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000
FXUS65 KBOU 131128
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
528 AM MDT Sat Apr 13 2024

.KEY MESSAGES...

- Warm and dry weekend, continuing into Monday, with elevated
  fire weather conditions.

- A windy weather system will bring snow showers to the mountains
  with rain showers likely on the plains late Monday into Tuesday.

- Cool and windy weather for the rest of the week. Occasional snow
  showers are expected in the mountains with a chance of showers
  on the plains, most likely still rain.

&&

.SHORT TERM /Through tonight/...
Issued at 405 AM MDT Sat Apr 13 2024

Changes with respect to yesterday`s weather will be very subtle
today. The upper-level ridge fills back in following the weak
shortwave that has been swinging through early this morning, and
producing a few isolated light showers in the high mountains.
Warming aloft will see little change, with subsident flow
persisting. As such, expect similar temperatures with highs into
the upper 70`s for the urban corridor and locally scraping the low
80`s in the eastern plains.

Moisture will remain in place above 600mb, with marginal
instability late morning through the afternoon. However, near-
surface conditions will be exceptionally dry once again. All in
all, there may be a slightly higher potential today for some virga
and/or brief sprinkles (20-25% chance), mainly along and north of
I-76, but it`s questionable if much would make it to the ground.
We`ll be deeply mixed, but winds aloft under the ridge won`t be
particularly strong. Thus, 25 mph seems quite reasonable as an
upper end for wind gusts this afternoon across the plains, with
many staying under that. This should limit fire weather concerns a
little, but elevated to locally near-critical conditions can
still be expected.

&&

.LONG TERM /Sunday through Friday/...
Issued at 405 AM MDT Sat Apr 13 2024

Sunday should be the warmest day, as we`ll still be under dry air
with the low/mid level flow becoming more southerly with time.
Forecast temperatures just a couple degrees warmer than Saturday
look good.

There`s still tight clustering on the track and timing of the low
for Monday into Tuesday. There is a trend towards slightly slower
and perhaps a little further north, which would push most of the
precipitation into Monday night and Tuesday morning for the
plains. This also makes the upslope later and a little longer,
although most of the models also keep the best of this further
north. Some of the models are producing quite a bit of snow in the
Medicine Bow Range (over two inches of liquid in some runs though
1-1.5 is more common), and that could include Larimer county
above about 7000 feet. Further south, there will probably be less
precipitation and the snow level will be slower to lower. Higher
elevations throughout the northern Colorado mountains should get
several inches of snow from a prolonged showery period, while the
valleys and lower foothills will have mostly rain with some snow
mixed in later Monday night and Tuesday morning. For the plains,
there will be some rain but the real story might be the wind as
the low level pressure fields ramp up Monday night through
Tuesday. It doesn`t look like there`s that much of a high wind
threat, but it could be close for a while over the northern and
eastern parts of our plains depending on the strength of the
development. The wind should be much less by Wednesday morning as
the low moves eastward.

For the later part of the week, the 12z Friday EC model jumped
northward quite a bit with its low center in the Canadian prairies
about 300 miles further north, making Colorado warmer and drier.
This looks to be an anomaly as about a third of its ensemble runs
were more consistent and closer to the GFS. The 00z operational EC
is back to where it was yesterday. There is a little northward
trend in the rest of the model guidance, with the result of a
lower chance of dropping into the 40s for highs late in the week
or seeing any snow on the plains. QG lift and related moisture
being further north may also mean less shower activity and our
chance PoPs through this period may be too high. For now the NBM
seems appropriate with cooling into the 50s. There will still be a
decent cold front and some upslope/convergence and a little QG
lift sometime late Wednesday/early Thursday, but we may just be
cool and stable after that.

&&

.AVIATION /12Z TAFS through 12Z Sunday/...
Issued at 525 AM MDT Sat Apr 13 2024

VFR conditions will prevail for all terminals through the TAF
period.

Southwest drainage winds will become northwesterly mid to late
morning, with speeds generally 10-15 kts. Expecting general
direction to hold fairly steady throughout the day, although a
brief period of more northerly or even northeasterly flow can`t be
ruled out, mainly for KDEN/KAPA between 1700-2000 MT. Then expect
a return to SSW drainage flow in the evening.

&&

.FIRE WEATHER...
Issued at 405 AM MDT Sat Apr 13 2024

Very dry once again with minimum afternoon humidity values of
9-14% being relatively widespread across the lower elevations,
translating into elevated fire weather conditions for most areas.
Despite a well-mixed environment (and good smoke dispersal as a
result), winds will remain relatively light, with gusts largely
below 20 mph today except for a few pockets nearing 25 mph over
the Cheyenne Ridge, northern plains, and Lincoln County. There
areas could see a couple hours of near-critical conditions, but
winds/duration not quite there for any headlines today, at least
for now.

Sunday will be pretty similar to today, with near critical
conditions for a few hours in the afternoon over the lower
elevations. On Monday, a low pressure system will intensify over
northeastern Colorado. There will be warm, dry, and windy
conditions south of the low, south of Interstate 70 or Interstate
76, with critical fire weather conditions possible in that area.
Further north, it will become windy but humidities may be higher.

It will be windy Tuesday with cooler temperatures, and some
precipitation late Monday into Tuesday should mitigate the fire
weather threat. Cooler weather is expected for the rest of the
week with occasional mountain snow and a chance of showers on the
plains, and less wind.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...Rodriguez
LONG TERM...Gimmestad
AVIATION...Rodriguez
FIRE WEATHER...Rodriguez/Gimmestad