Golden, Colorado Weather Forecast Discussion

919
FXUS65 KBOU 161805
AFDBOU
Area Forecast Discussion
National Weather Service Denver/Boulder CO
1205 PM MDT Tue Sep 16 2025
.KEY MESSAGES...
- Scattered showers and thunderstorms through this evening. A few
  may be strong to severe in the plains.
- Shower/t-storm potential will linger into Wednesday, with cooler
  conditions through Thursday.
- Drier weather Thursday onward, with warmer temperatures
  beginning Friday.
&&
.UPDATE...
Issued at 1155 AM MDT Tue Sep 16 2025
Some concern with model performance today. The current convection
and associated pressure surge across southeast Wyoming now into
the Nebraska panhandle is not handled well. Mesoscale models were
trying to push the moisture in Kansas and Nebraska westward across
northeastern Colorado, but instead, we`re getting postfrontal air
from eastern Wyoming which is potentially cooler, with dew points
in the 40s. There may be some dew point recovery as winds go
northeast in the wake of the current convection, but it will be
cooler air. So model CAPES of 1500 or 2000 J/kg across the
western half of our plains are looking pretty unlikely, it will
more likely be 500-1000. In particular, the tornado threat looks
lower with north to northeast surface winds, less CAPE, and the
main boundary pushed well to the east near the eastern border of
Colorado. We`ll make some adjustments, but there still may wind up
being decent coverage of showers in the late afternoon/early
evening between the diurnal mountain convection and some mid level
QG lift. It`s just that the intensity won`t be there.
Further east, there still may be a threat of strong to severe
storms near the eastern border, although that wind shift line may
continue to chug eastward and get the risk east of our area by mid
afternoon. We`ll see if it can stall out but it still seems to
have some momentum to it. East of that boundary, there are high
CAPEs, though the shear may not be as good as previously
advertised.
&&
.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 /18Z TAFS through 18Z Wednesday/...
Issued at 1155 AM MDT Tue Sep 16 2025
VFR conditions will prevail through tonight. Scattered showers and
thunderstorms are expected from 20z through 04z, but the risk of
wind shifts with strong gusts now appears low.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
UPDATE...Gimmestad
DISCUSSION...Meier
AVIATION...Gimmestad

NWS BOU Office Area Forecast Discussion