777  
FXUS65 KSLC 272259  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
359 PM MST SUN NOV 27 2022  
   
SYNOPSIS
 
A STORM WILL IMPACT MUCH OF THE STATE MONDAY INTO  
TUESDAY, WITH A MUCH COLDER AIRMASS SETTLING IN FOR MIDWEEK. ANOTHER  
STORM IS EXPECTED FRIDAY INTO SATURDAY.  
 

 
   
SHORT TERM (THROUGH 00Z WEDNESDAY)
 
AFTERNOON UPPER AIR AND  
SATELLITE ANALYSIS INDICATES AN UPPER LEVEL TROUGH SHIFTING SOUTH  
FROM CANADA INTO THE NORTHERN TIER OF THE WEST. MEANWHILE, A  
NORTH/SOUTH ORIENTED JET FROM NEAR THE ARCTIC CIRCLE SOUTH TO THE  
PACNW IS LOCATED ON THE WEST SIDE OF THE DEVELOPING LONGWAVE  
TROUGH.  
 
WHILE THERE IS NO PRECIPITATION ON RADAR NOW, THIS WILL BE  
TEMPORARY AS THE LONGWAVE TROUGH SHIFTS SOUTHWARD THROUGH TUESDAY.  
 
A WINTER STORM WILL IMPACT MUCH OF UTAH MONDAY INTO TUESDAY. THIS  
STORM WILL LIKELY FEATURE TWO MAIN PARTS...AT LEAST FOR NORTHERN  
UTAH. BY MONDAY MORNING, MOIST WESTERLY FLOW WILL RESULT IN  
OROGRAPHICALLY ENHANCED PRECIPITATION ACROSS PORTIONS OF NORTHERN  
UTAH, ESPECIALLY IN NORMALLY FAVORED LOCATIONS SUCH AS THE  
NORTHERN WASATCH FRONT BENCHES OGDEN AREA MOUNTAINS, AND THE BEAR  
RIVER RANGE. DURING THIS TIME, NET MID-LEVEL COLD AIR ADVECTION  
WILL BE ONGOING. A WEAK SURFACE FRONT WILL ENTER NORTHERN UTAH  
MONDAY MORNING.  
 
WITH INCREASING FAVORABLE JET DYNAMICS, THE COLD FRONT WILL  
STRENGTHEN DURING A PERIOD OF FRONTOGENESIS, LIKELY SOMEWHERE NEAR  
OGDEN NEAR 21Z. THIS IS EXPECTED TO HELP DEVELOP A BAND OF  
MODERATE TO HEAVY SNOW THAT WILL IMPACT PORTIONS OF THE WASATCH  
FRONT AND ADJACENT MOUNTAINS DURING THE MONDAY EVENING COMMUTE.  
MODEL SOUNDINGS INDICATE THE POTENTIAL FOR SIGNIFICANT LIFT WITHIN  
THE DENDRITIC GROWTH ZONE. ALL THIS TO SAY, THERE MAY BE A PERIOD  
OF SNOW RATES NEAR 1-2 INCHES AN HOUR WITH THIS BOUNDARY FROM  
ROUGHLY OGDEN SOUTHWARD DURING THE MONDAY EVENING  
COMMUTE...ESPECIALLY ALONG THE BENCHES.  
 
ONCE THE FRONT CLEARS THE AREA, DEEP, MOIST NORTHWEST FLOW WILL  
CONTINUE ACROSS NORTHERN UTAH, FAVORING THE USUAL SUSPECT FOR  
OROGRAPHIC ENHANCEMENT (SUCH AS THE COTTONWOODS). DURING THIS  
PORTION OF THE STORM, SOME LOCATIONS MAY SEE SNOW DECREASE OR EVEN  
STOP FOR A TIME...BUT THE NEXT SHORTWAVE TROUGH WILL BRING ANOTHER  
ROUND OF SNOW TO PORTIONS OF NORTHERN AND CENTRAL UTAH MONDAY  
NIGHT INTO AT LEAST TUESDAY MORNING.  
 
THE BIG QUESTION MARK IS THE POTENTIAL FOR LAKE EFFECT SNOW,  
PRIMARILY FOR LOCATIONS FROM BOUNTIFUL SOUTH TO SALT LAKE COUNTY.  
WITH 700MB TEMPERATURES NEAR -14 TO -16C (WITH THE LAKE NEAR  
3-4C), DEEP MOISTURE AND NORTHWESTERLY FLOW, EXPECT THE THREAT OF  
LAKE EFFECT SNOW OR LAKE ENHANCED SNOW SHOWERS TO IMPACT THESE  
LOCATIONS. NOTABLY, THE BREADTH OF AVAILABLE CAMS SHOW A DISCRETE,  
HEAVY LAKE EFFECT SNOW BAND IMPACTING SALT LAKE COUNTY INTO THE  
COTTONWOODS MONDAY NIGHT INTO TUESDAY MORNING.  
 
