Arriba, Colorado Weather Forecast Discussion

726
FXUS65 KBOU 152339
AFDBOU
Area Forecast Discussion
National Weather Service Denver/Boulder CO
539 PM MDT Mon Sep 15 2025
.KEY MESSAGES...
- A slight chance of a weak afternoon shower or thunderstorm
  through this evening.
- More unsettled and cooler Tuesday through Thursday, with
  scattered to widespread showers and thunderstorms expected.
&&
.DISCUSSION /Through Monday/...
Issued at 150 PM MDT Mon Sep 15 2025
Water vapor satellite imagery showing a large upper level trough
over the northwest part of the country with drier air and weak
ridging over Colorado. Other than a couple high based showers, dry
conditions are expected through tonight. Satellite imagery is
also showing a strong shortwave trough spinning near the
Idaho/Wyoming border within the large upper level trough. There is
also a second weaker shortwave trough near the Washington/Oregon
border. This second one will track southeast bringing scattered
showers and thunderstorms Tuesday afternoon and evening. A weak
cold associated with this system will bring cooler temperatures
Tuesday. The cold front stalls over far eastern Colorado Tuesday.
Along and east of this CAPE reaches 2000 J/kg, which may lead to a
few strong to severe thunderstorms. On Wednesday, this trough
closes off somewhere over northeast Colorado to western Nebraska
and becomes part of the larger upper level trough over the central
part of the country. For Wednesday, temperatures cool more with
showers likely. SBCAPE is reaches up to 500 J/kg, so we should see
isolated to scattered storms during the afternoon and early
evening.
Come Thursday we will see a broad upper level low over the
Northern and Central Plains and ridging to the west. Across
Colorado, a north to northwest flow aloft will prevail. Cool
temperatures will persist again with highs in the 60s across
northeast Colorado. Scattered showers will be possible Thursday,
but rainfall amounts should be light.
The ridging off to the west slides eastward Friday and should be
centered over Colorado late in the day. Expect dry conditions to
return to the area with temperatures warming into the 70s over
northeast Colorado.
For the weekend models trend towards a zonal flow, but differ on
the placement on the shortwave troughs and ridges. Chances for
precipitation look low under this pattern, so will keep the
forecast mostly dry. Temperatures will be near to slightly above
normal with highs in the upper 70s to mid 80s over northeast
Colorado. For early next week, models indicate ridging builds over
the southwest part of the country and could extend eastward into
the Rockies. Expect dry conditions and above normal temperatures
under this pattern.
&&
.AVIATION /00Z TAFS through 00Z Wednesday/...
Issued at 533 PM MDT Mon Sep 15 2025
There could be an isold high based shower thru 7 pm but have
decided to not mention VCSH/Prob30 in the new Tafs.  Winds will
shift from ESE to south by 03z. By 09z they will become light and
variable. On Tue, a cold front will move across by 17z with winds
becoming north. By 20Z winds will become NE. There will be a chc
of showers/tstms by 21z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Meier
AVIATION...RPK

NWS BOU Office Area Forecast Discussion