Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 271004

Area Forecast Discussion
National Weather Service Denver/Boulder CO
404 AM MDT WED JUL 27 2016

.SHORT TERM...(Today and tonight)
Issued at 331 AM MDT Wed Jul 27 2016

An upper level ridge of high pressure will be centered
over the Great Basin....with a northwesterly flow aloft over
northern Colorado.  In the mid levels...the plume of subtropical
moisture is progged to get shifted more to the south and east with a
drier mid level flow expected.  At the surface however...a weak
frontal boundary will push into the northeast plains from the east
this morning and will settle along the Front Range/Palmer Divide
regions by this afternoon.  As a result...low level moisture will
increase as higher dewpoints advect into the cwa from the
east/southeast.  NAM12 boundary layer CAPES are progged to range
from 1500-3000 j/kg east of a line from new raymer to last chance by
00z this evening.  As a result...the strongest storms may develop
further east along the kansas/nebraska borders this evening.  Some
directional shear to work with and should be sufficient to produce a
couple of severe thunderstorms if the cap can get broken.  The front
will help infuse the low levels with more moisture by late this
afternoon with temperatures will be similar to yesterday.  Should
see isolated high based thunderstorms in the high country...with
better tstms coverage over the northeast plains.  Spatial cross
sections should sufficient boundary layer moisture around
overnight to support fog/stratus as will add at least
patchy coverage in the grids after 06z.

.LONG TERM...(Thursday through Tuesday)
Issued at 331 AM MDT Wed Jul 27 2016

The center of the upper ridge is forecast to remain just to our
west through the end of the week, keeping weak northwesterly flow
aloft across Colorado. The ridge axis is then expected to shift
eastward to the southern plains by early next week. In the
meantime, the pattern with warm days and afternoon showers will
continue. It appears that a significant upper disturbance will
pass over the state Thursday afternoon and combine with abundant
low level moisture over western Kansas to produce a significant
convective outbreak that gets its beginning over far northeast
Colorado. Have increased the pops over the northeast corner of the
state for the Thursday evening period. Cooler temperatures are
expected for Friday after a significant outflow push from Thursday
night`s convective outbreak moves over northeast Colorado. High
temperatures may only be in the mid to upper 80s across northeast
Colorado, and the stage may be set for another convective outbreak
Friday afternoon.

Over the weekend, as the upper ridge axis transitions to the
southern plains, temperatures across Colorado are expected to rise
again. A Monsoonal moisture plume may also develop early next week
which may begin producing more diurnal shower activity to the
western and central parts of the state. The general summer pattern
over northeast Colorado with afternoon thunderstorms is also
expected to continue. Will need to keep an eye out for heavy
rainfall from the afternoon and evening thunderstorms through the
entire forecast period. The threat of damaging hail will be
somewhat reduced due to the airmass being so warm, but severe
weather can not be ruled out entirely. Storm motions will be the
key to rainfall amounts that are produced.


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 331 AM MDT Wed Jul 27 2016

VFR conditions expected through 06z this evening...but MVFR
cig/vsby restrictions may develop as low level stratus and fog
develops. For now wl go with patchy coverage around the Denver
area. A weak front will push into the urban corridor fm the east
after 12z with nely sfc winds developing. Winds should become
east/sely by late in the aftn. Best chance of tstms late this aftn
and evening will be north and east of Denver but isolated storms
still possible after 23z...not enough confidence to included them
in the tafs at that time.


.BOU Watches/Warnings/Advisories...


LONG TERM...Dankers
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