498
FXUS65 KBOU 170624
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1224 AM MDT Fri May 17 2024

.KEY MESSAGES...

- Much warmer and drier Friday.

- Breezier Sunday into Monday with localized fire weather concerns
  possible depending on fuel conditions.

- Cooler and potentially more unsettled Monday/Tuesday with
  increasing precipitation changes region-wide.

&&

.UPDATE...
Issued at 819 PM MDT Thu May 16 2024

Mid level moisture is moving southeast from WY which has allowed
for some virga near the CO-WY over the plains. This activity
should end in the next few hours. Otherwise, only minor
adjustments to current fcst.

&&

.SHORT TERM /Through Friday/...
Issued at 233 PM MDT Thu May 16 2024

A few showers/storms will remain possible over the higher terrain
through early evening. Most of this activity is expected to be
south of I-70. The airmass quickly stabilizes this evening leading
to mostly clear skies with a few high clouds at times
overnight.

Upper level ridge moves across Colorado tonight and Friday
morning bringing warm and dry air with it. Temperatures are
expected to reach the 80s across northeast Colorado Friday
afternoon, warmesttemperatures so far this year. Cross sections
show some high based cumulus clouds for Friday, otherwise mostly
sunny skies and dry conditions will prevail. The ridge shifts east
of the state Friday afternoon. Westerly flow behind it will
increase. These stronger winds aloft will mix down bringing gusty
winds to 35 mph the higher terrain and also across far northern
Colorado.

&&

.LONG TERM /Friday night through Thursday/...
Issued at 233 PM MDT Thu May 16 2024

A broad upper trough will extend from the Pacific Northwest into the
Northern Great Plains States Friday night with a moderate westerly
flow aloft over Colorado. A shortwave moving across the Northern
Rockies will help push a cold front across the Northeastern Colorado
Saturday morning resulting in breezy conditions and cooler
temperatures on the plains. Some of the models are now showing some
moisture return behind the front which could lead to isolated to
scattered (10% to 40%) showers and storms across the forecast area
during the afternoon and evening hours.

On Sunday, a similar upper level pattern remains in place with some
downsloping flow east of the mountains and breezy to windy
conditions in the foothills. This should flush out the surface
moisture on the plains, resulting in a dry and warmer day with
temperatures climbing back into the 80s. However, higher dewpoints
may linger across the far eastern zones with the potential for
some stronger storms by late afternoon or evening. In addition,
there should be enough mid level moisture combined with daytime
heating to produce isolated to scattered high based showers and
storms across the remainder of the forecast area.

On Monday, the upper level flow over colorado strengthens and
becomes more southwesterly in response to and upper level trough
deepening over the Intermountain West. Models are showing a 110KT+
upper jet over the southeastern half of Colorado with a surface low
over Southeastern Colorado advecting low level moisture into the far
northeastern plains. With this pattern, there would be a large
amount of shear and ample lift to produce severe weather across
far northeastern Colorado. However, there is some uncertainty in
how much low level moisture and instability will be available. If
the moisture remains to the east of Colorado, the severe weather
threat would be over Kansas and Nebraska. However, if the higher
dewpoints are pulled further to the west, it could be a pretty
active day across the far northeastern corner of the state.

Cooler unsettled weather will be possible on Tuesday as the upper
trough and associated cold front moves across the state.

For Wednesday and Thursday, Colorado will be under the influence of
a quasi-zonal flow aloft with some drier air moving into the state
from the west. Therefore, warmer temperatures along with decreased
precipitation chances are expected.

&&

.AVIATION /06Z TAFS through 06Z Saturday/...
Issued at 1158 PM MDT Thu May 16 2024

VFR conditions through the TAF period. There will be healthy
drainage the rest of the night. Winds will become weak this
morning and into the early afternoon. The winds in the mid to late
afternoon will be very tricky, especially at DEN. There will be
periods of gusty westerly winds that mix down and some of the
westerly winds could reach around 20 knots. However, there is
expected to be plenty of periods of very light winds in the
afternoon as well.

During the evening, there will be westerly flow and not the usual
drainage winds at DEN and APA. A cold front will move through the
terminals between 08-11Z Saturday shifting winds to the NNE.

&&

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

&&

$$

UPDATE...RPK
SHORT TERM...Meier
LONG TERM...JK
AVIATION...Danielson