933  
FXUS65 KSLC 190433  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
1033 PM MDT TUE AUG 18 2026  
   
KEY MESSAGES  
 
- BUILDING HIGH PRESSURE WILL BRING A STEADY WARMING TREND IN  
TEMPERATURES THROUGH THURSDAY AS CONDITIONS DRY.  
 
- MONSOON MOISTURE WILL MOVE BACK INTO UTAH AND SOUTHWEST WYOMING  
LATE IN THE WEEK, PERSISTING THROUGH AT LEAST EARLY NEXT WEEK.  
THIS WILL BRING AN INCREASED THREAT OF SHOWERS AND THUNDERSTORMS  
CAPABLE OF PRODUCING FLASH FLOODING.  
 
 
   
DISCUSSION  
HIGH PRESSURE CENTERED OVER WESTERN AZ TONIGHT  
THROUGH WEDNESDAY WILL MAINTAIN AN DRY WEST-NORTHWEST FLOW OVER  
UT. LATEST ANALYSIS SHOWS AROUND 0.8-0.9 INCHES OF PWAT ACROSS  
THE AREA. THIS SHOULD BE ENOUGH TO RESULT IN ISOLATED TO WIDELY  
SCATTERED DIURNAL AND MOSTLY TERRAIN-BASED SHOWERS AND  
THUNDERSTORMS.  
 
THE HIGH PRESSURE WILL GRADUALLY SHIFT EAST TOWARDS CO/NM BY  
FRIDAY, AND A BIT FARTHER EAST FOR THE WEEKEND. THIS WILL BRING A  
GRADUAL RETURN OF MONSOONAL MOISTURE TO THE AREA, WITH SHOWERS  
AND THUNDERSTORMS INCREASING OVER THE MOUNTAINS AND SOUTHERN UTAH  
THURSDAY BEFORE BECOMING MORE WIDESPREAD OVER THE FORECAST AREA  
FRIDAY THROUGH AT LEAST THE EARLY PART OF NEXT WEEK. WITH THE  
INCREASED COVERAGE OF THUNDERSTORMS AND ARRIVAL OF DEEPER  
MOISTURE COUPLED WITH ADDED DYNAMICS FROM A SERIES OF WEAK  
DISTURBANCES CROSSING THE AREA, THE THREAT OF FLASH FLOODING WILL  
INCREASE DURING THIS TIMEFRAME. A MARGINAL RISK OF EXCESSIVE  
RAINFALL BEGINS AS SOON AS THURSDAY ACROSS PORTIONS SOUTHERN UTAH  
AND WILL BE MORE WIDESPREAD ACROSS THE AREA BY SATURDAY.  
 
WITH THE ARRIVAL OF THE DEEPER MOISTURE, TEMPERATURES WILL TREND  
DOWNWARD TOWARDS THE END OF THE WEEK INTO NEXT WEEK. UNTIL THEN,  
HOWEVER, TEMPERATURES WILL REMAIN ON THE WARM SIDE, WITH HIGHS  
AROUND 5-10 DEGREES ABOVE NORMAL. THE NBM CURRENTLY HAS A 25-30%  
CHANCE OF SLC REACHING 100F THURSDAY-FRIDAY. HOWEVER, WITH THE  
WARM BIAS COMMONLY EXHIBITED LOCALLY BY THE NBM IN THE WARM  
SEASON, SUSPECT THAT THE CHANCE OF REACHING 100F IS MUCH HIGHER,  
ESPECIALLY ON THURSDAY, SO HAVE ADJUSTED TEMPERATURES TO REFLECT  
THIS THINKING. HEATRISK ALSO FALLS INTO THE RED (MAJOR) CATEGORY  
IN MANY VALLEY AREAS ON THURSDAY, BUT THE INCREASED THREAT OF  
HEAT RELATED ILLNESS WILL BE MITIGATED DUE TO OVERALL ACCLIMATION  
DURING THE SEASON.  
 
 
   
AVIATION...KSLC  
THERE IS LOW CONFIDENCE IN WIND DIRECTION  
OVERNIGHT; ALTHOUGH SOUTHEASTERLY IS LIKELY TO BE THE DOMINANT  
DIRECTION, THERE IS A CHANCE TO GO BACK TO NORTHERLY AROUND 4-7KTS  
BETWEEN 06-11Z. OTHERWISE, EXPECT VFR CONDITIONS WITH FEW-SCT  
MID-LEVEL CLOUDS.  
 
REST OF UTAH AND SOUTHWEST WYOMING...WINDS WILL REMAIN FAIRLY LIGHT  
AND TERRAIN-DRIVEN OVERNIGHT, WITH VFR CONDITIONS PREVAILING.  
ISOLATED THUNDERSTORMS WILL REDEVELOP WEDNESDAY AFTERNOON ACROSS  
PRIMARILY EASTERN UTAH WITH CHANCES FOR GUSTY OUTFLOW WINDS.  
 
 
   
FIRE WEATHER, ISSUED 414 PM MDT TUE AUG 18 2026  
 
HIGH PRESSURE TO THE WEST OF UTAH WILL BRINGING A  
WARMING AND DRYING TREND THROUGH THURSDAY, BRINGING TEMPERATURES  
UP TO 10F ABOVE SEASONAL NORMALS BY THURSDAY AFTERNOON. RELATIVE  
HUMIDITIES WILL DROP, WITH POCKETS OF CRITICALLY LOW RH VALUES  
DEVELOPING BY THURSDAY. WINDS COULD BE ENOUGH TO BRING ISOLATED  
POCKETS OF CRITICAL FIRE WEATHER CONDITIONS THURSDAY AFTERNOON,  
BUT COVERAGE IS LOOKING INCREASINGLY LIMITED. AS THE RIDGE MOVES  
EASTWARD FRIDAY, MONSOON MOISTURE WILL MOVE INTO THE AREA FROM THE  
SOUTH, REMAINING IN PLACE THROUGH EARLY NEXT WEEK. THIS WILL  
BRING INCREASED POTENTIAL FOR WETTING RAINFALL, IMPROVED RH  
VALUES, BUT ALSO THE POTENTIAL OF STORMS THAT COULD PRODUCE HEAVY  
RAIN THAT COULD LEAD TO FLASH FLOODING.  
 
 
   
SLC WATCHES/WARNINGS/ADVISORIES  
 
UT...NONE.  
WY...NONE.  
 
 
 
 
PUBLIC...CHENG  
AVIATION...CUNNINGHAM  
FIRE WEATHER...TRAPHAGAN  
 
FOR MORE INFORMATION FROM NOAA'S NATIONAL WEATHER SERVICE VISIT...  
HTTP://WEATHER.GOV/SALTLAKECITY  
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