102  
FXUS65 KSLC 050921  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
321 AM MDT SUN OCT 5 2025  
   
SYNOPSIS  
A TRAILING SHORTWAVE BEHIND THE EXITING PACIFIC STORM  
SYSTEM WILL BRING SCATTERED SHOWERS TO NORTHERN UTAH AND SOUTHWEST  
WYOMING AS TEMPERATURES STAY ON THE COOL SIDE. OTHERWISE, DRY  
CONDITIONS WILL PERSIST FOR THE FIRST HALF OF THE WEEK, WITH  
TEMPERATURES WARMING BACK TO SEASONAL NORMALS BY MIDWEEK.  
 
 
   
SHORT TERM (THROUGH 12Z/6AM TUESDAY)  
THE PACIFIC STORM SYSTEM  
THAT BROUGHT SUBSTANTIAL PRECIPITATION TO NORTHERN UTAH AND  
SOUTHWEST WYOMING IS EXITING THE AREA THIS MORNING. HOWEVER, SOME  
SHOWERS STILL PERSIST OVER NORTHERN UTAH, IN PARTICULAR FOR THE  
NORTHERN WASATCH FRONT. THESE SHOWERS WILL TEND TO DIMINISH DURING  
THE MORNING. HOWEVER, A TRAILING SHORTWAVE WILL BRING ADDITIONAL  
INSTABILITY TO NORTHERN PORTIONS OF THE AREA, RESULTING IN  
SCATTERED CONVECTION, PARTICULARLY FOR AREAS CLOSER TO THE  
UTAH/IDAHO BORDER, THROUGH THE AFTERNOON. IN THE WAKE OF THE STORM  
SYSTEM, TEMPERATURES WILL REMAIN ON THE COOL SIDE, WITH MAXES  
AVERAGING 10F BELOW SEASONAL NORMALS.  
 
BY MONDAY, A REX BLOCK PATTERN IS EXPECTED TO DEVELOP OFF THE  
PACIFIC COAST, WITH A LOW SITUATED OFF THE SOUTHERN CALIFORNIA  
COAST AND A RIDGE OVER THE PACIFIC NORTHWEST. THIS WILL BRING  
SEVERAL DAYS OF DRY CONDITIONS WITH A GRADUAL WARMING TREND IN  
TEMPERATURES.  
   
LONG TERM (AFTER 12Z/6AM TUESDAY)  
SOUTHWEST WYOMING AND UTAH WILL  
BE DRY WITH CONDITIONS WARMING MUCH OF THE WEEK. ENSEMBLES ARE IN  
GOOD AGREEMENT THAT HIGH PRESSURE TO THE SOUTHEAST WILL RETROGRADE  
THROUGH FRIDAY INTO THE SOUTHWEST. TEMPERATURES WILL BE AROUND 5F  
COOLER THAN NORMAL TUESDAY. LOWS TO START THE DAY WILL BE COLD  
ENOUGH FOR FREEZE CONDITIONS FOR MANY VALLEYS, NOT INCLUDING THE  
URBAN CORRIDOR OF NORTHERN UTAH. VALLEY HIGHS WILL GENERALLY RANGE  
FROM THE MID 60S TO LOW 70S.  
 
WEDNESDAY AND THURSDAY WILL BE SIMILAR, WITH TEMPERATURES WARMING  
AROUND 5F EACH DAY.  
 
AS THE RIDGE TRACKS INTO THE SOUTHWEST, THERE WILL BE OTHER STORM  
SYSTEMS THAT APPROACH THE REGION. ENSEMBLES ARE IN GOOD AGREEMENT ON  
A LONGWAVE TROUGH APPROACHING THE WEST COAST, WHICH WILL ENHANCE  
SOUTHWEST WINDS FROM WEDNESDAY LIKELY INTO THE WEEKEND. THE OTHER  
FEATURE WILL BE REMNANTS OF A TROPICAL SYSTEM. TROPICAL STORM  
PRISCILLA, WHICH IS SOUTH OF BAJA CALIFORNIA, IS FORECAST TO BECOME  
A HURRICANE AND THEN BACK TO A TROPICAL STORM DURING THE WEEK AS IT  
TRACKS WEST OF BAJA CALIFORNIA. ENSEMBLES HAVE A RANGE OF TRACKS  
WITH THIS SYSTEM THAT WOULD INTERACT WITH THE RIDGE AND LONGWAVE  
TROUGH AS IT PUSHES INTO THE SOUTHWEST. THE DIFFERENT TRACKS MAKE  
FOR A RANGE OF PRECIPITATION TOTALS BETWEEN ENSEMBLE MEMBERS.  
 
REGARDLESS, PRECIPITATION PROBABILITY WILL PICK UP FRIDAY INTO THE  
WEEKEND. DEPENDING ON THE TRACK AND TIMING OF THE LONGWAVE TROUGH  
AND TROPICAL SYSTEM, PORTIONS OF UTAH COULD BE IN A LOCATION FOR AN  
IMPRESSIVE RAIN EVENT.  
 
 
   
AVIATION...KSLC  
DRY CONDITIONS WILL LAST THROUGH THE MORNING,  
WITH AROUND A 30% CHANCE FOR RAIN SHOWERS FROM 18-22Z. LIGHT  
SOUTHEAST WINDS WILL TRANSITION TO NORTHWEST AROUND 18Z.  
   
REST OF UTAH AND SOUTHWEST WYOMING  
SCATTERED RAIN SHOWERS WILL  
LAST THROUGH AROUND 00Z FOR SOUTHWEST WYOMING AND FAR NORTHERN UTAH.  
WINDS WILL BE LIGHT THROUGHOUT SOUTHWEST WYOMING AND UTAH, GENERALLY  
FROM THE NORTH OR NORTHWEST.  
 
 
   
FIRE WEATHER  
THE ROBUST STORM SYSTEM THAT BROUGHT SIGNIFICANT  
PRECIPITATION TO PORTIONS OF THE STATE IS EXITING THE AREA THIS  
MORNING, THOUGH SHOWERS CONTINUE OVER NORTHERN UTAH. A TRAILING  
SHORTWAVE WILL KEEP SCATTERED SHOWERS GOING THROUGH THE AFTERNOON,  
PARTICULARLY FOR AREAS NEAR THE UTAH/IDAHO BORDER, WITH DRY  
CONDITIONS FOR CENTRAL AND SOUTHERN UTAH. AFTER THAT, A REX BLOCK  
PATTERN WILL KEEP CONDITIONS DRY OVER UTAH THROUGH AT LEAST THE  
MIDDLE OF THE WEEK, WITH TEMPERATURES STEADILY WARMING BACK TO  
NEAR NORMAL FOR THIS TIME OF YEAR WITH LIGHT WINDS. AS SOUTHWEST  
FLOW DEVELOPS LATE IN THE WAKE, MOISTURE IS EXPECTED TO MOVE BACK  
IN, BRINGING INCREASING PRECIPITATION CHANCES, PARTICULARLY FOR  
SOUTHERN UTAH.  
 
 
   
SLC WATCHES/WARNINGS/ADVISORIES  
 
UT...NONE.  
WY...NONE.  
 
 
 
 
SHORT TERM/FIRE WEATHER...TRAPHAGAN  
LONG TERM/AVIATION...WILSON  
 
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...  
HTTP://WEATHER.GOV/SALTLAKECITY  
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