Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Salt Lake City Utah
423 am MST Wednesday Nov 26 2014
Synopsis...high pressure aloft across the Great Basin will bring
dry and mild conditions to the region through the first half of
the upcoming weekend.
Short term (until 00z sunday)...the strong upper ridge currently
over the West Coast states will flatten as it expands eastward
across the Great Basin today. The resultant broad low-amplitude
ridge will keep cold air and deep layer well removed to the north
of Utah through the end of the week. Maximum temperatures will trend
upward across the forecast area today...then level off a bit but
remain above late November normals through at least Saturday.
A series of shortwaves embedded within the west-southwest flow
over the top of the ridge will slowly lower heights across
northern Utah late Friday through Saturday. A remote chance for
precipitation will exist near the Idaho border late Saturday. The
increasingly moist warm advection pattern sagging into far
northern Utah could generate sufficient lift for light precipitation
late Saturday afternoon.
Long term (after 00z sunday)...a moist convergent zonal flow
continues through the weekend. Latest models more convinced that
a short wave passing through the state on Sunday will deliver
precipitation to northern Utah. As such have ramped up probability of precipitation a
bit in this region.
Heights rise on Monday as a Pacific trough nudges toward Utah. Winds
increase significantly statewide and temperatures hover well above
normals in the well-mixed environment. Both the European model (ecmwf) and GFS global
models continue to agree on the likelihood of the system splitting
as it nears the state. Both push back the timing of precipitation
onset and suggest a surface front plowing into the northern region
on Tuesday...with precipitation continuing into Wednesday. 06z run of GFS
much closer to ec in keeping warm temperatures through duration of
precipitation...which at this point would suggest a primarily rain event
for the valleys with rather high snow levels. However...too much
overall inconsistency to alter current snow levels and temperatures to
reflect this latest model solution.
Aviation...VFR conditions with any ceilings well above 6000 feet above ground level
are expected at the kslc terminal through taf period. Southerly
surface winds should continue into the afternoon...with a 30 percent
chance of switching to the northwest after 20z.
For more information from National oceanic and atmospheric administration/S National Weather Service visit...
http://weather.Gov/saltlakecity (all lower case)
For frequently asked questions about the area forecast discussion
http://weather.Gov/saltlakecity/general/afd_faqs.Php (all lower case)