Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

Home | 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

FXUS65 KBOU 260931

Area Forecast Discussion
National Weather Service Denver/Boulder CO
331 AM MDT FRI AUG 26 2016

.SHORT TERM...(Today and tonight)
Issued at 330 AM MDT Fri Aug 26 2016

An upper level trough over northeast Utah will move east across
Colorado this morning. Lift ahead of the trough is producing
widespread clouds along with scattered to isolated showers. The
showers are expected to shift east across the state this morning.
So far, rain has been spotty and light. Given the cooler
temperatures expect light snow has fallen above 11000-12000 feet.

For the rest of this morning, forecast is unclear. General
consensus among the models is that scattered showers will drift
east early this morning. Then a band of rain will form over the
northeast corner of the state. Models vary on the amount of rain
that will fall under this band. The ECMWF shows around an inch of
rain over Washington county while the GFS has a few tenths. The
HRRR has a bullseye over Logan county with almost nothing over
Washington county. So far models, have over predicted rainfall.
Will have likely pops over the northeast corner with scattered
pops elsewhere.

Expect some partial clearing late this morning and early
afternoon along the Front Range. This should allow temperatures
to climb into the lower 70s. Airmass becomes slightly unstable
over the mountains and Front Range. Expect scattered to isolated
storms this afternoon, with the best chance being over the higher
terrain. The airmass dries tonight and expect precipitation to
end by mid evening if not sooner.

.LONG TERM...(Saturday through Thursday)
Issued at 330 AM MDT Fri Aug 26 2016

On Saturday a weak southwesterly flow aloft will be over Colorado.
The mdls show a weak trough over the desert southwest Saturday
aftn...this feature then shifts even further south on Sunday as an
upper level ridge builds into NV. As a result...the mdls shift the
plume of subtropical moisture more to the south and east over the
weekend...which will allow the airmass to become drier and warmer.
Will hold onto sct pops in the mountains on Saturday...then go
with isolated coverage on Sunday.

By early next week a ridge of high pressure will be over the
west. Some subtropical moisture will be around...but the best
chance of thunderstorms each aftn and evening will be over the
mountains of CO. The latest GFS/ECMWF maintains a weak
southwesterly flow over the state which could allow for a better
influx of moisture over cwa by the middle of next week. The ridge
at that time is progged to set up over the southeastern u.s. For
now will keep the pops each aftn/evng primarily in the mountains
...but could see pcpn coverage start to increase a bit by late
next week.


.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
Issued at 330 AM MDT Fri Aug 26 2016

An upper level trough will bring clouds and scattered showers
this morning. Low clouds will be possible with ceilings falling to
2000 to 4000 feet around 12z. There will also be a slight chance
for fog after 12z. Southerly winds will persist through around
13-14z, then shift to the northwest as a Denver cyclone shifts
east. Clouds will clear some and rise after 15z as the airmass
warms and dries. However ceilings of 4000 to 8000 are expected to
continue through early afternoon. Winds will shift to the
southeast after 18z. There will be a chance for a weak short lived
thunderstorm 21z to 01z.


.BOU Watches/Warnings/Advisories...


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