National Weather Service Forecast Discussion

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578
FXUS65 KBOU 040027
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
627 PM MDT Thu Jul 3 2025

.KEY MESSAGES...

- Scattered thunderstorm activity over the mountains this evening
  with a slight chance over the plains tonight into Friday
  morning.

- Less numerous, scattered showers and thunderstorms are expected
  Friday afternoon, diminishing from west to east in the evening.

- A chance of afternoon and evening thunderstorms and above normal
  temperatures are expected for the weekend into early next week.

&&

.DISCUSSION /Through Thursday/...
Issued at 239 PM MDT Thu Jul 3 2025

Thunderstorms have developed over western Colorado, but are slow
to spread east so far this afternoon as the storm motions are
south to north. This area of convection will creep eastward
through this evening, and eventually most of the mountains should
have some showers. It`s questionable if there will be anything
east of the mountains this evening, however. The main threat will
be gusty winds, though a few spots could get a brief heavy rain.

As the shortwave trough moves eastward, it should interact with
the moisture on the plains later tonight into Friday morning. This
will likely produce another batch of showers and thunderstorms. If
they`re able to develop along the I-25 corridor it would likely be
just before or around sunrise, then the threat out on the
northeast plains is in the morning hours. There may be enough
CAPE/moisture for a few strong storms in the northeast corner if
the timing is slow enough (late morning), but the severe threat
looks low.

For later in the day, the winds aloft will become more
northwesterly with some drying and a little cooling. There will
likely still be some afternoon convection, although it might not
be much. With continued drying into the evening, the activity will
likely be over for the mountains and I-25 corridor by sunset, or
at least pretty minimal coverage.

The models continue with subtle day to day changes with a low
amount of moisture around and temperatures a little above the hot
summer normals. There`s not great confidence on how the details
will affect convective trends, but it looks like there will be
increasing moisture coming into the northeast plains Saturday
afternoon which could be a focus for a few strong to severe
storms. Model soundings suggest 1000-1500 J/kg of CAPE with
sufficient shear for supercell structures.

The theme for the next week will be a gradually strengthening
ridge over the Rockies. But a shortwave passing over the northern
Rockies about Sunday may restrain the warming and force some
convection Sunday and Monday. The ridge is more likely to
strengthen near us by the middle of the week.

&&

.AVIATION /00Z TAFS through 00Z Saturday/...
Issued at 624 PM MDT Thu Jul 3 2025

Models keep southeasterlies going at DIA this evening, with
drainage winds kicking in by 04Z/05Z. Some of the models bring a
surge of northerly winds in after midnight associated with an
upper trough. Some also showing scattered convection possible so
will keep the PROB30 group in for -SHRA after 10Z. Will also
leave in a PROB30 group for afternoon convection on Friday. There
will be no ceiling issues.

&&

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

&&

$$

DISCUSSION...Gimmestad
AVIATION.....rjk

NWS BOU Office Area Forecast Discussion