10/29/26 Thursday
Quick Note: Models show the storm speeding up through the first half, with 0.30″-0.60″ of liquid precipitation by Saturday afternoon.
Conversely, they are slowing the Sunday system; it may be with us most of Monday.
I continue to see high snow levels of 10,000’+ until the last 6 to 10 hours of the storm. That will make for a difficult snow forecast for anyone trying to figure it out.
The latest from NWS
Hydrologic Outlook COC007-033-067-083-113-UTC037-302100- Hydrologic Outlook National Weather Service Grand Junction CO 1053 AM MDT Thu Oct 29 2026 Low pressure begins to dig southward from the PACNW on Friday, tapping into a fetch of Pacific moisture that will evolve into an atmospheric river streaming into the Desert Southwest this weekend. Showers and thunderstorms develop on Friday and Saturday across the region. Lighter rainfall totals Friday and Saturday will reflect, initially lower, moisture. However, a few thunderstorms could produce impactful downpours on saturated soils left over from last weekend`s historic rainfall. Deeper moisture develops Saturday night and early Sunday. This is expected to produce heavier and more widespread rainfall across southeast UT and southwest CO Sunday and Monday, mostly below 10000 feet. While rivers are forecast to remain below action stage, a growing concern lies in the potential for runoff around saturated hillsides in the region. This could produce rock, mud, and debris flows onto roadways, as well as flash flood prone burn scars, washes, slot canyons, and arroyos. Early estimates predict an area of 1 to 2 inches of new rainfall for portions of southeast UT and southwest CO. This is a preliminary forecast that hinges on slight shifts in a strong moisture plume impacting the region. It also attempts to capture the most statistically likely outcome, despite stronger and weaker outlier predictions. Outdoor enthusiasts, motorists, and residents of recent flood impacted areas are encouraged to remain abreast of the developing forecast in the coming days.
Finally, at least an acknowledgment. But I have seen no models that show only 1-2 inches of rain. Grand Junction NWS is still downplaying the event, saying the rivers will flow below action stage. Apparently they did not see this:
Keep in mind: bad data in, bad data out, so if they expect this peak with 1-2 inches of rain, what would double do?
I dug deep and found those model runs from before the last event. Overall, the GFS AI and Canadian are very similar to before- remember, those were the most accurate models last time. The similarity ends with the European. I will be watching that closely.
Here are some comparison model runs: current vs. last week.
Current GFS AI
Last week GFS AI
Current Canadian
Last week Canadian
Current European
Last week European
That’s all I have for now. If something changes before the morning, I will jump back on.