322  
FXUS65 KSLC 222313  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
413 PM MST WED JAN 22 2020  
   
SYNOPSIS
 
HIGH PRESSURE ALOFT WILL SHIFT EAST ACROSS THE GREAT  
BASIN AND BRING MORE STABLE CONDITIONS TO THE AREA TOMORROW. A FAST-  
MOVING TROUGH WILL CROSS NORTHERN UTAH ON FRIDAY, FOLLOWED BY  
ANOTHER STORM SYSTEM ON MONDAY.  
 

 
   
SHORT TERM (THROUGH 12Z SATURDAY)
 
THE UPPER TROUGH AND  
ASSOCIATED JET AXIS HAS SHIFTED EAST OF THE AREA THIS AFTERNOON.  
MEANWHILE, THE 700MB BAROCLINIC ZONE HAS WEAKENED ACROSS THE SALT  
LAKE AND UTAH VALLEYS. AS SUCH, PRECIPITATION HAS BEEN ON THE  
DECLINE THE PAST SEVERAL HOURS, ALTHOUGH LOW CLOUDS AND LIGHT  
MOUNTAIN SNOWFALL CONTINUE TO PERSIST ACROSS PORTIONS OF NORTHERN  
UTAH.  
 
WARM ADVECTION HAS ALREADY BEGUN JUST UPSTREAM, AND WILL SHIFT  
ACROSS NORTHERN UTAH TONIGHT INTO TOMORROW MORNING. A SLIGHT UPTICK  
IN SNOW IS EXPECTED ACROSS MAINLY THE NORTHERN MOUNTAINS WITH THIS  
WARM ADVECTION. OTHERWISE, UTAH WILL REMAIN UNDER NORTHWESTERLY FLOW  
THROUGH TOMORROW AS HIGH PRESSURE BUILDS UPSTREAM.  
 
THE STABLE AIRMASS WILL MAINTAIN INVERSION CONDITIONS ACROSS THE  
EASTERN VALLEYS. FAIRLY EXTENSIVE LOW STRATUS REMAIN IN PLACE THERE  
CURRENTLY, AND THE INCREASING NORTHWEST WINDS ALOFT TONIGHT ARE NOT  
EXPECTED TO SURFACE EXCEPT POSSIBLY IN THE IMMEDIATELY DOWNSLOPE  
REGIONS. AS SUCH, EXPECT STRATUS TO CONTINUE THROUGH AT LEAST  
TOMORROW, WITH SOME PATCHY FOG DURING THE NIGHTTIME AND MORNING  
HOURS.  
 
THE NEXT TROUGH WILL MOVE QUICKLY ACROSS THE AREA ON FRIDAY,  
BRINGING ANOTHER ROUND OF PRECIPITATION TO NORTHERN UTAH. THE AIRMASS  
WILL REMAIN RELATIVELY MILD, AND AS SUCH, MOST VALLEYS EXCEPT THOSE  
ALONG THE IDAHO BORDER ARE EXPECTED TO SEE MOSTLY RAIN ONCE AGAIN.  
   
LONG TERM (AFTER 12Z SATURDAY)
 
BRIEF RIDGING WILL SHIFT ACROSS  
THE REGION FOR THE FIRST PART OF THE LONG TERM FORECAST PERIOD.  
PERSISTENT INVERSIONS MAY CONTINUE ACROSS THE EASTERN VALLEYS INTO  
SATURDAY AND POTENTIALLY SUNDAY. THIS WILL LIKELY SUPPRESS  
TEMPERATURES IN THESE AREAS.  
 
A SOMEWHAT DISORGANIZED SHORTWAVE...LIKELY IN THE PROCESS OF  
SPLITTING...WILL MOVE ACROSS THE REGION SUNDAY AFTERNOON INTO  
MONDAY. CURRENT MODEL TRENDS WOULD BRING THE MAIN AREA OF  
PRECIPITATION ACROSS THE VALLEYS LATE SUNDAY INTO EARLY MONDAY.  
PROFILES ARE LARGELY SUPPORTIVE OF RAIN OR RAIN MIXED WITH SNOW AT  
ONSET, GRADUALLY CHANGING TO SNOW BY MONDAY MORNING. ACCUMULATIONS  
WILL BE POSSIBLE FOR MOST OF THE STATE. NORTHWEST FLOW WILL REMAIN  
IN THE WAKE OF THIS SYSTEM. SEVERAL SYSTEMS EMBEDDED IN THIS FLOW  
MAY CONTINUE THE THREAT OF SHOWERS THROUGH MIDWEEK.  
 

 
   
AVIATION
 
THE SLC TERMINAL WILL SEE VFR CONDITIONS THROUGH THE  
EVENING WITH CIGS AROUND 6000 FEET AGL. LIGHT NORTHWEST WINDS ARE  
EXPECTED TO SHIFT TO THE SOUTHEAST BETWEEN 03Z AND 05Z.  
 

 
   
SLC WATCHES/WARNINGS/ADVISORIES
 
 
UT...NONE.  
WY...NONE.  

 
 

 
 
CHENG/KRUSE/TRAPHAGAN  
 
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  
 
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