468
FXUS65 KBOU 190512
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1112 PM MDT Sat Apr 18 2026

.KEY MESSAGES...

- Dry and warmer weather continues through Wednesday, with well-
  above-normal temperatures expected by Monday.

- Elevated to critical fire weather conditions are expected on
  Wednesday, potentially persisting into Thursday.

- A series of Pacific storm systems should result in unsettled
  weather Thursday and beyond.

&&

.DISCUSSION /Through Saturday/...
Issued at 1045 PM MDT Sat Apr 18 2026

Rather quiet weather is expected across the forecast area for the
next few days as upper-level ridging builds over the western CONUS.
Models are fairly consistent with a pattern change coming by
midweek, though inconsistencies remain on the forward progression of
smaller disturbances within the larger scale flow of the next
approaching upper-level system. Expect a warming trend through
Wednesday, with some locations seeing high temperatures reach 20F+
above normal for Tuesday and Wednesday. With multiple days of
well-above-normal temperatures, dry conditions, and widespread
drought in place, critical fire weather concerns will ramp up by
midweek.

For tonight, current water vapor imagery shows mid- and upper-level
moisture upstream within northwesterly flow aloft that will move
high clouds across the forecast area from west to east through the
evening. Overnight lows will be warmer than last night`s hard
freeze, but still remain below freezing for portions of the plains
for one more night, whereas the urban corridor should remain just at
or above freezing.

Colorado will be on the eastern side of a building upper-level ridge
on Sunday, with 700 mb temperatures expected to warm by 2-10C over
Saturday`s. This will translate to afternoon high temperatures in
the 70s across the plains, and initiate a multi-day warming trend
across the forecast area. Dry conditions are expected across the
plains through at least Wednesday, with ensembles and cross sections
showing just enough mid-level moisture move into the mountains to
keep a slight chance for light precipitation Tuesday night, mainly
for the highest elevations. 700 mb temperatures will warm by a few
deg C each day through Wednesday as the ridge moves east,
translating to afternoon high temps also increasing by a few degrees
each afternoon across the forecast area, reaching widespread 80s
across the plains by Tuesday, and approaching 90F by Wednesday
across the far eastern plains.

Southwest flow aloft will return Tuesday night as the next upper-
level trough moves ashore California. Ahead of the approaching
trough, a surface trough will deepen on the lee of the Rockies and
the associated southwest flow aloft will increase across Colorado
through the day Wednesday. At this time, there are still some
inconsistencies with just how strong surface winds will be,
however, the NBM joint probability of RH dropping below 15%
coincident with winds gusting greater than 25 mph shows 60%
chances or greater for a wide majority of the CWA Wednesday
afternoon and early evening, with 80% and greater for much of our
southern plains. With RH expected to drop into the single digits
and fuels given ample time to dry out after Friday`s
precipitation, fire weather highlights are looking likely for most
of the CWA on Wednesday. Overnight recoveries don`t look very
good Wednesday night into Thursday either, and despite afternoon
high temps expected to drop towards normal seasonal values
Thursday afternoon, elevated to critical fire weather conditions
are likely to persist into Thursday as enhanced drying from
downslope winds and elevated wind speeds continue as the surface
trough continues to deepen over the eastern plains.

As stated previously, there are some lingering uncertainties
amongst guidance about how some smaller scale features progress
within the larger scale flow after Wednesday/Thursday, but at
least for now, things do look to be more active into the weekend,
with the majority of GEFS and EPS members bringing at least some
light precip and a few cold fronts to the forecast area by the end
of the week, though there is still quite a spread in QPF amounts.

&&

.AVIATION /06Z TAFS through 06Z Monday/...
Issued at 1110 PM MDT Sat Apr 18 2026

VFR conditions thru the period.  Winds will be drainage overnight
and then become light and variable by 15z.  Winds by 19z will
become light easterly and then southeast by 01Z Sun evening.

&&

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

&&

$$

DISCUSSION...9
AVIATION...RPK

NWS BOU Office Area Forecast Discussion