482  
FXUS65 KSLC 170918  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
318 AM MDT WED SEP 17 2025  
   
SYNOPSIS
 
THE STORM SYSTEM IS EXPECTED TO PUSH EAST THIS EVENING  
MAKING WAY FOR HIGH PRESSURE WITH DRY AND WARM CONDITIONS ON  
THURSDAY. MOISTURE INCREASES AGAIN FRIDAY INTO THE WEEKEND BEFORE  
DRIER AND WARM CONDITIONS RETURN EARLY NEXT WEEK.  
 

 
   
SHORT TERM (THROUGH 12Z FRIDAY)
 
AN UPPER LOW REMAINS CENTERED  
OVER WYOMING THIS MORNING. ONE FINAL EMBEDDED VORT MAX CURRENTLY ON  
THE NORTHWESTERN PERIPHERY OF THE LOW IS PROGGED TO ROTATE INTO  
NORTHEAST UTAH AND SOUTHWEST WYOMING THIS AFTERNOON, WHICH WILL AID  
IN THE DEVELOPMENT OF A FEW SHOWERS AND THUNDERSTORMS. HOWEVER, THE  
AIRMASS WILL QUICKLY STABILIZE THIS EVENING AS THIS FEATURE AND THE  
ASSOCIATED UPPER LOW SHIFTS EAST OF UTAH.  
 
A SHORTWAVE RIDGE IS THEN PROGGED TO SHIFT INTO UTAH TOMORROW,  
BRINGING WARMER AND DRY CONDITIONS TO THE AREA. AFTERNOON MAX  
TEMPERATURES WILL RISE FROM SLIGHTLY BELOW NORMAL TEMPERATURES  
TODAY TO NEAR CLIMATOLOGICAL NORMALS TOMORROW.  
   
LONG TERM (AFTER 12Z/6AM FRIDAY)
 
UTAH AND SOUTHWEST WYOMING'S  
WEATHER WILL REMAIN MODESTLY ACTIVE MOVING FORWARD, WITH THE  
HEMISPHERIC WAVE NUMBER FAVORING A MORE PROGRESSIVE PATTERN OVERALL.  
AFTER A BRIEF BREAK IN THE ACTION EARLIER IN THE WEEK, MOISTURE WILL  
RETURN ON FRIDAY AS THE UPPER-LEVEL RIDGE OVERHEAD SHIFTS EASTWARD,  
RESULTING IN OVERALL MOIST, SOUTHWESTERLY FLOW. SHOWERS AND  
THUNDERSTORMS ARE LIKELY TO DEVELOP ACROSS SOUTHWESTERN UTAH ON  
FRIDAY, INCREASING IN COVERAGE/INTENSITY DURING THE AFTERNOON. THERE  
IS STILL SOME QUESTION AS TO HOW FAR NORTH AND EAST THESE STORMS  
REACH ON FRIDAY, DEPENDING ON 1) HOW QUICKLY THE MID-LEVELS MOISTEN  
AND 2) IF THERE IS MORE SYNOPTIC SUPPORT FROM A WEAKENING CLOSED LOW  
OVER THE GREAT BASIN. COMPARED TO YESTERDAY, MODELS FAVOR A MORE  
WESTERN TRACK OF THIS LOW OVER NEVADA, MEANING THAT NORTHERN  
UTAH/SOUTHWEST WYOMING ARE LESS LIKELY TO SEE THESE SHOWERS ON  
FRIDAY AFTERNOON.  
 
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL REDEVELOP ON  
SATURDAY AFTERNOON ACROSS THE FORECAST AREA. DRY MICROBURSTS WILL BE  
THE MAIN THREAT ON BOTH DAYS GIVEN DRY LOW LEVELS, WITH PERHAPS AN  
ISOLATED FLASH FLOOD THREAT ACROSS SOUTHWESTERN UTAH. SUNDAY WILL  
BRING MORE ISOLATED STORMS, LIKELY TIED TO HIGHER TERRAIN GIVEN LACK  
OF SYNOPTIC SUPPORT.  
 
HEADING INTO EARLY NEXT WEEK, A BRIEF PERIOD OF ZONAL FLOW IS  
EXPECTED ACROSS UTAH, WITH A TROUGH PASSING WELL TO OUR NORTH  
HELPING TO BRING DRIER AIR TO OUR AREA. A RIDGE WILL REDEVELOP  
FOLLOWING THIS TROUGH, PRODUCING GRADUALLY WARMING TEMPERATURES AND  
OVERALL QUIESCENT CONDITIONS. HOWEVER, THIS QUIET WEATHER MAY NOT  
LAST LONG. WHILE STILL A WAYS OUT IN THE FORECAST TIMELINE, REMEMBER  
THE OVERALL PROGRESSIVE NATURE OF THE PATTERN; AROUND 60-70% OF  
ENSEMBLE MEMBERS CURRENTLY SUGGEST THE DEVELOPMENT OF A LONGWAVE  
TROUGH POTENTIALLY REACHING THE WESTERN US LATE NEXT WEEK.  
 

 
   
AVIATION...KSLC
 
WINDS WILL CONTINUE TO BE LIGHT AND VARIABLE  
THROUGH THE MORNING, TRANSITIONING TO NORTHWESTERLY AROUND 8-12KTS  
AFTER 17Z. VFR CONDITIONS WILL PREVAIL WITH MOSTLY CLEAR SKIES.  
   
REST OF UTAH AND SOUTHWEST WYOMING
 
WINDS ARE FAIRLY LIGHT AND  
TERRAIN-DRIVEN ACROSS MOST LOCATIONS EARLY THIS MORNING, BUT ARE  
EXPECTED TO BECOME NORTHERLY AROUND 8-15KTS IN MOST AREAS THIS  
AFTERNOON. VFR CONDITIONS WILL PREVAIL WITH MOSTLY CLEAR SKIES, THE  
EXCEPTION BEING OVER THE UINTA MTNS AND UINTA CO., WY WHERE ISOLATED  
SHOWERS COULD DEVELOP THIS AFTERNOON, BRINGING SCT-BKN MID-LEVEL  
CLOUDS.  
 

 
   
FIRE WEATHER
 
A STORM SYSTEM CENTERED OVER WYOMING AND CARVING  
INTO NORTHEAST UTAH WILL MAINTAIN A FEW SHOWERS AND THUNDERSTORMS  
OVER THE UINTA MOUNTAINS AND UINTA BASIN THIS AFTERNOON. THIS  
ACTIVITY WILL QUICKLY WIND DOWN THIS EVENING AS THE STORM SYSTEM  
SHIFTS EAST OF THE AREA. FAIRLY BENIGN WEATHER CAN BE EXPECTED  
TOMORROW WITH WARMER AND DRIER CONDITIONS EXPECTED. MOISTURE IS THEN  
EXPECTED TO INCREASE AGAIN FROM THE SOUTH AND SOUTHWEST FRIDAY INTO  
THE WEEKEND. THIS WILL BRING INCREASES IN RELATIVE HUMIDITIES IN  
ADDITION TO INCREASING SHOWER CHANCES. THEREAFTER, WARM AND DRY  
CONDITIONS LOOK TO RETURN FOR THE FIRST HALF OF NEXT WEEK.  
 

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

 
 

 
 
CHENG/CUNNINGHAM  
 
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...  
HTTP://WEATHER.GOV/SALTLAKECITY  
 
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