970
FXUS65 KBOU 100927
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
327 AM MDT Fri May 10 2024

.KEY MESSAGES...

- Showers will gradually decrease over the mountains and foothills
  through the day today. Will leave the Snow Advisory going for
  Zones 34, 36 and 37 through this morning where possibly 3 more
  inches of snow will fall.

- The western half of the plains can expect scattered rain showers
  today, with nothing over the east.

- Temperatures will stay below seasonal normals today.

- Gradual warming this weekend and through Tuesday along with
  scattered showers and thunderstorms, most numerous this weekend
  and Tuesday onward.

&&

.SHORT TERM /Through tonight/...
Issued at 327 AM MDT Fri May 10 2024

Area radars, observations and web cameras indicated light rain
showers over the southern plains and Palmer Ridge of the CWA at
this time. Light to moderate snow is falling over the southwestern
CWA, including Park County. Temperatures are currently in the upper
30s to mid 40s over the plains, and 30s in the foothills.

Models show an upper closed low over the southern Great Basin into
central Utah today with a weak upper tough axis stretched west to
east across the CWA.  By 12Z Saturday morning, the upper low is over
northwestern Arizona with the upper trough axis across the northern
border area of the CWA.  QG fields have weak upward vertical
velocity for much of the CWA today and tonight. The low level wind
and pressure fields show weak to no upslope for the plains today.
For tonight, weak drainage winds are progged.

There is fairly deep moisture in place today for much of the CWA.
Moisture decreases this evening and overnight in all areas. There
is weak CAPE progged this is afternoon and evening, mainly over
the mountains and foothills. Will keep the basic trend going with
the pops in the forecast. The highest pops will be over the alpine
areas and southwestern CWA this morning, with a gradual decrease
through the day. There will be low to no pops over the eastern
half of the plains today with "scattered" pops for the western
half. Will leave the winter weather highlights going in Zones 34,
36, and 37 through 18Z today.

For temperatures, today`s highs look to get 1-3 C warmer over most of
the CWA compared to yesterday`s readings. However readings will
stay below seasonal normals.

&&

.LONG TERM /Saturday through Thursday/...
Issued at 136 AM MDT Fri May 10 2024

Over the weekend, the upper-level low previously to our southwest
will reverse course as building high pressure pushes it northeast
into the plains, and it will weaken slightly as it does so.
Thermal ridging will be more evident across the lower levels,
allowing for temperatures to climb into the upper 60`s for the
majority of the lower elevations. Marginal instability with MLCAPE
values 400 J/Kg or less and lingering mid-level moisture will
sustain isolated to scattered showers/thunderstorms, most numerous
in the mountains. Moisture looks more vertically consistent during
the morning and early afternoon hours Sunday, so have adjusted
timing of higher PoPs to reflect this. Snow levels during the
weekend will generally hover around 10,000 ft during the warmer
parts of the day.

The ridge axis should become more prominent over the region by
Monday, bringing weaker northwest flow aloft and additional
warming. Temperatures will climb into the 70`s for the plains and
urban corridor, returning to near or slightly above normal values.
QG forcing appears minimal and forecast soundings suggest a more
stable profile, so showers/thunderstorm coverage should be notably
more isolated, and largely confined to the higher terrain.

Tuesday will start to usher in some pattern changes as a
developing trough impacts the northern Rockies. Flow aloft will
become more westerly/southwesterly, with increasing PWAT values.
Differences in timing among ensemble guidance starts to become
more significant around this time, but the overall consensus
suggests an increase in thunderstorm coverage across the region.
Low-level flow may still be rather subsident with drier downslope
flow in the lee of the Front Range, which will help sustain warmer
temperatures well into the 70`s. This could ultimately taper the
precipitation potential in the afternoon for areas along the I-25
corridor, with higher potential focused over the plains where
instability looks to be maximized.

Expect cooler temperatures Wednesday into Thursday as a cold front
pushes south through the region, along with precipitation chances
ticking up another notch.

&&

.AVIATION /00Z TAFS through 00Z Friday/...
Issued at 318 AM MDT Fri May 10 2024

Model cross sections show fairly low ceilings at DIA through 16Z
this morning.  Will go with BKN-OVC010-020.  Will start to bring
them up after that, expecting BKN-OVC045-050 by 21Z-00Z this
afternoon. Will go with a VCSH from 17Z to 03Z this evening.
Winds are progged to be pretty weak with an upslope direction much
of the day. Weak drainage wind patterns should kick in around 03Z
this evening.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until noon MDT today for COZ034-036-037.

&&

$$

SHORT TERM...RJK
LONG TERM....Rodriguez
AVIATION.....RJK