852 
FXUS65 KBOU 091102
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
502 AM MDT Wed Sep 9 2026

.KEY MESSAGES...

- Mainly dry today through Friday with warmer temperatures for 
  Thursday and Friday.

- Return to more unsettled pattern and cooler weather favored for
  next weekend with a chance of thunderstorms each afternoon.

&&

.DISCUSSION /Through Tuesday/...
Issued at 228 AM MDT Wed Sep 9 2026

For today, drier in westerly flow aloft will be over the area as a 
cold front move across the plains early this mornng.  As a result, 
expect dry conditions with cooler temps as highs finally drop back 
to more seasonal levels.

By tonight, the flow aloft will become more WNW as low level 
southeast flow develops which will lead to some return of moisture 
across the east central plains.  Meanwhile, a weak disturbance 
embedded in WNW flow will combine with warm air advection and bring 
some nocturnal tstms, to portions of the sern plains overnight. 
Current data still keeps most of this activity over sern CO, with
srn Lincoln county, being on the nrn fringe. For now have kept in
chc pops mainly across srn portions of Lincoln county overnight.

On Thu, the flow aloft will remain WNW as southerly level flow is 
across the plains.  MLCAPE will rise up to 1000 j/kg over portions 
of the plains by aftn.  For now, chances for tstms stll look on the 
low side as I can't find a focus for activity. However, can't rule 
out an isold storm or two across Lincoln and Washington counties. 
Meanwhile, temps will begin to warm as readings reach the upper 80's 
to lower 90's over nern CO.

Looking ahead to Fri, zonal flow aloft will be over the area as a 
sfc lee trough develops over the plains.  This will lead to another 
warm day as highs rise into the upper 80's to mid 90's over the 
plains.  Meanwhile, models have some mid level moisture embedded in 
the flow, which may lead to a slight chc of higher based 
showers/tstms over the higher terrain.  Across the plains, MLCAPE is 
rather minimal so chances of precip look low.

For Fri night into Sat, zonal flow aloft will continue.  Meanwhile, 
a cold front will move across Fri night into Sat morning.  This 
front will drop temps back to more seasonal levels across nern CO. 
MLCAPE is fcst to be in the 500-800 j/kg across the plains with 
lower values across the higher terrain. Thus will keep in a 
slight chc for showers/tstms across the area for the aftn/early 
evening hours.

By Sun, an upper level trough will move into the nrn Rockies with 
increasing WSW flow aloft across the area.  At the sfc, a lee trough 
will intensify east of the mtns with southerly low level flow across 
the plains.  MLCAPE is fcst to increase to 1000-1500 j/kg over 
portions of the the plains east of a pseudo dryline.  Thus may see a 
few stronger storms by late aftn thru the evening hours.  Highs on 
Sun, will likely rise back to above normal levels.

Looking ahead to Mon, rather dry WSW flow aloft will be over the 
areas a cool front moves across the plains Sun night into Mon 
morning.  Latest data still doesn't show much low level moisture 
behind the front, so it may end up being dry with temps dropping 
back to seasonal normals.

&&

.AVIATION /12Z TAFS through 12Z Thursday/...
Issued at 459 AM MDT Wed Sep 9 2026

VFR condition thru the period. A cold front will move across the
area between 12z and 13z with north winds developing. Winds will
then become NE by 17z and then more easterly by 21z.  For this
evening, winds will go ESE by 03z and then to light south by 06z.

&&

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

&&

$$

DISCUSSION...RPK
AVIATION...RPK