Pierce, Colorado Weather Forecast Discussion

173
FXUS65 KBOU 100053
AFDBOU
Area Forecast Discussion
National Weather Service Denver/Boulder CO
653 PM MDT Tue Sep 9 2025
.KEY MESSAGES...
- Chance of a couple severe storms in the northeast plains through
  early evening.
- Continued isolated to scattered showers and thunderstorms the
  next few days. Better chances for rainfall Thursday through
  Friday.
- Warm weather continues all week, with 90F possible Wednesday and
  Thursday. Slightly cooler temperatures this weekend into next
  week.
&&
.DISCUSSION /Through Tuesday/...
Issued at 222 PM MDT Tue Sep 9 2025
A weak upper level ridge axis continues to drift eastward today. A
weak mid-level trough, combined with modest instability across the
region, has allowed for widely scattered convection to develop
across our forecast area over the last couple of hours... and this
should continue through at least the early evening. Chances for
meaningful rainfall will be fairly low today, but we could see a
couple stronger storms further east (along/east of an Akron to
Limon line) where there`s a little more instability and deep layer
shear. Short term guidance isn`t particularly bullish with the
threat and with the better severe environment further east, I
suspect we`ll get a couple strong storms with a brief hail/wind
threat before they drift out of the CWA.
The forecast pattern the rest of the week still looks fairly
straightforward, as deep trough over the Mountain West develops
and stalls out. Guidance shows near to above normal moisture
across the region, but with daily chances for showers/storms. The
better chances will be over the far western edges of the CWA, with
lower chances along and east of the I-25 corridor. With the
increased southwesterly/downslope flow, we`ll also see
temperatures warm slightly... with some guidance hinting at 90F
highs both tomorrow and Thursday over most of the metro/plains.
It`s been quite some time since we`ve seen a 90F high in Denver
(August 21st), but 90s in early/mid September isn`t particularly
rare.
The upper trough should eventually eject into the northern
Rockies/Great Plains by Friday or Saturday. With the increase in
PVA/QG ascent, there would be better support for convection across
the lower elevations, though most guidance is still fairly dry
overall. PoPs will at least go up 10-20% compared to
Wednesday/Thursday, but at this point the trough passage won`t be
too impressive. On the other hand, the shift to a cooler zonal
flow should get temperatures closer to normal (upper 70s to low
80s).
Forecast certainty decreases quite a bit beyond the trough
passage, with significant differences in the upper level pattern
by Monday/Tuesday of next week. The NBM/multi-model mean appears
good enough in this period and few changes were made beyond the
weekend.
&&
.AVIATION /00Z TAFS through 00Z Thursday/...
Issued at 646 PM MDT Tue Sep 9 2025
VFR through Wednesday. The threat of showers or any strong wind
gusts for the rest of the evening is low, but there are still some
boundaries around making the direction forecast uncertain through
03z, especially for KDEN. After that, normal south/west drainage
winds are expected into Wednesday morning. Scattered thunderstorms
are expected again Wednesday afternoon, with a chance of wind
shifts with gusts up to 35 knots after 20z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Hiris
AVIATION...Gimmestad

NWS BOU Office Area Forecast Discussion