473
FXUS65 KBOU 031814
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1214 PM MDT Fri May 3 2024

.KEY MESSAGES...

- Isolated showers on the northeast plains tonight.

- Warmer and windy on Sunday.

- Sunday night into Monday will see a good chance of snow showers
  in the mountains. Windy and cooler over the entire area.

&&

.UPDATE...
Issued at 1041 AM MDT Fri May 3 2024

Fairly quite morning weather-wise with temperatures rising into
the 60s across the plains. It is plenty breezy across most of
northeast Colorado with gusts 20-30 mph with locally higher gusts
in the mountains. With plenty of sunshine and a shortwave trough
passing to the north, instability continues to build across the
region. Satellite shows cumulus development across the mountains
with a few shower echos already forming in the northern mountains.
The plains remain more stable this morning, but will become more
unstable through the afternoon. This keeps the forecast on track
for the scattered shower/storm threat mainly for the higher
terrain and far east plains. A few strong to severe storms are
possible on the far east plains with gusts up to 60 mph and up to
quarter size hail. Made minor changes to the precipitation
probabilities to better reflect timing of shower/storm chances
for the northeast corner.

&&

.SHORT TERM /Through tonight/...
Issued at 336 AM MDT Fri May 3 2024

GOES-18 Mid-level Water Vapor displays showers and storms located in
Wyoming this morning. The shortwave trough axis will likely stay to
the north but our area should receive an increase in mid-level
starting late morning. Additionally, a breezy day will occur through
this evening across the region with wind gusts up to 35 mph as the
shortwave trough lifts north. 700mb temperatures reach 6-8C; this
will allow for afternoon temperatures to reach the upper 60s to
lower 70s across the urban corridor and plains. Mountains and
valleys should warm up to the mid 40s to 50s this afternoon. Weak
instability between 100-300 J/kg will likely support scattered
showers and storms this afternoon. Favorable conditions for severe
storms are mainly along the Kansas Colorado border late afternoon
and early evening. If a storm is able to develop in that
environment, expect 1 inch hail and wind gusts up to 60 mph. With
snow level roughly near 8k ft, higher elevations especially along
the Park Range could accumulate snow up to 1-4 inches through
Saturday morning.

Late afternoon, a cold front will sweep into the CWA increasing wind
gusts once more. This may produce wind gusts up to 45-50 mph. As the
cold front passes, it is possible the environment becomes too stable
to support any additional thunderstorm development. Tonight, drier
air enters our region. Low temperatures remain near normal.

&&

.LONG TERM /Saturday through Thursday/...
Issued at 336 AM MDT Fri May 3 2024

The flow aloft will become WSW on Sat as a weak sfc lee trough
develops by aftn.  This will allow for SSE low level flow to develop
across the plains. Some moisture will affect the higher terrain
by aftn with MLCAPE around 200 j/kg. As a result, there will be a
chc of aftn showers and a few tstms, especially over the higher
terrain along and south of I-70. Across the plains it will be dry
and cooler with highs in the 60`s.

By Sun, SW flow aloft will increase across the area as a storm
system moves into the Great Basin. In addition, sfc low pres will
intensify from central WY into ern CO with stg southerly flow in
the lower levels. As a result, will likely see winds gusts in the
45-55 mph range across the plains Sun aftn. As far as precip
chances, MLCAPE will rise to around 300 j/kg over portions of the
plains, however, there is a capping inversion which probably will
inhibit tstm development. Meanwhile, highs will be warmer over
most of the plains as readings rise into the 70`s. The only
exception would be over the far ern plains, where highs may stay
in the mid to upper 60s due to low level cloud cover.

For Sun night into Mon, the storm system over the Great Basin will
move quickly ENE with an intense upper level low moving into ern
WY, by Mon aftn. As the srn extent of the upper level trough
moves across nrn CO, there will be a round of snow in the mtns Sun
night into Mon morning. Across the plains, a bora type front will
move across during the day with gusty WNW winds developing by
midday. There also could be a chc of showers in the morning as a
quick shot of mid level ascent moves across. Highs across the
plains will drop back into the 60`s.

Looking ahead to Mon night into Tue, an intense storm system will be
over the nrn Plains.  This will allow for brisk WNW flow aloft
across the area.  Cross-sections, show enough moisture embedded in
the flow to bring a chc of orographic snow showers to the mtns.
Across the plains, it will be dry with gusty WNW winds continuing.

On Wed, the storm system will move slowly eastward with WNW flow
aloft remaining over the region.  Once again, there will be some
moisture embedded in the flow to bring a chc of snow showers to the
mtns.  Across the plains, it will remain dry and windy with highs
remaining in the 60`s.

By Thu, the flow aloft will become more NW as a shot of cooler air
moves into the area behind a front.  In addition, there may be a
disturbance embedded in the flow which could bring a chc of precip
to the region as well.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1155 AM MDT Fri May 3 2024

VFR conditions expected for the TAF period. Breezy S/SSE winds
being observed at the terminals early this afternoon. This puts a
slight delay on the forecasted SW winds. Within the next 1-2
hours winds should turn more SW ahead of the incoming front. Front
will likely across the terminals in the 21-23z timeframe with a
brief push of gusty N/NNE winds behind in (Gust 25-35kts). Winds
turn more NE after 00z with weaker gusts than the initial push
(G20-25 kts). Showers and storms develop on the plains around the
front timeframe. Although they should remain clear of the
terminals, can`t rule out the potential for outflows/variable
gusts from showers set up to the north and east. Ovenright, winds
decrease becoming light ENE/NE. Saturday morning winds turn SE
increasing to 8-10 kts by late morning.

&&

.FIRE WEATHER...
Issued at 256 AM MDT Fri May 3 2024

It will be windy over the plains Sunday through Tuesday. Humidity
levels will gradually drop from Monday into Tuesday. However,
recent rainfall combined with greening up of vegetation could
reduce fire danger across portions of the plains. At the time,
the most likely area for increasing fire danger would be over
southern Lincoln county.

&&

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

&&

$$

UPDATE...Mensch
SHORT TERM...AD
LONG TERM...RPK
AVIATION...Mensch
FIRE WEATHER...RPK

NWS BOU Office Area Forecast Discussion