450
FXUS65 KBOU 080301
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
901 PM MDT Sun Jul 7 2024

.KEY MESSAGES...

- Strong to severe thunderstorms are expected today across much of
  the plains, particularly east and southeast of Denver.

- Drier starting Monday with a prolonged warming trend kicking
  off.

- Starting Thursday through next weekend, prolong well above
  normal temperatures are likely.

&&

.UPDATE...
Issued at 901 PM MDT Sun Jul 7 2024

Severe threat has ended, and convection is winding down as we
continue to stabilize. There are a few weak showers over the
mountains and still streaming in from the northwest, but overall
the drying and clearing trend is beginning. Lingering convection
should be all but done before midnight, with clearing skies
overnight. Enjoy the cool, crisp night before the heat arrives
later this week.

&&

.SHORT TERM /Through Monday/...
Issued at 233 PM MDT Sun Jul 7 2024

Satellite imagery exemplifying today`s setup, with shallow
strati-cu streaming westward and slowly but steadily advecting in
better low-level moisture under an upslope flow regime. Meanwhile,
thunderstorms have developed across northern Larimer and Weld
Counties and is gradually pushing southeastward, with some
secondary focal points for initiation beginning to show up across
the foothills and north of Pikes Peak.

Not much has changed with respect to the forecast over the past
few hours. As convection continues marching into the plains, it
will begin to encounter a more favorable environment for
strengthening with moderate MLCAPE of 500-1,000 J/Kg and, more
notably, impressive deep-layer shear which could exceed 50 kts per
SPC`s latest mesoanalysis forecasts, roughly coinciding with the
Slight Risk area. Still anticipate comparatively lesser coverage
for locations roughly along and west of I-25, where instability
will be a little more marginal and dewpoints may struggle to crack
50 degrees. The greater threat for severe weather will be
concentrated along an axis from Morgan County southward into
Elbert and Lincoln Counties. Since early this morning, guidance
has come into quite good agreement when it comes to the
progression of today`s convection. As far as timing is concerned,
expect the main window for severe weather threats and large hail
to be through mid evening, although it`s possible we could see
some convection linger across the southernmost portion of our
forecast area through late evening.

Looking ahead into Monday, the trough will have moved due east of
Colorado with subsident northwest flow filling in aloft. We`ll be
quite a bit more stable and any afternoon showers or storms should
be isolated, generally confined to our southern mountains and Park
County where we`ll see light southerly winds near the surface and
thus enhanced orographics. Otherwise, expect a much drier day,
kicking off a prolonged warming trend. There`s high confidence in
Monday being the coolest day of this upcoming week. Highs will be
near normal, mostly in the low to mid 80`s in the plains, and 70`s
for most mountain communities.

&&

.LONG TERM /Monday night through Sunday/...
Issued at 233 PM MDT Sun Jul 7 2024

Not many changes to the overall long term forecast period. As the
shortwave trough exits, lingering mid level moisture could lead to
weak diurnal convection for areas above eight thousand feet each
afternoon Tuesday and Wednesday. Storms will likely remain sub-
severe due to a lack of shear and instability. This should also
keep the flood threat low for the burn areas.

Starting Thursday, an upper level ridge finally arrives over
Colorado. Cross sections indicate dry air throughout the 500-700mb
layer. With the lack of moisture, only isolated chances (10-20%)
of thunderstorms exists for Park, Summit, and Clear Creek counties.
With strong ensemble agreement, widespread upper 90s to low 100s
are likely starting Thursday through next weekend. NBM handles max
temperatures well across the region. This heat may lead to
tied/break max temperature records especially east of I-25.

&&

.AVIATION /00Z TAFS through 00Z Monday/...
Issued at 552 PM MDT Sun Jul 7 2024

Main thunderstorm threat has shifted to the south and east of the
Denver area TAF sites, but still a low (10-20%) threat of thunder
with still a little instability in northwest flow. A passing
shower til about 02Z or 03Z would be more likely, however, given
most instability has been worked over. Northerly winds will
prevail early, then becoming variable toward 02Z-03Z before skies
clear and normal light drainage winds settle in through 05Z.

On Monday, the airmass will be more stable with only SCT clouds
developing at 8000 ft AGL or higher. Normal diurnal wind patterns
should prevail at speeds 10 kts or less.

&&

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

&&

$$

UPDATE...Barjenbruch
SHORT TERM...Rodriguez
LONG TERM...AD
AVIATION...Barjenbruch