174
FXUS65 KBOU 160314
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
914 PM MDT Mon Jul 15 2024

.KEY MESSAGES...

- Still hot today, but a few degrees cooler than this weekend.

- Scattered afternoon showers and thunderstorms today with a
  couple severe storms possible over the plains.

- Higher chance of showers and thunderstorms both Tuesday and
  Wednesday, with an uptick in storm intensity and severe threat.
  Temperatures cooling to below normal levels for Wednesday.

- More typical summer weather for the latter half of this week
  with scattered afternoon showers and storms most days.

&&

.UPDATE...
Issued at 901 PM MDT Mon Jul 15 2024

Scattered showers are still ongoing across a few different spots
of the CWA, with gusty outflow winds noted from a few of these
showers. This activity has been slowly weakening over the past
couple of hours, and this trend should continue through the rest
of the evening.

Main adjustment this evening was to update the PoPs and winds in
the next few hours to better match current observations.
Otherwise, the previous forecast was largely in good shape.

&&

.SHORT TERM /Through Tuesday/...
Issued at 255 PM MDT Mon Jul 15 2024

Storms continue to develop in the foothills spreading to the plains
until late evening. A few outflows have recently reported 25-30 mph
gusts along coop sensors along the I-25 corridor. Storms will likely
produce little rainfall and gusty winds up to 45 mph through this
evening. There is potential for severe storms mainly near the
northeast corner this evening where storms could produce wind gusts
up to 60 mph. Tonight, clouds should clear.

Tuesday, 700mb temperatures range between 12-13C which should lead
to cooler surface temperatures. Expect areas above 8 thousand feet
to range between 63-78F. There is a chance that Denver could break
90F but mid-level clouds arrive quickly by early afternoon thus will
keep a forecast high of 89F. Low elevations will range between 82-
92F. A shortwave trough sweeps across northeast Colorado bringing
scattered showers and storms by Tuesday afternoon. PWATs hover near
normal between 0.65-0.80 inches and storm motion should move rather
quickly thus the flood threat should remain limited for both the
East Troublesome and Cameron Peak burn scars.  Additionally,
favorable MLCAPE values near 1000 J/kg, bulk shear values near 40-
45kts and mid-level rates between 7-8 C/km could lead to potential
severe storms mainly for the Palmer Divide and plains.

&&

.LONG TERM /Tuesday night through Monday/...
Issued at 255 PM MDT Mon Jul 15 2024

Similar conditions are expected Wednesday with cooler temperatures
and increased moisture. Northeast Colorado remains on the eastern
periphery of an upper level ridge with a trough settling across the
Great Lakes and Midwest. Although we won`t completely tap into the
cooler airmass, we will benefit from another frontal push of cooler,
upslope flow from the northeast early Weds morning. Can`t rule out
some stratus development across the plains behind the front through
the morning hours. With that being said, there will be sufficient
advection of moisture in the lower levels from east to west,
bringing higher dewpoints further westward than Tuesday. Higher
values will exist over the far east plains in the low 60s with 50s
pushing toward the I-25 corridor. Upper level support will be
minimal, but a jet max positioned to the northeast will provide weak
ascent and sufficient deep layer shear. The higher instability will
co-locate with the best moisture and daytime heating with MLCAPE
values in the 1000-2000 J/kg range across the I-25 corridor. The
northeast corner may remain stable due to the AM stratus. All in
all, this will support scattered showers and thunderstorms in the
afternoon with a couple strong to severe storms. Highs range in
the mid to upper 80s across the plains. A welcome cooling from
previous days.

Thursday and Friday, ensemble guidance shows a consensus on the
upper level ridge centering over the Great Basin/Desert Southwest.
Northeast CO sits within the northerly flow aloft on the east of the
ridge. Ensemble means show slight warming closer to normal
temperatures with scattered showers and thunderstorms both days with
the highest chances over the mountains and foothills.

Ensemble guidance show a few embedded waves that move through the
northerly flow over the course of the weekend. This generally will
keep temperatures below normal. Moisture remains in place to support
scattered afternoon showers and thunderstorms each day.

&&

.AVIATION /00Z TAFS through 00Z Wednesday/...
Issued at 537 PM MDT Mon Jul 15 2024

Weak showers around the terminals are likely to continue for the
next couple of hours. Radar shows quite a few showers/storms
upstream across the I-70 mountain corridor, with this activity
generally drifting east. With temperatures in the low to mid 70s,
the chances for organized convection is low but a few TS can`t be
completely ruled out. The main concern over the next few hours is
how the winds play out with showers continuously spitting out
outflow with varied directions.

The weather should quiet down by later this evening, with VFR
conditions expected overnight. Tomorrow`s weather looks fairly
similar today, with enough moisture/instability for widely
scattered TS by the mid-afternoon. Main threat tomorrow will again
be gusty outflow winds.

&&

.HYDROLOGY...
Issued at 255 PM MDT Mon Jul 15 2024

Above normal moisture moves into the region starting Tuesday with
scattered afternoon showers and thunderstorms. Some stormy will be
capable of localized heavy rainfall. Storm motions won`t be
concerningly slow; however, the marginal winds aloft will warrant
a low risk for flash flooding over the burn areas for at least
Weds and Thurs.

&&

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

&&

$$

UPDATE...Hiris
SHORT TERM...AD
LONG TERM...Mensch
AVIATION...Hiris
HYDROLOGY...Mensch