Area Forecast Discussion
Issued by NWS Denver/Boulder, CO

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959
FXUS65 KBOU 111814
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1214 PM MDT Fri Jul 11 2025

.KEY MESSAGES...

- Scattered afternoon and evening thunderstorms today, producing
  locally heavy rainfall and/or flash flooding.

- Afternoon showers/thunderstorms to continue most days, albeit
  with slightly lesser coverage Sunday and Monday.

&&

.UPDATE...
Issued at 204 AM MDT Fri Jul 11 2025

Scattered thunderstorms will push off the higher terrain and into
the urban corridor and plains mid-afternoon. Model guidance
remains fairly bullish with PWAT forecasts, with upwards of 1"
across the lower elevations through tonight. Modest shear should
keep convection marginally severe at most, however ample moisture
will promote heavy rainfall under thunderstorm cores which will be
capable of localized flash flooding from the lower foothills into
the northeast plains through this evening.

&&

.DISCUSSION /Through Thursday/...
Issued at 242 PM MDT Thu Jul 10 2025

Convection is developing across the CWA this afternoon. Radar and
observations are showing outflow winds from the storms were
gusting up to 65 mph. Earlier this morning, a gust to 70 mph was
recorded at DIA at 1010Z.

Concerning the convection for the rest of this afternoon and
evening, models, including the CAMs, are all indicating scattered
coverage for much of the CWA, but only through this evening; no
later than 02Z.

There will be weak northwesterly flow aloft Friday into Saturday
with a weak upper trough developing just east of Colorado Saturday
mid day. Models continue to show decent CAPE. Progged precipitable
water values continue to be over 1.00 inch for the eastern 2/3rds
of the CWA Friday through Saturday night. The best rainfall
amounts on the QPF grids are progged for late day Friday, less
late day Saturday. Temperatures are below seasonal normals both
Friday and Saturday.

On Sunday, the upper ridge builds in from the west and the
airmass dries out a bit with temperatures getting above seasonal
normals. Pops will be pretty low and confined to the mountains and
higher foothills. The plains look to have poor instability with
low CAPE and a mid level cap in place.

For the later days, Monday through Thursday, the upper ridge is
around on Monday with temperatures to stay above normal.  There is
weak upper troughing Monday evening into Tuesday with a decent cold
front to move down across the CWA. Flat upper ridging is progged
on Wednesday and Thursday with the below normal temperatures to
continue. For pops, Monday is the driest day, with scattered
convection relegated to just the mountains. Late day convection
and precipitation are pretty decent Tuesday through Thursday, with
Wednesday having the highest pops.

&&

.AVIATION /18Z TAFS through 18Z Saturday/...
Issued at 1203 PM MDT Fri Jul 11 2025

Frontal boundary has pushed through the terminals during the late
morning hours, leaving generally N-NE winds. A little uncertainty
with how winds evolve through the early/mid afternoon hours, but
guidance is in reasonably good agreement that we should maintain
an east/northeast wind at DEN with weaker and perhaps more
variable winds at APA/BJC.

Scattered convection is still expected to develop in the 21-22z
window this afternoon and will push across the terminals through
02-03z. Main threat will be gusty outflow winds.

Beyond the convective threat this afternoon, additional moist
upslope flow should allow for the development of a widespread
low/mid cloud layer by around 06z. While the TAF does have MVFR
cigs overnight into tomorrow, there are some hints of an IFR
ceiling prevailing at the terminals. Stratus should slowly erode
tomorrow as winds turn more to the southeast.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 6 PM MDT this evening through late tonight for
COZ042-044-048>051.

&&

$$

UPDATE...Rodriguez
DISCUSSION...rjk
AVIATION...Hiris