611
FXUS65 KGJT 110515
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1115 PM MDT Sun May 10 2026

.KEY MESSAGES...

- Temperatures will begin to surge well above normal Monday,
  approaching record values through Wednesday.

- Localized critical fire weather conditions continue, becoming
  more widespread Wednesday ahead of an approaching front. Fire
  Weather Watches are in place Wednesday.

- Dry thunderstorms could impact the region Wednesday, favoring
  the terrain of southwest CO.

- A pattern shift is expected mid-week which will prompt
  stronger winds and a few showers along the higher terrain.

&&

.DISCUSSION...
Issued at 1005 PM MDT Sun May 10 2026

Hot, Dry, Windy

High pressure is still forecast to amplify across the Southwest
early this week. This will push temperatures nearly 20 degrees
over mid-May climatology, including some record highs. Monday`s
record of 90 degrees at Grand Junction has stood since 1934.
Tuesday looks like the best bet for records though, as 500mb
heights reach their peak then. Well mixed conditions should
bring surface winds up each afternoon on the terrain. Hot, dry,
windy conditions with relative humidities in the teens will
produce localized critical fire weather Monday and Tuesday. Held
off on any headlines for Monday, as it looks like winds will be
too spotty across northwest CO to necessitate a warning.
However, I did issue a Fire Weather Watch for
Wednesday(explained below). Low pressure will push across the
Great Basin Wednesday night, this is expected to tighten
surface gradients and drive up winds Wednesday afternoon. Some
weak moisture works beneath the departing ridge and afternoon
instability/orographics will likely produce some terrain-based
showers. Dry boundary layer conditions could lead to dry
lightning and gusty outflow winds.

Cooler?

Deterministic models begin to diverge from one another quickly
on Wednesday following our mini heatwave. The GFS is taking a
deeper, colder low southward, while the Canadian/EC both prefer
an open wave that modifies the existing airmass very little.
There are bigger fish in the pond to worry about for now, but
temperatures Thursday and Friday are expected to modify downward
some, but I wouldn`t expect a seismic shift. Non zero chances
for showers west of the Divide could help cool things down too.
Winds remain gusty late week and relative humidities hover
around critical value for fire weather. I do believe June has
plans for a visit sooner than later.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 1114 PM MDT Sun May 10 2026

Winds will follow typical terrain driven patterns, with some
afternoon gusts of 15 to 20 knots after 18z tomorrow. Skies will
be mostly clear and VFR conditions will prevail.

&&

.FIRE WEATHER...
Issued at 1005 PM MDT Sun May 10 2026

High pressure will break down Wednesday ahead of a low working
from NORCAL westward across the Great Basin. This promises to
ratchet up surface winds across the region following a period of
anomalously high temperatures and low relative humidities. A
Fire Weather Watch has been issued for northwest CO, where
relative humidities will be in the upper single digits to low
teens, with winds gusting to around 35 mph. Given, non-critical
fuels across the remainder of the region, COZ200 and COZ202 were
the only fire zones included for the time being. Should fuels
in other zones respond to the hot and dry conditions early this
week, we will have to include others in the likely critical fire
weather headlines, as much of the region will be within
critical fire weather wind speed/relative humidity values. SPC
has also highlighted a 10 percent chance for dry thunderstorms
thanks to some moisture sneaking beneath the ridge on Wednesday
afternoon.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...Fire Weather Watch from Wednesday afternoon through Wednesday
     evening for COZ200-202.
UT...None.

&&

$$

DISCUSSION...LTB
AVIATION...TGJT
FIRE WEATHER...LTB