FXUS65 KPUB 261734

Area Forecast Discussion
National Weather Service Pueblo CO
1134 AM MDT Tue Mar 26 2019

.SHORT TERM...(Today and tonight)
Issued at 400 AM MDT Tue Mar 26 2019

Currently there are low clouds and fog over the eastern plains
stretching from Baca County all the way to El Paso County. KCOS
airport has observed, at times, visibilities of 1/4 of a mile. The
fog and low clouds will last through the mid morning hours, but will
quickly dissipate as the atmosphere mechanically mixes out. Some
afternoon mountain top thunderstorms are possible this afternoon
over the southern Sangre de Cristo Mountains, but the most likely
outcome will be thunderstorms remaining over northern New Mexico.
Some gusty west to southwesterly winds will develop over the I-25
corridor and San Luis Valley (SLV), which will also aid in lowering
the dew point temperatures, due to downslope effects off of the
Rocky Mountains. The arid air and gusty winds will create near
critical fire conditions over the I-25 corridor, especially over Las
Animas County, but there isn`t a Red Flag Warning due to criteria
not being met for a full three hours.

The forecast high temperatures this afternoon have been bumped up
compared to guidance due to how dry the air is. One stronger gust
recorded over the region will rapidly warm the air. Over the plains,
70s are expected, with the potential for an isolated 80F possible
around the La Junta region. The SLV will be in the 60s, the upper
Arkansas River Valley will span the 50s and 60s, and the mountains
will span the 30s and 40s, depending on elevation.

Overnight low temperatures over the plains will be well above normal
for this time of year due to added moisture in the air and winds
continuously mixing the atmosphere. The plains will be in the 40s,
the SLV will be in the upper 20s to low 30s, the upper Arkansas
River Valley will be in the 30s, and the mountains will be in the
20s.  No precipitation or fog is expected over the region during the
overnight hours.

.LONG TERM...(Wednesday through Monday)
Issued at 400 AM MDT Tue Mar 26 2019

...Spotty critical to near critical fire weather conditions through
mid week...

Warm and dry conditions will continue through Wednesday as the upper
ridge flattens and shifts eastward allowing flow aloft to transition
to southwesterly.  Lee side surface low will cause breezy west winds
across the higher terrain to spread down into the adjacent lower
elevations of the I-25 corridor where fuels are deemed critical. For
Wednesday getting spotty areas of critical fire weather conditions
in Huerfano county...though the duration and coverage look too
limited to warrant fire weather watches at this point.

A weak wave translates through southwest flow aloft which helps push
the lee side surface low eastward Wednesday night.  This in
combination with mid/high cloudiness should keep overnight lows on
the mild side.  Cold front backdoors into eastern Colorado on
Thursday though there doesn`t appear to be that significant of a
cool down with it...at least initially.  Critical fire weather
conditions could end up being a little more widespread Thursday
afternoon, particularly for the San Luis Valley and southern I-25
corridor of Huerfano and western Las Animas counties.

Low clouds will develop across the southeast plains Thursday night
as the cold front works westward into the I-25 corridor. Meanwhile,
broad upper trof moving through the western U.S. and across the
Central Rockies will spread snow into the mountains, and rain showers
across the plains by Friday in area of overrunning atop cold dome.
GFS suggests extreme southern I-25 corridor could see another round
of critical fire weather conditions Friday afternoon, though suspect
that cold air will be tougher to mix out than GFS suggests.

Upper jet lays along or just south across southern Colorado into the
weekend bringing colder temperatures and periods of mountain snows
and lower elevation rain/snow showers.  Too soon yet to judge
impact, with GFS suggesting a much wetter solution than ECMWF.  But
both are consistent with a cooler and unsettled solution through mid
day Sunday with some snow accumulations for the mountains.

The weather dries out into early next week though long range models
suggest another upper trof will bring more unsettled weather to
southern CO before mid week.  -KT


.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1131 AM MDT Tue Mar 26 2019

VFR and dry conditions are expected at the three TAF sites (KALS,
KCOS, KPUB) over the next 24 hours. Winds will follow typical
diurnal patterns, and generally remain less than 15 knots.





NWS PUB Office Area Forecast Discussion