LAKE EFFECT SNOW BANDS ARE DIFFICULT TO PREDICT WITH THIS MUCH  
LEAD TIME DOWN TO SPECIFIC LOCATIONS AND SNOW ACCUMULATIONS AS A  
RESULT OF THESE BANDS DEPEND ON WHETHER THE BAND IS FAIRLY  
PERSISTENT AND STATIONARY OR MORE PRONE TO A WAVERING PORTION.  
HOWEVER, EXPECT AT LEAST SOME LAKE EFFECT/LAKE ENHANCED SNOW WILL  
IMPACT THE TUESDAY MORNING COMMUTE FOR A PORTION OF FAR SOUTHERN  
DAVIS OR SALT LAKE COUNTY (AND POTENTIALLY THE SANTAQUIN TO  
SPANISH FORK AREA OFF UTAH LAKE). IF THIS DOES OCCUR AND THE BAND  
IS DISCRETE AND PERSISTENT IN ONE LOCATION, FORECAST SNOW TOTALS  
WILL BE ON THE LOW SIDE.  
 
ISSUED WINTER WEATHER ADVISORIES FOR THE WASATCH FRONT FROM  
WEBER/DAVIS COUNTY SOUTH TO UTAH COUNTY AS WELL AS THE WASATCH  
BACK AND UINTA COUNTY, WY. ALSO ADDED THE CENTRAL AND SOUTHERN  
MOUNTAINS...BASED ON THE EXPECT IMPACT TO MOUNTAIN ROUTES.  
WILL NEED TO MONITOR THE POTENTIAL FOR UPGRADES EITHER WITH A  
SIGNIFICANT IMPACT TO EITHER THE MONDAY EVENING OR TUESDAY MORNING  
COMMUTES, OR AN EXPECTED DISCRETE, HEAVY SNOW AREA OF LAKE EFFECT  
SNOW.  
   
LONG TERM (AFTER 00Z WEDNESDAY)
 
COLD CONDITIONS ARE EXPECTED AT  
THE BEGINNING OF THE LONG TERM. AS A TROUGH EXITS THE REGION, COLD  
AIR WILL FOLLOW BEHIND IT. THIS WILL BRING TEMPERATURES DOWN TO 10  
TO 15 DEGREES BELOW AVERAGE. LOW TEMPERATURES WEDNESDAY MORNING WILL  
BE NEAR ZERO OR SLIGHTLY BELOW ZERO FOR SOME NORTHEASTERN UT VALLEYS  
AND UINTA COUNTY WY. AS FOR MOST OF THE OTHER VALLEYS TEMPERATURES  
WILL BE IN THE SINGLE DIGITS TO MID TEENS. LOWER WASHINGTON COUNTY  
IS EXPECTED TO BE IN THE MID TO UPPER 20S. PRIOR TO THE COLD AIR ON  
WEDNESDAY MORNING, SOME LINGERING MOUNTAIN SNOW SHOWERS WILL BE  
POSSIBLE TUESDAY NIGHT.  
 
AFTER THIS TROUGH MOVES OUT, RIDGING WILL TAKE OVER THE AREA AND  
PROVIDE A BRIEF BREAK BEFORE ANOTHER TROUGH EFFECTING OUR AREA LATER  
THIS WEEK. TEMPERATURES ARE EXPECTED TO REBOUND FROM WEDNESDAY  
MORNING AND BE CLOSER TO AVERAGE, HOWEVER THIS MAY NOT BE THE CASE  
AS VALLEY INVERSIONS COULD FORM PENDING ON HOW MUCH SNOW IS ON THE  
GROUND FROM THE EARLY WEEK STORM. SOUTHWEST FLOW KICKS IN AHEAD OF  
THE INCOMING TROUGH WHICH WILL RESULT IN GUSTY SOUTHWEST WINDS  
DURING THE DAY ON THURSDAY. CURRENTLY THESE WIND GUSTS ARE AROUND  
ADVISORY LEVEL FOR WESTERN UT. THIS WILL BE SOMETHING TO MONITOR TO  
SEE IF WIND HEADLINES WILL BE NEEDED FOR THURSDAY.  
 
