textproduct: Pueblo

KEY MESSAGES

- Significant and dangerous flooding is expected to start today across portions of the San Juan Mountains and adjacent San Luis Valley.

- Heavy and wet snow is expected across the San Juan Mountains late tonight into tomorrow morning.

- Unsettled pattern continues through the week, with additional disturbances passing over.

SHORT TERM /THROUGH MONDAY NIGHT/

Issued at 102 AM MDT Sun Nov 1 2026

Today - Tomorrow Night: Through Sunday and Monday, dangerous and high impact flooding is expected across the San Juan Mountains, as another round of heavy precipitation impacts the region.

Synopsis: A dynamic pattern will take place today through Monday across south central and southeastern Colorado. The subtropical jet will be pushing northward, as a digging trough advances southeastward/eastward on the north side of the subtropical jet. This will bring a prolonged period of forcing and moisture into the region. With the forcing and moisture in place, widespread precipitation is expected, with the heaviest and most impactful moisture across the San Juan Mountains. In addition, as the storm pattern pushes eastward, strong winds are expected both today and tomorrow, with the strongest winds on Monday across the plains. Given various complex hazards, this discussion has been broken down into the main concerns with this storm system.

Precipitation/Flooding San Juan Mountains: As this storm system impacts the area, widespread precipitation is anticipated, with the heaviest and most prolonged showers across the already soaked San Juan Mountains. This is going to lead to a significant flooding event across the San Juan Mountains and adjacent San Luis Valley. Examining the latest data, there has been a concerning trend with this storm systems evolution, primarily that of the subtropical jet pushing further north and slowing the forward progression of the trough. What this ultimately means is that colder air with the trough will be slower to get into the region, which means snow levels will be higher to start, and slower to fall heading into Monday morning. This all comes together to mean more rain and more rain-on-snow melting, and overall less snow. In addition, another concerning trend within the latest guidance is an increase in QPF, with many high-res models and ensembles strongly supporting 4-6 inches of liquid, and potentially locally higher amounts. The latest forecast will reflect this trend. All of this will greatly increase the flooding potential and risk, and several rivers are expected to rise into Moderate to Major flood stages starting this evening and through Monday, with some rivers even expected to set new record crest levels. There is a realistic possibility that current river forecast are too conservative with how high they take the flooding. Along with that, road washouts will be possible and mudslides/rockslides can be expected. To those in the San Juan Mountains and the adjacent San Luis Valley, please heed any evacuation warnings and road closures, and please do not drive through flood waters... remember, Turn Around, Don't Drown... doing these things could save your life. Finally, once the trough does start to push over, and cooler air filters in, snow levels are expected to lower. Overall, about 8-14 inches of heavy wet snow is anticipated along the San Juan Mountains. This could cause dangerous and slick travel along mountain roads, especially by late Sunday night and Monday morning, when colder air is pushing into the area.

Precipitation Elsewhere: Across the rest of the forecast area, showers can be expected, though to a lesser degree. Across the rest of the mountains, snow can also be expected, with the greatest snow again late Sunday night and into Monday as the colder air with troughing filters in. Most other ranges can expect to see around 4- 10 inches of heavy wet snow. This snow may still cause pockets of slushy and slick roads, so extra caution should still be given across the rest of the higher terrain when it's snowing. For the valleys and plains, rain showers will dominate, with no snow anticipated. Coverage for showers across these areas will be greatest Sunday for the valleys, and then Monday for the plains as the storm system pushes eastward and a cold front drops southward, bringing additional surface forcing. Along with that, a band of highly forced convective thundershowers along the leading eastern edge of the troughing/subtropical jet interface will be possible across the eastern plains late Sunday evening. These showers may bring pockets of gusty winds around 45-50 mph and occasional rumbles of thunder.

With all of that said, any precipitation across the area late Monday is expected to start decreasing in coverage and intensity, as the broader storm system continues to push eastward, and both forcing and moisture lessen.

