106  
FXUS65 KSLC 270938  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
338 AM MDT TUE OCT 27 2020  
   
SYNOPSIS
 
HIGH PRESSURE ALOFT CENTERED NEAR THE WEST COAST  
WILL LEAVE UTAH UNDER A DRY AND STABLE NORTH TO NORTHWEST FLOW  
ALOFT THROUGH MIDWEEK. A GRADUAL WARMING TREND WILL ENSUE, WITH  
TEMPERATURES RETURNING TO TYPICAL LATE OCTOBER READINGS LATE IN  
THE WEEK.  
 

 
   
SHORT TERM (THROUGH 12Z FRIDAY)
 
A LARGE SCALE OMEGA BLOCK  
EXTENDS ACROSS THE EASTERN PACIFIC/WESTERN CONUS EARLY THIS  
MORNING, WITH THE DOWNSTREAM UPPER LOW SPINNING OVER SOUTHERN  
ARIZONA, AND THE UPPER RIDGE CENTERED OFF THE PACIFIC COAST.  
THIS IS MAINTAINING A VERY COOL AND DRY AIRMASS ACROSS THE  
FORECAST AREA, WHERE TEMPERATURES WILL MODERATE A BIT TODAY, BUT  
REMAIN WELL BELOW CLIMO AREA-WIDE. GUSTY NORTH TO NORTHEAST WINDS  
WILL CONTINUE ACROSS SOUTHERN UTAH, BUT SHOULD BE WEAKER THAN WHAT  
WAS OBSERVED MONDAY.  
 
THE BLOCKING PATTERN WILL GRADUALLY BREAK DOWN THROUGH MIDWEEK AS  
THE UPSTREAM RIDGE VERY SLOWLY SHIFTS EASTWARD TOWARD THE PACIFIC  
COAST, WHILE THE UPPER LOW SLOWLY TRANSLATES EASTWARD TOWARD THE  
SOUTHERN PLAINS BY WEDNESDAY. THIS WILL ALLOW FOR A GRADUAL  
WARMING TREND WEDNESDAY INTO THURSDAY, HOWEVER A REDUCED SUN ANGLE  
AND COLD AMBIENT AIRMASS WILL LIKELY TAPER THIS WARMING TREND A  
BIT ACROSS THE VALLEYS, AND HAVE LEANED TOWARD THE LOWER END OF  
THE GUIDANCE ENVELOPE FOR TEMPERATURES, WHICH SHOULD FINALLY  
RETURN TO NEAR CLIMO BY THURSDAY.  
 
   
LONG TERM (AFTER 12Z FRIDAY)
 
RIDGING BUILDING IN FROM THE WEST  
BEHIND THE SAME TROUGH THAT PROVIDED WINTRY WEATHER AND COLD  
TEMPERATURES LOCALLY HAS TRENDED STRONGER AMONG RECENT MODEL RUNS.  
A DRY WEATHER STRETCH IS ANTICIPATED, WITH WARMING CONTINUING  
EACH DAY THROUGH AT LEAST SATURDAY. AS THE RIDGE ESTABLISHES  
ITSELF OVER THE GREAT BASIN, GUIDANCE SHOWS 700 MB TEMPERATURES  
CONSISTENTLY IN THE 5-7 DEGREE C RANGE. WE CAN EXPECT TEMPERATURES  
AROUND 5-10 DEGREES WARMER THAN CLIMO FOR UTAH AND SOUTHWEST  
WYOMING FOR THE START OF NEXT MONTH. THAT RIDGE IN PLACE WILL  
RESULT IN MORE CONSISTENCY IN TEMPERATURES AS WELL.  
 
ADJUSTED HIGH TEMPERATURES SUNDAY AND MONDAY UP SLIGHTLY FROM  
NBM, AS IT HASN'T SHOWED ENOUGH INCREASE AFTER RIDGING SETTLES IN.  
OVERNIGHT INVERSIONS COULD LIMIT AFTERNOON TEMPERATURES, AND  
ADDED MIXING WILL ELIMINATE THOSE QUICKER. THAT WILL ALSO PLAY A  
ROLE IN THE TEMPERATURE FORECAST.  
 

 
   
AVIATION
 
VFR CONDITIONS ARE EXPECTED AT KSLC THROUGH THE VALID  
TAF PERIOD. SOUTHEAST WINDS WILL TRANSITION TO THE NORTHWEST  
AROUND 19Z WITH CLEAR SKIES. NORTHWEST WINDS WILL TRANSITION TO  
SOUTHEAST AGAIN AROUND 03Z WITH A FEW HIGH CLOUDS.  
 

 
   
FIRE WEATHER
 
A COOL AND DRY AIRMASS WILL REMAIN IN PLACE  
ACROSS THE REGION TODAY, TO THE NORTH OF A LOW PRESSURE SYSTEM  
SPINNING OVER THE DESERT SOUTHWEST. GUSTY NORTH TO NORTHEAST WINDS  
WILL PERSIST ACROSS SOUTHERN UTAH AGAIN TODAY, WHILE HIGH  
PRESSURE BEGINS TO BUILD ACROSS NORTHERN UTAH. THIS HIGH WILL  
BECOME THE DOMINANT WEATHER FEATURE THROUGH THE REMAINDER OF THE  
WEEK MAINTAINING DRY WEATHER AREA-WIDE. TEMPERATURES WILL SLOWLY  
WARM THROUGH THE WEEK, RETURNING TO NEAR NORMAL BY THURSDAY THEN  
WARMING ABOVE NORMAL HEADING INTO THE UPCOMING WEEKEND.  
 

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

 
 

 
 
SEAMAN/WILSON  
 
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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