726
FXUS65 KBOU 142057 CCA
AFDBOU

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

...Corrected for typo...

.KEY MESSAGES...

- Scattered showers/thunderstorms through early eyening, most
  numerous along/south of I-70 where a few could be strong and
  produce hefty outflow winds.

- 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.

&&

.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 /18Z TAFS through 18Z Wednesday/...
Issued at 1147 AM MDT Tue May 14 2024

West-northwest winds will continue to spread east off the
foothills, bring gusts to 25 knots and drier air. Satellite
showing some cumulus clouds forming, indicating we are starting to
reach our convective temperature. The question...is there enough
moisture for showers and storms? Model trends are leaning towards
no in the DEN area and likely in the APA area. May be able to
remove the VCTS from the DEN TAF in the next couple hours if the
drying trend pans out. Still may see a gusty outflow the
convection to the south of DEN.

Cold front will bring northeast to north winds mid evening, around
03Z. Will see an improved chance for showers with a slight chance
(20%) for a thunderstorm behind the cold front. The airmass
moistens up and low clouds are expected to form 09-12Z with
ceilings of 2000-4000 feet. The clouds slowly rise Wednesday
morning and afternoon, but expect ceilings to stay below 6000
feet. Scattered showers and thunderstorms are expected to form
after 20Z Wednesday.

&&

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

&&

$$

SHORT TERM...Meier
LONG TERM...JK
AVIATION...Meier