Forecast Discussions mentioning any of "ACARS" "MDCRS" "AIRCRAFT" "TAMDAR" "AMDAR" "WVSS" received at GSD on 04/26/21

Area Forecast Discussion

National Weather Service Pueblo CO

 809 PM MDT Sun Apr 25 2021

.UPDATE...
Issued at 802 PM MDT Sun Apr 25 2021

Updated to expire the Red Flag Warning at 8 PM. Winds have begun
to subside across much of the region. A few gusts are still
possible through this evening, especially along the lee slopes of
the southern Sangre de Cristo Mountains. Humidity recoveries are
expected to be poor overnight, leading to an early start for Red
Flag conditions on Monday.  Mozley

&&

.SHORT TERM...(This evening through Monday)
Issued at 312 PM MDT Sun Apr 25 2021

...Critical Widespread Red Flag Conditons Throughout the Evening...

...Extreme Widespread Red Flag Conditions Favorable for Monday...

This evening and tonight...

Red Flag conditions will continue into this evening until 02Z, and
then all of the lastest models indicate that the winds will decrease
below the threshold as mixing down to the surface weakens over most
of the CWA. Very poor humidity recoveries are expected tonight over
much of the areas, especially along the eastern facing slopes with
adiabatically warming and drying downsloping winds continuing
throughout the night. Relatively warmer temperatures for tonight
over much of the area due to the winds inhibiting radiational
cooling, with 40s to 50s over the plains and 30s in the higher
mountain valleys that are sheltered from the winds.

Monday...

As the major shortwave upstream continues to propagate towards the
region throughout the day tomorrow, the set up synoptically is very
favorable for serious and possibly extreme widespread red flag
conditions over much of the area, with very low minimum relative
humidity values later in the afternoon in the single digits over
much of the mountain valleys and plains. Winds will continue to
strengthen again later in the morning this will help to further
increase the critical fire weather concerns by later in the
afternoon, as gusts in certain areas could peak out as high as 50
mph, especially in and around the mountain passes and canyons. High
temperatures will be very warm again tomorrow, with highs in the mid
to upper 80s over much of the central and eastern plains. And still
well above the seasonal average for all other areas of the CWA as
well with the persistent south to southwesterly flow. Please avoid
all activities that may cause a fire for fire growth will be rapid
and hard to contain.

.LONG TERM...(Monday night through Sunday)
Issued at 312 PM MDT Sun Apr 25 2021

Main Forecast Concerns/Challenges:

1) Critical fire weather conditions possible over the southeastern
plains on Tuesday afternoon.

2) Cold front passage on Tuesday afternoon will bring rain showers
to the plains and snow showers over the eastern mountains.

Meteorological Discussion:

Monday Night:

Red Flag conditions are expected to dissipate by around 8PM on
Monday night, but there may be spotty areas that last a little
longer, but the winds are expected to be weak enough to be below
criteria at that time. A warm night is expected over the region due
to lingering winds and mechanical mixing in the atmosphere. Low
temperatures are expected to be in the 40s over the plains (higher
near the mountains), the 30s over the mountain valleys, and the
teens over the mountains. Snow showers ar expected to begin over the
Continental Divide at around midnight.

Tuesday and Wednesday:

Much of the following will be dependent on the speed, intensity, and
location of the evolution of the closed low pressure center. There
is high confidence that the low will propagate from the Great Basin
all the way down to southern New Mexico from late Tuesday through
Wednesday afternoon. There is high confidence that snow showers will
start around midnight and will last throughout the day on Tuesday
over the mountains. The lowest confidence is when the cold front
will propagate over the region. Models are hinting at a late day
frontal passage, but cold fronts notoriously arrive and move more
quickly than the models suggest. So expect a midday frontal passage.
Timing is crucial for multiple reasons, the first being timing of
when rain showers will develop over the plains and snow showers over
the eastern mountains. The other reason is if critical fire weather
conditions will exist for long enough to warrant a fire weather
highlight issued for the southeastern plains. Again, all of this is
dependent on how quickly the front passes. Currently the thought is
that the far southeastern plains will have critical fire weather
conditions on Tuesday afternoon. No fire weather watch will be
issued today due to how many Red Flag Warnings are out right now,
but look for highlights soon.

Snowfall amounts aren`t expected to cause much of an impact, though
the existence of a small amount of CAPE over the mountains tops may
cause lower visibilities under the strongest bands of snow. Current
thoughts are for a around 4 to 6 inches over the higher elevations
of the Continental Divide, 2 to 4 over the eastern mountains, and
around an inch for the Palmer Divide. Note that most of the snow
over the Palmer Divide will melt on contact.

An upper level jet will develop over the region on Wednesday and
lingering easterly flow will keep snow showers going through the day
on Wednesday

Thursday through Sunday:

An upper level ridge develops over the western US from Thursday
through Sunday, which will start a warming trend over southern
Colorado. Expect temperatures to soar into the 80s and into the 90s
by next weekend over the plains and the 70s to 80s over the mountain
valleys. There is some concern of another couple of critical fire
weather days next Saturday and Sunday, but there is a lot of
uncertainty of where the next low will track and if the area will be
in "green-up" status by then.

&&

.AVIATION...(For the 00Z TAFS through 00Z Monday evening)
Issued at 312 PM MDT Sun Apr 25 2021

VFR conditions will prevail at all TAF sites for the forecast
period. Strong and gusty winds will continue throughout the early
evening, will cause light to moderate CAT to be present near the
surface over most of the region. Some isolated areas, especially
near the mountain valleys, could experience weak LLWS conditions as
well. Mid to high level clouds will be few to scattered and mountain
waves could develop downwind on the leeward (eastern) side of the
major mountain ranges later this afternoon. Tomorrow morning the
winds will begin to increase again and be even stronger over much
of the region by tomorrow afternoon. Moderate and even possibly
severe CAT for smaller aircraft possible after 17Z, especially in
and around mountain canyons and passes.


&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 9 AM to 8 PM MDT Monday for COZ220-222-
224>237.

&&

$$

UPDATE...MOZLEY
SHORT TERM...STEWARD
LONG TERM...SKELLY
AVIATION...STEWARD