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Area forecast discussion 
National Weather Service Salt Lake City Utah
446 am MST Wednesday Feb 10 2016

Synopsis...high pressure aloft will remain the dominant weather
feature over the intermountain west through the end of the week.
A couple of weak weather disturbances will cross northern Utah
this weekend.

&&

Short term (until 00z sunday)...the strong upper ridge centered
across the intermountain region will remain in place as the
dominant weather feature through the end of the week. Stratus that
expanded rather quickly across the northwest desert yesterday now
encompasses much of the northern and western valleys early this
morning. Looking at some erosion of the stratus around the
perimeter this afternoon...though suspect most of this will return
again tonight.

The areal extent of fog continues to increase underneath the
valley inversions across western and northern Utah. Pockets of
dense fog have been observed...with the most notable increase
near the Great Salt Lake. Suspect that fog will remain an issue in
many of the same areas the next couple of nights as long as the
upper ridge remains locked in on the Great Basin.

A series of weakening shortwaves will at least temporarily knock
down the ridge this weekend. Enough lift could be generated by
these passing features to bring light precipitation to the far northern
zones Saturday. More importantly sufficient cooling aloft could
weaken over even mix out entirely the valley inversions in place
across northern Utah Saturday afternoon.

Long term (after 00z sunday)...the ridge will be flattened by a
trough that right now appears to have enough cold air to eradicate
the inversion according to the GFS. However...the once colder
solution (the ec) is not as cold as previous forecast from more than
12 hours ago. The fact that the GFS went away from the colder solution
for the 12z run but now has come back to nearly where it was 24 hours
ago with -7 to -10 degrees c my confidence is increasing that our
inversion will be broken here over the weekend. Due to the cold air
erasing the inversion...valley temperatures along the Wasatch front and
other valley will benefit for at least one day with better air.
Temperatures are expected to rise moderately due to the increased
instability.

Have boosted probability of precipitation over northern Utah and southwest Wyoming Saturday
night through Monday as a series of weak ripples move through. The
temperature difference between 700 mb and 500 mb is right at the threshold
to allow for some instability showers.

Tuesday the ridge rebuilds ahead of a stronger looking trough
scheduled for the end of the work week. Winds are expected to pick
up ahead of this latter storm system which will aid in dispersing
the stagnant air in the valleys and keep temperatures relatively
mild.

&&

Aviation...the slc terminal will have periods of vlifr and MVFR
conditions through about 17-18z this morning before becoming steady
MVFR conditions from 18z to 01z. There is a 40 percent chance of
dense fog after about 03z over the northwest corner of the slc
terminal and across the entire airfield after 05-06z. Winds will not
be a factor as speeds less than 5 miles per hour are expected through the taf
period.

&&

Slc watches/warnings/advisories...
Utah...none.
Wyoming...none.
&&

$$

Short term...Conger
long term/aviation...struthwolf

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