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fxus65 kbou 162124 
afdbou

Area forecast discussion
National Weather Service Denver/Boulder Colorado
224 PM MST Sat Nov 16 2019

Short term...(this evening through sunday)
issued at 224 PM MST Sat Nov 16 2019

The real cold front will be dropping through our area during the
mid to late afternoon. The main associated weather is a fairly
quick drop to the mid 30s, 30-40 mph wind gusts for a few hours,
and a band of mostly light showers that looks to last for a coupld
of hours. The shower activity will likely get broken up by the
downslope coming out of Cheyenne, and increase again south of
Denver, which is fairly well depicted in the existing forecast.

Drying and subsidence aloft moves in quickly around midnight.
Temperatures at low levels will have to recover from tonight's
cooling, which should make it a little cooler tomorrow afternoon
than the current readings. The mountains will be warmer, and we
raised the expected highs there a few degrees. Moderate northwest
flow aloft combined with the subsidence inversion should create
some wave amplification over the Front Range from late tonight
through Sunday. It doesn't look like much of a high wind threat,
but enough to keep 40-50 mph winds going over the ridges and
higher east slopes.

Long term...(sunday night through saturday)
issued at 224 PM MST Sat Nov 16 2019

Long term...for Sunday night and early Monday, there is a weak
disturbance in the northwest flow pattern which will move through
Colorado. Cross sections show shallow layer of moisture in the
mountains and given some orographic flow, we may be able to
squeeze out some snow showers over the higher mountains. Given
shallow moisture depth not expecting any significant accumulation.
Some clouds and gusty northerly winds on the plains but looks too
dry for any showers.

The high pressure ridge aloft will build across Colorado from Monday
night through Tuesday with drying and warming conditions. The flow
aloft will turn more westerly on Tuesday which will result in some
increased westerly winds over the mountains and foothills. Cross
sections show some potential of winds in the 40 to 50 mph range over
higher mountains and exposed east slopes. 700mb temperatures climb
to around +7c during the day which will result in afternoon
temperatures in the upper 60s to lower 70s. Tuesday will be the
warmest day of the week before winter returns for Wednesday and
Thursday.

As Wednesday approaches, several systems to the west of Colorado
will begin to bring a weather change. First an upper low off Baja
California will weaken but increase moisture ahead of the low and
advect moisture into Colorado during Wednesday. In addition, a
Pacific storm system will gather across the Great Basin and
through Southern California, while an associated cold front will
drop down into eastern Colorado. The combination of the colder air
with the front and moisture and energy from the west will bring a
good chance for snow to much of the area. There will be some weak
to moderate qg ascent which will also aid in shower development.
700mb temperatures drop colder than -6c by Wednesday evening.

There are however a wide range of solutions based on the long range
models. The GFS is more progressive in bringing the Pacific low
closer to Colorado while the European and Canadian solutions keep
the low initially much further west, especially the European model
which doesn't eject the low until even Friday. For now will
certainly have colder temperatures and at least a good chance for
showers from late Wednesday and into Thursday. Depending on the
track of these systems will determine how much "weather" will linger
into Friday. Won't be making changes based on future uncertainty
and current forecasts have reasonable chance to low likely chances
of snow for the mid week period.

&&

Aviation...(for the 18z tafs through 18z Sunday afternoon)
issued at 224 PM MST Sat Nov 16 2019

A cold front will move through the Denver area around 00z with a
couple hours of north winds gusting to 35 knots at kden/kapa and
25 knots at kbjc. Scattered showers are expected between 00z and
05z when instrument approaches to kden will likely be needed.
There may be an hour or two of IFR visibilities in snow showers.
Conditions will rapidly improve between 04z-06z with VFR
conditions after that through the day Sunday.

&&

Bou watches/warnings/advisories...
none.
&&

$$

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