low (PWAT`s 90-130% of normal) will
result in primarily orographically-driven showers, though the
further reduced temperatures associated with the system would
favor more mountain snow and valley rain as snow levels drop to
around to 7.5-8.5 kft.

The rapidly evolving upper-level pattern regarding the slow-
moving trough and the southwards-moving closed low leaves the
early-week weather difficult to pinpoint. One way or another,
widespread precipitation favoring higher terrain where
orographics can better support storms is expected to occur.
However, timing and intensity remains unclear, and future
forecast discussions should provide more clarity on the details
as more short-range model guidance becomes available.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 521 PM MDT Fri May 16 2025

A few high based showers or virga will continue to bring a
threat of gusty winds to the northern TAF sites through sunset.
Otherwise mid to high level cloudiness will be drifting through
leaving VFR conditions in place. Once again moisture and winds
will combine to bring a threat of more afternoon gustiness to
the TAF sites on Saturday with the PROB30 statements places at
KHDN and KVEL with this forecast issuance.

&&

.FIRE WEATHER...
Issued at 245 PM MDT Fri May 16 2025

Critical fire weather conditions are expected across east-
central and southeast Utah as well as west-central and southwest
Colorado. The only area that is currently seeing critical fuels
though is east-central and southeast Utah (Utah Fire Weather
Zones 490 and 491). Therefore, the Fire Weather Watch has been
upgraded to a Red Flag Warning for the areas where fuels are
critical and conditions look to be met. This Red Flag Warning is
in effect Saturday from noon to 8 pm MDT. Critical fire weather
concerns lessen Sunday through mid week as we welcome the
arrival of a cooler and wetter storm system. However, dry and
warmer weather looks to return by late next week which could
lead to elevated fire weather concerns.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...None.
UT...Red Flag Warning from noon to 8 PM MDT Saturday for UTZ490-491.

&&

$$

SHORT TERM...MDA
LONG TERM...BW
AVIATION...TGJT
FIRE WEATHER...TGJT