Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 160629

Area Forecast Discussion
National Weather Service Grand Junction CO
1229 AM MDT Sun May 16 2021

.SHORT TERM...(Tonight through Sunday night)
Issued at 216 PM MDT Sat May 15 2021

Showers and thunderstorms are moving across northern portions of
western Colorado at this hour. With relatively dry lower levels,
these storms aren`t likely to produce much in the way of rainfall,
and the main threat will be gusty outflow winds, possibly in
excess of 50 mph. These storms will continue to push north
through the afternoon, eventually moving out of Colorado
altogether. Overnight, a finger of elevated subtropical moisture
is forecast to push north into the area as the broad deformation
zone associated with the next Pacific system moves through. HiRes
models are still suggesting some nocturnal showers or storms over
the northern San Juans and into the central mountains, but this
is likely to be mainly accas. Tomorrow is expected to be mainly
dry, though the chance for showers and storms returns again in the
afternoon across northern portions of the CWA. Temperatures are
expected to remain 5-10 degrees above normal. The resulting highly
mixed atmosphere will lead to gusty afternoon winds and localized
critical fire weather conditions across the Four Corners region.

.LONG TERM...(Monday through Saturday)
Issued at 216 PM MDT Sat May 15 2021

The closed low will be parked almost directly over the Four Corners
Monday morning and will remain there for much of the day. Both the
GFS and EC deterministic models agree with this solution and both
also highlight some precip along the Divide and also across the Book
Cliffs in the afternoon. Some minor circulation at the H7 level
along with some deformation and daytime heating will allow some
showers and storms to form.  Who knows...maybe some precip will even
reach the ground...time will tell.

By Tuesday, the low over the Four Corners will have filled while
another forms on the Front Range. Some residual showers will persist
over the higher terrain in the afternoon but QPF amounts look to
remain below .1 inch for every 3-hr period so more clouds than
actual precip hitting the ground will be the case.

Wednesday, a fairly stout closed low comes ashore over the PacNW. A
weak wave well ahead of this low will move across the CWA Wednesday
bringing another round of clouds...showers and storms. The good news
is that PWATs look to increase to around .5 to .75 inches across the
forecast area so maybe...just maybe...some rain will actually hit
the ground.

On Thursday, the closed low starts to move across the Great Basin
and as small pieces of energy break off from the parent low and move
across the forecast area, we`ll continue to see some
showers/storms in the afternoon. Friday and Saturday look to be
fairly dry for us but the location of the low and increased upper
level winds will likely bring some stronger winds to the surface
for both days. Fire weather concerns may become an issue as we
head into the weekend. Here`s hoping the low tracks a bit further
south giving us a chance for some precip. We`ll be keeping an eye
on things...


.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
Issued at 1229 AM MDT Sun May 16 2021

Mid and high level cloudiness will drift across the region
overnight with the outside chance of a terminal seeing a sprinkle
with no impacts to flight criteria. Similar conditions expected on
Sunday with isolated to widely scattered storms over the mountains
and northern valleys of Utah and Colorado. Gusty outflow winds
will the main threat from showers and storms tomorrow afternoon.




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