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000 
FXUS65 KSLC 300304
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
904 PM MDT Wed Mar 29 2017

.SYNOPSIS...The next Pacific storm system will cross the area 
Thursday through Friday. High pressure returns for the weekend.

&&

.DISCUSSION...An upper trof is centered off the PacNW coast this
evening with a flat ridge downstream over the Great Basin. Skies 
were mostly clear across the CWA today and temps warmed to near or
a little above seasonal norms. 

The ridge shifts east overnight as the upper trof moves inland and
digs south. Moisture out ahead of this trof will spread into the
nwrn CWA tonight bringing scattered showers. The trof continues to
dig south into the Great Basin Thu with increasing lift across the
CWA and showers becoming more widespread over the north in the
morning spreading south in the aftn. 

The p-type problem for the Wasatch Front valleys has still yet to
be resolved with the 18z GFS similar to the 12z run pushing the 
front about half way thru the CWA by 00z Fri and bringing the cold
air far enough east to change precip over to snow. Meanwhile the 
new 00z NAM has leaned heavily towards the slower warmer EC 
solution with the front not reaching SLC until after 00z and 700 
mb temps over SLC never getting below -4C thru 12z Fri, keeping
precip rain in the valleys. 00z GFS not in yet. 

The 00z NAM run also shuts down Wasatch Front precip on Fri as 
the easterlies aloft pick up and advection flips from warm to 
neutral to cold during the day. Other lower confidence portions of
the forecast include the potential the airmass stays too warm 
across swrn WY thru Fri and precip type there becomes a rain snow 
mix or wet snow that has limited impact on travel. The other area 
could be post frontal winds across the northwest, as there may end
up being less cold air pushing in behind the front up north. 

It still looks good for snow to the valley floors across central
and swrn UT as well as in the central and srn mtns. 

The potential for canyon winds along the Wasatch Front is still
modest at best as there is little in the way of a surface gradient
that develops in spite of the stronger winds aloft and the weak
cold advection at 700 mb. 

For now, do not plan on making any changes to the existing suite
of Winter Weather and Wind highlights. Current short term forecast
for tonight on track and no updates planned. 

&&

.AVIATION...VFR conditions will prevail overnight at the SLC 
terminal although cloud cover will be increasing and cigs lowering. 
Expect cigs to dip below 7k feet around 13-15Z in association with 
prefrontal showers moving in vicinity of terminal. Southerly winds 
will become prevailing by 04z and persist overnight at the SLC 
terminal with the potential for periods of gusty winds increasing
tomorrow morning with the approach of precip. 

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Storm Warning from 6 PM Thursday to 6 AM MDT Saturday for 
     UTZ009-015-016-517-518.

     Winter Weather Advisory from 6 PM Thursday to 6 AM MDT Saturday 
     for UTZ007-008-010-014.

     High Wind Watch from Thursday afternoon through late Thursday 
     night for UTZ005.

WY...Winter Weather Advisory from 6 PM Thursday to 6 AM MDT Saturday 
     for WYZ021.

&&

$$

Wilensky/Carr

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