Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 261631
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1031 AM MDT TUE JUL 26 2016

.UPDATE...
Issued at 1031 AM MDT Tue Jul 26 2016

Looking at the latest observations and model runs, appears the
best chance for thunderstorms today will be over the higher
terrain and along and east of a surface trough over the eastern
plains. The timing of thunderstorms is expected to be earlier with
most of the activity occurring this afternoon. The first cell of
the day already formed just southwest of Evergreen. East of the
boundary CAPE will be 1000 to 2000 J/kg. Even though shear is not
that great, could see a brief severe storm or two with large hail
and strong winds. West of the boundary, westerly flow will help
dry the airmass and is expected to limit convection. Will adjust
pops to fit the above mentioned scenario.

&&

.SHORT TERM...(Today and tonight)
Issued at 409 AM MDT Tue Jul 26 2016

An upper level ridge with warm temperatures and weak winds aloft
will be over the state through today, bringing another hot day to
the plains and a chance of thunderstorms during the afternoon. At
the surface, a low pressure area over Wyoming will keep a moist
southerly flow across the northeast Colorado plains. Temperatures
at 700 mb are expected to be around +15C, which may keep the
airmass over the plains capped and stable. However, the NAM model
shows the right entrance region of a weak upper level jet over
northeast Colorado this afternoon and evening. The low level
instability axis is forecast to be in place along the eastern
Colorado border through the afternoon, making it prudent to
mention up to scattered pops on the plains through the late
afternoon and evening. Gusty winds, brief heavy rain and some hail
will be the main threats from storms. With the weak flow pattern
aloft, some storms may be slow-moving which will increase the
threat of locally heavy rain.

In the mountains, daytime heating over the elevated terrain will
be enough to de-stabilize the airmass by midday with scattered
thunderstorms developing. Storms will have a propensity to move
eastward as they develop. Temperatures across the forecast area
should be around where they were yesterday afternoon.

.LONG TERM...(Wednesday through Monday)
Issued at 409 AM MDT Tue Jul 26 2016

The upper level ridge will move over the SE Great Basin on
Wednesday bringing increased NW flow over the region through the
remainder of the week. This will move the brunt of the monsoonal
moisture to the south lowering chances of afternoon convection
across the CWA. Shortwaves embedded in the NW flow aloft will help
push cold fronts into NE Colorado on a few separate occasions.
This added moisture will help to fuel afternoon convection on the
eastern plains. Some frontal boundaries could make it into the
foothills and help spread storms westward but overall coverage
over the higher terrain will be limited. The instability will
increase closer to the KS and NE borders as moisture spread is
better. Temperatures will hover between the upper 80s to lower 90s
through the week ahead with the warmest days projected to be over
the weekend.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1031 AM MDT Tue Jul 26 2016

There will be a slight chance for thunderstorms at the Denver
airports through 02z. Gusty outflow winds to 40 knots and brief
heavy rain will be the main threats from the storms. Outflow winds
from the thunderstorms may produce a wind shift or two through
02z. Other than gusty outflow winds from thunderstorms, winds will
be on the light side.

&&

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

$$

UPDATE...Meier
SHORT TERM...Dankers
LONG TERM...Bowen
AVIATION...Meier



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