520
FXUS65 KBOU 101808
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1208 PM MDT Fri Apr 10 2026

.KEY MESSAGES...

- A brief cool down today with scattered rain showers. Isolated
  thunderstorms will also be possible over the higher terrain and
  portions of the I-25 Corridor.

- Scattered showersSaturday with a few thunderstorms, mainly
  over the mountains andfar northeast plains.

- Warm and dry Sunday and Monday, with breezy/windy conditions
  possible along with increasing fire conditions.

&&

.DISCUSSION /Through Thursday/...
Issued at 1051 PM MDT Thu Apr 9 2026

SW flow aloft will be over the area today with southeast low level
flow across the plains.  Expect a decent Denver cyclone to develop
although not sure exactly where it will be located.  Initial
thoughts would be to have it over nrn Douglas county. There will
be a convergence zone associated with it which may act as a focus
for tstm development late in the aftn into the early evening
hours. MLCAPE up to 500 j/kg will develop along and south of the
boundary in the aftn. If convective temps can be reached then may
see a few stronger storms with a weak landspout or two possible
along the boundary. Temps will be a problem as readings to the
north and west of the Denver cyclone will be cooler than south and
southeast of the cyclone. Thus have modified readings to account
for this. Over the plains, stratus may hold thru much of the aftn
which may keep highs in the upper 40`s to lower 50s. Over the
higher terrain will see a chc of aftn showers and tstms.

For Sat, SW flow aloft will remain in place.  Cross-sections show an
increase in moisture over the higher terrain with favorable lapse
rates. As a result, will see a good chc of showers and a few
tstms. Across the plains, the low level flow will be SSW with
best moisture confined to the far nern plains, where SBCAPE may
be up to 1000 j/kg. Thus will see a chc of high based showers and
a few storms in the aftn, with a few stronger storms, possible
over the far nern plains. Highs will be warmer with readings in
the 70`s over the plains.

By Sun, drier air in SW flow aloft will spread over the area with
little chc for pcpn.  Temperatures will remain warm across the
plains with increasing wind over the higher terrain and portions of
the plains.

On Mon, an upper level trough will move into the Great Basin with
stg SW flow aloft.  Meanwhile, sfc low pres will be located across
the plains.  Overall, it looks like another day of mainly dry
weather across the plains with above normal temps and gusty winds.
Over the mtns, latest data suggest best chc for showers and a few
tstms will be Mon night and not during the aftn. In addition,
expect windy conditions as well.

By Tue, there is still a lot of disagreement as to the track of an
upper level low.  The ECMWF has it now moving across WY while the
GFS has an open wave trough affecting the area.  For now, it appears
best chc of precip will be over the mtns with quite a bit of
uncertainty across the plains.

For mid week, the flow aloft will become more westerly which will
lead to a drier pattern along with warmer temperatures.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1205 PM MDT Fri Apr 10 2026

The Denver Convergence Vorticity Zone (DCVZ) is still likely (80%)
to develop near/south of KDEN this afternoon around 18z to 20z.
This is expected to bring E/SE winds to KDEN during that
timeframe. Winds at KAPA are expected to be S/SW. The exact
location of this feature will dictate the wind direction this
afternoon, especially at KDEN and KAPA. As the afternoon
progresses, we expect isolated thunderstorms and scattered
showers to develop for all three TAF sites. The highest likelihood
of showers and thunderstorms (40-50% chance) will be from about
20z to 00z this afternoon, but lower chances will continue through
at least 02z ending from west to east. Therefore, we have -TSRA
included in the TAF with the possibility for sustained winds to be
around 10 to 20 kts and gusts up to 35 kts with any gusty outflow
winds from these showers.

Following the showers and storms this afternoon, stronger than
typical drainage winds will occur at KDEN and KAPA overnight. For
KBJC, we expect lighter winds overnight. These will generally be
NE, but could be VRB for several hours according to the latest hi-
res guidance. For tomorrow afternoon, we again expect another
round of showers and thunderstorms could affect all three sites.
Instability should be slightly lower today and the overall shower
chances are a bit lower than today (30-40%), so we opted for a
TEMPO -SHRA for this package. These chances will likely extend a
few hours after 00z Sunday. There is again the possibility for
sustained winds to be around 10 to 20 kts and gusts up to 35 kts
with any gusty outflow winds from these showers.


&&

.FIRE WEATHER...
Issued at 1051 PM MDT Thu Apr 9 2026

Elevated to critical fire conditions will return to the plains,
higher valleys and foothills Sunday into Monday. Gusty southwest
winds will occur in some areas along with low humidity levels.

&&

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

&&

$$

DISCUSSION...RPK
AVIATION...MV
FIRE WEATHER...RPK

NWS BOU Office Area Forecast Discussion