Romeo, Colorado Weather Forecast Discussion

726
FXUS65 KPUB 091736
AFDPUB
Area Forecast Discussion
National Weather Service Pueblo CO
Issued by National Weather Service Denver CO
1134 AM MDT Tue Sep 9 2025
.KEY MESSAGES...
- Slight uptick in activity today, with showers and
  thunderstorms moving from the mountains to the plains late in
  the day. Some strong to severe possible out east.
- Daily storms continue over the mountains into midweek, with
  lower chances over the plains.
- Greatest coverage of showers and storms Friday, with the
  highest chances and locally heavy rain threat over the
  mountains.
- Drier again into the weekend but a little cooler.
&&
.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 337 AM MDT Tue Sep 9 2025
Today and Tonight...
As an upper low continues moving along the west coast, flow
aloft will increase and become more southwesterly today,
bringing in more monsoonal moisture across the region. PWAT
values will steadily increase into this afternoon, allowing for
better coverage of showers and thunderstorms into this evening.
Storms will form mid-late afternoon over the central mountains,
pushing from northwest to southeast into the evening. Out over
the plains, lee troughing will allow for southerly surface
winds, proving some low-level moisture and a good setup for
shear. Models show a narrow corridor of CAPE values over 1000
J/kg along the Colorado-Kansas border, with values increasing
later in the evening as more moist air is advected in from the
southeast. Meanwhile, bulk shear values should be pushing 30-40
knots over the same area. Lingering dry air closer to the
mountains/plains interface, particularly at the low levels, may
keep storms from moving into that better air, but if they do,
strong to severe storms will be possible, with large hail and
strong winds that last into the overnight hours. Meanwhile,
temperatures will be warm once again, with 80s-90s over the
plain and high-70s for the valleys.
Wednesday...
The upper low will stall out on Wednesday, with a weak upper-
level disturbance passing over our forecast area. The extra
forcing will help spark showers and thunderstorms during the
afternoon, mainly confined to the mountains and high valleys.
Storms should move east and dissipate later in the evening.
Current model guidance is scarce with instability along the
mountains/plains interface, though some of the more aggressive
models do have some higher CAPE values along the KS border
again. In general, it will be difficult for storms to move off
of the higher terrain and last long enough to reach any
potentially more unstable air. As such, the plains are currently
expected to remain largely dry. In general, strong outflow
winds and local heavy rainfall will be the main concerns, with
the potential for locally high values of DCAPE indicating strong
downdraft potential. Temperatures will be similar to Tuesday,
with 80s-90s for the plains and 70s for the high valleys.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Issued at 337 AM MDT Tue Sep 9 2025
Wednesday Night and Thursday:
The upper level low located over the western United States will
continue to emit weak waves over southern Colorado which will
keep thunderstorms going for 1 to 2 hours after the beginning of
the long term forecast period (6PM on Wednesday). Environmentally,
there isn`t much to talk about since any CAPE over the region will
be on the decrease as we lose heating. The storms are pegged to
develop over the southern I-25 corridor, which hosts CAPE values of
less than 500 J/kg with a hefty amount of CIN. Main hazard will be
gusty winds of up to 40 MPH as the storms dissipate and the cores
drop. For Thursday, the closed low slides slightly closer to
Colorado which will emit a wave that is a little strong than that on
Wednesday. The main vorticity stream extends SW to NE from the San
Luis Valley towards the Pikes Peak Region, which is where the
convection is expected to develop. Once again, the instability is
lacking with values less than 1000 J/kg, so the main risks will be
gusty thunderstorm outflow winds with gusts up to 50 MPH, small
hail, and lightning. Showers and thunderstorms would continue
overnight over the Continental Divide.
Friday:
Friday is the day that the closed low finally gets caught up in
the upper level flow and begins to make its exit out of the
western half of the United States. The strongest waves will pass
overhead as the primary trough propagates SW to the NE. The
main energy will be focused over the West-Northwest portion of
Colorado, which is where the majority of the convection will
develop  so expect widespread thunderstorms over the mountains
and mountain valleys. The highest CAPE values will be near the
New Mexico border in the San Luis Valley, but those values are
at most around 800 J/kg. However, the CAPE is long skinny CAPE,
meaning that the sounding is pretty saturated throughout the
entire layer, which makes sense since the source of moisture
with this low-pressure system originates from the Pacific. I
think there will be some sneakily heavy rainers that form from
these storms and flooding and flash flooding needs to be
monitored. Lingering showers will continue through the early
morning hours on Saturday.
Saturday through Monday:
Drier conditions are expected as the drier airmass and the
height rises from the backside of the passing low-pressure center
develop over southern Colorado. Perhaps we`ll see an isolated
stronger thunderstorm on the east side of the dryline near the
Kansas border, but the rest of the region will be warm and dry. The
same sentiment exists on Sunday, as well. I suppose one thing we`ll
have to worry about are fire weather conditions on both Saturday and
Sunday, as the upper level pattern will be SW flow over the region,
which tends to indicated elevated fire weather concerns.
&&
.AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/...
Issued at 1134 AM MDT Tue Sep 9 2025
VFR conditions anticipated across much of the forecast area over the
next 24 hours, including the three main TAF sites of KCOS, KPUB and
KALS. Showers and thunderstorms will fire over the higher terrain by
18z-19z, gradually spreading across the I-25 Corridor affecting KCOS
and KPUB in the 23z-00z time frame. Maintained PROB30 wording for -
TSRA and variable gusts to 30 kts for those two sites, with
intermittent MVFR conditions possible.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...GARBEROGLIO
LONG TERM...SKELLY
AVIATION...MOORE

NWS PUB Office Area Forecast Discussion