Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Current Version | Previous Version | Text Only | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33

FXUS65 KBOU 241234

Area Forecast Discussion
National Weather Service Denver/Boulder CO
634 AM MDT Fri Mar 24 2017

Issued at 630 AM MDT Fri Mar 24 2017

Snow ending fairly quickly on the western part of the cwa this
morning so have canceled the Winter Weather Advisory for zone 34
and 39. Also downgraded the winter storm warning for zone 36 to a
Winter Weather Advisory. main concern will be extreme southern
Jefferson and western Douglas counties. Will leave the rest of the
highlights as is.


.SHORT TERM...(Today and tonight)
Issued at 311 AM MDT Fri Mar 24 2017

Changes occurring quickly this morning as the system wraps up over
southeastern CO. Highlights for the Palmer Divide appear to be
panning out with moderate to heavy snowfall observed at Monument.
Further north especially from around Boulder northward,
temperatures have not been cold enough for snow with low level
downslope off the Cheyenne Ridge. Will let the Winter Weather
Advisory for zone 39 to continue but this will be primarily for
southern Jefferson County. Marginal snow amounts for the Winter
Storm Warning in zone 36, but still a good chance of moderate to
heavy snowfall south of Evergreen toward northeast Park and
Douglas Counties so will let that highlight continue there as
well. Strong winds will continue today, strongest east of
Interstate 25 and south of Interstate 70. Should see a gradual
decrease in pcpn developing from northwest to southeast after 15z
this morning as this upper low moves eastward. Increasing qg
descent and subsidence tonight as a ridge of high pressure moves
into the region from the west.

.LONG TERM...(Saturday through Thursday)
Issued at 311 AM MDT Fri Mar 24 2017

An upper level ridge will build over the area on Sat in advance of
an upper level trough that will move across the area late Sat night
into Sun. Sat will be mainly dry except for a chc of showers in
the mtns by late aftn. Temperatures will be warmer on Sat across
the plains with readings in the upper 50s to mid 60s.

For Sat night into Sun the next upper level trough will move across
the area.  QG fields show some mid lvl ascent Sat night into Sun
morning with cross-sections having increasing moisture.  In addition
a cool fnt will move across the plains by Sun morning as well.
Overall should see a good chc of snow in the mtns Sat night into
Sun morning with a chc of rain showers across the plains as temps
will not be cold enough for snow. Highs on Sun will be in the 50s
over nern CO.

For Sun night into Mon an upper level ridge rebuilds over CO in
advance of another upper level trough which moves into the Great
Basin.  Moisture will increase in the mtns by aftn with some minor
mid lvl ascent so will keep in a chc of showers over the higher
terrain. Over nern CO it will be dry with highs in the upper 50s
to lower 60s.

For Tue both the ECMWF and GFS show an upper level low developing nr
the four corners which is fcst to move into ncntrl NM by Tue night.
Run to Run consistency has been awful the last few nights with this
system so have rather low confidence in current solutions from
either model.  Both models dvlp a sfc low over nrn NM on Tue and
then show a cool fnt moving across nern CO by late aftn or evening.
This leads to an increase in upslope flow flow along with abundant
moisture.  Naturally if this were to happen then there would be a
good chc of pcpn especially in the foothills and across the plains
Tue night.

On Wed the upper level low is fcst to move ese into wrn TX.  The
ECMWF keeps the low more over the TX pnhdl while the GFS is
further south. As a result th ECMWF keeps some pcpn across the
plains into Wed morning while the GFS shifts the pcpn into sern
CO. At this point really hard to say where this low will be so
will keep in 20% to 30% pops across the plains.

By Thu a flat upper level ridge will move into the area as another
upper level trough dvlps over the wrn US.  The GFS has this trough
over the Great Basin while the ECMWF is further west.  Both models
show some moisture affecting the mtns so will keep in low pops over
the higher terrain.  Over nern CO it will be dry with highs in the
lower to mid 60s.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 311 AM MDT Fri Mar 24 2017

Strong northerly winds will continue through the day but the
stronger gusts should decrease after 18z. MVFR/IFR cigs will
persist until around 15z at KDEN and KAPA with light snow and blow
snow around, at KBJC improvement should start sooner with drier
air moving in from the north. VFR conditions expected after 18z
with ILS restrictions diminishing by 20z. No aviation impacts


Winter Weather Advisory until noon MDT today for COZ036-040-049.

Blizzard Warning until noon MDT today for COZ041-045-046.

High Wind Warning until 6 PM MDT this evening for COZ047.



AVIATION...Cooper is the U.S. government's official web portal to all federal, state and local government web resources and services.