Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

fxus65 kbou 182200 
afdbou

Area forecast discussion
National Weather Service Denver/Boulder Colorado
300 PM MST Mon Nov 18 2019

Short term...(this evening through tuesday)
issued at 300 PM MST Mon Nov 18 2019

Northwest winds continue across most of the area and pushed across
most of the city of Denver this afternoon, though there's still a
bit of a Longmont anticyclone circulation with light east/southeast
winds from Fort Collins to areas just east and southeast of
Denver. We still expect these lighter winds to push back towards
the mountains a bit, but it's looking like the west winds will
continue over the western part of the city. There's not much
temperature difference anyway. All of this will gradually diminish
this evening with a return to typical drainage winds in the
valleys and some enhancement to west/southwest winds over the
mountains/foothills and plains ridges. With better mixing today
and still some wind overnight, we raised tonight's lows a little
in most places and did the same for highs Tuesday as we will start
warmer and be a bit better mixed even with less wind tomorrow.
High clouds overnight with a little warm advection, then we're on
the warm side of the jet and should have less cloud cover on
Tuesday.

Long term...(tuesday night through monday)
issued at 300 PM MST Mon Nov 18 2019

Tuesday night, the southwesterly flow aloft will increase as the
ridge axis shifts to the east of Colorado. A weak upper level
disturbance will be over baja, with the main closed upper low over
central California. Mid and upper level moisture move into western and
southern Colorado on Wednesday, as the weak upper level disturbance
moves into southern Colorado. A cold front will push into northeast Colorado
by midday Wednesday, with the upslope increasing up to 750 mb late
Wednesday afternoon and Wednesday night. Weak dynamics associated
with the disturbance aloft will amount to just light snow in the
high country. Upslope in the Post frontal airmass will usher in
much cooler temperatures with light snow especially in and near
the Front Range foothills and Palmer Divide Wednesday night. No
significant changes to the ongoing forecast at this time. Thursday
and Thursday night, the main closed low will make its way slowly
eastward. It will be near the four corner region by Thursday
afternoon, then over east central Colorado by midday Friday. This will
result in continued cold and unsettled weather. The overall
dynamics however will remain weak in the high country with
generally weak orographics so still anticipate a 3-day period of
light snowfall. As for the northeast plains, continued cool with a
chance for light snow at least into Thursday night or early Friday,
but limited accumulation there as well. By the weekend, a dry
northwesterly flow aloft will be over the forecast area. The flow
aloft will transition more of a west/northwesterly component for
Sunday into Monday and remain dry through Sunday night. The next
trough is forecast to drop out of the Pacific northwest and into
Colorado Monday into Monday night, bringing cooler temperatures
and a chance of snow to the mountains as well as the northeast
plains.

&&

Aviation...(for the 00z tafs through 00z Tuesday evening)
issued at 300 PM MST Mon Nov 18 2019

VFR through Tuesday. Some uncertainty about wind direction at
kden/kapa the rest of the afternoon as there is a wind shift line
oscillating near these terminals. There should be a northerly
component at both airports during this time. Winds should shift to
southerly sometime between 00z and 03z. At kbjc, winds will likely
remain west with 20-25 knot gusts until 00z, then decrease to
around 10 knots by 02z.

&&

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

$$

National Weather Service Glossary of Abbreviations