Area Forecast Discussion
Issued by NWS Grand Junction, CO

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FXUS65 KGJT 150944

Area Forecast Discussion
National Weather Service GRAND JUNCTION CO
344 AM MDT Sat Jul 15 2017

.SHORT TERM...(Today through Sunday)
Issued at 344 AM MDT Sat Jul 15 2017

The cyclonic circulation trapped under the ridge appears to have
cleared the divide overnight as is spinning over the eastern High
Plains of Colorado. This has circulated in some drier air with
PWAT now sitting at under 3/4 of an inch. There is enough moisture
for storms to fire over the terrain and mainly drift southward
over the next few afternoons. The southern mountains should see
slightly better coverage with storms then drifting into the
southern valleys. Shear still weak and do not expect much chance
of many other valleys seeing storms except where outflow
boundaries collide. Gusty outflow winds will continue to be the
main threat over the next few days before a better return of
moisture arrives later in the new week. Temperatures remain above
normal with triple digits found over the lower desert valleys of
southwest CWA.

.LONG TERM...(Sunday night through Friday)
Issued at 344 AM MDT Sat Jul 15 2017

As would be expected this time of year the stronger energy is in
the higher latitudes. Some of this energy is forecast to eject
from the Low of the Left Coast and travel through the Canadian
Prairies before being absorbed by a large circulation over
Northeast NOAM. The ridge appears to be strong enough to deflect
the stronger westerlies to the north though the ridge axis will be
slowly pushes east onto the Plains by mid week. Tuesday night into
Wednesday the position of the High circulation looks to be
favorable to bring up another batch of monsoonal moisture.
Ensemble anomaly progs do not suggest this is an huge push but we
should see better coverage of clouds and afternoon precipitation
mid-week onward. This will hold temperatures back down closer to
normal through at least Thursday afternoon. By late in the week
another Pacific storm wants to eject from the parent trough and
move across the CA/US border in the West. The Euro continues to be
a bit stronger with this system and pushes the northern extent of
the ridge a bit farther south. This would allow stronger westerly
flow to dip across the Great Basin and lean the southern moisture
tap to our southeast. The GFS isn`t buying into this and keeps at
least residual moisture in place over our CWA. Two outcomes leads
to very low confidence past midweek.


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 344 AM MDT Sat Jul 15 2017

Drier air should lead to lesser coverage of storms this afternoon.
Most TAF sites will remain precipitation free with the exceptions
at KTEX and KDRO where better storm coverage is expected. The
main threat will be gusty outflow winds with the drier air in
place. Outflow boundaries should be fairly visible on radar and
will be monitored for TAF updates. VFR conditions will prevail
over the next 24 hours and besides outflow winds, general winds
should remain light and follow the typical diurnal valley




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