Arapahoe Basin

000
FXUS65 KGJT 111138
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
538 AM MDT Fri Sep 11 2026

.KEY MESSAGES...

- Mostly dry and warm conditions prevail through the weekend
  with a gradual increase in afternoon shower and thunderstorm
  activity each day. 

- Daytime highs remain 5 to 10 degrees above normal through
  Sunday before a shift to cooler temperatures for next week. 
 
- Unsettled conditions persist for much of next week as moisture
  continue to feed into the area.

&&

.DISCUSSION...
Issued at 1030 PM MDT Thu Sep 10 2026

The 11/00Z H500 hand analysis map is showing a high amplitude 
Rex pattern over the E.Pac leading to downstream troughing over 
W.Canada to near the US border. A jet max aloft is moving over 
zonal flow over the northern states which is pulling moisture 
across the northern Great Basin this evening according to GOES 
ALPW. This moisture as weak ascent from the jet looks to at 
least pull some thicker cloud cover across the norther toward 
sunrise with some small chances of some sprinkles hitting the 
ground. The CAMS/RRFS are bit more bullish with this an have 
introduces some low end PoPs through the AM hours mainly north 
of I-70. The focus for convection shift more southward by mid-
day and through the evening as SubTrop moisture being pulled 
northward into the 4 Corners region arrives. Again the ascent 
may be coming from the stronger winds aloft which will combine 
with orographics and favor the southern CWA terrain before 
settling down through the late evening hours. Profiles show a 
lot of dry air to overcome in the low layers with dewpoints 
still in the single digits to teens currently. This sets the 
stage for gusty outflow winds being more of a threat than heavy 
rainfall. The dry air and breezy winds in the afternoon also 
look to bring localized areas of critical fire weather. As 
upstream troughing deepens over and swings through the PacNW 
this weekend...SubTrop high pressure will be pushed over and 
East of the Southern Rockies. This will give a more direct feed 
of moisture strengthening SW flow aloft. The strongest forcing 
remains well upstream near the progressive trough. Forcing over 
our CWA looks tied more to orographics for storm initiation on 
Saturday with outflow boundary interactions bringing some chance
for storms over the lower elevations. Sunday appears to have an
uptick in activity as the upstream trough and jet aloft begins 
to swing through the Intermountain West. The better chances 
could be overnight into Monday with weak surface frontal forcing
undercutting the ascent aloft. PWAT during this time looks to 
run some 150 to 200 percent of normal over all but the northwest
CWA where the SW fetch aloft will be from a drier upstream 
source. Temperatures through the weekend look to stay above 
normal then cool Monday with the weak frontal passage and lower 
heights aloft. A static pattern of upstream troughing over the 
PacNW and downstream high pressure over the Southeast US means 
persistent moist SW flow into the Great Basin. So cooler and 
unsettled conditions look to linger through much of next week. 
We're getting to that time of year when overnight precipitation 
is likely to bring a short- lived dusting of snow on the top of 
the peaks at sunrise as well.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 538 AM MDT Fri Sep 11 2026

VFR conditions are forecast through the TAF period. Increasing
cloud cover and periodic afternoon gusts up to 25-30 knots
highlight today's forecast. An isolated shower or storm cannot
be ruled out at mountain terminals, but the potential is too 
low to include in the TAFs. 

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

DISCUSSION...TGJT
AVIATION...TGJT