


Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
910 FXUS65 KGJT 300553 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 1153 PM MDT Fri Aug 29 2025 .KEY MESSAGES... - Showers and thunderstorms expected this afternoon, tapering off this evening. - Temperatures trend nearly 10 degrees below normal today. - Warmer and drier conditions develop this weekend with some terrain based showers in the forecast. && .SHORT TERM /THROUGH SATURDAY NIGHT/... Issued at 135 PM MDT Fri Aug 29 2025 A shortwave trough is currently progressing eastward over the forecast area, and is associated with an expansive shield of stratiform mainly north I-70. The wave did bring abundant moisture so there are also scattered showers south of I-70. This is where there are breaks in the clouds and perhaps pockets of instability. Therefore thunderstorms will be possible for these locations this afternoon and evening. The stronger cells may be capable of moderate to heavy rainfall, which could lead to localized flooding. Cloud cover and rain cooled air will keep temperatures well below normal for most of the area. By midnight the wave crosses the Divide and most of the showers dissipate. Any clearing tonight could result in localized dense fog overnight especially where it rains today. Tomorrow dry air continues to filter in from the northwest, but there may be enough mositure for afternoon showers and storms over high terrain near the Divide with a few possible further west near the state line. Can rule out a brief down pour with these showers given a little more instability compared to today. && .LONG TERM /SUNDAY THROUGH FRIDAY/... Issued at 135 PM MDT Fri Aug 29 2025 On Sunday PWAT anomalies will fall to below normal across the CWA, bringing an end to the brief return of the monsoon. Terrain based afternoon convection is still in the forecast Sunday, but elevated PoPs are primarily located over Colorado`s southern mountains where PWAT anomalies are expected to be the greatest. Moisture will linger in the southern mountains while the rest of the CWA remains dry, leading to forecasts for afternoon convection on Monday and Tuesday that look similar to Sunday`s. Some guidance suggests a weak return of moisture as early as midweek, which would allow for afternoon convection to become more widespread over the higher terrain. However, there is little agreement between ensembles on the timing of this moisture push. Temperatures begin to climb this weekend, resulting in near normal high temperatures through the long term. && .AVIATION /06Z TAFS THROUGH 06Z SUNDAY/... Issued at 1144 PM MDT Fri Aug 29 2025 Residual cloud cover and a few stray showers linger on the steps of the west side of the Continental Divide this morning. This will slowly erode before daybreak and mostly VFR conditions will preside over the terminals. Some doubt to whether fog and stratus will become a problem exists. Given any fog/stratus in the valleys, it should burn off around 0900 MDT. VFR conditions are expected across eastern Utah and western Colorado Saturday. Some thunderstorms were introduced for the mountains with PROB30 for KHDN, KEGE, KASE, KGUC, and KTEX. These will come with some brief ceiling issues and gusty outflow winds as they decay. Storms will be short-lived Saturday and clear, quiet conditions return to the region Saturday night to close out this TAF period. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...KJS LONG TERM...GF AVIATION...TGJT