583
FXUS65 KGJT 030519
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
1119 PM MDT Tue Sep 2 2025

.KEY MESSAGES...

- Temperatures trend about 5 degrees above normal through
  Wednesday before a cooler and more active storm system moves
  in by Friday.

- More widespread precipitation is possible on Friday and into
  the weekend as rich extra-tropical moisture moves into the
  region with a potential for heavier rain on the recent fire
  scars.

&&

.SHORT TERM /THROUGH WEDNESDAY/...
Issued at 259 PM MDT Tue Sep 2 2025

High pressure drives the forecast tomorrow bringing continued
warm and dry conditions. High temperatures continue to run
around five degrees above normal for early September with
isolated afternoon showers and storms over the Divide mountains.
Coverage of convection looks to be less than what we`re
experiencing this afternoon.

Cloud cover increases from the southwest Wednesday night with
portions of southeast Utah and southwest Colorado seeing warmer
than normal nighttime lows.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
Issued at 259 PM MDT Tue Sep 2 2025

A pattern shift will allow for a return of moisture beginning
Thursday afternoon. A trough pushing inland off the Pacific will
begin to break down the high pressure centered over the Four
Corners region. As it does so, moisture will advect into the
region, first in southeastern Utah before becoming widespread
over the CWA late this week. On Thursday elevated PoPs are
mostly confined to south of I-70, where moisture is most
abundant during the afternoon hours. PoPs in this region remain
elevated overnight, and less tied to the terrain, as a passing
weak wave of energy provides upper-level support while moisture
continues moving in. By Friday PWATs will be anomalously high
across the whole region, peaking near 150% of normal through
Saturday. This means widespread chances for showers and
thunderstorms across the CWA over the weekend, even outside of
the high terrain. A factor adding uncertainty into the forecast
is the impact of a tropical disturbance in the Pacific, which
recently became Tropical Storm Lorena. If the remnants of Lorena
move into the Southwest, there could be potential for
additional moisture advection to occur with the monsoonal push
from the pattern change. However, the forecast for this is still
uncertain between models, so not much can be said with
confidence. Moisture looks to slowly move out of the area
towards the end of the long term. Temperatures are expected to
cool this weekend with the increase in moisture, dropping highs
below normal.

&&

.AVIATION /06Z TAFS THROUGH 06Z THURSDAY/...
Issued at 1113 PM MDT Tue Sep 2 2025

Expect VFR conditions with light terrain driven winds through
the TAF period with mostly scattered mid to high clouds across
the region. Isolated showers and thunderstorms will develop
over the San Juan Mountains in southern Colorado between 18Z
and 00Z with lightning and gusty outflow winds the primary
threats.


&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...KAA
LONG TERM...GF
AVIATION...DB