612
FXUS65 KGJT 161116
AFDGJT

Area Forecast Discussion
National Weather Service Grand Junction CO
516 AM MDT Thu May 16 2024

.KEY MESSAGES...

- Scattered showers and thunderstorms favored over the southern
  mountains and adjacent valleys today with a few isolated
  storms possible into the central mountains. Gusty outflows
  and small hail are the main threats.

- Drier and warmer conditions move in tomorrow with
  temperatures running around 5-10 degrees above normal.

- Warm temperature persist through the weekend with isolated
  afternoon thunderstorms possible...before a general cool down
  begins for next week as the weather pattern becomes more
  unsettled.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 320 AM MDT Thu May 16 2024

The northern and southern stream systems are finally phasing
early this morning. An area of channelized vorticity extends
from the trough over the Northern Plains to the upper low moving
through the 4 Corners. This area of PV is showing up clearly on
H2O imagery and will be dropping through the southern half of
the CWA through the day. The bigger impacts will be over the
southern mountains and adjacent valleys when this forcing moves
through closer to peak heating for scattered shower and
thunderstorm development. Gusty outflow winds should continue to
be the main threat though a few of the stronger updrafts may be
capable of throwing out some small hail. This phasing system is
all being kicked eastward by a more robust upstream system that
will be arriving to PacNW by this evening...forcing a
transitory ridge across our CWA Friday for a warmer and drier
forecast across the board. High temperatures today...outside of
the stormier south...will be near to slightly above normal and
by tomorrow most areas should reach the 5 to 10 degrees above
normal mark.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 320 AM MDT Thu May 16 2024

The upper level trough, centered over southern Saskatchewan, will
continue to push into the Northern Rockies on Friday night, shifting
flow aloft across the forecast area to the west. A quick shower or
two may develop near the Wyoming border as the base brushes by but,
overall, Friday night will remain quiet with just some passing
clouds. This system will exit to the northeast for Saturday, making
room for yet another trough to dig into the Pacific Northwest during
the day. Additionally, a weak circulation hovering off the coast of
southern California will gradually lift into the Desert Southwest,
kicking off some light isolated to scattered showers and storms over
the southern mountains Saturday afternoon. The pattern gets muddled
going into the latter half of the weekend as the aforementioned
upstream trough pushes farther inland across the Intermountain West,
eventually absorbing this weak boundary coming up from the Four
Corners. Showers will begin to favor the northern tier of the region
for Sunday afternoon but orographics will likely fire off additional
convection for our other mountain ranges, or at least plenty of
clouds.

On Monday troughing aloft becomes more organized, hovering near the
Canadian border as it dominates the western CONUS. Southwest flow
will become more pronounced by Monday morning before it continues to
strengthen into Monday night. Still quite a bit to work out as far
as available moisture goes but, with this tightening gradient,
breezy conditions can be expected at the surface Monday afternoon.
There will be clouds and some showers to contend with so just how
windy remains to be seen. The main trough axis lifts overhead before
the midweek point with active weather looking to prevail going into
late May.

Unseasonably warm temperatures will dominate the weekend under mild
southwest flow. Afternoon highs will remain 6 to 12 degrees above
normal both Saturday and Sunday before values drop to just a few
degrees above normal for much of the region on Monday. If the trough
remains on track and pushes through early next week, Tuesday`s highs
will be below normal area-wide. Overnight lows through the long
term period will generally be on the mild side.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 515 AM MDT Thu May 16 2024

VFR conditions under mid to high cloudiness is expected over the
next 24 hours. A few showers and storms are possible over SW
Colorado this afternoon but coverage will be limited enough to
keep VC in the TAF forecast for now. Gusty winds remain the
main threat near storms.

&&

.GJT WATCHES/WARNINGS/ADVISORIES...

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

&&

$$

SHORT TERM...15
LONG TERM...MMS
AVIATION...TGJT