257
FXUS65 KBOU 061756
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1156 AM MDT Sat Jul 6 2024

.KEY MESSAGES...

- Near average temperatures on Saturday before a dip on Sunday.

- Cooler temperatures and scattered storms are possible early
  Sunday morning until late afternoon across the region.

- Lower thunderstorm chances and warmer next week.

&&

.UPDATE...
Issued at 948 AM MDT Sat Jul 6 2024

Difficult to spot a single cloud in the sky this morning as
subsident flow prevails over the region. Temperatures remain on
track to climb into the low 90`s for the warmest spots around the
Denver metro and plains. No changes to this evening`s
precipitation potential - still anticipate that only the northeast
corner of our plains have a real shot at any stronger storms, and
it`s possible that much of the activity will be focused overnight
with assistance from the incoming front.

One highlight was issued this morning for South Park, where
efficient mixing over the next few hours should allow for winds to
pick up and produce gusts in the 25-30 mph this afternoon. Thus, a
Red Flag Warning will now be in place from 2-8 pm.

&&

.SHORT TERM /Through tonight/...
Issued at 445 AM MDT Sat Jul 6 2024

Water vapor imagery reveals dry west-northwesterly flow over
Colorado with a shortwave trough over the North Dakota/South
Dakota border and another near Glacier National Park. Our forecast
area will be under mostly zonal and dry flow today before the
trough near Glacier NP arrives late tonight. Plenty of sunshine
and downslope winds will result in high temperatures returning to
the 90s across the urban corridor.

Models had been forecasting a dryline to set up on the eastern
edge of our CWA but the latest runs push this dryline farther
east. That should keep the primary area of severe weather well to
the east of our CWA. However, in Logan, Phillips, and Sedgwick
Counties, there will be enough lingering moisture and elevated
instability this evening that a strong to severe storm or two
could form. The primary threats would be hail and strong wind
gusts from these storms. A few light showers and perhaps a
thunderstorm or two may form over the higher terrain and the
northern plains south of the Cheyenne Ridge this afternoon.
Showers and storms may increase in coverage this evening as QG
ascent ahead of the trough arrives. A cold front/outflow boundary
will move through our forecast area after midnight tonight. This
will decrease temperatures and may initiate a few showers and
storms. Gusty winds up to 35 mph can be expected with this front.

&&

.LONG TERM /Sunday through Friday/...
Issued at 445 AM MDT Sat Jul 6 2024

The shortwave trough now exiting Alberta will move across
northeast Colorado early Sunday. Most of the QG forcing should be
in the morning, but there`s a little cooling aloft which will
likely combine with weak low level upslope to keep showers and
thunderstorms going into the afternoon. The focus may initially be
over the northeast plains, then shift to upslope driven showers by
afternoon. There may be up to 1000 J/kg of CAPE briefly in the
middle of the day, but with the cloud cover and wind structure the
severe threat looks low. There could be a bit of a focus for
convective development around the Cameron Peak burn area, though
moisture availability is limited with precipitable water likely
0.5 to 0.75 inch and cells should be moving at least 10 mph. So
there is a threat of heavy rain, but the flood threat should be
limited. Previous forecast of scattered to likely PoPs during the
day, decreasing from north to south overnight still looks good
along with highs mostly in the 70s.

On Monday, drier air is drifting in from the northwest along with
a little subsidence/warming aloft. There`s probably still enough
low level moisture for some diurnal showers/storms but they should
be weak, and maybe confined to the east slopes of the Front Range
and adjacent plains. Cell motions may be weak, but with low CAPES
and less available moisture, we don`t think there`s much of a
flood threat. Tuesday looks similar, with temperatures warming but
still some low level moisture around.

The upper level ridge over the western U.S. will slowly nudge
eastward later this week into the weekend. This will bring a
warming trend. Low level winds will be southeasterly, keeping some
foothills convergence and low level moisture, so there will likely
still be a little thunderstorm activity mainly over and near the
foothills. The more aggressive scenarios with the eastward spread
of the ridge could result in very limited thunderstorm activity by
Friday along with near record temperatures (101 Friday and 100
Saturday and Sunday in Denver). Northwest flow over the ridge may
delay this a little longer or keep us slightly cooler, but we`ll
be on the edge of pretty hot air centered over the Great Basin.

&&

.AVIATION /18Z TAFS through 18Z Sunday/...
Issued at 1153 AM MDT Sat Jul 6 2024

Favoring continued northerly winds this afternoon, despite some
guidance suggesting a push of northwesterlies off the higher
terrain. So far, that doesn`t appear to be materializing. An
outflow boundary from convection in Kansas looks to produce a
period of enhanced northeast flow this evening, before a cold
front arrives shortly after midnight. CIGS 020-035 look likely to
develop behind the cold front, with a possibility of a few
showers. Better potential for a few thunderstorms tomorrow
afternoon, assuming the low stratus is able to dissipate early
enough.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning until 8 PM MDT this evening for COZ214.

&&

$$

UPDATE...Rodriguez
SHORT TERM...Danielson
LONG TERM...Gimmestad
AVIATION...Rodriguez