Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 291551
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
951 AM MDT Mon May 29 2017

.UPDATE...
Issued at 927 AM MDT Mon May 29 2017

Ongoing forecast looks good with only some minor trend changes.
Should have a better chance for showers and storms today due to
higher moisture levels and slightly warmer temperatures.
Precipitable water values are up about 2 tenths from yesterday
readings along with a slight increase in surface dewpoints.
Surface based CAPES forecast ranging from 400-900j/kg for this
afternoon over the plains so mainly rain/gusty winds and maybe
some small hail. Jet streak over northern high plains embedded in
the northwest flow aloft will also aid shower development today.

&&

.SHORT TERM...(Today and tonight)
Issued at 444 AM MDT Mon May 29 2017

Ribbon of lift on the right rear part of a jet streak will drift
across northeastern Colorado today. This will keep clouds around,
and help develop showers and thunderstorms this afternoon. There
is also some weak surface convergence under the same area, what is
left of yesterday`s better defined cold front which is very subtle
now. There will be a little more low level moisture today, which
will generate a bit more instability. Afternoon CAPEs are expected
to be 400-800 j/kg over the plains, so there will likely be a bit
more intensity today, but still a pretty low risk of anything more
than brief heavy rain and gusts to around 40 mph. Reasonable
agreement in starting convection near the Wyoming border in the
early afternoon and moving it south and east by late afternoon, so
prime time for the Denver area should be 3 PM - 7 PM. Less
moisture and instability over the mountains, so like yesterday
there may not be any more activity there than over the plains.

Warming/drying aloft will move in as the jet streak pulls eastward
this evening. Light downslope winds should prevent any fog and
keep temperatures the same or a little warmer than this morning.

.LONG TERM...(Tuesday through Sunday)
Issued at 444 AM MDT Mon May 29 2017

Weak northwesterly flow aloft is over the CWA on Tuesday, then an
upper ridge moves into Colorado Tuesday night into Thursday.
There is benign synoptic scale energy in place Tuesday through
Wednesday night. Normal diurnal low level wind patterns are likely
through Wednesday night. For moisture, precipitable water values
are in the the 0.5 to 0.75 inch range for the plains and foothills
all four periods. Dew point readings are in the 40s to lower 50s
F range all for periods for those areas. There is some CAPE mainly
in the mountains and foothills late day Tuesday. There is higher
CAPE progged late day Wednesday and it covers all the CWA. The
lapse rate fields show a fairly strong mid level cap over the
plains late day Tuesday, but not on Wednesday. The QPF fields have
some measurable precipitation mainly over the mountains with more
over the southern half late day Tuesday. There is tiny bit over
the southern plains in the evening. Wednesday`s amounts are
similar to Tuesday, but there is some over all the plains. Nothing
significant either day. For pops, will go with "chance"s in the
mountains late day Tuesday and late day Wednesday. Will go with
0-30%s over the plains bot h late day periods. For temperatures,
Tuesday`s highs are 1-3 C warmer than today`s. Wednesday`s highs
are 1-4 C warmer than Tuesday`s. For the later days, Thursday
through Sunday, there is upper ridging for the CWA on Thursday. On
Friday, a dieing weak upper trough moves across Colorado. There
is more upper ridging on Saturday, then southwesterly flow aloft
on Sunday. There may be enough moisture for limited pops mainly in
the mountains. Temperatures get a bit above seasonal normals all
four days.

&&

.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
Issued at 927 AM MDT Mon May 29 2017

Expect scattered showers/thunderstorms today over all terminals
with best chances between 20z-01z. Mainly brief rain and gusty
winds to 30kt with the storms with ILS conditions with the
showers. Light easterly winds will develop before noon before
returning back to drainage winds by this evening.

&&

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

$$

UPDATE...Entrekin
SHORT TERM...Gimmestad
LONG TERM...RJK
AVIATION...Entrekin


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