928
FXUS65 KGJT 210523
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1123 PM MDT Wed Aug 20 2025

.KEY MESSAGES...

- High pressure overhead keeps hot and dry conditions in our
  area through the end of the week.

- Isolated convection will continue through the evening over the
  San Juans and Abajos.

- Confidence is high that moisture will return tomorrow,
  increasing chances of precipitation and bringing some cooler
  temperatures for the weekend.

&&

.SHORT TERM /THROUGH THURSDAY/...
Issued at 236 PM MDT Wed Aug 20 2025

Short range models were indicating a slight uptick in moisture
for the foothills of the San Juans and over the San Juans
themselves this afternoon. With daytime heating, that`s all that
was needed as some showers and storms have fired there this
afternoon. Lightning and some gusty outflow winds are expected
from the stronger cells. Elsewhere, conditions will almost be
exactly the same as we saw yesterday though highs will increase
a few degrees. Also, the HRRR is indicating some smoke from the
Derby Fire dropping down into the I-70 corridor later this
evening and overnight. Question is whether it`ll drop in the
valley itself or stay aloft. Either way, there`ll be smoke.

Thursday, the moisture we`ve been talking about finally starts
moving into the area. Flow around the high pressure will tap
into moisture to our south and bring it into the region and will
bring a prolonged period of afternoon and evening convection.
Coverage will be over the higher terrain to start of Thursday but
with such dry subcloud layers, would expect more virga than
wetting rain though some precip may hit the ground. High temps
will continue their above normal run though a significant drop
is expected next week.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
Issued at 236 PM MDT Wed Aug 20 2025

On Friday moisture will continue to filter in under the high
pressure, which means more showers and storms for our area. The
higher terrain will be favored for showers while gusty outflow winds
will be favored in the valleys. A few locations may actually
see some measurable rain. High temperatures around record values
are expected for places that do not get any cloud cover.
Saturday the moisture could get shunted slightly to the south by
a passing trough, but overall not much changes. Temperatures
drop by a few degrees overall although still above normal. On
Sunday, the moisture once again fills back into the high
pressure that begins to migrate southward. This could be the
point at which we see more measurable rain and the chances for
heavy rain increases. The longer the moisture stays around the
better are the chances for beneficial rainfall. Increasing
rainfall rates would be an issue with the recent burn scars and
other susceptible spots, so debris flows cannot be ruled out
during this stretch. One unknown is how the very dry soils are
going to react to any rainfall. Early next week the high
continues southward, but moisture remains in our area under the
large- scale ridge. Like with every moisture push morning cloud
coverage will have a significant impact on whether strong
convection forms in the afternoon or a more stratiform event
occurs. If daytime heating is at a maximum, some storms will
likely bring heavy showers while cloudiness will bring a more
soaking type of rain.

&&

.AVIATION /06Z TAFS THROUGH 06Z FRIDAY/...
Issued at 1120 PM MDT Wed Aug 20 2025

Moisture is beginning to infiltrate the region, leading to more
mid and high level clouds at this hour. This cloud cover will
persist through the period. A chance of showers and
thunderstorms over the southern and central mountians has the
potential to impact KTEX and KDRO, with gusty and erratic winds
and lightning the main concerns. Additionally, smoke from the
nearby Derby fire will lead to periods of reduced visibility at
KEGE and KASE through the period. Winds will be generally light
and terrain driven. VFR conditions will prevail, although
periods of MVFR conditions will be possible due to smoke or
passing showers or storms.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...TGR
LONG TERM...KJS
AVIATION...TGJT