National Weather Service Forecast Discussion

000
FXUS65 KBOU 310907
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
307 AM MDT Tue Mar 31 2020

.SHORT TERM...(Today and tonight)
Issued at 251 AM MDT Tue Mar 31 2020

Water vapor imagery shows the trough over the Pacific NW with the
jet rounding out the base just to the north of the state. The
subsident side of the jet will clip the northern and central
portions of the state bringing enough stability for a weak
mountain wave to form and increased winds to the high country.
Current model cross sections show component along winds with
values in the 50 to 55 kt range bringing winds of 60 mph across
the higher passes and mountain ridges. The strongest winds are
expected during the morning hours as the stability decreases
through the day. These increased winds will push down into the
lower foothills with gusts of 45 to 50 mph possible. The strong
westerly flow will help to bring temperatures across the plains
into the 60s with winds gusting up to 25 mph in some places.

By the evening hours winds will diminish with temperatures
overnight staying more mild with lows in the mid to upper 30s.

.LONG TERM...(Wednesday through Monday)
Issued at 251 AM MDT Tue Mar 31 2020

For Wednesday, Colorado will be under a moderate  southwest flow
pattern with a large, broad upper trof carved out across the
Northwest portions of the United States, including the Northern
Rockies. Temperatures will be quite warm on Wednesday as 700mb
temperatures will range from +3 to +6C which will support high
temperatures around 70 degrees over the plains. Moisture and
instability are marginal during the day on Wednesday and looks
like the only chances of showers/few thunderstorms will be over
the far northern mountains and northern sections of Colorado
bordering Wyoming. These areas will be in closer proximity to the
developing storm system over the Northern Rockies. An associated
initial cold front will sweep southward over Eastern Colorado
Wednesday evening while surface low pressure deepens over
southeast Colorado. A moist, yet shallow northeast upslope flow
will develop behind the front which should allow low clouds to
envelop much of the plains by Thursday morning. Could also be an
increase threat of showers with the cold front interaction during
the night and possibly some light rain showers/drizzle Thursday
morning if the moisture deck is deep enough but uncertain at this
time.

Thursday looks to be much cooler given a mostly cloudy day
and under a cooler airmass. Northern sections of Colorado may even
struggle to get out of the 30s. Will continue to trend downward
temperatures on Thursday given a moist, upslope flow in place. The
main trof and a secondary, stronger surface cold front will bring
the main precipitation event across Northern Colorado from late
Thursday afternoon through Thursday night with enhanced upslope
flow up towards mountain top. The synoptic scale lift on the QG
fields is mainly only weak but there is some decent frontogenesis
with this event. Given the colder air which has already settled in
on Thursday, any precip will most likely change to all snow rather
quickly either by late Thursday afternoon/evening hours. QPF
fields from the models as usual are quite varied with drier
European/NAM run from .10-/25 of an inch while GFS is wetter with
.25-.50 an inch of liquid. Given mainly a night time event may end
up with some light snow amounts for much of the area.

Rapidly improving conditions during the day on Friday as upper trof
has moved east of Colorado and replaced by a drying and more
subsident airmass. Still quite chilly though as 700mb temperatures
still around -7c at Denver in the afternoon. High temperatures will
only be in the upper 30s and lower 40s, especially cooler with
possible snow cover on the ground.

Over the weekend will look for a warming and drying trend as the
flow aloft returns more southwesterly and temperatures rapidly climb
back into the 60s/70s across lower elevations.  Might be just enough
moisture/marginal instability for a few showers across the
mountains.

&&

.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 251 AM MDT Tue Mar 31 2020

VFR conditions are expected through the period. Winds will
increase from the southwest around 15z with gusts between 15 and
18kts before transitioning more westerly after 19z with gusts
increasing up to 25 kts. Winds are expected to diminish after 02z
with drainage through the evening.

&&

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

$$

SHORT TERM...Bowen
LONG TERM...Entrekin
AVIATION...Bowen

NWS BOU Office Area Forecast Discussion