Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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FXUS65 KBOU 250245
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
845 PM MDT Fri May 24 2019

.UPDATE...
Issued at 845 PM MDT Fri May 24 2019

Isolated snow shower coverage over the mountains is coming to an
end with the loss of daytime heating. Skies over northeast
Colorado have become mostly clear except for an area of altcumulus
over the Denver area. Low level moisture is beginning to move in
from western Kansas, as evidenced by satellite imagery. This
moisture is forecast by the HRRR to remain east of the Denver
metro area. Although dew points are surging into the mid and upper
40s over Lincoln County, the HRRR and other models drop the dew
points back into the 30s overnight, which will keep fog and
stratus from developing. There must be enough veritcal mixing of
the westerly flow aloft allowing the airmass to absorb the influx
of moisture. Current forecast package captured all of the current
trends, so will not be making any changes to the forecast at this
time.

&&

.SHORT TERM...(This evening through Saturday)
Issued at 200 PM MDT Fri May 24 2019

An upper level trough can be seen on water vapor moving NNE out of
central Utah. Some height falls and lift associated with the upper
jet will bring isolated to scattered convection over the higher
terrain by the afternoon, mainly over the northern mountains where
better moisture exists. With the subsident side of the jet lifting
to the NE, winds have decreased over the higher terrain, however
some gusting up to 55 mph will still be possible into the early
evening hours over the higher passes. At lower elevations,
moderate westerly flow has helped to dry out the eastern plains
with mostly sunny skies and warming temperatures back closer to
seasonal normals. Some mid level clouds will move in by the
evening as the upper disturbance moves over, which will help to
keep overnight temperatures warming than the past few days.

For Saturday, Colorado will continue to be in southwesterly flow
aloft as another trough over the West coast moves inland. Dry mid
level flow will push in keeping skies mostly sunny through most of
the day. Surface flow will mainly be from the SSE that will help
to usher in some weak moisture through the day. By the late
afternoon there is a slight chance of some isolated convection
over the central mountains, but most of the higher chances of
convection lie further South and East. Temperatures will continue
to rebound with highs on the plains expected to be in the mid
70s.

.LONG TERM...(Saturday night through Friday)
Issued at 200 PM MDT Fri May 24 2019

For Saturday night and Sunday, the next storm system will be
dropping southward across California with a strong southwest flow
aloft over Colorado. At the surface, increasing southeast winds
will bring in a moist low level flow Saturday night which will
increase low clouds and possible fog across portions of northeast
plains of Colorado. Low confidence on how far west the low
clouds/fog make but for now will keep the clouds/fog north and
east of the Denver area.

From late Sunday afternoon through Sunday night, the upper low
begins to move eastward into Nevada Utah with continued strong
southwest flow aloft over Colorado. With strong southerly flow,
temperatures will approach 80 degrees on the plains as 700mb
temperatures rise to around +10c. Could see a potential dry line
set up over the far northeast plains with a potential for severe
storms with over 2000k/kg of available CAPE and sufficient shear
profile for super cells. Best chances would be east and north of a
line from from Anton to Sterling. SPC also has most of far
eastern Colorado under a slight chance for severe storms for
Sunday afternoon/evening.

On Monday, the Great Basin upper low will be lifting northeast
across northwest Colorado and into Wyoming and Nebraska Monday
evening with moderate QG upward forcing over our northern mountains.
 The European solution is further south and slower with the track
of the low (more across central Colorado) which would give much
of the northern portions of our CWA better chances of showers and
a few thunderstorms. 700mb temperatures drop to around 0C so
certainly more snowfall can be expected over the mountains and
higher foothills above 7500 feet or so.

Tuesday will remain unsettled with continue cool conditions and lingering
showers, especially over northeast Colorado if the European track
verifies.  There will be continued weak troughiness across much
of the west through the week, so there will still be some moisture
and limited instability over Colorado for mainly isolated late
day showers and storms. Temperatures will climb back towards
seasonal normals by late next week.

&&

.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 845 PM MDT Fri May 24 2019

No aviation impacts expected overnight as skies become mostly
clear and winds gradually return to typical drainage patterns.
tomorrow morning will also see mostly clear skies along with
southeasterly winds. During the afternoon there may be a slight
chance of thunderstorm activity developing. Coverage of showers
should be very spotty, so will leave the mention of showers out of
the TAF products until there is a stronger indication that enough
moisture will be present to support better shower coverage.

&&

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

$$

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


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