Weather

520 
fxus65 kslc 060426 
afdslc 


Area forecast discussion 
National Weather Service Salt Lake City Utah 
926 PM MST Monday Jan 5 2009 


Synopsis...a moist west northwest flow will continue to affect 
southwest Wyoming and mainly northern and central Utah through 
Tuesday night. High pressure will return for Wednesday and 
Thursday. 


&& 


Discussion...warm advection precipitation has ended as upper trough axis 
moves past and instability plus orographics are the remaining 
driving forces for lift. These should be sufficient to keep 
scattered to numerous snow showers going along the windward slopes 
of the northern and central mts and a bit upstream into the adjacent 
valleys for several more hours. So will keep advisories going for 
now. 


Snow showers wind down late tonight and early Tuesday as middle level 
airmass warms and low levels remain cold. Low level warm advection 
starts again by midday Tuesday strong enough to generate another round 
of precipitation. This should be mainly confined to about Utah County 
northward but should be snow down to the valley floors due to cold 
air remaining near the surface in spite of the warming aloft. 


The upstream ridge moves inland far enough by Wednesday morning to shut 
off most of the precipitation but models indicate there will not be any 
real drying of the low levels so the northwestern valleys could 
keep cold air trapped and with the addition of moisture from the 
precipitation...could fill with stratus. 


This would persist until the next cold front forecast to move 
through the County Warning Area Thursday night and Friday with enough of a northerly 
surface gradient behind to mix out the valleys. 


Updated forecasts earlier to indicate a more showery and scattered 
nature to the precipitation and adjusted probability of precipitation somewhat. May update again 
to remove some of the advisory highlights if situation warrants. 


&& 


Aviation...VFR or high end MVFR ceilings are expected to continue 
at the slc terminal through the night. Isolated IFR conditions from 
03z to 06z in heavier snow are possible. VFR conditions are expected 
after 06z with isolated MVFR conditions until 12z. The terminal will 
see light and variable winds throughout the remainder of the night. 


&& 


Slc watches/warnings/advisories... 
Utah...Winter Weather Advisory until 4 am Tuesday for utz001-utz002- 
utz003-utz004-utz006-utz007-utz008-utz009. 


Wyoming...none. 


&& 


$$ 


Wilensky/Young 


For more information from National oceanic and atmospheric administration/S National Weather Service visit... 
http://weather.Gov/saltlakecity (all lower case)