Area Forecast Discussion
Issued by NWS Pueblo, CO

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FXUS65 KPUB 191001

Area Forecast Discussion
National Weather Service Pueblo CO
401 AM MDT Wed Jun 19 2019

.SHORT TERM...(Today and tonight)
Issued at 353 AM MDT Wed Jun 19 2019


Analysis of water vapor satellite imagery and upper air data reveals
a weak shortwave trough moving into northern Colorado from the
northwest with dry northwest flow increasing behind it across the
northwest US and northern Rockies. Atmospheric moisture over
Colorado is already starting to decrease as the drier airmass begins
to establish itself per NESDIS Blended TPW imagery. Weak lift
associated with the wave is forcing the development of mid/upper
level clouds over much of the state, while high cloud cover
associated with an exiting MCS lingers over eastern Colorado. The
forecast area is dry, and winds are generally weak. Temperatures
across the plains span the 50s, while the high valleys are in the

Today and tonight...

The aforementioned shortwave will have pushed southeast through
Colorado and into the central US plains by around 18Z today.
Subsidence behind the trough and continued drying of the atmosphere
will lead to a mainly dry day across southern Colorado, in contrast
to recent days. Weak trailing energy and strong daytime leading may
allow for the development of very isolated showers and weak
thunderstorms over the high terrain this afternoon. Additionally,
cooling aloft and weak lift under the shortwave and convergence
associated with a lee surface trough may support the development of
a very isolated strong to severe storm over the far eastern plains
during the afternoon. However, latest CAM guidance produces very
little convection, and keeps the majority along just east of the
border. If a storm does manage to develop in our forecast area just
west of the border, it has the potential to produce a brief instance
of hail up to the size of quarters and wind gusts to around 60 mph
given MLCAPE of around 1000 j/kg and deep layer shear of only ~25

Otherwise, temperatures will be slightly warmer today, with highs
into the mid 80s across the plains, and upper 70s in Colorado
Springs and the high valleys. Winds will generally remain light
across the eastern plains, but will be breezy in the valleys and
gusty over the mountains. Skies will become partly cloudy to clear
for most locations.

.LONG TERM...(Thursday through Tuesday)
Issued at 353 AM MDT Wed Jun 19 2019

...Unsettled for the weekend...

Guidance indicates the end of the week will be quite warm, but
things will become unsettled for the weekend. How unsettled it will
become still needs to be determined as guidance is not in
agreement with a trough passage during the weekend time period.
Weather will be more seasonable into next week.

Thursday will be hot and mainly dry. The best chance of showers and
isolated storms will be over the Pikes Peak region, and any storms
are likely going to be high based with gusty winds. Over the
remainder of the region isold storms will occur in the mtns with
primarily dry wx over the plains. Max temps this day will be well
into the 90s across the most of the plains, with 80s over the
divides. Valleys will be in the 80s.


Trough to our west moves east with a sharp baroclinic zone pushing
into the state from the NW. This will drag a rather sharp sfc front
across the state. This front will affect the central mtns during the
afternoon and possibly the Palmer Divide by late in the day. The
remainder of the forecast area will remain rather warm and dry as
rather strong sw flow continues south of the baroclinic zone. Max
temps this day on the plains will vary from the 70s across the
Palmer Divide to the 90s over the far southeast plains. 70s and 80s
will occur in the valleys. Central mtns area will be quite cool with
50s and 60s in the Upper Ark Rvr Valley.

With the boundary moving into the northern tier of the fcst area,
showers and thunderstorms will be possible by afternoon and evening
over the central mtns and Pikes Peak region. One or two strong
storms will be possible Friday over the Palmer Divide.

For the weekend...

Confidence is high that a trough will move across the region during
this period; the question is how intense will the trough be? EC has
a fairly stout trough moving across, but this trough is open and
progressive. The GFS on the other hand actually has a closed 500 mb
circulation developing over Utah and then moving it across central
Colorado. The NAM is somewhere in-between. The GFS`s more closed
circulation is slower while the open trough of the Ec is quicker.

I am somewhat suspicious of the GFS solution as it looks rather
strong for this time of the year, but given the NAM is hinting at a
stronger trough I cannot rule it out. Given the above, believe
best chance of POPs over the region will be Saturday afternoon
with a good chance of pops over the S mtns/I-25 corridor region
during the afternoon. It will be cooler Saturday, but not as cool
as Sunday as Sundays max temps will likely fall into the 60s and
70s across the region, especially in the GFS verifies.

There is quite a bit of uncertainty in the sensible weather for this
weekend given the disagreement between the guidance, so expect some
changes in later forecasts.

Next week...

flow will become more zonal and weaker, and expect more typical late
June weather to occur over the region. /Hodanish


.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 353 AM MDT Wed Jun 19 2019

VFR and dry conditions are expected at the three TAF sites (KALS,
KCOS, KPUB) over the next 24 hours.


Flood Watch through Thursday afternoon for COZ065>068-070-071.



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