Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 230929

Area Forecast Discussion
National Weather Service Denver/Boulder CO
329 AM MDT SAT JUL 23 2016

.SHORT TERM...(Today and tonight)
Issued at 234 AM MDT Sat Jul 23 2016

A ridge of high pressure aloft will be oriented west to east
across the southwest US today and tonight...while an upper trough
moves from montana to minnesota in the next 24 hours. A surface
trough will move into the high plains today...with a surface high
building into northeast colorado tonight.

today will be hot with temperatures in the mid to upper 90s across
northeast colorado. There is some moisture trapped in the ridge of
high pressure...this will lead to scattered thunderstorms
developing over the high country this afternoon...and spreading
east along the cheyenne ridge and palmer divide late this
afternoon. The northeast plains may be too capped for
thunderstorms today.

all in all the only change to previous forecast was to increase
pops eastward late this afternoon along the palmer divide and
cheyenne ridge.

.LONG TERM...(Sunday through Friday)
Issued at 234 AM MDT Sat Jul 23 2016

The upper level high will remain over the srn Rockies on Sun with
wly flow aloft across the area which shifts subtropical moisture
southward.  Thus tstm activity over the higher terrain will probably
be more isold to wdly sct.  Over nern CO ely low lvl flow will be in
place behind a cool fnt.  There is still a big difference as to
placement of best instability by aftn.  The GFS continues to show
the best cape fm the srn Foothills across the Palmer Divide while
the NAM...ECMWF and Hi Res models have higher cape values covering
much of nern CO except for the far nern corner.  Meanwhile gridded
data shows slight cooling aloft along with an increase in the mid
lvl flow.  Thus there would be some potential for svr storms fm late
aftn into the early evening hours due to favorable shear. The
only thing that could inhibit tstm development would be cap
however expect convection would still develop over the srn
Foothills and move east across the Palmer Divide. Thus will keep
the highest pops in these areas. As for highs readings should be
mainly in the 85 to 90 degree range over the plains.

On Mon the upper level high will expand back into the area with
weaker flow aloft.  May see some increase in subtropical moisture
across the higher terrain which may lead to an increase in tstm
activity.  Over nern CO the low level flow will become more sly
however deeper low lvl moisture will continue over the plains but
may mix out closer to the foothills.  Outflow boundaries fm higher
terrain convecton will lead to development of wdly sct tstms across
the plains by mid to late aftn into the evening hours.  As for highs
with some warming in the 850-700 mb lyr readings will rise back
into the lower to mid 90s over nern CO.

By Tue the ECMWF and GFS show a disturbance moving across in wk flow
aloft.  The ECMWF has this feature moving into nern CO by 18z while
the GFS is roughly 6 hours slower.  If this feature is real then
could see a better chc of showers/tstms on Tue.  As for highs
will keep readings in the lower to mid 90s across the plains
although it could end being a few degrees cooler if showers/tstms
dvlp by midday as ECMWF shows.

For Wed into Thu the upper level high will begin to shift westward
and eventually be centered over the Great Basin.  This will allow
the flow aloft to become more wnw and shift subtropical moisture to
the south.  Thus tstm chances over the higher terrain will decrease.
Across nern CO tstm activity will be more isold on Wed as well with
highs in the 90s.  For Thu a cool fnt may move into nern CO during
the aftn bringing an increase in low lvl moisture along with a
better chc of storms across the plains.

On Fri the upper level high will remain over the Great Basin with
wnw flow aloft remaining over the area.  Once again the best chc of
storms will be over the plains where deeper low level moisture and
decent instability will be in place.  Over the higher terrain
activity will be more isold.  850-700 mb temps are fcst to drop fm 3
to 4 degrees c which would keep highs in the 80s over nern CO.


.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
Issued at 234 AM MDT Sat Jul 23 2016

vfr conditions can be expected today and tonight. late this
afternoon and this evening isolated to scattered thunderstorms may
impact the arrival gats south and northwest of DIA...the airport
can expect isolated thunderstorms early this evening. The
thunderstorms today may contain gusty outflow winds and locally
heavy rain.


.BOU Watches/Warnings/Advisories...


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