Area Forecast Discussion
Issued by NWS Pueblo, CO

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FXUS65 KPUB 251753

Area Forecast Discussion
National Weather Service Pueblo CO
1153 AM MDT Tue Jul 25 2017

.SHORT TERM...(Today and tonight)
Issued at 409 AM MDT Tue Jul 25 2017

...Increased Storm Activity Today...

Satellite and radar show a monsoon disturbance tracking across
western Colorado early this morning, with fairly widespread showers
along and west of the Continental Divide for this time of night.  No
thunder recently but could be an isolated strike or two around at
times.  A batch of showers associated with this disturbance is
currently working across the Poncha Pass area at the Junction of the
Sawatch Range to the north and the adjoining Sangre De Cristo Range
to the south.  A little bit of shower activity clipping the Hayden
Pass area but nothing too heavy.

The disturbance will round the ridge over Colorado and move east
across the area this afternoon.  It will bring a burst of increased
westerly flow with it as it moves across.  This will give storms
more of west to east movement this afternoon than previous days,
allowing activity to work off the mountains and across the plains.
It will also increase the severe potential some as shear values go
up.  SPC currently has a portion of the far eastern plains outlooked
for a marginal risk of severe weather.  This looks good for now.
Today`s storms will again carry risks of flash flooding on burn
scars, strong gusty winds and lightning.  In addition, a few storms
out across the plains could carry some 1 inch hail and winds up to
60 mph as they gain strength moving east into better moisture late
in the day.

.LONG TERM...(Wednesday through Monday)
Issued at 409 AM MDT Tue Jul 25 2017

...Locally heavy rainfall and the potential for Flash Flooding
Wednesday and Thursday over and near the higher terrain...

A more active period, especially over and near the higher terrain,
remains on tap for the Wednesday and Thursday timeframe, with weak
westerly flow aloft expected across the area as upper high remains
south and west of the state. Models continue to indicate a minor
disturbance moving across the northern fringe of the high across the
Northern Rockies, which sends a re-enforcing front across the
eastern plains through the day Wednesday, with moist low level
upslope flow persisting across the eastern plains Wednesday night
and Thursday. Latest model data also indicate monsoonal moisture
plume to be across the area with PWATS running between 1 and 1.5
inches (150 to 200 percent of normal). With the moisture in place,
should see widespread showers and storms developing over the higher
terrain in the late mornings and afternoon`s, with storms spreading
east across the adjacent plains through the late afternoon`s and
evenings. Some model differences on how far east storms will spread
and how long convection will persist through the late evenings and
overnight hours, and have kept the highest pops over and near the
higher terrain. With the abundant moisture in place and expected
weak flow aloft, the main storm threats will be locally heavy
rainfall and the potential for flash flooding, especially across
urban areas and area burn scars. WPC also has areas over and near
the higher terrain in a marginal to slight risk for excessive
rainfall both Wednesday and Thursday. With the expected increase
in convection and abundant moisture in place, temperatures will be
at and below seasonal levels Wednesday and Thursday.

Friday-Monday...There looks to be a slow warming and drying trend
for the end of the work week through early next week, as some drier
air moves into the region within weak north to northwest flow aloft,
as the upper high retrogrades into the Desert Southwest and Great
Basin. There, however, will be enough moisture to support at least
scattered afternoon and evening storms through the weekend, with the
best coverage over the higher terrain. Temperatures look to warm
back to at and slightly above seasonal levels through the period.


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1151 AM MDT Tue Jul 25 2017

Primarily VFR conditions are expected at KCOS, KPUB, and KALS over
the next 24 hours. Showers and thunderstorms will develop across the
mountains during the early afternoon and expand east into the plains
this afternoon into the early evening. Brief periods of MVFR
conditions will be possible at any of the three TAF sites should
moderate to heavy rainfall move into the vicinity. AT KPUB and KCOS,
winds will shift to northerly and gust to 20 to 25 mph during the
early evening for a few hours.




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