Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 170448
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
948 PM MST Thu Feb 16 2017

.UPDATE...
Issued at 945 PM MST Thu Feb 16 2017

A tranquil upper ridge weather pattern now in place over
northeast Colorado. Skies are clear and winds are generally
light. After a day of record breaking temperatures, readings
at this hour on the plains are still hovering in the 40s, which
is around the normal high temperature for this time of year. No
changes to tonight`s forecast planned at this time.

&&

.SHORT TERM...(This evening through Friday)
Issued at 311 PM MST Thu Feb 16 2017

An anomalously strong thermal ridge aloft over Colorado has resulted
in a 2nd day of record breaking temperatures this afternoon. 700
mb temps are around +7 degC this afternoon across along and east
of the I-25 corridor. It`s been so warm over the last 7 days
overall that for the first time since last Fall, dual-pol radar
returns are indicating the presence of insects in the boundary
layer. Needless to say we will have mostly clear skies and dry
area-wide through Friday.

Tonight will be another good radiational cooling night along the
South Platte and other lower valleys east of the mountains. A
pressure gradient sets up between the surface high in Western
Colorado and the lee trough east of the Rockies, resulting in an
increase in downslope winds in the foothills tonight which will
again keep minimum temperatures quite warm in an near the
Foothills. Low temps in the mountains will be similar to last
nights.

On Friday the ridge responsible for this mid-spring like weather
will move east and bring an end to the record breaking warmth. 700
mb temps cool 5-6 degC and a weak cool front will move across the
Plains of Eastern Colorado. At this time is looks like the front
will enter Colorado mid-morning and reach the Denver metro area
around 9AM. Winds will pick up out of the north 15-20 mph far
eastern Plains, and east-northeast 6-12 mph across the I-25 urban
corridor, while a surface ridge will build from the north. The
weak front and departure of the thermal ridge aloft means high
temps should be about 10 degrees cooler area wide on Friday
compared to Thursday. Southwest flow aloft resulting from a
strong/deep trough off the coast of CA will start to advect
Pacific moisture into the mountains Friday evening, but it is not
looking good for precipitation chances.

.LONG TERM...(Friday night through Thursday)
Issued at 311 PM MST Thu Feb 16 2017

Still looking at a mild week ahead for northeast Colorado as upper
ridging remains over the region most of the time. Early in the
forecast period, the upper low diving into southern California and
northwest Mexico will throw an upper ridge over the southern
plains and mild southerly winds aloft over Colorado. This will
keep the warm and dry airmass in place over northeast Colorado
through Sunday. By late Sunday, mid-level moisture will begin
increasing from the south as the upper low tracks towards Texas. A
weak and diffluent upper air pattern will be over Colorado which
may produce some light precipitation over the mountains. Snow
levels will be quite high, maybe above 10,000 feet Saturday
evening. Some cooling will occur Sunday allowing snow levels to
come down to about 7000 feet through Monday morning.

Another ridge will build over the southwestern U.S. Monday night
through Wednesday with a return of dry and warm weather to the
region through the middle of the week. The next chance for
precipitation will be next Thursday when the ECMWF carves a trough
out over the western U.S. with the first wave of energy rotating
over Colorado. This may lead to a shift in the flow pattern across
the U.S. which brings some more active weather back to Colorado.
Time will tell. Until then, a chance of rain and snow Sunday night
and Monday morning with warm and dry conditions before and after
that.

&&

.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 945 PM MST Thu Feb 16 2017

VFR conditions likely at Denver metro area airports for the next
12 hours. Winds at KDEN and KAPA will be south-southwesterly at
7-13 kts overnight...and west-southwesterly at 8-16 kts at KBJC
near the foothills.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

UPDATE...Baker
SHORT TERM...Schlatter
LONG TERM...Dankers
AVIATION...Baker



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