Area Forecast Discussion
Issued by NWS Salt Lake City, UT
FXUS65 KSLC 281621
Area Forecast Discussion
National Weather Service Salt Lake City UT
1021 AM MDT Tue Mar 28 2017
.SYNOPSIS...High pressure aloft will expand across the Great
Basin tonight through Wednesday. The next Pacific storm system
will bring a cold and wet end to March late in the week.
.DISCUSSION...The axis of the upper trough along the Utah/Colorado
border will continue east today. A increasingly dry/stable air
mass will follow the exiting trough as the upper ridge currently
along the west coast expands east across the Great Basin tonight
The next storm system to impact Utah will originate from a
shortwave currently over the western Gulf of Alaska. This feature
will translate east, reaching the Pacific Northwest coast
Wednesday night, From there this feature driven by strong jet
support will turn hard to the southeast and deepen as it settles
into the western Great Basin late Thursday.
Both the 12Z GFS and 00Z ECMWF developed a closed circulation by
Thursday evening, with this circulation tracking slowly east
across the Basin through Friday. A rather tight low-level
baroclinic zone associated with this upper level feature will
enter western Utah late Thursday. Strong low-level cold advection
across southwest Utah along with dynamic lift from the advancing
mid-level circulation and favorable upper divergence in the left
exit region of the jet should support widespread convective precip
across much of southern/central Utah Thursday night, The northern
extent of this baroclinic zone over northern Utah will see
somewhat less thermal advection, though as the upper low becomes
better developed the resultant easterly flow aloft will create
low-level convergence along the boundary and decent lift to
support widespread precip.
The heaviest precip Friday will remain in the best synoptic-scale
lift near the center of the upper low over the southern/central
portions of the state. Up north a deepening east-northeast flow
aloft will create downsloping west of the Wasatch range which
should result in significantly less precip as the day progresses.
Precip will wind down Friday night as the center of the upper low
moves east of the four corners region.
Issued an earlier update to reduce cloud cover and pops today.
Remainder of the forecast packages looks good at this time.
.AVIATION...Northerly winds will remain in place at the KSLC
terminal through today. Ceilings near 5000-5500 feet AGL are
expected to gradually diminish through 16-17Z.
UT...Wind Advisory until noon MDT today for UTZ019.
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