Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 261553

Area Forecast Discussion
National Weather Service Denver/Boulder CO
953 AM MDT Sun Mar 26 2017

Issued at 950 AM MDT Sun Mar 26 2017

Some increase in showers across the front range urban corridor as
winds turn more northeasterly upslope. Surface and upper low is
currently over southeastern Colorado. The main precip band in our
forecast area continues to stretch from Logan County southwest
into Elbert and Lincoln counties. A thunderstorm was observed just
south of Limon a couple hours ago, shouldn`t see any more the
rest of this morning. Satellite imagery already showing the
mountains and northern foothills becoming convective. With drying
expected to push further east off the mountains through the day,
conditions should allow for a slight chance of thunderstorms later
this afternoon with some solar heating. Have updated forecast
with this slight chance, mainly over the southern half of the
forecast area.


.SHORT TERM...(Today and tonight)
Issued at 402 AM MDT Sun Mar 26 2017

Main upper level low early this morning is south of Pueblo nr the CO-
NM border based on GOES16 imagery.  This low is fcst to move into
far sern CO by midday and then into cntrl KS by early this evening.
There will be some wk mid lvl ascent over the plains thru 18z, and
as a cdfnt moves across this morning a band of pcpn will dvlp.  Hi
res data has been consistent so far in showing this pcpn band mainly
along and east of a line from Castle Rock to Denver to Fort Morgan.
Further west little pcpn is shown along and west of I-25 from Denver
north to the WY border.  In the mtns cross-sections show drier air
moving in by late morning with weak orographics so any additional
snowfall will be on the light side with mainly sct -shsn this aftn.

By late aftn there will be some lingering showers over the far ern
plains.  Along the front range urban corridor soundings show minor
cape with some potential for convective showers in the 21z-00z time
period.  As for highs will keep readings in the 50s over the plains.

For tonight shower activity will end by early evening however cloud
cover will linger through much of the night.

.LONG TERM...(Monday through Saturday)
Issued at 402 AM MDT Sun Mar 26 2017

An active springtime storm track has established itself over
Colorado and is projected to remain in place over the region
during the upcoming week and possibly well into next weekend.
Global forecast models show a series of progressive mid-
tropospheric waves crossing the eastern Pacific and eventually
propagating eastward over the central and southern Rocky Mountain
region starting with the weather system today. The next in this
series of moisture bearing large scale pertabations moved along
by a strong Pacific Jet is progged to dig over the Desert
Southwest on Monday and later track across southern Colorado/
northern New Mexico as a deep closed low Tuesday night into
Wednesday. That one is forecast to exit the region Wednesday night
allowing a shortwave upper ridge to bring dry and warmer weather
to the CWA on Thursday before the next Pacific storm system makes
its way out of the Great Basin and across the 4-corners area
Friday night. From there...models diverge as some show the center
of this storm system tracking across Colorado as a deep closed
low Saturday night into Sunday. While others show this potent
storm containing ample moisture taking a more southerly path
across southern New Mexico/west Texas. Even if the upper low takes
this more southerly track, models still indicate a period of moist
upslope flow and measurable precip over the forecast area late in
the weekend.

All-in-all, north central and northeast Colorado should see periods
of light to moderate precip...mainly snow in the high country and
rain at lower elevations with each passing system, a goodly
amount of cloud cover with periods of moist easterly/upslope flow.
Temperatures this week are forecast to stay near to slightly
above average even with each passing storm system. That said,
snow levels will fluctuate anywhere from 9000-9500 ft ASL during
the afternoon hours on Monday, Thursday and Friday to around 6500
ft ASL during the nighttime hours Tuesday, Wednesday, Saturday
and Sunday. Confidence in the forecast out through Friday is
moderate-high as the models have shown run-to-run consistency past
few days. Beyond that, confidence in the forecast drops to low-


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 950 AM MDT Sun Mar 26 2017

Winds continue to become NNE with an increase in shower coverage,
and should continue through 18z. Ceilings and visiblities may
drop down to MVFR under the showers during this period. Hi res
data continues to show some instability by late aftn so will
likely see another chc of showers between 21z and 00z, with a
slight chance of VCTS, for now will keep out of TAF until a better
confidence on location and timing. Will keep ceilings mainly
around 5000 ft after 21z.

For tonight, ceilings may linger around 5000 ft through the
evening hours but should rise above 10000 ft around midnight.
Winds should be light NE in the evening but should switch to
drainage by 06z.




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