Cardiff, Colorado Weather Forecast Discussion

487
FXUS65 KGJT 051808
AFDGJT
Area Forecast Discussion
National Weather Service Grand Junction CO
1208 PM MDT Fri Sep 5 2025
.KEY MESSAGES...
- Scattered to widespread showers and thunderstorms will bring
  heavy rain, gusty winds, and lightning across the region
  today, tomorrow and Sunday.
- Burn scar flash flooding will be possible through the weekend
  if any of the stronger cells with heavy rain move over the
  recent burn scars.
- Temperatures will remain around climatology before a warmup
  starts Monday onwards.
&&
.SHORT TERM /THROUGH SATURDAY/...
Issued at 341 AM MDT Fri Sep 5 2025
Radar indicates the mesovortex/disturbance as predicted by the
models is slowly moving to the northeast from Monticello up towards
Montrose keeping light showers going through the night from the Four
Corners up across the San Juans into the Uncompahgre Valley. Another
disturbance, and outflow boundary that moved down from Wyoming was
enough to touch off a few light showers up north and is kicking up a
few showers in the Eagle Valley. Satellite shows plentiful moisture
in place across eastern Utah and Western Colorado, and with very
weak flow aloft, it will remain in the area for another round of
showers and thunderstorms again today supported by diurnal heat, the
mesovortex and weak speed divergence aloft of an entrance region to
a jetstreak. The dynamics move out of the region this evening to
shut down convective activity, but a shortwave moves through from
the west Saturday with an increased surge of moisture out of the
Great Basin and possibly some remnants of Lorena.
For the forecast, look for scattered showers and thunderstorms
generally across the southern areas this morning spreading north to
the I-70 corridor through the afternoon. With the more saturated
atmosphere, outflow winds will only gust around 30 mph, but with the
deep moisture and weak flow aloft, expect more areas of heavy rain
and localized flooding due to training and stalled storms. If these
conditions occur on one of the fire scars, significant flash
flooding and debris flow may result. Saturday will be very similar
with the showers and thunderstorms pushing farther north over the
Tavaputs, the Roan and the Flat Tops. With the surge of moisture
Saturday, the risks for heavy down pours with localized flooding
will peak through the afternoon. If you plan to be out in areas
prone to flash flooding or in the vicinity of the fire scars, stay
aware of your surroundings and the weather in the area. Flash
flooding and debris flows can occur miles from where the rain
falls. Check the forecast before you go out and have alerts active
on your phone, but know that many of these areas don`t have cell
service available.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
Issued at 203 PM MDT Thu Sep 4 2025
Monsoonal moisture will be well established over the region on
Saturday, allowing for PWAT anomalies to peak around 150-175% of
normal. As such, widespread showers and thunderstorms continue to be
in the forecast on Saturday. The precipitation activity will be
supported by a shortwave moving across the region through early
Sunday. The support from the shortwave may increase the chances of
heavier rainfall, which could raise flash flooding concerns over the
new burn scars in the region. Relatively drier air in the northern
most part of the region keeps PoPs lower there, and increases the
chances of gusty outflow winds with storms. PoPs are expected to
stay elevated through the night with the shortwave passage before
Sunday`s afternoon convection begins. On Sunday, moisture
remains but begins to make its way out of the area resulting in
mostly terrain driven convection from the decrease in moisture
and loss of upper-level support. PWAT anomalies fall closer to
normal on Monday, leading to decreased coverage of terrain based
convection through the early workweek. Increased cloud cover
should keep daytime high temperatures down to 5 degrees below
normal through the weekend, but the decrease in moisture next
week should increase highs to near or just above normal.
&&
.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1207 PM MDT Fri Sep 5 2025
Showers and thunderstorms continue from the Uncompaghre Plateau over
to the Elk Mountains, and points south late this morning as a
remnant MCV from overnight convection continues to meander south-
southeast. This circulation is already sparking early thunderstorm
development near KTEX and the San Juans and will likely continue to
cause scattered thunderstorms through the afternoon there as well as
south to KDRO as these thunderstorms exit the high terrain in the
northwest to northerly flow.
Elsewhere, lingering higher PWATS will promote shower and
thunderstorm development over the higher terrain during the mid-
afternoon from the Grand Valley into the Elk Mountains, with
showers/storms coming off of the terrain and moving northwest to
southeast into the early evening. Generally where thunderstorms are
expected, ceilings down to 5000 to 8000ft may occur. Otherwise cloud
bases will be 10000ft or higher. Large surface Tdds may support some
sporadic gusty winds with storms as well.
KCNY and TAF sites north of the Flat Tops/northern edge of the CO
plateau will likely stay dry through today with some mild intrusions
of wildfire smoke at the surface. Vis down to 6SM may occur.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...None.
UT...None.
&&
$$
SHORT TERM...DB
LONG TERM...GF
AVIATION...CAM

NWS GJT Office Area Forecast Discussion