985
FXUS65 KPUB 091729
AFDPUB

Area Forecast Discussion
National Weather Service Pueblo CO
1129 AM MDT Thu May 9 2024

.KEY MESSAGES...

- A much cooler day is expected for our Thursday, with rain,
  snow, and lots of cloud cover.

- Winter Weather Advisories go into effect over most mountain locations
  above 8,500ft after Noon today, where around a foot of new
  snow is expected to fall by tomorrow evening.

- Scattered to numerous showers and thunderstorms will continue
  over the area (most numerous in the mountains) from Friday
  into Sunday, then a slow drying trend develops early next
  week.

- Snow levels climb toward 10,000 feet from Friday into the
  weekend, which will limit any additional snow accums to mainly
  the higher peaks.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 341 AM MDT Thu May 9 2024

Currently..

Satellite imagery shows the low and broad trough still meandering
southwesterly towards the Great Basin this morning, bringing
increasing cloud cover to Colorado. Observations also show that our
surface winds have begun to shift easterly on our plains. This wind
shift, along with increasing moisture across the area, will help to
deepen upslope and eventually lead to low ceilings and rain for our
mountain adjacent plains later this afternoon. Currently though,
temperatures are in the 30s and low 40s across our plains and
mountain valleys as of 3am.

Today and Tonight..

Models bring the low over eastern Utah by this afternoon and wrap it
up a bit more by that timeframe as well. Given that recent model
runs have trended towards a deeper and closed off low over the Great
Basin, along with a trend towards higher QPF amounts over our
mountains, went ahead with Winter Weather Advisories for all of our
mountain zones above 8,500ft where snowfall totals are expected to
be around a foot or so by tomorrow evening. For the most part, light
to moderate snowfall rates are expected, though quick heavier bursts
are possible this afternoon and this evening. Some zones that are in
the Winter Weather Advisory could see a very sharp cutoff from where
there are high snow totals, to where there is no snow at all and
everything falls as rain. This will be especially true for Teller
County and lower elevations included in the Wet Mountain zone.
Please use caution on area roadways, especially in areas where
conditions could change rapidly with elevation and through mountain
passes. For the I-25 corridor, expect upslope to develop by late
this morning, with steadier rain showers that could persist
throughout the afternoon and well into the overnight hours. All
precipitation below 8,500ft or so is expected to fall as rain.
Daytime highs today will be around 15 degrees below normal, with our
far eastern plains warming into the 60s, and mountain valleys and
the I-25 corridor remaining in the 40s and 50s. Rain chances over
lower elevations and snow over the mountains will continue into the
overnight hours, with continued cooler than normal temperatures
persisting into tomorrow morning as well.

&&

.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
Issued at 341 AM MDT Thu May 9 2024

Upper level low over NV Friday morning will very slowly drift
eastward through the central Rockies Fri/Sat, before emerging
into the High Plains during the day Sun. Isentropic upglide and
low/mid level upslope look best Friday morning as weak short
wave ejects eastward across the area, then a weakening of
upward motion develops Friday afternoon/evening as we briefly
lose the upslope component under temporary upper ridging behind
the departing wave. Upward motion then strengthens again Sat as
main upper low moves through and low level sly flow/associated
isentropic upglide redevelop. Above scenario would suggest
steadier precip Friday morning tapering to lighter/scattered
showers Friday afternoon/evening, before more widespread showers
and thunderstorms return on Saturday. Snow level slowly climb
toward 10000 feet during the day Friday, limiting accums to
mainly the higher peaks through the weekend. Sunday precip
chances still somewhat of a question, as model timing
differences regarding the speed of the departing low develop,
and at least a few solutions (09/00z GFS and NAM) are fast
enough with the trough to suggest the bulk of the heavier
precip will be east of the KS border by Sun afternoon. Forecast
pops follow the rather wet NBM at this point for Sun (though QPF
is light), but wouldn`t be too surprised if we end up needing
to reduce precip chances at least back toward the Continental
Divide by afternoon.

Enough moisture lingers for scattered convection Monday, though
precip amounts look light as forcing will be weak. Most models
then show a quick moving wave and cold front sometime Tue/Tue
night, with ECMWF/EPS family having higher precip
amounts/coverage than GFS/GEFS. Low confidence trend toward
drier weather after Tue, as model spread widens. Overall, stuck
close to the rather wet looking NBM Mon-Wed, though if trend
toward drier conditions seen in some of the 00z data persists,
some downward revisions to pops may be needed.

Coolest temps of the long term period look to occur on Friday
with clouds and precip widespread, then a gradual warming trend
begins from Saturday into next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1120 AM MDT Thu May 9 2024

Conditions will deteriorate to mvfr/ifr by this evening at all 3
taf sites, KPUB, KALS and KCOS. in the meantime, cigs will
slowly decrease this afternoon as upslope develops as an areas
of low pressure develops over the greater 4 corners region.
Showers are expected at all of the taf sites by later this
evening and lasting into tomorrow morning. Some snow will be
possible at KALS later tonight, but any accums should be mainly
on grassy areas.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
Winter Weather Advisory until 6 PM MDT Friday for COZ058-060-
061-063-066-068-072>076-079>082.

&&

$$

SHORT TERM...EHR
LONG TERM...PETERSEN
AVIATION...HODANISH