310
FXUS65 KBOU 292357
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
557 PM MDT Fri Aug 29 2025

.KEY MESSAGES...

- Scattered to numerous showers and a few thunderstorms this
  evening and tonight. Some storms will produce locally heavy
  rainfall across the northeast corner of the state throughout the
  night tonight. An isolated severe storm is possible as well.

- Isolated coverage of showers and storms on Saturday with brief
  heavy rain and small hail possible.

- Warmer and drier Sunday through Tuesday.

&&

.DISCUSSION /Through Friday/...
Issued at 256 PM MDT Fri Aug 29 2025

Water vapor imagery shows a shortwave trough over eastern Utah
with healthy mid-level moisture out ahead of it over western
Colorado. As this trough progresses eastward, it will provide
forcing to help generate storms across our CWA. Currently, there
has been enough clearing during peak heating to allow temperatures
to reach the low 80s on the plains. 1,000 j/kg of mixed-layer CAPE
has formed over Lincoln County and with moderate deep layer shear
ahead of the trough, strong to severe storms will form. A Severe
Thunderstorm Watch was issued for Lincoln County until 11pm.
Elsewhere, instability is lower with the ACARS soundings showing
almost no CAPE at the moment. For the majority of our CWA, there
will be widespread showers and weak thunderstorms late this
afternoon and through tonight.

The shortwave trough will move directly over northeast Colorado
late tonight. Some high resolution models indicate an area of
showers and storms producing very heavy rainfall over the
northeast corner of Colorado. The HREF indicates there is a chance
that over 3" of rain could occur by Akron and Sterling. There was
consideration for issuing a Flood Watch but it seems the limited
instability will make it tough for storms to be intense enough to
produce such heavy rainfall. Therefore, a Flood Watch was not
issued.

There will be northwest flow aloft during the day Saturday with
lingering low level moisture. There will be isolated showers and
storms throughout much of the day. There is very little threat of
strong to severe storms and the storms will be moving fast enough
to not be worried about heavy rain.

Colorado will be under northwest flow from Sunday through most of
next week. On Sunday and Monday, there will be subsident flow with
cool surface temperatures which will lead to dry conditions. A
shortwave trough within the northwest flow will near the area on
Tuesday and Wednesday. This will bring a chance for showers and
storms back into the forecast. Models differ greatly on the trough
placement during the end of next week. Overall, the long term
period will be cool with most days having highs in the 70s across
the plains.

&&

.AVIATION /00Z TAFS through 00Z Sunday/...
Issued at 557 PM MDT Fri Aug 29 2025

Showers and a low threat of thunderstorms will start this TAF
period. The showers will likely remain in the area through
03Z-04Z, with a gradual decrease thereafter. VRB wind gusts to
~25 kts possible near any of the showers. Ceilings are expected
to remain above MVFR for most of this period, but IMC may be met
as scattered showers and local ceilings down to 5000-6000 feet can
be expected through 15Z. There is a chance (30%) of lower
IFR/MVFR ceilings 11Z-15Z considering a light northwest or
northerly wind push expected.

On Saturday, another round of scattered showers/storms can be
expected, so Prob30 -TSRA with variable winds is a good place to
start. Main threat of thunder would be after 20-21Z.

&&

.HYDROLOGY...
Issued at 256 PM MDT Fri Aug 29 2025

There is ample moisture across northeast Colorado and there will
be moderate forcing from a shortwave trough that will pass
through tonight. Heavy rainfall is possible from a cluster of
storms overnight tonight. There was consideration for issuing a
Flood Watch but there will be limited instability which will make
it tough for storms to be intense enough to produce such heavy
rainfall. Therefore, a Flood Watch was not issued. Nonetheless,
heavy rain and flooding is possible across the northeast corner.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

DISCUSSION...Danielson
AVIATION...Barjenbruch
HYDROLOGY...Danielson