260
FXUS65 KBOU 051752
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1152 AM MDT Sat Sep 5 2026

.KEY MESSAGES...

- Remaining warmer than normal through most of next week.

- Isolated to scattered showers expected today, with a few
  thunderstorms this afternoon and evening for the northeast
  plains.

- Higher coverage of showers/storms expected Sunday into Monday,
  although mostly on the weaker side. Daily shower potential will
  carry into most of next week as well.

&&

.DISCUSSION /Through Friday/...
Issued at 137 AM MDT Sat Sep 5 2026

I`m not sure if I have anything insightful to add in this forecast
discussion, as the forecast pattern over the next several days has
not changed significantly in quite a while.

Weak south-southwesterly flow aloft is noted across the forecast
guidance today. A modest plume of moisture is still evident on
water vapor satellite across portions of southeastern Colorado,
which should nudge its way into our forecast area later today.
That should lead to a minor increase in surface moisture this
afternoon, with surface dew points in the upper 30s to low 40s
across the metro. Forecast soundings aren`t impressive, but do
feature meager CAPE (~100-250 J/kg) and sufficient DCAPE for a few
gusty showers or perhaps a weak thunderstorm later this afternoon.
Further east, where >50F Td exists, a few thunderstorms could
develop along the instability gradient - generally to the
east of a Fort Morgan to Limon line. The HRRR is rather bullish on
the potential across far northeast Colorado, though most other
CAMs don`t show nearly as much convective coverage. Meanwhile, it
will still be hot today, with highs again in the low to mid 90s.

Continued gradual moisture advection is expected on Sunday as we
remain on the western periphery of a large ridge centered over
western Oklahoma. While there will be a little more instability to
work with (MLCAPE >500 J/kg), there is essentially no synoptic
support and any afternoon convection would be initially be
confined to the higher elevations... and any storms across the
I-25 corridor or plains would be dependent on boundary
interactions. Temperatures should be slightly cooler but forecast
highs are still around 90F for the plains.

Moisture will continue to slowly increase for early next week. We
may briefly have some upper level support from the right entrance
of a 70-80kt jet streak moving across northwestern Colorado Monday
evening/night, which will lead to increased chances of
precipitation across the region.

The forecast pattern becomes a little less clear by Tuesday, as
the ridge begins to flatten/stretch west westward. Either very
weak flow aloft or zonal flow is expected to develop over the
forecast area by Tuesday or Wednesday, though a decent amount of
moisture remains trapped under the ridge here. A look at ensemble
members overnight still implies high confidence in above normal
temperatures continuing in this period, with lower confidence in
how much moisture/precipitation to expect across the region.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1152 AM MDT Sat Sep 5 2026

Northeast winds will continue this afternoon and slowly turn
clockwise, becoming southeast this evening, after 00Z. The PROB30
for variable winds and showers was pushed back to begin at 02Z.
This lines up with recent model guidance which shows the best lift
occurring later. A wind shift or two will be possible from passing
by showers. For tomorrow, better instability and moisture will
lead to about a 30 percent chance for thunderstorms late Sunday
afternoon, after 22Z.

&&

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

&&

$$

DISCUSSION...Hiris
AVIATION...BM