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

000
FXUS65 KBOU 271541
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
941 AM MDT Tue Sep 27 2016

.UPDATE...
Issued at 940 AM MDT Tue Sep 27 2016

Forecast grids required only minor adjustments this morning...
namely to accelerate warming on the plains by a degree or two and
to hang onto the swly breezes on the plains for an hour or two
longer this morning. Otherwise clear/mostly clear skies are in
order today with strong subsidence and drying aloft associated
with the overlying ridge.

&&

.SHORT TERM...(Today and tonight)
Issued at 327 AM MDT Tue Sep 27 2016

An upper ridge from northern California down through Texas is
between two upper lows, one over the Great Lakes region and one over
Baja. This ridge will bring warm and dry conditions under clear
skies. Warm advection at mid levels will bring above average
temperatures, with readings in the low to mid 80s over the plains
and in the upper 50s to mid 70s for the high country. Very weak
surface pressure gradients will keep windspeeds light.

Even though clear skies are expected overnight, warmer daytime
temperatures will produce slightly warmer overnight temperatures
compared to this mornings readings. Lowered some of the
forecasted low temperatures for the urban corridor. There was
thought that there would be slight downsloping, however modeled
surface pressures have backed off on this pattern.

.LONG TERM...(Wednesday through Monday)
Issued at 327 AM MDT Tue Sep 27 2016

Blocking pattern is expected to gradually break down Wednesday,
with the upper level ridge axis shifting slowly east across the
forecast area. This will bring another dry and mild autumn day
with sunny skies.

By Thursday and Friday, the flow aloft is expected to shift more
southwesterly as the ridge continues to migrate ever so slowly
eastward. However, overall the high amplitude pattern and upper
low settling into the Ohio River valley means we`ll likely see
only little eastward progression of the pattern. As a result,
the main push of mid and upper level subtropical moisture should
remain just to our west. Remnants of Tropical Storm Roslyn will
also get caught up in the flow but again most of this stays to
just to our west. Will continue to keep the best chance of showers
and a few thunderstorms in the mountains with only a slight chance
of a storm or two drifting northeast onto the nearby adjacent
plains by late Friday or Saturday. Temperatures will remain
several degrees above normal with the mild southwest flow aloft in
place.

There will be a deeper upper level trough working into the western
U.S. for Sunday into early next week. This would bring breezy
conditions and cooler weather toward Monday or Tuesday, while the
chance of showers would stay mainly in the high country with
stronger westerly flow aloft developing.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 940 AM MDT Tue Sep 27 2016

Denver area terminal forecasts appear to be in good shape at this
time. Light s-swly sfc flow in the metro area will gradually turn
clockwise and come out of a n-nely direction by early in the
afternoon. Speeds at that time not much more than those at this
hour. Should see this clockwise turning continuing through the
afternoon with a light s-sely wind component by 23z/Tue-01z/Wed...
where they should remain overnight at speeds generally under 10
kts under a clear sky.

&&

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

$$

UPDATE...Baker
SHORT TERM...Kriederman
LONG TERM...Barjenbruch
AVIATION...Baker



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