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 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

FXUS65 KBOU 182146

Area Forecast Discussion
National Weather Service Denver/Boulder CO
346 PM MDT Fri Aug 18 2017

.SHORT TERM...(This evening through Saturday)
Issued at 344 PM MDT Fri Aug 18 2017

Very little going on right now. There is limited convective
cloudiness over the mountains, foothills and Palmer ridge. Perhaps
25% coverage of flat Cumulus. There are no cells on the area
radars over the CWA at present. Models have an upper ridge
flattening with weak zonal flow aloft tonight and Saturday. There
is benign synoptic scale energy progged both periods. Normal
diurnal wind patterns are expected tonight and Saturday.
Precipitable water values are in the 0.50 to 0.80 inch range
tonight and Saturday. There is minor CAPE over the southern and
eastern CWA this evening. By Saturday afternoon there is minor
CAPE mainly over the mountains, with slightly higher values over
the eastern border. The QPF fields have a tad of measurable
precipitation over the southern and far eastern CWA Saturday
afternoon. Will go dry tonight and 0-20%s pops Saturday
afternoon. For temperatures, Saturday`s highs will be 0-3 C warmer
than today`s highs.

.LONG TERM...(Saturday night through Friday)
Issued at 314 PM MDT Fri Aug 18 2017

Forecast area under zonal flow aloft Sat night and Sun with lowering
PW values with downsloping flow off the Front Range and Cheyenne
Ridge. T-storm chances remain low on Sun, with convection mainly
confined to the high terrain during the afternoon, with a bit more t-
storm activity across southwest sections of the CWA during the
evening hours with the arrival of moisture up from the Desert
Southwest. Temperatures on Sun slightly above average with low/mid
90s on the plains.

Monday`s big focus is on the solar eclipse. Right now most models
are indicating clear/mostly clear skies across the CWA to start the
day...then a gradual increase in mid and high clouds through the
afternoon. With a continued increase in moisture over the high
country, should see a bit more t-storm coverage up there with gusty
outflow winds. The NAM indicates the most cloud coverage while the
ECMWF the least, the GFS down the middle. Otherwise, Mon temps
should be similar to those on Sun.

Mon night, models show a cold front pushing south across the area
with weak post-frontal upslope flow along the Front Range by
morning. Will see cooler temps and a chance of t-storms over the
Front Range and South Park during the afternoon and evening hours.
Precip amounts on the light side. Otherwise, should be drier Mon on
the nern plains with an increasingly drier northwest flow aloft with
an upper ridge building over the Four Corners region.

Tue through Fri...models show the upper ridge out west slowly
shifting over Colorado. Ridge appears to contain a decent amount of
subtropical moisture carried north by a south-southwesterly low
to mid-level flow. Should see an increase in t-storm activity
during this period, starting in the high country on Wed. Thu looks
pretty wet across the CWA. And, with the increase in cloud
coverage, daytime temps during this period will run near to
slightly below average.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 344 PM MDT Fri Aug 18 2017

East-northeasterly winds did come to DIA as models predicted.
winds will likely become southeasterly late afternoon into mid
evening, then normal drainage patterns should kick in by 05Z.
There will be no ceiling issues.




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