Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Salt Lake City Utah
951 am MDT Wednesday Aug 27 2014
Synopsis...an upper low over central Utah will move east out of
the area tonight. High pressure will follow for Thursday and
Discussion...an upper low spinning across the forecast area this
morning will slowly work its way eastward through the remainder of
the day. An embedded shortwave lifting northward along the eastern
periphery of this low is resulting in a cluster of showers and
thunderstorms across eastern Utah...while a broad plume of wrap-
around moisture is noted across southwest Wyoming/far northern
Utah...where an additional area of showers is noted. GOES
precipitable water imagery shows values of 0.75 to 1 inch across
northern and central Utah...while lower values are noted across
southern Utah owing to substantial drying aloft.
As the day wears on and the upper low slowly progresses
eastward...additional showers and thunderstorms are expected to
fire this afternoon...as a combination of lingering moisture...a
cold pool aloft...and a bit of surface heating result in modest
instability. These storms should be most numerous across the
higher terrain of northern and central Utah. Light flow aloft should
yield very slow cell movement...which could result in an isolated
heavy rain threat this afternoon.
As this upper low shifts east of the area this evening...shortwave
ridging will build across the Great Basin resulting in a drying
and warming trend through Friday.
Updated earlier to adjust morning probability of precipitation/weather based on radar
trends...and will likely update later on to remove morning
wording and refine afternoon probability of precipitation/weather if necessary.
Aviation...light and variable winds are expected to become
primarily northwest between 17-18z. Showers and possibly a few
thunderstorms will develop across the Salt Lake Valley this
afternoon and may cause gusty and erratic winds at times. There
is a 20 percent chance winds will remain primarily south through
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)