Wind: Along with the precipitation, this pattern will bring strong winds to the region both today and tomorrow, though in different fashions. Throughout Sunday, strong southerly to southwesterly winds can be expected ahead of the storm system. Winds will be greatest across the mountains and San Luis Valley simply given closer proximity to the stronger flow aloft, and then across the far eastern plains, where the surface gradient will tighten in response to lee troughing development. Winds in these regions will be sustained around 20-35 mph, with gusts up to around 50 mph. Then heading through Sunday afternoon into Monday morning, strong winds are expected to continue, though primarily across the southern Sangre de Cristo Mountains and the northeastern portions of the Raton Mesa. Reverse shear, and an eventual mountain top inversion, will help to force stronger winds aloft to the surface, with pockets of 50-60 mph likely along the immediate leeward side of these features. Isolated 70 mph wind gusts can not be ruled out. Finally, heading through Monday, as the storm system pushes east, winds will become northerly to northwesterly across south central and southeastern Colorado. Strong winds will again be expected Monday, though with the strongest primarily across the eastern plains, where the gradient will tighten through the day and into the night as the trough becomes more wrapped up across the central US. Winds gusts across the region will be 30-50 mph, with the strongest of those gusts across the plains. As the storm system treks east, winds will lessen Monday night, though will remain gusty across the plains.

Other: Outside of the flooding and wind concerns, you can expect a fairly typical setup with a stormy pattern in place. Much of the area will have mostly cloudy to cloudy skies through Monday as the system passes over. Then as for temperatures, values will be warmest and above seasonal values Sunday ahead of the system, especially across the plains as downsloping takes place. Then for Monday, temperatures cool some as the system passes over and a cold front starts to push southward, with values near to slightly below seasonal values.

LONG TERM /TUESDAY THROUGH SATURDAY/

Issued at 102 AM MDT Sun Nov 1 2026

Tuesday - Saturday: For the remainder of the forecast period, active weather can be expected for south central and southeastern Colorado. While the Sunday-Monday storm system will be exiting the region through Tuesday, additional waves are anticipated to pass over the area through the week, which will bring brief periods of increased precipitation chances and breezier winds. Any precipitation chances will be greatest along the mountains, where forcing will be maximized. With that all said, while confidence is high (60-70%) in the unsettled pattern, uncertainty does still remain in how individual waves will evolve given the messy pattern that develops. Otherwise, mostly clear to partly cloudy skies and fairly stable, and near seasonal, temperatures can be anticipated through the week.

AVIATION /18Z TAFS THROUGH 18Z MONDAY/

Issued at 1111 AM MST Sun Nov 1 2026

At KALS, MVFR/occasional IFR with periods of rain showers this afternoon and tonight, then cigs/vis improve to VFR after 12z Mon with a lingering VCSH possible.

At KCOS, still a period of LIFR cigs/vis possible til 19z-20z, then fog begins to lift/vis improves through the remainder of the afternoon. IFR cigs persist a few hrs after fog lifts, before cigs become VFR after 23z, with a potential vcsh 23z-06z. Westerly wind component should keep fog/stratus east of the terminal overnight into Mon morning, though western edge of lower clouds/fog could be close, and will have to monitor cloud trends.

At KPUB, MVFR stratus early this afternoon will gradually dissipate, with VFR cigs returning after 21z. VFR with a risk of a vcsh 00z-06z, then westerly wind component should end shower chances and keep lower clouds/fog east of the terminal through the remainder of the night into Mon morning.

HYDROLOGY

Issued at 100 PM MDT Sat Oct 31 2026

Main concern continues to be flooding along the Conejos River and the South Fork of the Rio Grande, especially Sunday night into Monday morning. Models today have come in slightly wetter and warmer with incoming Pacific weather system, and a prolonged period of rain on snow looks likely in the San Juans well into Sunday evening. Snow level rises to above 11000 feet during the day Sunday, and only slowly falls to around 10000 feet Sunday evening, then below 9000 feet by Monday Morning. QPF over/along the Continental Divide has come up to between 3-4 inches of liquid (some of which will be snow) which will be sufficient to cause flooding even without the additional potential runoff from melting snow. Runoff peak should be late Sun evening, before snow level falls and run-off starts to decrease early Mon morning. River stage forecasts continue to indicate significant flooding, with the South Fork of the Rio Grande at South Fork and the Conejos River at Mogote rising well above flood stage Sunday evening, cresting overnight into early Monday morning. These high flows will then move downstream Mon/Tue/Wed with flooding possible on the mainstem Rio Grande at Del Norte/Monte Vista and Alamosa and along the Conejos River east of Mogote through the period. Flood watch remains in effect for all of the San Luis Valley from late Sun night into Tue morning, mainly for mountain runoff, as rainfall in the Valley itself should be between .5 and 1.5 inches.

PUB WATCHES/WARNINGS/ADVISORIES

Flood Watch through Monday morning for COZ067-068. Winter Storm Warning from 5 PM this afternoon to 11 AM MST Monday for COZ068. Flood Watch from 5 PM MST this afternoon through late Tuesday night for COZ069>071.