Thornton, Colorado 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

999
FXUS65 KBOU 152156
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
356 PM MDT Thu May 15 2025

.KEY MESSAGES...

- Breezy to windy conditions through Friday with fewer showers,
  mainly over the mountains in the afternoons. A small increase in
  the showers Saturday.

- Windy again with increased shower and thunderstorm activity
  expected starting Sunday.

&&

.DISCUSSION /Through Thursday/...
Issued at 338 PM MDT Thu May 15 2025

We bumped up PoPs through early evening as there`s a pretty good
crop of light showers over northwestern Colorado heading east.
They`ll be fighting the downslope, so we only made minor changes
for the I-25 corridor, but there`s a pretty good chance of off and
on showers in the mountains through early evening. The snow level
is still around 8,000 feet, but it`s warm enough that
accumulations should be limited to areas above 10,000 feet with
just light amounts above that.

Winds are gradually decreasing overall. There may be a little pop
of stronger winds in the foothills west of Denver and Boulder
later tonight as a weak shortwave trough passes. This should be
fading again in the morning.

Friday will be drier, but still some low PoPs. There will also
still be some wind, but it will be less than this afternoon.
There`s fair agreement now on some increase in moisture over
northern areas on Saturday, so we`ll have a modest increase in
PoPs for the afternoon and evening.

Sunday through Tuesday remains a question mark. The models have
trended back towards each other and the idea of two shortwaves
rotating around the mean trough. One would pass Sunday and another
late Monday or early Tuesday. There`s still some wobble in the
latitude of the low on Sunday, which would decide whether it`s a
stormy day or a warm/dry/windy day. Current NBM solution has this
gradient over our area, which seems reasonable. It`s not the best
setup for severe weather across most of our area, but there could
be some dryline action out near the eastern border if it all sets
up right. While the upper level features are uncertain, we should
get a surge of cooler and moister low level air. That will be
reinforced Tuesday behind the second part of the trough. Right now
it looks like just a little cooling with increased moisture, which
could create an increased severe threat, though the cooler
temperatures and position north of the jet should reduce the
ingredients. We`ll be warmer and drier again for Wednesday and
Thursday, either under a weak ridge, or possibly with a shortwave
passing north of us or approaching by Thursday. NBM PoPs through
all of this are looking better today, although they may still be
too high Sunday, and too low Tuesday.

&&

.AVIATION /18Z TAFS through 18Z Friday/...
Issued at 1141 AM MDT Thu May 15 2025

VFR conditions expected through the TAF period. Strong WNW winds
will continue through tonight gusting up to 35 kts before
decreasing by 03-05Z. There could be VCSH by 21Z, which would
cause gusty westerly outflow winds up to 30 kts. Winds will return
to drainage around 07Z. Friday morning will see winds pick up
again from the west, with gusts up to 20 kts expected.

&&

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

&&

$$

DISCUSSION...Gimmestad
AVIATION...Ideker