


Area Forecast Discussion
Issued by NWS Grand Junction, CO
Issued by NWS Grand Junction, CO
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304 FXUS65 KGJT 292315 AFDGJT Area Forecast Discussion National Weather Service Grand Junction CO 515 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 /00Z TAFS THROUGH 00Z SATURDAY/... Issued at 513 PM MDT Fri Aug 29 2025 Widespread showers with a few stronger, embedded storms will continue to drift across the area through sunset. These showers and storms have produced heavy rain, reducing visibility and resulting in brief drops to MVFR conditions. Activity will taper after sunset, with winds becoming light and terrain driven. Skies will gradually clear through the night. Another round of showers and storms is expected tomorrow afternoon, with the main concerns again being heavy rain and lightning. VFR conditions will prevail, although again drops to MVFR due to heavy rain will be possible. && .GJT WATCHES/WARNINGS/ADVISORIES... CO...None. UT...None. && $$ SHORT TERM...KJS LONG TERM...GF AVIATION...TGJT