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Area forecast discussion 
National Weather Service Denver/Boulder Colorado
955 am MST Sat Feb 28 2015

issued at 941 am MST Sat Feb 28 2015

Stubborn fog lingering over parts of Denver so will add patchy
coverage in the zones through early afternoon. Also adjusted the
probability of precipitation and potential snow amounts downward slightly through through
this afternoon. Spatial cross-sections keep a dry middle layer 650-750
mb...through 00z which may limit snow potential somewhat this


Short term...(today through tonight )
issued at 429 am MST Sat Feb 28 2015

Will see cloud cover increasing from the south through the early
morning hours as high level moisture increases. As cloudiness
increases...temperatures will stay cold through the day. The
cloudiness will be associated with the deformation zone downstream
from a developing upper trough over California and Nevada. At the
same time the upper level jet will be arcing across Colorado
helping to lift the middle-level moisture presently over northern
Arizona and northern New Mexico. The heaviest snowfall from this
system is expected to be over the southwest part of the
state...but light snow will extend over the northern mountains and
eventually across the northeast Colorado plains tonight. Mountain
areas could see 2 to 5 inches of snow today and another 2 to 4
inches tonight...mainly over zone 34. No period of intense snow is will not issue any highlights at this time.

The plains could see up to a couple inches of snow through the
evening and overnight...but it is difficult to tell how far north
any snow on the plains will extend. Another cold day and cold
night will result as the Arctic airmass remains well entrenched
over northeast Colorado.

Long term...(sunday through friday)
issued at 429 am MST Sat Feb 28 2015

West-southwest flow aloft will continue over the area sun through Sun night as an
upper level low remains over Southern California. Cross-sections show
varying amounts of moisture in the mountains with only some minor middle level
ascent with fairly unstable lapse rates. Will see periods of light
snow however at this point accumulations should stay below advisory
criteria in most areas. At lower elevations there will be weak
upslope flow over northestern Colorado with quite a bit of low level moisture.
With weak middle level ascent there will be a chance of light snow mainly in
and near the foothills. As for highs will keep readings in the lower
to middle 20s over northestern Colorado. For Sun night the low level flow will become
more southerly with still some weak ascent over the plains so will mention a
chance of light snow mainly from Akron south towards Limon.

On Monday the upper level low over Southern California will begin to move
east-northeast with increasing southwesterly flow aloft over the area. Cross-sections
show increasing moisture in the mountains with favorable lapse rates
along with some middle level ascent so should see periods of snow in
areas favored by southwesterly flow. Over northestern Colorado a surface low will develop with
gusty southerly winds over the plains. With some middle level ascent and
decent lapse rates could see a few -shsn as well. As for highs
should see warmer temperatures over northestern Colorado with readings in the 35 to 40
degree range.

By Monday night the remnants of the upper level low will move east-northeast
across the area as surface low pressure remains somewhere over eastern Colorado. Last
night this low was more over southeastern Colorado while tonight its forecast over
northestern Colorado. Meanwhile a strong cold front is now 6-12 hours slower than what
was shown previously. With rather strong middle level qg ascent and steep
lapse rates forecast over northern Colorado Monday night...if the surface low ends up
over southeastern Colorado and the cold front moves south faster than currently shown
then could end up with a decent snow event Monday night into early
Tuesday from the mountains across the northern foothills and adjacent plains.
Right now the heaviest precipitation is forecast to be in the northern mountains and over
Wyoming however it would not be a total surprise if its ends up being
further south.

On Tuesday the initial disturbance will move quickly east of the area in
the morning as a secondary upper level trough moves across the region
Tuesday afternoon through Tuesday night from the northwest. Meanwhile much colder air will
move across northestern Colorado Tuesday morning with favorable upslope flow through
Tuesday evening. Cross-sections show abundant moisture with middle level
ascent as well so should see a good chance of snow through the day into
Tuesday night. In the mountains orographics will become more favorable so
should see periods of snow as well. As for highs readings over
northestern Colorado will peak in the morning as then steadily fall through the
day with readings in the teens by afternoon.

By Wednesday the upper level trough will gradually move southeast of the area by
afternoon as cold surface high pressure resides over the area. Cross-sections
still show quite a bit of moisture through midday with weak upslope flow
thus may see a chance of light snow mainly along and near the foothills
and in the mountains latest 850-700 mb temperatures would keep highs in the
lower to middle teens over the plains.

For Thursday and Friday dry northwesterly flow aloft will be over the region. Temperatures
should begin to moderate with highs in the 30s on Thursday with 40s by
Friday over northestern Colorado.


Aviation...(for the tafs through 18z Sunday morning)
issued at 941 am MST Sat Feb 28 2015

Occasional MVFR visibility restriction associated with stubborn fog may linger
into early this afternoon at kden and kbjc. This afternoon...the wind will
switch from west-northwesterly to northeasterly and some light snow late in the day as
moisture in middle levels starts to increase from the south and west.
Areas of snow will increase in coverage...bringing MVFR conditions
down to occasional IFR tonight. Snow accumulations could be one or two
inches...highest at kbjc and kapa.


Bou watches/warnings/advisories...


short term...dankers
long term...rpk

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