FXUS65 KGJT 031117
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
517 AM MDT Sat May 3 2025

.KEY MESSAGES...

- Increasing elevated moisture will work into the area this
  afternoon afternoon...bring a modest uptick in shower and 
  storm coverage.

- A slow-moving area of low pressure will bring a prolonged
  period of cooler temperatures and precipitation to the area
  starting tomorrow and continuing through Thursday. High 
  elevation snow and widespread shower and thunderstorm activity
  is expected with this system.

- Warmer and drier conditions return by the late week period.

&&

.SHORT TERM /THROUGH SUNDAY/...
Issued at 320 AM MDT Sat May 3 2025

The H500 hand analysis map at 03/00Z is showing a developing
blocky Omega pattern setting up across much of NOAM early this
morning. A downstream trough is carving deeper into the MO/OH
valleys which will be stalling into a closed low over much of
the East early next week. Upstream another trough is digging 
through the EPac which becomes a stalled low over the 
Intermountain West pushing out the current resident Rex high 
into the Plains. Needless to say this pattern will present an
unbiased scenario for some decent precipitation totals across 
our entire CWA...including some significant high elevation 
snowfall amounts. Details and impacts still are bit unclear as 
this will remain a fairly warm system with very low SLR at most 
elevations below 10kft. Looking at several point 
locations...multi model ensemble plumes continue to have 
astronomical spreads in QPF/Snowfall output (5 to 50 inches at 
Coal Bank Pass) so confidence is still less than stellar. 
However until then the short term forecast will be a bit drier 
as we ramp up moisture and await the arrival of the larger 
western system. With the arrival of the trough to the Pacific 
Coast today the high will shift across the divide. The height 
falls to the west look to enhance the southeasterly flow this 
afternoon which moisture transport vectors suggest pull in 
elevated Gulf moisture through the afternoon. The Rex low has 
sheared apart but the remnants of it look to also be pulled 
northward in the flow and this leads to a an uptick in afternoon
convection across the southern CWA which lingers well into the 
night with a least an isolated coverage. Things really begin to 
ramp up on Sunday as the southerly flow continues to draw in 
both Gulf and Pacific moisture. The main cyclonic circulation of
the upstream trough will be dropping in to the Southwest by 
tomorrow afternoon. Ascent over our CWA will begin to work on 
the moisture thanks to a strong cyclonically curved jet digging 
south of the 4 Corners. A good batch of moderate precipitation 
producing convection will be lifting across the southwestern 2/3
of the CWA through the day. Snow levels look to remain at 10kft
or higher though convection can always drive that downward. The
high peaks of the southern San Juans will be favored to pick up
this slushy snow with little to no impacts to the travel 
corridors anticipated through sunset. Another warm day is on tap
today ahead of all this change...but we begin a downward trend 
tomorrow by several degrees as the precipitation and clouds 
increase.

&&

.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
Issued at 320 AM MDT Sat May 3 2025

PWATs peak Sunday evening into Monday at around 175-200% or 
normal. QPF seems to favor the southern mountains through Monday
morning. Precipitation chances may become more focused on the 
northern mountains Monday evening as this system slowly 
continues its eastward progression. Although some discrepancies 
between models reduce confidence on impacts from this system 
next week, agreement on the slow movement of the low makes 
widespread, unsettled weather a likely scenario for our CWA 
through midweek. Both the ECMWF Ens and the GFS Ens keep PWAT 
anomalies generally above normal through the long term, although
not at the magnitude expected Sunday evening through Monday. On
Sunday high temperatures will be near or below normal for the 
southern half of our CWA, and about 5 to 10 degrees above normal
for the northern half. However, beyond Sunday high temperatures
drop to below normal as cooler air moves in with the passing 
system. High temperatures should begin to rebound late in the 
workweek.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 514 AM MDT Sat May 3 2025

Clear skies and light winds will keep widespread VFR conditions
in place through the morning hours across eastern Utah and
western Colorado. Shower and thunderstorm development is
forecast over the southern mountains this afternoon then across
much of the 4 Corners region through the evening as moisture
increases on southerly flow. VFR should hold over much of the
next 24 hours though may temporarily drop to MVFR in showers at
KTEX if a shower moves across the terminal. 

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...15
LONG TERM...GF
AVIATION...TGJT