792
FXUS65 KBOU 010825
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
225 AM MDT Sat Jun 1 2024

.KEY MESSAGES...

- Afternoon showers/thunderstorms possible today, strongest from
  Morgan County east in the late afternoon/evening.

- Still a chance of a couple severe storms Sunday over the
  northeast corner of the state

- Summer heat through most of next week, with a few 90 degree
  readings over the plains.

&&

.SHORT TERM /Through tonight/...
Issued at 225 AM MDT Sat Jun 1 2024

The thermal ridge amplifies today underneath largely zonal flow,
with temperatures climbing approximately 10F for the plains/urban
corridor and mostly 5 degrees or less in the mountains. Meanwhile,
a weak shortwave will traverse northeast Colorado. Ample
instability in excess of 1,000 J/Kg should be in place across the
eastern plains come the afternoon, aligning with an area of
enhanced surface moisture with dewpoints into the 50`s. Those
numbers will be closer to 35-40F with increased proximity to the
foothills. Despite the humbling past couple of days of convective
forecasts across the urban corridor, believe the notably drier
conditions near the surface and more marginal instability should
prevent development of any overly strong thunderstorms, instead
favoring mostly high-based showers and thunderstorms for the I-25
corridor and mountains. Conditions will become progressively more
favorable for deeper convection late afternoon and into the
evening as storms push into the eastern plains, with the greatest
potential for severe hail and winds or an isolated tornado focused
generally from Morgan County eastward.

&&

.LONG TERM /Sunday through Friday/...
Issued at 225 AM MDT Sat Jun 1 2024

Sunday will see further warming, with downslope flow and lee
troughing on the increase. While most areas continue to dry, low
level moisture appears to hold over the northeast plains. When
combined with daytime heating, MLCAPE near 1000-1500 J/kg and
still sufficient shear will result in potential of a severe storm
or two. Appears the main chance of that would be east of a
Sterling to Akron line. With regard to the heat, Denver will have
a chance of seeing it`s first 90F degree day. However, we do see
enough mid and upper level moisture for convective cloudiness in
the afternoon which could very well keep most highs on the plains
in the upper 80s, despite the downslope. Outside of the northeast
plains, it appears there is just enough moisture for virga and/or
a passing light shower/weak storm, but that will spell gusty
outflow winds and enhanced downslope breezes off the Front Range.

Monday will feature a continuation of very warm weather with a
flat ridge spreading across the Central Rockies. High temperatures
should warm another degree or two with a little less convective
cloud cover and the flat ridging, so many plains locations should
reach 90F. We`ll still have a chance of high based late day
shower/storm over the mountains and northern border area.

By Monday night and Tuesday, a passing shortwave across the
northern U.S. will push a "cold" front across northeast Colorado.
We`ll use that term loosely, since this will be a relatively
shallow push and warm temperatures remain aloft. Nonetheless,
we`ll likely shave a few degrees off our highs for Tuesday. Warmer
weather should then return for Wednesday with near 90, before
gradual cooling (at least in the ensembles) is indicated for the
end of next week. There is a fair amount of uncertainty here, and
any chance of meaningful precipitation will likely hold off until
at least Friday or Saturday.

&&

.AVIATION /06Z TAFS through 06Z Sunday/...
Issued at 1123 PM MDT Fri May 31 2024

Believe potential for any low clouds tonight is rather low
considering favored southwest drainage flow through early morning
and lack of observed precipitation Friday in the Denver metro, so
have removed any mention of this from the TAF. VFR conditions
should prevail for all terminals through the TAF period.

Winds will become light and variable after ~15Z Sat, with
generally east/southeast flow favored later in the day. However,
wind direction is the most uncertain variable for Saturday and
will likely be driven by thunderstorm outflows in the afternoon.
Primary window for any convective activity in the vicinity of the
Denver metro is 20-02Z. Dry low levels should lead to relatively
high bases at/above 080-090, so leaning towards mostly isolated
high-based showers/virga for I-15 corridor, with stronger storms
more favored for areas to the east of KDEN. Expect return to
south/southwest drainage flow Saturday evening.

&&

.HYDROLOGY...
Issued at 225 AM MDT Sat Jun 1 2024

With the arrival of summer heat, snowmelt season and runoff will
really get rolling over the next few days. Hydrologic forecasts
from the River Forecast Centers show a few streams getting to
action stage by Monday or Tuesday, which means flows will be high
and fast but flooding threat appears limited. Please use caution
and respect these fast moving and cold flows in the high country.

&&

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

&&

$$

SHORT TERM...Rodriguez
LONG TERM...Barjenbruch
AVIATION...Rodriguez
HYDROLOGY...Barjenbruch