402
FXUS65 KBOU 180527
AFDBOU

Area Forecast Discussion
National Weather Service Denver/Boulder CO
1127 PM MDT Tue Mar 17 2026

.KEY MESSAGES...

- Significant warm and dry period through Saturday. All-time new
  March record high temperatures likely for the plains Thursday,
  Friday and Saturday.

- Record high temperatures and low humidity levels will sustain
  prolonged elevated-to-critical fire weather conditions for
  portions of the plains Wednesday, then across much of the
  forecast area Thursday through Saturday.

&&

.DISCUSSION /Through Tuesday/...
Issued at 1058 PM MDT Tue Mar 17 2026

Current water vapor satellite imagery shows northwest flow aloft for
much of the state this evening, with a well-defined upper level
ridge over southern California. With this strong northwest flow
aloft, winds have been gusting up to 50-60 mph across the Front
Range mountains, with some wind-prone areas along the base of the
foothills periodically gusting up to 50 mph. Winds should retreat
back up to the mountains tonight, with gusty winds prevailing across
the high terrain overnight.

The anomalously strong upper level ridge will continue to dominate
the weather pattern for Colorado for the rest of the week. Warm and
dry air will continuously be advected into the region, leading to
record-breaking temperatures for the next few days. 700-mb
temperatures are expected to reach up to +10 C on Wednesday and up
to +15 C by Saturday. This will promote  temperatures in the mid-to-
high 70s on Wednesday across the plains and the 80s Thursday through
Saturday. Even the higher elevations will see anomalous warmth this
week, with high temperatures of the 60s possible.

Current records and forecasted high temperatures for the Denver
area are as follows:

March 19: 81 (1907) / Forecasted High: 82
March 20: 80 (1907) / Forecasted High: 83
March 21: 78 (1995) / Forecasted High: 86

In addition, we likely will break the highest temperature of the
month of March this this week. Current record is 84 degrees which
was set March 26, 1971.

Along with warm and dry conditions this week, breezy northwest winds
aloft will likely mix down to the surface, which will create a
prolonged period of elevated-to-critical fire weather conditions
across portions of the plains (See fire weather discussion below).
By Thursday/Friday winds will likely weaken as the upper level ridge
pushes the 700-mb jet further east. However, intermittent breezy
northwest winds are still possible at times, particularly off the
Cheyenne Ridge.

By Saturday, guidance continues to indicate the upper level ridge
flattening as the high pressure treks southeast into Mexico. A weak
shortwave will traverse across the northern United States, with an
associated cold front brining in a cooler airmass sometime late
Saturday/Sunday. Temperatures should moderate to the 60s on Sunday.
In terms of any precipitation, mid-level moisture will be advected
into the region, with some deterministic models showing measurable
QPF across portions of the mountains and plains. However, ensemble
guidance seems less enthusiastic about moisture for the plains, with
only a few solutions showing QPF on Sunday/Monday (all less than
0.10"). Most likely, scattered light showers are possible over the
high terrain while the plains remain dry.

&&

.AVIATION /06Z TAFS through 06Z Thursday/...
Issued at 1121 PM MDT Tue Mar 17 2026

VFR conditions to continue thru the period.  Will keep winds at
DIA WWSW/SW and then have them turning more WNW by 18z and then
NW by 21z. Gusts from 25 to 30 mph will occur after 18z.

At APA will have winds going drainage by 07z with a more westerly
component by 16z. WInds will become more WNW by 18z and then
NW by 21z.  Gusts from 25 to 30 mph will occur after 18z.

BJC will stay mainly west overnight with some gusts thru 08z.
Winds will increase from the west by 15z and go more WNW/NW
by 20Z.  Gusts from 25 to 35 mph will occur after 15z.

Winds at all three sites will decrease by early Wed evening
with directions from the WNW.

&&

.FIRE WEATHER...
Issued at 1058 PM MDT Tue Mar 17 2026

Critical fire weather conditions expected across the plains on
Wednesday as anomalously warm temperatures and dry conditions are
expected to prevail. Modeled Skew-T soundings indicate the breezy
northwest winds aloft mixing down to the surface throughout the
afternoon. Wind gusts of 30-40 mph are expected, with slightly
stronger winds possible off the Cheyenne Ridge. A Red Flag Warning
remains in effect from 11 AM to 7 PM. Expect conditions to
improve after sunset.

Warm and dry conditions will persist through the end of the week and
into the weekend. However, there will be weaker winds across the
forecast area by Thursday, as the 700-mb jet gets pushed east. The
only exception will be portions of the northern plains, where
downsloping west/northwest winds are still expected off the
Cheyenne Ridge Thursday afternoon. For this reason, have decided
to issue a Fire Weather Watch for parts of Larimer and Weld
counties. The greatest threat will be areas north and northeast of
Fort Collins. Breezy and dry conditions are likely in South Park
as well on Thursday. However, the recent precipitation has limited
fire weather concerns for that area.

Elevated-to-critical fire weather conditions are possible Friday and
Saturday across the forecast area. Saturday remains to be the
highest concern of the two days, as that will be the warmest and
`driest` day. Relative humidity values are expected to be in the
teens along the high terrain and single digits across the plains. In
addition, with the upper level ridge flattening on Saturday, gusty
cross-barrier winds are likely in the mountains, with breezy
downsloping winds possible in the plains. Fuels remain critical for
the plains. However, with the recent precipitation along the higher
terrain, fuels have not been deemed critical there, which will
mitigate fire weather concerns for now. Will continue to monitor
for changes.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning from 11 AM to 7 PM MDT Wednesday for COZ238>240-
242>245-248>251.

Fire Weather Watch from Thursday morning through Thursday
evening for COZ238-242.

&&

$$

DISCUSSION...MAI
AVIATION...RPK
FIRE WEATHER...MAI

NWS BOU Office Area Forecast Discussion