558
FXUS65 KPUB 271813
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1213 PM MDT Sun Sep 27 2026

.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 SATURDAY/...
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 /18Z TAFS THROUGH 18Z MONDAY/...
Issued at 1202 PM MDT Sun Sep 27 2026

VFR conditions are expected at COS, PUB and ALS over the next
24 hours, with increasing clouds through the overnight hours.
Showers are expected to increase across the ContDvd through
early Monday morning, with any precipitation at the terminals
likely holding off until the tail end of this taf period.
Increasing southwest flow aloft will help develop lee troughing
across the plains with breezy south to southeast winds at the
terminals through the early evening, along with the potential
for breezy southerly winds developing once again at the tail
end of the period.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Flood Watch from Monday morning through late Tuesday night for
COZ067-068.

&&

$$

SHORT TERM...MOZLEY
LONG TERM...MOZLEY
AVIATION...MW