994
FXUS65 KBOU 311922
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
122 PM MDT Mon Aug 31 2026

.KEY MESSAGES...

- Better precipitation chances today, with the potential for a few
  rounds of afternoon/evening showers and storms, a few may
  become severe over the eastern plains.

- Warmer and drier conditions expected from Tuesday through
  Friday.

- Return of better moisture by the weekend increasingly likely for
  the high country.


&&

.DISCUSSION /Through Monday/...
Issued at 117 PM MDT Mon Aug 31 2026

Southwest flow aloft continues pumping more monsoonal moisture into
our area. Today will have the highest rainfall chances of the week
as an embedded shortwave moves through overhead. This will bring a
push of moisture set to arrive to our forecast area this afternoon
and evening. In fact, showers and thunderstorms are already ongoing
across the Four Corners region and Southwest CO as of 1pm. At the
same time, a jet streak is departing the region to the east putting
us in the favorable right entrance region this afternoon. It is
important to note that SPC mesoscale analysis currently shows
instability lacking across our area, which could limit the severe
potential, especially for the I-25 urban corridor and adjacent
plains.

The main concern with storms today will be gusty and erratic outflow
winds as well as microbursts capable of producing wind gusts of 40
to 50 mph as DCAPE is expected to be around 1000 J/kg. MLCAPE is
forecast to reach around 1000 J/kg, mainly for the far eastern
plains. 0-6 km bulk shear should be about 30 to 40 kts with the
greatest shear expected in our eastern plains where temperatures
have warmed into the mid 80s as of 12pm. Therefore, a low risk for
hail of 1 to perhaps 1.5 inches in diameter exists for the far
eastern plains. There is also a low flood threat given that the
ingredients are in place, but storm motion should be rather quick
this afternoon with mean wind around 30-40 kts- limiting the overall
threat. A decent moist vertical profile for the area means PWATs of
150-175% of average for this time of year. Thus, burn scars, areas
where storms linger, and locations that receive multiple rounds of
heavy rainfall today would be most susceptible to minor flooding.
The warm cloud layer depth is relatively shallow, further limiting
the flooding threat.

CAMs are in decent agreement that there will be at least two rounds
of showers and storms this afternoon and evening. Showers and storms
should overspread the southern high country as early as 2-3pm. The
most widespread showers for the high country and Urban Corridor
should be between about 4pm and 8pm. These should then push off to
the north and east. An additional round or two of showers and storms
is possible for the evening and overnight hours through about 2am
tomorrow morning. Tonight, some low clouds and patchy fog are
possible for the plains following the rain. Some light rain showers
could linger into tomorrow morning for the plains, though the odds
are rather low.

High temperatures for today and tomorrow will be near average- in
the mid 80s for the plains. Some isolated storms are possible for
the high country and areas south and east of Denver tomorrow
afternoon. There will likely be a low threat for severe weather near
the Palmer Divide with any storms that could form, but moisture and
lift will be lacking compared to today. The high pressure shifts off
to the mid-Atlantic and Southern US shutting off the monsoonal
moisture feed into our area by Wednesday. High temperatures will
return to above average- in the mid 80s and low 90s across the
plains- for the end of the week and into the weekend. Little to no
rainfall is expected through at least Friday.

By the weekend, south to southwest flow aloft could return. Moisture
from a tropical disturbance in the Pacific could also be pulled into
the Western US, but as of now the deepest moisture looks to miss our
area to the west. Thus, the highest rainfall chances should stay
confined to the high country until Sunday or Monday.

&&

.AVIATION /18Z TAFS through 18Z Tuesday/...
Issued at 1219 PM MDT Mon Aug 31 2026

Current observations show light and variable (

NWS BOU Office Area Forecast Discussion