890
FXUS65 KGJT 220004
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
604 PM MDT Thu Aug 21 2025

.KEY MESSAGES...

- Near-record heat lingers through tomorrow, before increased
  clouds and showers bring a significant cool-down for early
  next week.

- Isolated to widely scattered convection is expected over the
  higher terrain today, with gusty winds and lightning still the
  main threats. Light to moderate rainfall will be possible over
  the San Juans.

- Moisture is expected to continue increasing over the next
  several days, with widespread shower and storm activity
  expected. Potential for heavy rain and debris flows over burn
  scars will increase from Sunday into early next week.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 1256 PM MDT Thu Aug 21 2025

High pressure remains overhead with moisture trying to fill in from
many directions. Currently there is enough moisture across the
eastern and southern third of the area for showers and storms this
afternoon and evening. These showers have better chances of
producing gusty winds than rainfall especially in the lower
elevations. The high pressure has resulted in record heat for a good
portion of the area. Tomorrow moisture fills in from the west, which
will increase the coverage of afternoon showers. Once again, the
temperatures will be near record values for many locations. This
will inhibit rainfall rates and promote gusty outflow winds. Some of
the higher elevations could actually see moderate rates and
measurable rain. That signal is strongest across the southern San
Juans.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 1256 PM MDT Thu Aug 21 2025

Saturday looks to be the quietest day with regards to weather. While
moisture continues streaming into the area, a passing disturbance is
expected to keep the deeper moisture to our south. After that
though, moisture really starts moving into the region and will
persist through much of the week. Several pieces of energy will
rotate around the high pressure through this period and cause
widespread convective activity. Heavy rain will be a distinct
possibility under the stronger cells and showers that form. This
will be welcomed and is needed...except for the burn scars. If this
heavy rain does fall over recent burn scars and other susceptible
areas, debris flows may be possible. Something else to consider will
be the amount of cloud cover that persists overnight and in the
morning hours. Without daytime heating, this precip could be more
stratiform in nature with some embedded storms. Those areas that see
sunshine can expect more robust convection and those heavy rainers.
More good news is that fire weather concerns will drop considerably
thanks to the cloud cover and precipitation...it`ll be that much
harder to get any fire starts.

Temperatures will start out above normal but once the clouds and
precip move in, high temperatures will start dropping. Sunday, high
temperatures will hover around normal and by Wednesday, they`ll be
several degrees below normal. We`ll take it.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 547 PM MDT Thu Aug 21 2025

Shower and thunderstorm activity has diminished across much of
the region, but may continue through the evening. Tomorrow will
bring another round of isolated to widely scattered afternoon
convection. PROB30 has been included for sites where confidence
is higher. The primary concerns will be lightning and strong
outflow gusts near any showers or thunderstorms. Smoke from the
Derby Fire will continue to impact KASE and KEGE, potentially
dropping visibilities at times. VFR conditions are expected to
prevail and winds will become light overnight.


&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

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