888
FXUS65 KBOU 191953
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
153 PM MDT Sat Oct 19 2024

.KEY MESSAGES...

- Scattered rain/snow showers over the mountains Sunday afternoon.
  Any rain or snowfall will be very light.

- Dry with above normal temperatures Tuesday into next weekend.

&&

.SHORT TERM /Through Sunday/...
Issued at 153 PM MDT Sat Oct 19 2024

Upper level low will continue to spin over Arizona through
tonight and Sunday morning. It finally begins to lift
northeastward during the afternoon, making it to the Four Corners
around 00Z Monday. Nearly all of the precipitation associated with
this system will remain over southern Colorado and southwards. A
few weak showers may stray far enough north to reach Park and
Lincoln counties through this evening Any rain or mountain
snowfall will be very light. Low levels stay somewhat moist and
with some clearing, fog will be possible, mainly over the low
lying areas north of Denver. Dew points are running in the 40s
over northeast Colorado. This help keep temperatures from cooling
much overnight with lows mainly in the 40s across northeast
Colorado.

On Sunday, a surface low forms over north central Colorado. This
will produce gusty south winds across the eastern plains. Where the
southerly winds prevail, highs are expected to reach the 70s. A
Denver cyclone will form and bring northerly winds to the northwest
part of the urban corridor. Here, highs will be cooler with readings
in the upper 60s to lower 70s. Only chances for showers will be over
southern parts of Park and Lincoln counties and then also over the
higher terrain Sunday afternoon due to a little afternoon
instability.

&&

.LONG TERM /Sunday night through Saturday/...
Issued at 153 PM MDT Sat Oct 19 2024

Models show the upper closed low to get right over the Four
Corners by 00z late Sunday afternoon. Now the track of this
feature is progged to move due easterly from there across southern
Colorado into the southeast corner of the state by 18Z Monday.
This path puts some upward synoptic scale energy over the CWA
Sunday into Monday morning, with subsidence for the rest of
Monday. Flat upper ridging moves into the forecast area for Monday
night through Tuesday night with moderately strong west-
northwesterly flow aloft.

Looking at moisture, it is okay over the mountains, Sunday night
into early Monday with limited measurable precipitation according
to the QPF fields. For the plains, moisture is more limited, with
the QPF fields showing even less measure rainfall and mostly over
the southern half. There is just some upper level moisture progged
for Monday night through Tuesday night, and not all much anyway.
Will keep the 30-60% pops going in the mountains, and 0-30%s late
Sunday night into Monday morning for the plains.

The thickness grids show highs around 70 degrees across the
plains Monday, warming into the mid 70s on Tuesday.

For the later days, Wednesday through Saturday, upper ridging is
progged over the forecast area through Friday, with some zonal
flow on Saturday. The airmass looks to be dry and warm all four
days with temperatures well above the seasonal normals for all
days but Wednesday. A weak cold front is progged for the plains
late Tuesday night/early Wednesday, so highs over the plains will
be around 70 degrees in most areas. Some areas across the plains
could reach 80 degrees for highs Thursday and Friday.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1136 AM MDT Sat Oct 19 2024

Low threat (less than 20%) for ceilings under 6000 feet for the
rest today and evening. Winds will be tricky with the development
of a Denver cyclone after 18Z. Winds to start off southeast to
easterly and could remain this direction through 00Z. If the
cyclone forms/shifts east/southeast of DEN, a wind shift to the
north would occur. Southerly winds to prevail around 02Z once the
Denver cyclone breaks down. Fog is expected to form to the north
of DEN early Sunday morning. If a Denver cyclone forms and brings
NW to N winds to DEN it would bring the fog with it. About a 20-30
percent chance for the fog to reach DEN after 11Z Sunday.

&&

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

&&

$$

SHORT TERM...Meier
LONG TERM....RJK
AVIATION.....Meier