Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 180043
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
643 PM MDT Fri Mar 17 2017

.UPDATE...
Issued at 543 PM MDT Fri Mar 17 2017

Current satellite imagery showing mid and high level moisture
moving over upper ridge into NE Colorado. As the ridge builds
eastward 700 mb temps increase that will help to bring overnight
lows into the mid to upper 40s and temperatures for the weekend
into the lower 80s. Made some adjustments to sky and wind and
dewpoint grids for Sunday to coordinate with increased fire
weather concerns. Otherwise forecast is on track.

&&

.SHORT TERM...(This evening through Saturday)
Issued at 207 PM MDT Fri Mar 17 2017

A strong upper level ridge centered over the Great Basin will
shift east over Colorado Saturday. This will keep dry air across
the Central Rockies. Expect mostly clear skies tonight and
Saturday as drier air moves over the area. It will be warmer under
the ridge Saturday with highs climbing into the upper 70s and
lower 80s. The record high for Denver on Saturday is 82 and could
be broken or tied. A lee side surface trough will form over
eastern Colorado. This is expected to bring westerly winds to the
Front Range and southerly winds to the eastern plains. Wind speeds
are expected to be on the light side, less than 20 mph, so no Red
Flag Warnings are anticipated.

.LONG TERM...(Saturday night through Friday)
Issued at 207 PM MDT Fri Mar 17 2017

A dry zonal flow aloft will be over the region Saturday night.
The NAM12 spatial cross-sections show a weak mountain wave
developing in the foothills by 09z Sunday, with some gusts in the
40-50 mph range around 12z Sunday. For Sunday, another chance to
tie or break the record high of 81 for Denver. The upper ridge
will flatten a bit and shift more to the east on Sunday with an
increasing west/southwesterly flow aloft. Stronger winds coupled
with the record high temperatures will heighten the fire danger
across the region some concern there as well. Sunday night into
Monday, the flow aloft will remain zonal, weak mid level qg ascent
to the north and west of Colorado with surface high moving into
the great plains. There may some some light showers developing in
the mountains north of I-70 by 00z Tuesday. Maybe some isold pops
for the plains as well Monday night, but mainly along the northern
border. Tuesday night into Wednesday, the models keep much of the
moisture and energy to the west and north of the state, with a
ridge aloft over the cwa. The ridge moves to the east on Wednesday
with an increasing southwesterly flow ahead of the next Pacific
trough. The GFS has the system over the Great Basin by 00Z Thu
then moves it across CO late Wednesday night through Thursday
night. Good qg ascent over the region on Thursday for the entire
cwa. The ECMWF however is weaker and further north with this
system, while the Canadian mdl still keeps the trough over the
Great Basin. Timing wise, will keep the best pops across the
forecast area for Thursday/Thursday night. Cooler as well, but
primarily rain for the plains Thursday aftn, mixing with or
changing to snow Thursday night. The trend of Friday will be for
drier conditions a slightly warmer temperatures.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 543 PM MDT Fri Mar 17 2017

VFR conditions will persist through Saturday. Stronger easterly
winds with gusts up to 20 knots will continue through about 02Z,
and then should begin to weaken and turn more southeasterly and
eventually southerly through 06Z. However, a Denver cyclone is
developing so that may create variable winds for a few hours this
evening until cyclone washes out and more normal drainage winds
set in overnight. On Saturday, expect a diurnal southeasterly to
develop and remain in place most of the day. A chance that
west/northwest of 10-15 knots may eventually mix onto the plains
after 21Z.

&&

.FIRE WEATHER...
Issued at 543 PM MDT Fri Mar 17 2017

A Fire Weather Watch was issued for Sunday afternoon for areas in
the Northern foothills and plains counties bordering WY and KS
then south to I-70. Elevated fire conditions will exist by late
morning hours on Sunday and continue into the evening. RH values
will drop into the lower to mid teens over most of the area with
wind gusts up to 35 mph to the north and 25 to 30 mph south. This
conditions combined with continue to support rapid fire growth.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Sunday afternoon through Sunday evening
for COZ215-238>240-242>245-248>251.

&&

$$

UPDATE...Bowen
SHORT TERM...Meier
LONG TERM...Cooper
AVIATION...Barjenbruch
FIRE WEATHER...Bowen



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