323
FXUS65 KBOU 150535
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1135 PM MDT Tue May 14 2024

.KEY MESSAGES...

- Additional showers and isolated storms expected late this
  evening and overnight mainly across northern Colorado.

- Front brings cooler and wetter weather on Wednesday. Light snow
  for elevations mainly above 10,000 feet.

- Warmer and generally drier starting Thursday, with lesser but at
  least isolated daily afternoon showers/thunderstorm coverage,
  highest for the mountains.

- A return to more active weather early next week with a better
  chance for afternoon and evening showers and storms.

&&

.UPDATE...
Issued at 753 PM MDT Tue May 14 2024

Water vapor imagery shows a well defined circulation center in the
mid levels over swrn WY. This feature will move across nrn CO/srn
WY overnight into early Wed. QG fields show some ascent with this
feature, thus may see additional shower development overnight
along with a few storms mainly across nrn areas of the CWA.

&&

.SHORT TERM /Through Wednesday/...
Issued at 247 PM MDT Tue May 14 2024

West-northwest winds have develop over the northern part of the
Front Range. The drying and subsidence associated with this has
kept showers and storms from forming. We are seeing scattered
showers and isolated storms develop else where. A severe wind gust
or two to 60 mph will be possible with this activity, but most
will see a quick weak moving shower/storm this afternoon with
gusty winds. Better chance for precipitation will come mid evening
through the overnight hours behind a cold front that will bring
northeast upslope winds. A jet streak and lift from the upper
level trough over northern Colorado may also provide lift for
showers and isolated thunderstorms through tonight.

Upper level trough will be over Wyoming and northern Colorado
through Wednesday. A wave dives down the backside of the trough
late tonight and tomorrow morning while the rest of the system
progresses eastward. This will shear the trough apart. However,
there should be plenty of cold air aloft to produce steep lapse
rates leading to scattered to numerous showers and storms. ML CAPE
up to 700 J/kg will prevail mainly over the Denver area and
south. Here, the stronger storms may produce hail up to penny size
with 40 mph winds. In addition to seeing the best instability,
the foothills and Palmer Divide will see northeast upslope flow,
which is expected to help showers and storms develop.

&&

.LONG TERM /Wednesday night through Tuesday/...
Issued at 247 PM MDT Tue May 14 2024

Wednesday night and Thursday, a split upper trough will stretch
from the upper Midwest into the Southwestern States. The main
piece of energy will be over the Arizona and New Mexico, with a
secondary branch over the Northern Great Plains States. Colorado
will in-between the main troughs under the influence of a weak to
moderate westerly flow aloft. Models are showing another cold
front sliding south across the Northeastern Plains late Wednesday
afternoon or early evening hours with some upslope flow behind it.
This combined with some lift from a 50Kt upper jet should keep
showers and a few storms continuing across the forecast area into
the evening hours. At this time, it appears the best chance for
measurable QPF will across the foothills and western sections of
the Palmer Divide with lesser amounts the further north and east
you go. The far Northeastern Plains may see little to no
precipitation with this system.

Warmer temperatures and decreased precipitation chances are expected
on Thursday as the upslope flow diminishes. However, there should be
enough lingering moisture combined with daytime heating to produce
isolated to scattered afternoon and evening showers and storms,
mainly over the higher terrain.

Dry and warmer conditons are expected on Friday as some upper level
ridging takes place over Colorado. With some downsloping flow east
the mountains, temperatures across most plains are expected to climb
into the lower to mid 80s. An upper level storm system is progged to
move across the Northern Rockies and Northern Plains States Friday
night and Saturday. Breezy to windy conditons may develop across far
Northeastern Colorado on Saturday as the upper shortwave and surface
low pressure pass to the north of Colorado. Temperatures once again
are expected to be quite warm on the plains with readings climbing
into the lower to mid 80s with temperatures approaching the 90
degree mark across Southern Lincoln County. The warm, dry and
breezy conditions may lead to increasing fire danger across the
northern sections of the plains along and near the Wyoming border
both Friday and Saturday afternoon.

Cooler temperatures are expected late Saturday and Sunday behind the
passage of a cold front. We may also see a return to isolated to
scattered afternoon and evening showers and storms in response to a
90KT upper jet moving across Southern Colorado.

Looking further ahead, it looks a little more active early next as
upper level troughiness develops across the Western U.S. With
occasional upper level shortwaves and jet streaks moving across
the region , there is the potential for some severe weather both
Monday and Tuesday across the plains.

&&

.AVIATION /06Z TAFS through 06Z Thursday/...
Issued at 1128 PM MDT Tue May 14 2024

Continue to favor drop in CIG heights after 09-10Z, with some
improvement and scattering mid to late morning ahead of the
development of scattered showers and thunderstorms in the
afternoon. This activity should hold off until 20Z at least,
possibly closer to 21Z, and convective bases will likely be lower
than previous days, around 040. Light drainage or variable winds
early this morning will transition to NNE or NE flow past sunrise,
strengthening some through the morning.

By Wed evening (00-02Z), thunderstorms should become less numerous
with a modest and temporary reduction in cloud cover, along with a
counter-clockwise rotation in winds back to light west or
southwest winds for the remainder of the evening and overnight
period. More stratiform rain showers should then begin to fill in
through the evening, most persistent across the foothills and
southwest metro, but likely impacting all Denver area terminals at
times for most of the evening with a return to lower CIG heights
in the 015-030 range.

&&

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

&&

$$

UPDATE...RPK
SHORT TERM...Meier
LONG TERM...JK
AVIATION...Rodriguez