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fxus65 kpub 222043 

Area forecast discussion
National Weather Service Pueblo Colorado
243 PM MDT Thu Aug 22 2019

Short term...(this evening through friday)
issued at 243 PM MDT Thu Aug 22 2019


At 2 PM, showers and thunderstorms were noted over the higher
terrain and were moving onto the plains. Storm Prediction Center mesoanalysis across the
region showed ml cape values ranged from about 500 down near ktad to
2000 over Kiowa County. Shear was also weakest down near ktad and
strongest (35 knts) over Kiowa. Given this shear/cape combo,
supercell composite values were registering in the 2 to 5 range
across the southeast plains.

Temps were well into the 80s across the plains with 70s in the
valleys. Dewpoints were around 50 along the I-25 corridor and around
60 out east. 20s and 30s were noted in the mtns.

Rest of today into tonight...

Given the cape/shear values, cant rule out a strong storm or two
across the Palmer Divide and far eastern plains the rest of this
afternoon and early evening. Overall best chance of storms per high
res guidance will be over El Paso and Kiowa counties with storm
coverage less over the rest of the plains.

Based off hi res guidance, storms will move generally east through
the evening hours although any stronger convection will move
southeast. Storms should be over with by midnight. Later tonight
some low clouds will be possible over the far NE sections of the
eastern plains, otherwise mostly clear skies are likely.

Long term...(friday night through thursday)
issued at 243 PM MDT Thu Aug 22 2019

Friday night:

A trough passage Friday night will keep thunderstorms, some strong
to severe, lingering into the later evening hours over Kiowa County.
To the south, upslope flow over the Raton Mesa will have sparked
thunderstorms, so counties like eastern Las Animas, Baca, bent, and
Prowers, may see some lingering thunderstorms as well. Cape values
over the far eastern plains around 600 - 1,500 j/kg, with the Kiowa
County around 1,500 and Baca closer to 700 j/kg. 0-6 km bulk shear
values will be around 30 to 40 kts, so if convection can reach the
eastern plains, some strong to severe storms are possible. The main
hazards will be quarter size hail and wind gusts up to 60 mph.


Saturday will be a relatively calm, albeit, hot day. The 500hpa
heights will rise after the trough passage and model derived skew-
T/log p diagrams show an inversion from the 800hpa-700hpa layer.
Without a strong lifting mechanism around (since The Heights are
rising), the cin aloft over the eastern plains shouldn't be broken.

The upper level flow will be from the northwest on Saturday, which
will warm the temperatures to around 5f to 10f above average for
this time of year. So expect temperatures in the upper 90s over the
plains, the mid 80s over the mountain valleys, and the 60s to 70s
for the mountains.


A jet streak with magnitudes around 40 to 50 kts (the stonger values
will be located over Wyoming and montana) will propagate over
northern Colorado on Sunday afternoon and depending on how far south
it travels, there could be some critical fire weather conditions
over the lower elevations mainly over El Paso, Pueblo, Fremont,
Chaffee counties. The GFS and European model (ecmwf) resolve a more southerly track
for the jet streak, meaning that the surface winds will be strong
enough for critical fire weather conditions, whereas the NAM has a
more northerly track, limiting the surface wind speeds. There is
higher confidence that the jet streak will make it over southern
Colorado, so critical fire conditions are expected. No matter what,
though, the air will be very dry with precipitable water values ranging from 0.3
to 0.5 inches, so at a minimum, near critical fire weather
conditions are expected.

Since the atmosphere will be so dry (less moisture means lower
specific heat values, therefore the air can warm up more quickly)
and the upper level flow orientation will be efficient for
downsloped air (compressional heating), near record high
temperatures are expected over the lower elevations. Expect upper
90s to low 100s over the plains, mid to upper 80s over the mountains
valleys, and mid 60s to low 70s over the mountains.


A broad trough will be over Manitoba, Canada, which will produce a
cold front that will propagate over Colorado. The GFS resolves a dry
outcome and the European model (ecmwf) resolves isolated thunderstorms over the
mountains. Theoretically, the gfs' outcome is the more believable
one. Precipitable water values over the mountains will be around 0.1 to 0.3
inches, which makes it difficult to produce any thunderstorms.
Mountain top cloud cover is expected, though. Otherwise, about a 10f
cool off is expected across the plains, with high temperatures in
the low 90s. The mountain valleys and mountains, on the other hand,
will remain unaffected by the cold front since the Front Range is
blocking the intrusion of cooler air, so expect similar temperatures
to Sunday.

Tuesday through thursday:

The upper level ridge returns to The Four Corners region beginning
on Tuesday afternoon, but it will take some time for the Pacific
based moisture to reach southern Colorado again. Expect dry and warm
conditions through Wednesday, with Thursday having the best chance
at afternoon thunderstorms over the mountains.


Aviation...(for the 00z tafs through 00z Friday evening)
issued at 243 PM MDT Thu Aug 22 2019

VFR is expected during the next 24 hours at all 3 taf sites, kpub,
kals and kcos. An isolated storm cant be ruled out of either of the
taf sites this afternoon/early evening. For tomorrow afternoon it
should be dry at kals through the day with an isolated storm
possible during the mid afternoon at kpub and kcos.


Pub watches/warnings/advisories...


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