571
FXUS65 KBOU 100557
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1157 PM MDT Thu Apr 9 2026

.KEY MESSAGES...

- A brief cool down Friday 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 /06Z TAFS through 06Z Saturday/...
Issued at 1157 PM MDT Thu Apr 9 2026

Main concerns surround chance of showers and a couple thunderstorms
with variable winds this afternoon, and a low chance of stratus
early this Friday morning.

A weak front pushed across the airports this evening, and another
easterly surge is still possible toward 10Z-12Z Friday. That later
surge would have enough cooling and upslope to bring a slight
(20%) chance of stratus and MVFR ceilings to KDEN with even
smaller chances at KBJC and KAPA.

A Denver Convergence Vorticity Zone (DCVZ) is expected to
develop, and the exact location will determine how winds evolve
through the day. At this time, we have fairly high confidence
(70%) that the cyclone will be developing and moving south of
KDEN which means Easterly winds should develop and hold through
most of the day, before becoming NW or VRB once convection
develops in the area. That cyclone and associated convergence
will also be the main driver of convective initiation, but
appears to be a rather late day with most shower/storm development
holding off til 22Z-01Z. We`ll keep the TEMPO -TSRA in the
forecast for that period of highest confidence, and also mention
VRB gusts to 25-30kts.

Convective activity is mostly agreed upon to move east and exit
the area by 02Z. Then winds should settle down and return to
fairly normal south/southwest winds by 04-07Z Saturday as the DCVZ
breaks down.

&&

.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...20
FIRE WEATHER...RPK

NWS BOU Office Area Forecast Discussion