textproduct: Pueblo

KEY MESSAGES

- Mostly dry today and warm, isolated storms Central Mountains, 70s and 80s across the Plains.

- Very wet conditions expected from Monday through Thursday or Friday. Flash flood watch in effect for the San Juan Mountains Monday into Wednesday.

- Significant rainfall on the Plains possibe depending on timing and storm track.

SHORT TERM /THROUGH TONIGHT/

Issued at 1232 AM MDT Sun Sep 27 2026

Currently...quiet conditions will continue to prevail through sunrise with upper level ridging moving across southern Colorado. Temperatures are currently in the 50s across the Plains, and 40s over the San Luis Valley. A few more degrees of cooling is forecast through the early morning hours.

Today and tonight...upper level ridging across Colorado will shift east into Kansas through tonight, as flow aloft transitions southwesterly ahead of an approaching upper low. Weak energy embedded in the flow may lead to a few showers and thunderstorms across the Central Mountains this afternoon and evening. The main concerns from thunderstorms will be lightning and outflow winds near 40 mph. This activity is forecast to dissipate this evening. Late tonight, as the upper low digs along the West Coast, moisture will increase, along with showers over the San Juan Range by Monday morning.

Temperatures will warm this afternoon into the upper 70s to mid 80s across the Plains, with 70s over the San Luis Valley. Overnight lows will into the 40s west, and 50s on the Plains.

LONG TERM /MONDAY THROUGH SUNDAY/

Issued at 1232 AM MDT Sun Sep 27 2026

Overall, models are in decent agreement with the overall pattern, with differences in speed of upper low ejection, and positioning as it does so. The ECMWF is remained consistently wet this week, with a slower progression, while the GFS is a bit faster and further east with the upper system. Ensembles, AI runs and NBM tend to lean towards the ECMWF with a slower, wetter solution, especially for the Plains.

Monday through Thursday...greatest confidence during this period. The tropical remnants of Hurricane Polo will get wrapped around an upper low moving slowly across the Desert Southwest, and northeast into southern Colorado for mid to late week. This is a deep, moist system, with the potential to produce heavy rainfall over multiple days, initially for the San Juan Mountains, then spreading east across the Plains. Early on, southwesterly flow ahead of the upper low will favor the San Juan mountains. Have issued a Flash Flood Watch from Monday morning through late Tuesday night/Wednesday morning for the San Juan range. QPF amounts in excess of 1.5 inches may be possible during this period. Given the tropical nature of this system, snow levels will be exceptionally high, with 1 to 3 inches possible for peaks above 12-13 kft.

As we move through Wednesday into Thursday, focus transitions to the Plains. This system is deep, and track will be important. How long it takes to track across the Desert Southwest, and finally eject northeast into Colorado or western Kansas will determine where on the Plains will see heavy rainfall. The ECMWF, NBM, AI versions of the long range models and ensembles are in the best agreement, and trends continue to show heavier precipitation for the Plains. All these solutions are slow at ejecting the low, with northeasterly deep upslope (through 500 mb) and deep moisture (PWAT values in excess of 1 inch) wrapping across the Plains. Areas along the Eastern Mountains and Raton Mesa could see a prolonged period of heavy rainfall Wednesday through Thursday, with activity slowly winding down Friday morning as the low moves into Oklahoma, and flow becomes northwesterly. This is the majority timing and track. QPF amounts will be tough, with widespread 1 to 3 inch amounts possible (locally higher according to some guidance), especially for areas south of Highway 50.

The GFS, is a faster and further east solution, and outlier compared to more other guidance. While the initial track is similar, it takes the upper low out of New Mexico and into western Kansas faster on Thursday, with drier conditions on Friday. While the GFS does have decent QPF amounts on the Plains, they are more focused across Baca County as the upper system lifts away. For comparisons, the GFS produces QPF amounts of less than 0.2 inches for Pueblo, while the remainder of the guidance has in excess of 0.75 inches (and some much higher).

Given the expected QPF amounts, we will likely need Flash Flood highlights for portions of the Plains Wednesday and Thursday. Hopefully the track, QPF amounts and timing come into better agreement over the next 24 hours. Snow levels will continue to be high, a couple inches of snow are likely above 12-13 kft during this period.

As for temperatures, Monday will be the warmest day with 70s on the Plains. Temperatures will cool for mid to late week, with 50s and 60s across the Plains. Would not be surprised if temperatures are a few degrees cooler than the current forecast.

Friday through Sunday...with models varying in how quickly they exit the upper system, Friday will either by dry (GFS), or a transition day with the upper system lifting away from the area (ECMWF). With a slower system departure, Friday, especially morning may continue to be wet, drying during the later part of the day. The GFS keeps the region dry through the weekend, with a dry cold front Saturday night into Sunday. The ECMWF is also dry over the weekend, but with more zonal flow and much weaker cold front.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 1107 PM MDT Sat Sep 26 2026

KALS:

VFR expected through the rest of the day and into tonight. Models show the chance for some brief patchy fog after about 10Z Sunday morning, which will mix out a bit after sunrise. Winds will remain light, around or under 10 knots.

KCOS and KPUB:

VFR expected through 24 hours. Winds will lighten overnight, turning more SE by Sunday afternoon as some mid-level clouds move past. Winds the in the afternoon on Sunday will be breezy, gusting 20-25 knots at times.

PUB WATCHES/WARNINGS/ADVISORIES

Flood Watch from Monday morning through late Tuesday night for COZ067-068.