9/16/26 Wednesday 5 am
Flood Watch
National Weather Service Grand Junction CO
304 AM MDT Wed Sep 16 2026
COZ018-019-021>023-162100-
/O.CON.KGJT.FA.A.0007.260916T1800Z-260918T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Northwest San Juan Mountains-Southwest San Juan Mountains-Four
Corners/Upper Dolores River-Animas River Basin-San Juan River
Basin-
Including the cities of Telluride, Mountain Village, Ouray, Lake
City, Sawpit, Pagosa Springs, Silverton, Rico, Cortez, Mancos,
Dolores, Dove Creek, Durango, Bayfield, and Ignacio
304 AM MDT Wed Sep 16 2026
...FLOOD WATCH REMAINS IN EFFECT FROM NOON MDT TODAY THROUGH THURSDAY
EVENING...
* WHAT...Flooding caused by excessive rainfall is possible.
* WHERE...A portion of southwest Colorado, including the following
areas, Animas River Basin, Four Corners/Upper Dolores River,
Northwest San Juan Mountains, San Juan River Basin and Southwest
San Juan Mountains.
* WHEN...From noon MDT today through Thursday evening.
* IMPACTS...Excessive runoff may result in flooding of rivers,
creeks, streams, and other low-lying and flood-prone locations.
This also includes the Gold Mountain, Elk and Ferris burn scars as
well as areas of steep, susceptible terrain.
* ADDITIONAL DETAILS...
- Recent heavy rainfall in southwest Colorado has led to already
saturated ground. In addition, multiple rounds of showers and
thunderstorms are expected Wednesday afternoon through Thursday
evening producing periods of heavy rainfall and potential flash
flooding.
This is what we could call a “blanket flood watch”. This is as widespread as you can get for our forecast area.
My only concern right now is poor model initialization. This means that when I look at what the models are forecasting for now, it is already wrong. Even with the latest GFS and Euro, which was generated within the hour. Same with the surface maps; the two versions I look at are completely different based on their latest obs, off by 500-1000 miles. That being said, we are under deep moisture, with dewpoints within a degree of current temperatures and current PWATs exceeding 200% of average.
Keep an eye on the cloud deck; if we get a few peaks of sun, it won’t take a lot to get things going, with residual moisture and forecasted PWATs continuing between 200-250% of average. The deeper moisture plume arrives later today and should overwhelm the atmosphere as those PWATs reach 300% of average.
So today, isolated showers should give way to scattered showers later today, followed by the potential for widespread heavy showers tonight. Assuming the models are correct.
As I said, if the cloud deck breaks open long enough to let the sun do its job, it will trigger thunderstorms earlier. The models are showing that happening just before noon; we’ll see.
If daytime heating isn’t enough to trigger convection, we will likely have to wait until that reinforcing moisture comes in later today/tonight.
That is the best I can do with the meteorological cards I was dealt this morning. My next hands will be dealt just before noon, and I will jump back on to see if we can narrow somethings down, or look at a different forecast.
If “the event” doesn’t come together, it would be the single worst model bust I’ve seen in 25 years. Stay tuned!