661
FXUS65 KGJT 021110
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
510 AM MDT Thu May 2 2024

.KEY MESSAGES...

- Cooler temperatures expected today in the wake of the cold
  front that brought a few showers and passed through yesterday.

- A disturbance will brush the northern tier of eastern Utah
  and western Colorado on Friday, bringing a few valley rain and
  mountain snow showers along with it.

- Warmer and mainly dry conditions return on Saturday before
  turning windy on Sunday and more unsettled early next week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 200 AM MDT Thu May 2 2024

Yesterday`s and last night`s showers, which were associated
with a passing cold front, have either diminished or moved east
and out of the area as of early this morning. In the wake of the
front, much drier air is currently working in from the west, as
evidenced by dew points in the single digits and teens.
Satellite imagery shows a few clouds lingering along the central
and southern Continental Divide mountains, but expecting these
to largely dissipate by sunrise. The mainly clear skies, very
dry air, and light winds will result in ideal radiational
cooling conditions this morning, which suggests a chilly start
as you`re walking out the door. Additionally, it`s not
completely out of the realm of possibility for some patchy frost
to develop in the typically colder spots across the CWA. Those
with agricultural interests may want to keep an eye on those
temperatures. Otherwise, we`re looking at a lot of sunshine this
morning before clouds start to increase across the northern
tier of eastern Utah and western Colorado this afternoon. Those
clouds are in response to a weak wave that will brush along the
Colorado / Wyoming border. Given the aforementioned dry air
moving in, not expecting anything in the way of precipitation
today, other than maybe a sprinkle way up high. The chilly
start, the increasing afternoon clouds, and the post-frontal air
mass will keep temperatures near or even slightly below normal
for this time of year.

After a quiet and seasonably cool night tonight, attention then
turns to a stronger wave that will again trek across the border
of Colorado and Wyoming on Friday. Despite having a fair amount
forcing both aloft and along a surface cold front, the dry air
still in place will keep almost everywhere dry except portions
of northeast Utah, northwest Colorado, and the northern Colorado
mountains from late morning into the afternoon and evening.
Even in those areas, the highest precipitation totals will
mainly be confined to the higher elevations with a tenth up to a
quarter of an inch of QPF expected... maybe a bit more in the
Park Mountains. It will still be cold enough for snow up there
above 7000 to 8000 feet, so some light accumulations are a
decent bet. Given the time of year, however, little to no
impacts are anticipated. The cold front will bring cooler air in
across the north on Friday, but will have a tough time making
it much farther south than the I-70 corridor before washing out.
Thus, little change in temperature is expected across much of
southeast Utah and southwest Colorado. In fact, the washed out
cold front will return northward as a warm front Friday night
into Saturday, bringing much warmer temperatures to start off
the weekend. More on that in the long term discussion below.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 200 AM MDT Thu May 2 2024

On Saturday, the low to the west moves ashore over southern
Oregon causing the area to fall under broad difluent southwest
flow aloft. Meanwhile, strengthening southwesterlies will drive
the cold front northward and out of the forecast area with much
warmer air filtering into the region during the day. Lingering
moisture is expected to yield isolated to scattered showers and
thunderstorms over the mountains of the Continental Divide
Saturday afternoon while the remainder of the region remains dry
and warmer with highs climbing to around 10 degrees above
normal.

From Saturday night to Sunday the closed low moves over the
Great Basin. Pre-frontal height packing ahead of the impressive
cold front associated with this system will result in windy
conditions from late morning Sunday into the early evening. Pre-
frontal wind gusts could be as strong as 50-60 mph. Virga
showers with the arrival of midlevel moisture will only increase
the potential for these gusts. Moisture arrives over northeast
Utah early with showers becoming likely for the eastern Uinta
Mountains during the afternoon with more scattered activity
north of the I-70 corridor and far northwest Colorado. The
models including operational and ensemble are in decent
agreement with the system timing, track and strength. The center
of the low pressure looks to pass just to our northwest late
Sunday and lift out over the Plains on Monday. This will be the
most active period of this storm. Snow levels at the onset will
be around 10 kft, but drop to 6 kft by Monday morning due to the
cold front and lower heights. The northern and central
mountains have the best shot at accumulating snowfall with
perhaps advisory amounts in the northern ranges. A secondary
wave trough sweeps over the area Monday night into Tuesday and
as a result, the chance for showers over the northern mountains
will continue.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 510 AM MDT Thu May 2 2024

Skies have cleared across eastern Utah and western Colorado
with the exception of some high clouds streaming in from the
northwest. High and mid level clouds will become more prevalent
across the north this afternoon as a weak disturbance brushes
past the Colorado/Wyoming border. Ceilings should mostly stay
above ILS breakpoints. South of the I-70 corridor, mostly sunny
skies will prevail today. Winds will become a bit breezy this
afternoon with gusts of 25 to 35 mph common, especially in the
higher elevations. Winds become light and terrain driven shortly
after sunset with quiet weather to follow overnight.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...MDM
LONG TERM...KJS
AVIATION...MDM