539
FXUS65 KBOU 012032
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
232 PM MDT Mon Jul 1 2024

.KEY MESSAGES...

- Isolated to scattered showers and thunderstorms expected today.
  A couple of stronger storms possible in far northeast Colorado
  this afternoon and evening.

- Downward trend in showers and storms beyond Wednesday.

&&

.SHORT TERM /Through Tuesday/...
Issued at 1246 PM MDT Mon Jul 1 2024

Satellite imagery shows cumulus developing across areas that got a
break from the mid-level clouds across the high country and east
plains and Lincoln County. These will be the more likely areas to
develop scattered thunderstorms this afternoon. Instability has
been low across the urban corridor and plains resulting in
scattered showers/convective showers rather than thunderstorms.
For the remainder of the afternoon and evening, expect scattered
showers and some thunderstorms. Elevated moisture and marginal
instability will warrant monitoring over the burn areas for any
training showers/storms. The better environment for stronger
storms was in the northeast corner, but may not be as favorable
with showers having gone through today. Overnight, scattered,
lower coverage showers are possible. A weak cold front moves
through early Tuesday morning with potential for development of
low stratus behind it. HREF guidance lacks agreement on how much
moisture will stick around overnight resulting in lower confidence
in the stratus chances.

Tuesday, the upper level trough remains over the region. An upper
level jet max positions to the north, increasing flow aloft over
Colorado. A weak upper level shortwave trough moves through the
flow. Moisture will be less than Monday, but will be sufficient to
support a low chance (< 25%) isolated showers and thunderstorms in
the afternoon. Marginal instability will also help keep chances and
coverage low with MLCAPE values > 500 j/kg and will keep the
"higher" chances confined to the southern Foothills, Palmer Divide,
and far east plains. A weak frontal passage and cloud cover will
keep temperatures cooler Tuesday with highs in the 80s on the
plains.


&&

.LONG TERM /Tuesday night through Monday/...
Issued at 1246 PM MDT Mon Jul 1 2024

West to northwest flow aloft is expected for the middle part of
the week. An upper level disturbance moves into the Wyoming
Wednesday and then into the upper Midwest by Friday. With the
upper level disturbance moving to our north Wednesday, southerly
surface winds increase across the eastern plains. While low level
moisture is limited for the western portion of the area, the
plains will see enough moisture for scattered thunderstorms to
develop. A few strong to severe thunderstorms are possible in the
northeast corner of the state. For the higher elevations, with
dry and breezy conditions, could have some areas with near
critical fire weather conditions. Currently looks like Fire
Weather zone 214 (Park County) may be the area of greatest
concern.

The cold front moves into the northeast plains late Wednesday
night and pushes south across the plains Thursday morning. A
breezy day is expected Thursday with cooler temperatures and drier
air in place. Pops are very lows for the plains Thursday, meaning
very low chances for any thunderstorms or precipitation. Thursday
will also be the coolest day of the week with highs in the 70s
and lower 80s. Fire Weather zone 214 again looks like it will
flirt with critical fire weather conditions, but the dry and
breezy weather across the CWA will mean that caution should be
exercised with outdoor burning and fireworks.

For Friday through Monday...the upper high remains over
California with northwest flow aloft continuing across the CWA
during this time. Generally dry conditions are expected through
the weekend with an isolated shower or thunderstorm producing only
gusty winds and very little rainfall. High temperatures on Friday
will be slightly below normal, but warmer temperatures return
Saturday through Monday with highs at the lower elevations
in the low to mid 90s.

&&


.AVIATION /18Z TAFS through 18Z Tuesday/...
Issued at 1220 PM MDT Mon Jul 1 2024

Westerly component winds this afternoon at 08-13 kts. Gusts up to
25 kts are possible through 19/20Z as a result of a weak mountain
wave that extended off the Foothills this morning. Showers this
early this afternoon with scattered thunderstorms possible after
20Z. Brief variable outflow gusts are possible in any
nearby/passing storms with gusts up to 30 kts.

Low coverage showers possible tonight. A weak cold front moves
through early Tuesday morning. Timeframe is low confidence as this
front is weak with no defined boundary/push of northerly winds.
Within in the 08-12Z timeframe, winds transition to north at 07-10
kts. There is potential for low stratus to develop post-front
(10-13Z). Confidence is still on the lower end with models unsure
of how much low level moisture will be available. For now,
messaging this in the TAF as SCT015 until confidence increases.
Tuesday, light winds turn to the WNW in the afternoon. There is a
low chance for isolated showers/storms in the afternoon, mainly
for APA.

&&

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

&&

$$

SHORT TERM...Mensch
LONG TERM...Stark
AVIATION...Mensch