ANOTHER ASPECT OF THIS TROUGH TO WATCH OUT FOR IS THE POTENTIAL FOR  
AN ATMOSPHERIC RIVER (AR) EVENT TO OCCUR. GUIDANCE IS GROWING IN  
CONFIDENCE THAT WHERE THE TROUGH IS POSITIONED AT WILL LEAD TO  
INCREASED AMOUNTS OF MOISTURE ACROSS THE WESTERN US. FOR OUR CWA,  
PWAT VALUES OF 0.3" TO 0.5" ARE EXPECTED BETWEEN THURSDAY AND  
FRIDAY. ANY MOISTURE THAT DOES FALL WILL BEGIN AS RAIN IN THE  
VALLEYS AND SNOW IN THE MOUNTAINS. VALLEYS WILL SEE A GREATER CHANCE  
AT SNOW WHEN THE COLD AIR ADVECTION MOVES IN FRIDAY  
AFTERNOON/EVENING. THERE IS A DECENT AMOUNT OF UNCERTAINTY REGARDING  
THIS AR EVENT. BOTH ENSEMBLE AND DETERMINISTIC GUIDANCE AGREE THAT  
THE TROUGH WILL MOVE INLAND BUT THE TIMING AND LOCATION OF THIS  
INLAND PUSH ARE UNCERTAIN. A COLD FRONT IS ALSO EXPECTED TO MOVE  
THROUGH THE AREA BUT GUIDANCE SHOWS IT MOVING THROUGH EITHER FRIDAY  
OR SATURDAY.  
 

 
   
AVIATION...KSLC
 
VFR CONDITIONS WILL PERSIST OVERNIGHT AND  
GRADUALLY TRANSITION TO MVFR AND BRIEF PERIODS OF IFR/LIFR  
CONDITIONS TOMORROW AFTERNOON. WINDS WILL REMAIN SOUTHERLY THROUGH  
TOMORROW AFTERNOON BEFORE TRANSITIONING NORTHWESTERLY BEHIND A  
COLD FRONT. AS THE DAY PROGRESSES PRECIPITATION WILL REACH VALLEY  
FLOORS WITH A FEW SNOW SHOWERS DURING THE AFTERNOON CREATING MVFR  
CONDITIONS WITH PERIODS OF IFR/LIFR CONDITIONS UNDER HEAVIER  
BURSTS OF SNOW, PARTICULARLY BETWEEN 22-01Z.  
   
REST OF UTAH AND SOUTHWEST WYOMING
 
FOR NORTHERN UTAH/SW  
WYOMING, VFR CONDITIONS WILL GRADUALLY TRANSITION TO THE MVFR AND  
BRIEF PERIODS OF IFR/LIFR CONDITIONS TERMINALS AS A WINTER STORM  
APPROACHES TOMORROW MORNING. AS THE DAY PROGRESSES PRECIPITATION  
WILL REACH VALLEY FLOORS WITH A FEW SNOW SHOWERS DURING THE  
AFTERNOON CREATING MVFR CONDITIONS WITH PERIODS OF IFR CONDITIONS  
UNDER HEAVIER BURSTS OF SNOW. THESE SPOTTY SNOW SHOWERS WILL  
TRANSITION TO A BAND OF MODERATE TO HEAVY SNOW AS THE MAIN COLD  
FRONT ARRIVES BETWEEN 22-01Z. CONDITIONS WILL LIKELY REDUCE VIS AND  
CIGS TO IFR/LIFR LEVELS FOR 1-2 HOURS. AHEAD OF THE COLD FRONT WINDS  
WILL REMAIN SOUTHERLY ~10KTS. BEHIND THE COLD FRONT WINDS WILL  
TRANSITION TO NORTHWESTERLY. AFTER THE MAIN FRONTAL SNOW BAND PUSHES  
THROUGH THERE IS A POSSIBILITY OF A LAKE EFFECT SNOW BAND SETTING UP  
SOUTHEAST OF THE GREAT SALT LAKE LATE MONDAY INTO EARLY TUESDAY.  
HEAVY SNOW WILL ACCOMPANY THIS BAND AND WILL REDUCE VIS AND CIGS TO  
IFR/LIFR.  
 
FOR SOUTHERN UTAH, VFR CONDITIONS WILL PREVAIL THROUGH MOST OF THE  
PERIOD AS THE AFOREMENTIONED STORM WON'T ARRIVE UNTIL AFTER 00Z  
TUESDAY.  
 

 
   
SLC WATCHES/WARNINGS/ADVISORIES
 
 
UT...WINTER WEATHER ADVISORY FROM 2 PM MONDAY TO 2 PM MST TUESDAY FOR  
UTZ102-104>106.  
 
WINTER WEATHER ADVISORY FROM 7 AM MONDAY TO 2 PM MST TUESDAY FOR  
UTZ108.  
 
WINTER WEATHER ADVISORY FROM 5 AM MONDAY TO NOON MST TUESDAY FOR  
UTZ110.  
 
WINTER WEATHER ADVISORY FROM 5 AM MONDAY TO 7 PM MST TUESDAY FOR  
UTZ111-112.  
 
WINTER WEATHER ADVISORY FROM 5 PM MONDAY TO 2 PM MST TUESDAY FOR  
UTZ117-125.  
 
WY...WINTER WEATHER ADVISORY FROM 7 AM MONDAY TO 2 PM MST TUESDAY FOR  
WYZ021.  
 

 
 

 
 
KRUSE/CECAVA/MAHAN  
 
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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