635 FXUS65 KSLC 210945 AFDSLC Area Forecast Discussion National Weather Service Salt Lake City UT 345 AM MDT Fri Jun 21 2019 .SYNOPSIS... The passage of a cold front will bring substantially cooler temperatures to the area today and tomorrow. Warm and dry conditions return next week. && .SHORT TERM (THROUGH 00Z TUESDAY)... Closed low currently over the Northern Rockies will tend to shear into a trough overhead tonight and tomorrow, before pressing eastward Sunday. The surface cold front has made it to the Arizona border, where locally enhanced northerly winds will continue this morning, and possibly re-develop for a few hours this evening. Experimental CIRA Advective Precipitable Water product shows the column moistening particularly in the 700-500mb layer over central and southern Utah. This anomalously rich moisture will support the development of weak instability near the boundary this afternoon. Expect convection to re-fire near the frontal zone. The next in a series of embedded waves rounds the closed low over northern Utah this morning, with a trailing one pivoting overhead this evening. The final kicker shears the system into a trough overhead tomorrow. Height falls are expected across the region through tomorrow morning, suggesting several periods of synoptic forcing. Am concerned by the 9km European model and our own in-house 3km WRF-ARW (HRRR/GFS boundary conditions) showing the potential for significant precipitation across portions of central and southern Utah late tonight into tomorrow morning as one of the aforementioned waves pivots overhead. None of the other Global or Convective Allowing Models viewed showed this scenario. Raised PoPs tonight, but not significantly, hoping the next shift sees better clustering of solutions. If it does occur, concern at low elevation of locally heavy rainfall and potential hydrologic impacts. The snow level will fall to mid-elevation, with accumulations likely especially above 9kft. The combination of building anticyclonic flow aloft, height rises and warming aloft, will end the threat of convective weather Saturday night. A warming/drying trend begins Sunday, and will continue next week. .LONG TERM (AFTER 00Z TUESDAY)... Quiescent weather should prevail through the long term as ridging becomes dominate downstream over the central CONUS and broad troughing resides along the PacNW coast. This will bring a prolonged period of southwesterly flow aloft to the FA for much of next week with warm and dry conditions persisting. The first 90 degree of the season is forecast for SLC by early to mid week. The winds across the western half of the FA will increase daily until Friday/Saturday due to a gradually tightening pressure gradient as the high to the east builds. Persistent warm, dry, and windy conditions will help dry and cure the fire fuels across portions of Utah over the course of next week. The continued warmth will also bring a return to rapid snowmelt and rises across area waterways. && .AVIATION... Northerly winds are expected to prevail at the KSLC terminal through the day. The wind speeds should increase through the afternoon with occasional gusts up to 15-20 kts possible. Mid level ceilings will intermittently prevail over the next 24-36 hours as weak shortwave troughs move through. The primary wx impact to operations today will be turbulence and icing across the southern arrival gates over the stalled out frontal boundary. && .FIRE WEATHER... ERC values are running below the 50th percentile, though values have risen during the past several days. The cold front has crossed all but far southeast Utah as of early this morning. Winds have diminished except for southern Utah near the boundary. Cooler with higher RH today and tomorrow. It will remain unsettled through Saturday across central and southern Utah. Snow is expected at high elevations of southern Utah and down into the mid elevations central Utah. A warming and drying trend begins Sunday and continues next week with breezy southwest winds. && .SLC WATCHES/WARNINGS/ADVISORIES... UT...None. WY...None. && $$ SHORT TERM/FIRE WEATHER...10 LONG TERM/AVIATION...Bonnette For more information from NOAA's National Weather Service visit... http://weather.gov/saltlakecity For frequently asked questions about the Area Forecast Discussion visit... http://weather.gov/saltlakecity/general/afd_faqs.php