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

120
FXUS65 KBOU 290202
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
802 PM MDT THU JUL 28 2016

.UPDATE...
Issued at 751 PM MDT Thu Jul 28 2016

Best storms have been over Lincoln county early this evening.
However with unstable airmass over the front range and nw flow
aloft will have to be on the lookout for nocturnal storm
development in the next few hours. Still can`t rule out a few svr
storms along the front range and across the palmer divide through
midnight.

&&

.SHORT TERM...(This evening through Friday)
Issued at 328 PM MDT Thu Jul 28 2016

Temperatures have been slow to warm today due to clouds and north
to northeast winds behind a front/outflow boundary. Eventually the
cap is expected to be broken as winds turn more easterly,
temperatures warm in the 80 and a short wave trough moves over
western Nebraska.

Northwest mid level winds around 40 knots above northeast to east
low level winds of 20 north will produce good shear. This combined
with CAPE in the 1000 to 2500 J/kg range will likely produce a few
super cells. Latest HRRR model runs show most of the storms
occurring after 00z. This makes sense due to the slow warming.
Once storms moves off to the east and dissipate, low clouds are
expected to form after midnight.

On Friday...low clouds will slow heating during the morning hours.
Highs will be on the cool side with readings in the lower to mid
80s across northeast Colorado. These cooler temperatures may make
it difficult to break the cap. Will have the highest pops over the
higher terrain where the chances of breaking the cap will be
better. Surface based CAPE climbs to 1000 to 2000 J/kg over the
plains, so any storms that are able to move off the higher terrain
could become severe.

.LONG TERM...(Friday night through Thursday)
Issued at 328 PM MDT Thu Jul 28 2016

Upper level high pressure will be centered over extreme southern
Nevada Friday night with a northwest flow aloft over Colorado.
The NAM...GFS and ECMWF all show an upper level disturbance caught
up in the flow moving across Colorado. Models show quite a bit
more QPF than previous runs. Therefore...have raised pops in the
grids. Soundings show enough moisture...instability and shear for
some stronger storms with hail...gusty winds and heavy rain over
portions of the foothills...Palmer Divide and eastern plains.
Storms should decrease after midnight...but could linger across
far eastern sections of the CWA through the early morning hours.

The upper high begins to shift westward over the Rocky Mountain
Region over the weekend. This should result in warmer and drier
weather across much of north central and northeastern Colorado.
There may be enough moisture combined with daytime heating to
produce a few high based afternoon and evening showers and storms
over higher elevations. GFS and NAM soundings suggest the
potential for a few strong to severe storms across the far
northeast corner of Colorado Saturday.

Next week the upper high is forecasted to move into the southern
plains states...which should allow some monsoonal moisture to
pump into colorado from the south. This pattern should allow for
an increase in shower and storm coverage with a gradual cooling
trend towards the middle of next week. The best chance for
meaningful precipitation should be over the high country. Across
the plains...PW`s above an inch combined with limited instability
may result in more clouds than precipitation across the
plains...with surface boundaries needed for more significant
precipitation.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 751 PM MDT Thu Jul 28 2016

Winds will remain ene however they may transition to more ese by
midnight. There is still some potential for storm through
midnight. Latest data keeps winds sely overnight with denver
Cyclone developing west of DIA. if that occurs stratus may stay to
the west and north late tonight thru Friday morning.

&&

.BOU Watches/Warnings/Advisories...
None.
&&

$$

UPDATE...RPK
SHORT TERM...Meier
LONG TERM...Kalina
AVIATION...RPK



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