Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 08/29/23

Area Forecast Discussion

National Weather Service Denver/Boulder CO

 757 PM MDT Mon Aug 28 2023

.UPDATE...
Issued at 753 PM MDT Mon Aug 28 2023

Most of the showers and thunderstorms occurring along and south of
a line extending from around Bailey to Denver to Brush at this
time, with little if any additional showers/storms north of this
line. Have adjusted the grids this evening to better reflect this
trend. Showers and storms should continue to weaken as they track
south into Elbert and Lincoln counties this evening. Strongest
storms may still produce locally heavy rain, small hail and wind
gusts up to 50 mph until 9 pm.

&&

.SHORT TERM...(This evening through Tuesday)
Issued at 223 PM MDT Mon Aug 28 2023

Radar shows scattered showers and storms mainly over the
mountains and foothills this afternoon. They are producing brief
heavy rainfall and small hail. The storms that move off the
foothills and onto the plains are struggling to maintain their
strength and most are dissipating quickly. This is likely due to
an inversion around 650 mb that is showing up on the ACARS
soundings. Some additional daytime heating will help to overcome
this inversion but, overall, it will limit the storm coverage
especially east of I-25. These showers and storms will continue
through the early evening and then the lack of instability will
result in them dissipating.

Skies will clear tonight with usual drainage wind patterns. Low
temperatures will be around normal.

Subsident flow will be over Colorado on Tuesday as the axis of a
ridge pushes out a shortwave trough. Sounding show it will be a
very stable airmass with an inversion near 550 mb. Much drier air
will be in place and the vast majority of the forecast area will
be dry tomorrow. The only exception will be the southern foothills
and South Park where a couple weak showers could form. The mostly
sunny conditions will allow temperatures to warm up a couple of
degrees compared to today`s temperatures. Highs will still be
below normal as it will be a gorgeous day.

.LONG TERM...(Tuesday night through Monday)
Issued at 223 PM MDT Mon Aug 28 2023

Wednesday, the upper ridge flattens in response to a shortwave
trough moving across the northern portion of the CONUS. As a result,
weak westerly subsident flow aloft works into the region keeping it
mainly dry. Marginal instability develops in the mountains & Palmer
Divide which can support low chances (< 30%) for scattered showers
and thunderstorms in the afternoon. Within the drier airmass,
temperatures increase back into the low 90s across the lower
elevations.

Thursday into Friday, an upper level trough pushes into the west
coast, helping induce southwesterly flow aloft across Colorado.
Ensemble guidance favors another "mainly dry" day with low chances
for scattered showers and storm over the high country. There is an
agreeable signal for increased moisture Friday and through the
weekend as monsoonal moisture re-enters the region. Ensemble
guidance shows a plume of above normal moisture being advected into
Colorado within the southwesterly flow aloft. This will bring
increased chances of showers/storms over the mountains(~40-60%),
foothills, and western Palmer Divide Friday through the weekend.
Adjacent plains will have low chances (< 30%) each day. Temperatures
continue to be above normal across the lower elevations with highs
in the lower 90s through the weekend.

Monday, ensemble guidance shows a general trend of the trough to the
west moving across Colorado. However, there are differences among
solutions regarding positioning and timing of this wave. Depending
on the solution, there could be increased shower/storm chances for
the high country and parts of the plains.

&&

.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 613 PM MDT Mon Aug 28 2023

Generally VFR conditions expected through the period. In the very
short term, through 02-03z, showers and thunderstorms moving out
of the foothills, along with outflow boundaries generated by
storms over Weld and Morgan counties, could still produce a
thunderstorms over the terminals so have opted to included vcts
until 02z, with a tempo group for -shra. Showers and storms moving
into Denver from the northwest should weaken as they continue to
track southeast. Brief broken ceilings 050-060 in shra/tsra
possible if a storm moves directly over the terminal. Improving
conditions by 05z with light winds switching to drainage, no
storms expected on Tuesday.


&&

.HYDROLOGY...
Issued at 223 PM MDT Mon Aug 28 2023

There is a threat of flash flooding this afternoon as storms
producing brief heavy rain are currently going over the recent
burn areas.

On Tuesday, there is no threat of flash flooding since it will be
dry.

The threat for flash flooding over the burn areas will be little to
none Wednesday. There is a decent chance these drier conditions
prevail Thursday as well resulting in very little risk for flash
flooding over the burn areas. Above normal moisture re-enters the
region by Friday, continuing through the weekend resulting in
increased chances for showers and thunderstorms over mainly the high
country. This may increase the threat for flash flooding over the
burn areas.

&&

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

$$

UPDATE...Cooper
SHORT TERM...Danielson
LONG TERM...Mensch
AVIATION...Cooper
HYDROLOGY...Danielson/Mensch