298
FXUS65 KGJT 181713
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1113 AM MDT Mon Aug 18 2025

.KEY MESSAGES...

- Unseasonably warm and dry conditions persist through the
  first half of the new week.

- Confidence continues to increase for a prolonged push of
  monsoonal moisture later this week.

&&

.SHORT TERM /THROUGH TONIGHT/...
Issued at 342 AM MDT Mon Aug 18 2025

Warm and dry conditions remain the focus of the short term
forecast as high pressure continues to build in form the
southeast. With PWATs continuing to fall, coverage of terrain-
driven showers and storms will also decrease but we cannot rule
out isolated convection along the Divide this afternoon. If
showers and storms develop, they will be capable of producing
gusty outflow winds up to 40-45 mph and dry lightning. Warm air
advection continues with southwesterly flow aloft, so
temperatures will continue to increase. Today`s afternoon highs
are forecast to be 5-10 degrees above normal for mid August area
wide.

&&

.LONG TERM /TUESDAY THROUGH SUNDAY/...
Issued at 150 PM MDT Sun Aug 17 2025

High pressure will remain overhead at the start of the long
term period as abnormally dry air also remains in place. PWATs
of 30 to 40% of normal are expected and don`t look to recover
until Thursday. Until then, high temps will reach well above
normal values with plenty of sunshine expected. While the
ensembles aren`t highlighting much in the way of convection, the
NBM is putting a 20 to 30% chance of precip over the higher
terrain of the San Juans for Tuesday and Wednesday. Not
completely sold on this solution but daytime heating and just
enough instability might allow some convection. Things get
interesting Thursday onwards as flow around the high pressure
starts to advect moisture back into the region from north to
south. This increase in moisture will then be worked on by
several pieces of energy, some more dynamic than others,
allowing afternoon and evening convection to fire. Forecast
PWATs are expected to reach right around normal values by Friday
and increase through the weekend. This is good news as we`ve
been so dry lately. As is always the case this far out, changes
to the forecast should be expected. Having said that, confidence
continues to slowly increase with each model run.

&&

.AVIATION /18Z TAFS THROUGH 18Z TUESDAY/...
Issued at 1113 AM MDT Mon Aug 18 2025

VFR conditions and light terrain driven winds are expected
through the taf period.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

CO...None.
UT...None.

&&

$$

SHORT TERM...KAA
LONG TERM...TGR
AVIATION...TGJT