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NWS Area Weather Forecast Discussion
County Warning Area [CWA]: BOU
Regional NWS Weather Office: Denver/Boulder, CO

000
FXUS65 KBOU 221633
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
933 AM MST Mon Jan 22 2018

.UPDATE...
Issued at 933 AM MST Mon Jan 22 2018

Gusty downslope winds have kicked up across the Front Range
Foothills and have spread onto the nearby plains. Have increased
the winds and added blowing snow across the wind prone areas
between Boulder and Golden, with some impacts noted on Highway 93.
Also increased winds a bit more across the northeast plains
through mid afternoon as blizzard wraps up in the Central Plains
and Upper Midwest. Most of the snow there has blown, but areas of
shallow blowing/drifting snow expected to continue until winds
subside late this afternoon and early evening.

Temperatures may be held back a couple degrees due to the fresh
nature of snow cover, but downslope should still help us reach the
mid 30s to near 40 over most of the plains.

&&

.SHORT TERM...(Today and tonight)
Issued at 312 AM MST Mon Jan 22 2018

Strong winter storm will continue to move northeast today and
exit the region this morning. Radar and web cameras are showing
light snow and blowing snow over far eastern Colorado at this
time. Didn`t see any blizzard conditions late this evening, so let
the Blizzard Warning expire and issued a Winter Weather Advisory
through 5am for the snow and blowing snow. Snow is expected to end
by 12Z. Conditions are slowing improving and expect to let the
advisory expire at 5am. Gusty northwest winds will continue to
produce areas of blowing snow into the morning hours.

Northwest flow aloft will keep temperatures cool today with highs
in the 30s to lower 40s over northeast Colorado. Light snow will
be possible over the mountains this morning before drier air moves
in. A weak wave embedded in the flow aloft will increase mid
level moisture tonight. This is expected to produce snow showers
in the mountains. Meanwhile, the lower elevations will remain dry.
Northwest facing slopes may see up to 3 inches of snow overnight.

.LONG TERM...(Tuesday through Sunday)
Issued at 312 AM MST Mon Jan 22 2018

A weak shortwave trough moved along by 45-60 kt nwly mid-level
flow is still forecast to pass over north central and northeast
Colorado Tuesday morning. Models show the bulk of the Q-G ascent
and instability with this system...albeit weak...passing to our
north Tuesday morning. And, yet many of the models continue to
generate light QPF...about a tenth of an inch or so...over the
northern mtn ranges by midday. Appears orographics and CAA will be
the primary producers of snow with this system, and the snowfall
that manages to form will probably be scattered over the higher
terrain where an inch or so of snow is possible. Elsewhere,
downslope flow off the Front Range mtns will keep the plains dry
on Tuesday, although cannot rule out a stray snow shower or two
across the far northeast corner of the state before noon on
Tuesday as the trough passes overhead. Otherwise a cool day
Tuesday with temperatures running 2-5 deg F below average.

On Wednesday warm-up begins as heights rise with an upper level
building to our west. A low-level southwesterly downslope flow
will also add to warming on the plains. Could see max temps jump
at least 10 deg F from the day before, and with the upper ridge
passing on Thursday, could see another 4-7 degs added to that.
May also become a bit more breezy in the mtns and along the
Palmer Divide. Nothing terribly strong, but mtn tops could see
southwest winds approaching 45 mph by the afternoon.

All this warming and wind will precede our next storm system to
swing down across the region on Friday. It now does not look as
impressive in the models as it did yesterday. Models show this
system remaining an open wave with the bulk of its energy and
moisture passing over Wyoming. Could see some snow and gusty winds
in the high country, and perhaps a shower or two moving off the
Front Range and out over the plains. Once the trough axis passes
by late on Friday, could see several hours of gusty Bora-type
winds in and near the Front Range foothills Friday night. Except
for a few lingering snow showers in the high country Saturday, the
weekend looks dry with below average temps to start and near
average temps on Sunday.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 933 AM MST Mon Jan 22 2018

VFR conditions will prevail through tonight. Mid and high clouds
will increase again tonight with passage of a weak system. There
is a chance ceilings fall as low as 8000 feet 06Z-12Z. A west to
northwest wind component at KDEN and KAPA should hold through mid
to late afternoon, with a chance winds turn more north or even
northeasterly 22Z-01Z before returning to normal south/southwest
tonight. KBJC will see occasional gusty west winds to around 30
knots til about 23Z.

&&

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

$$

UPDATE...Barjenbruch
SHORT TERM...Meier
LONG TERM...Baker
AVIATION...Barjenbruch

Forecast Discussion from: NOAA-NWS Script developed by: El Dorado Weather