394
FXUS65 KBOU 282051
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
251 PM MDT Fri Jun 28 2024

.KEY MESSAGES...

- Scattered showers and storms could produce gusty conditions
  until early evening across the mountains to the plains. Expect
  wind gusts up to 50 mph. A severe storm cannot be ruled for the
  northeast corner which could produce small hail and wind gusts
  up to 60 mph.

- Isolated to scattered thunderstorms this weekend, with a few
  strong to severe storms possible Sunday afternoon and evening.

- Drier conditions possible by mid next week.

&&

.SHORT TERM /Through Saturday/...
Issued at 242 PM MDT Fri Jun 28 2024

CSU TIME SLICE sounding this afternoon displays weak shear and
MLCAPE values near 400-500 J/kg. With large DCAPE values shown on
CSU and ACARS soundings between 1000-1400 J/kg, any delayed
convection that arrives will bring strong wind gusts up to 50 mph.
CAMs favor scattered showers and storms rolling off the foothills
into the plains between 4-8 PM MDT. In terms of severe chances, an
isolated storm or two could produce wind gusts up to 60 mph and
small hail but given our late warm up and dry soundings, the chances
are low. Partly cloudy skies clear tonight. A few hours after
midnight tonight, a cold front will sweep through the CWA. Northerly
winds could produce wind gusts up to 20-30 mph briefly overnight.
700mb temperatures drop between 9-12C as much cooler air
approaches from the north Saturday morning. Cold air advection
will lead to a afternoon temperatures slightly below normal
conditions. Expect low to mid 80s for the urban corridor and
plains; low 60s to mid 70s for the mountains, foothills and
valleys. Diurnal thunderstorms will develop once more mainly
south of I-70 for areas such as South Park, Douglas, Elbert and
Lincoln counties. These areas line up with SPC marginal risk of
severe storms. With decent conditions for development such as
steep mid- level rates between 7-8C/km, 25-30kt shear, and weak
instability, it is possible a few storms could produce small hail,
and gusty winds.

&&

.LONG TERM /Saturday night through Friday/...
Issued at 242 PM MDT Fri Jun 28 2024

Weak ridging aloft and subtle height rises increase mid-level
temperatures on Sunday. This will support a rebound in temperatures
back into the lower 90s across a good portion of the plains and
urban corridor. MLCAPE values are marginal (< 1000 J/kg) with normal
to slightly above normal moisture and weak ascent. The higher
chances will more likely be in the mountains/foothills, Park County,
and the Palmer Divide areas where the higher instability/moisture
is. Model soundings across the east plains show sufficient
instability, but are weakly capped, which may also thunderstorm
development/coverage. Shear will be sufficient to support a few
organized strong to severe thunderstorms.

Early next week to mid-week, the main axis of an upper level
trough positions to the west of Colorado. An upper jet situates to
the north, putting CO in an area of weak ascent. Moisture ranges
from above to just above average. As a result, each day will
feature afternoon/evening chances for scattered, lower coverage
thunderstorms with the higher chances for the higher terrain and
Palmer Divide. Towards the end of the week, moisture gradually
decreases as an upper ridge slowly pushes eastward across the
western CONUS.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1141 AM MDT Fri Jun 28 2024

VFR conditions are possible through the TAF period. There is a
chance of low clouds Saturday morning near 2-4k ft for all
terminals. This afternoon, scattered showers and storms will bring
wind gusts up to 35kts until 02Z. Typical drainage winds are
unlikely as a cold front will arrive between 07-0Z bringing
northerly winds between 12-15kts. By Saturday morning, weak
easterly winds are possible.

&&

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

&&

$$

SHORT TERM...AD
LONG TERM...Mensch
AVIATION...AD