Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 221020

Area Forecast Discussion
National Weather Service Denver/Boulder CO
420 AM MDT Thu Mar 22 2018

.SHORT TERM...(Today and tonight)
Issued at 420 AM MDT Thu Mar 22 2018

Warm temperatures are expected across northeast Colorado today as
an upper ridge moves over the state. Temperatures will be about 10
degrees warmer than yesterday, peaking in the lower to mid 70s. A
surface low pressure trough will be in place with light southerly
winds. The upper ridge contains a fair amount to high level
moisture, so sky conditions will be partly to mostly cloudy as
downsloping westerly winds at mid-levels provide the primary
warming mechanism. All in all a very nice early Spring day.

The unseasonably warm weather will extend into the mountains where
the lower elevations of western Grand County could see high
temperatures in the lower 60s, and other lower elevations of
Jackson, Summit and Park Counties could reach the upper 40s and
lower 50s. Even the mountain ridges and passes will see
temperatures in the upper 30s and lower 40s.

By evening, moisture levels will be on the increase over the
mountains as southwesterly flow aloft continues. As the airmass
reaches saturation this evening, precipitation is expected to
develop, and in today`s case, the warm temperatures will raise
the snow level to higher than 10,000 feet as the precipitation
begins. Snow levels will fall overnight as a short wave
disturbance embedded in the southwest flow moves over the
mountains. The Park and Gore ranges will eventually see the most
snow from this system, 4 to 8 inches overnight and through
tomorrow, so will issue Winter Weather Advisory for zone 31. Other
mountain areas will see less snow, probably in the 2 to 6 inch
range. The northeast Colorado plains are expected to remain dry as
the weather disturbance passes.

.LONG TERM...(Friday through Wednesday)
Issued at 420 AM MDT Thu Mar 22 2018

An upper level disturbance in SW flow aloft will move across the
area on Fri with a quick shot of mid lvl ascent.  Lapse rates will
be fairly unstable as well.  Cross-sections show favorable moisture
in the mtns thru midday with some decrease in the aftn.  Overall
some areas may receive advisory criteria especially in zn 31.
Across nern CO there will be enough instability for a chc of
showers and possibly a few tstms in the aftn.

By Fri night moisture will gradually decrease in the mtns so snow
chances should diminish.  Across nern CO there will be a slight chc
of showers in the early evening hours otherwise it will be dry.

On Sat drier air in SW flow aloft will be over the area with no pcpn
expected. Highs over nern CO will 10 to 15 degrees abv normal.
For Sun, moisture will begin to increase in the mtns as SW flow
aloft continues. With favorable instability will mention a chc of
showers for the aftn hours. Across nern CO it will reamin dry with
another day of abv normal temps.

By Mon an upper level trough will move into the Great Basin with
SSW flow aloft over the area. At the sfc, low pres will be over
sern CO as a cool fnt moves into nern CO with upslope low lvl
flow. Cross-sections show increasing moisture thru the day along
with favorable lapse rates. In addition the flow aloft will become
rather diffluent so expect there will be an increasing chc of
showers and possibly a few tstms by Mon aftn which will continue
into Mon Night. Thickness values would suggest rain would change
to snow at lower elevations Mon evening.

On Tue the upper level system is fcst to split as one piece of
energy moves into the nrn Rockies while the main energy moves
into the swrn US. This type of set up usually would lead to
decreasing pcpn chances across the area. By Wed, the main upper
level low will move across cntrl or srn New Mexico, and likely
will be too far south to produce any pcpn over the area except
possibly over far srn areas of the CWA.


.AVIATION...(For the 12Z TAFS through 12Z Friday morning)
Issued at 420 AM MDT Thu Mar 22 2018

No aviation impacts through the next 24 hours. Winds will be
generally light and out of the south to southeast. High clouds
will move over at times but ceilings should remain above 12,000


Issued at 420 AM MDT Thu Mar 22 2018

Gusty winds and low humidity will lead to elevated fire danger
over Lincoln Friday afternoon.


Winter Weather Advisory from 9 PM this evening to 6 PM MDT
Friday for COZ031.



SHORT TERM...Dankers
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