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 201547

Area Forecast Discussion
National Weather Service Denver/Boulder CO
947 AM MDT WED JUL 20 2016

Issued at 931 AM MDT Wed Jul 20 2016

No significant changes today. With a warm moist and marginally
unstable atmosphere in place along with southwest monsoonal
flow...we will have another round of thunderstorms beginning over
the higher terrain around midday...spreading along the palmer
divide and cheyenne ridge mid afternoon...and the northeast plains
early this evening. Precipitable water values are a bit under an
inch...slightly lower than yesterday.  With steering winds from
the southwest at 15 to 20 mph storms should move...but we cannot
rule out some localized heavy rain.

.SHORT TERM...(Today and tonight)
Issued at 350 AM MDT Wed Jul 20 2016

Little change in the overall weather picture through tonight.
Broad high pressure aloft remains over Oklahoma and Texas
Panhandle with a resultant Southwest aloft over Colorado. Water
vapor imagery showing deeper moisture continuing to steer into
Colorado from Arizona and New Mexico. Integrated PW from GPS
continue to show values over an inch over much of Colorado and
this not likely to change through tonight. Hard to pick out any
significant synoptic features in the flow but appears there is
one over the 4 corners and another over Southern Arizona which
will rotate through our area through tonight.

Like yesterday, main threat with storms will be heavy rain, gusty
outflow winds and flash flooding potential. Severe threat is low
with mid level flow around 15-20kt and surface based CAPES ranging
from 500-1100j/kg. Storm motions today only around 10kt or less
so any storms that sit around for long could cause flash flooding.
Hard to find a focus area today but mountains and foothills should
at least see likely coverage of storms. Temperatures today about
the same as Tuesday with readings well into the 90s over the

.LONG TERM...(Thursday through Tuesday)
Issued at 301 AM MDT Wed Jul 20 2016

The upper ridge over the Great Plains will begin retrograding
back west on Thursday. This will begin to decrease the amount of
monsoonal moisture that is fed into the state. With the dome of
warm air aloft....CAPE values will be less than over the last few
days. A weak northerly push in the morning will help focus what
moisture there is over the southern foothills and mountains
initially, but then models are showing a piece of energy to move
over the area later in the day. This may interact with a boundary
from the front and convection will spread east over the plains.
Over the far northeastern corner, ingredients may come together
for a few stronger storms that evening. Temperatures will
increase a degree or two Thursday.

On Friday, a shortwave trough will push into the Pacific Northwest
and across the Northern Rockies to flatten the ridge slightly. A
deepening surface trough and southwest flow aloft will bring even
warmer temperatures, about 5 to 10 degrees above average for the
date. Expect another day of diurnal convection with CAPES
relatively low.

A cool front is expected to push south into the area Saturday
morning, bringing cooler temperatures but will actually bring
relatively drier conditions as it pushes the moist airmass over
the plains to the south. This front will likely stabilize the
plains keeping afternoon storms over the high terrain, but there
will still be a slight chance for these storms to push east over
the plains during the evening. Sundays temperatures may drop
another degree or two as high surface pressure over the Great
Plains keeps upslope flow over the forecast area and an upper
trough passes overhead to increase the rain and storm coverage.

Weak upper trough will continue to be over the area Monday and
Tuesday for afternoon and evening thunderstorms and slowly warming temperatures.


.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 350 AM MDT Wed Jul 20 2016

Expect another round of storms to impact terminals and approaches
late this afternoon and early evening. looks like storms will not
move off the higher terrain until late expect best
chance of storms will be between 23z and 04z. Severe weather is
not expected...but expect locally heavy rain...strong chaotic
winds and local IFR conditions near thunderstorms.


.BOU Watches/Warnings/Advisories...


SHORT TERM...Entrekin
LONG TERM...Kriederman
AVIATION...Entrekin is the U.S. government's official web portal to all federal, state and local government web resources and services.