317  
FXUS65 KSLC 172156  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
356 PM MDT TUE JUL 17 2018  
   
SYNOPSIS
 
HIGH PRESSURE WILL STRENGTHEN FOR THE MID-WEEK PERIOD,  
BRINGING A DRYING TREND TO THE STATE. MOISTURE WILL SLOWLY CREEP  
NORTH LATE IN THE WEEK INTO THE WEEKEND.  
 

 
   
SHORT TERM (THROUGH 06Z SATURDAY)
 
THE JET ON THE BACKSIDE OF  
THE TROUGH THAT MOVED ACROSS NORTHERN UTAH LAST NIGHT IS STILL  
CREATING SOME LIFT ACROSS FAR NORTHERN UTAH THIS AFTERNOON.  
HOWEVER, MOISTURE IS BECOMING LESS AVAILABLE SO BELIEVE ISOLATED  
SHOWERS AND THUNDERSTORMS WILL END BEFORE SUNSET. FARTHER EAST AND  
SOUTH IN THE DEEPER MOISTURE THUNDERSTORMS ARE FIRING UP ONCE  
AGAIN THIS AFTERNOON AND ARE TRACKING MORE SOUTHEAST TODAY VS  
SOUTH OR SOUTHWEST WHICH HAS BEEN PROBLEMATIC FOR FLASH FLOODING  
SINCE MANY TRIBUTARIES ARE ORIENTED NORTH TO SOUTH OVER THE  
WESTERN HALF OF KANE COUNTY AND WASHINGTON COUNTY.  
 
THERE DOES NOT APPEAR TO BE ANY RELIEF IN THE DEEP MOISTURE OVER  
THE SOUTH THE NEXT FEW DAYS BUT THE FLOW DOES BECOME NEARLY  
STAGNANT WEDNESDAY INTO THURSDAY AS THE CENTER OF THE 500MB RIDGE  
MOVES OVERHEAD. THIS MAY INHIBIT THE STRENGTH OF THE THUNDERSTORMS  
AS THEY WILL BE VERTICALLY STACKED, MEANING THE UPDRAFT ENDS UP  
BEING DIRECTLY UNDER THE DOWNDRAFT ONCE IT FORMS WHICH WILL KILL  
THE UPDRAFT. THESE ARE CALLED PULSE STORMS BECAUSE THEY DON'T LAST  
LONG. BY LATE THURSDAY THE FLOW ALOFT BECOMES MORE SOUTHEAST  
ALOFT ACROSS SOUTHWEST UTAH AS THE RIDGE MOVES TO THE 4 CORNERS  
REGION AND FARTHER EAST. THIS RIDGE POSITION OPENS THE DOOR FOR  
MONSOONAL MOISTURE TO STREAM NORTHWARD FRIDAY AND BEYOND.  
 
THE HOTTEST TEMPERATURES ARE EXPECTED ACROSS NORTHERN UTAH  
WEDNESDAY AS THE 700MB TEMPS FLIRT WITH 17-18C. THE 700MB TEMPS  
WILL TEND TO LOWER A TAD THURSDAY AND FRIDAY AS MORE MOISTURE  
ENTERS THE PICTURE. SOUTHERN UTAH WILL HAVE NEARLY SIMILAR  
TEMPERATURES EACH DAY AND 700MB TEMPS REMAIN NEARLY CONSTANT.  
   
LONG TERM (AFTER 06Z SATURDAY)
 
WITH THE RIDGE AXIS FIRMLY IN  
PLACE OVER TEXAS BY SATURDAY MORNING, MONSOONAL MOISTURE CONTINUES  
TO STREAM NORTHWARD INTO THE FORECAST AREA OVER THE WEEKEND. WHILE  
GFS PWAT VALUES ARE NOT AS IMPRESSIVE AS PAST RUNS, MUCH OF THE AREA  
REMAINS IN 0.75 TO 1 INCH INTO MONDAY. MAINTAINING CONFIDENCE IN  
CONVECTIVE ACTIVITY THROUGHOUT THE WEEKEND, WITH TEMPS A BIT ABOVE  
SEASONAL NORMS.  
 
GLOBAL MODELS DIFFERING IN EXTENT OF DRYING EARLY IN THE WORKWEEK,  
AS SUCH HAVE LEFT SLIGHT CHANCE/CHANCE OF POPS INTO DAY 7. EXPECTING  
TEMPS TO BE RIDING ALONG SEASONAL NORMS FOR THE NORTH, A BIT ABOVE  
IN THE SOUTH.  
 

 
   
AVIATION
 
CONDITIONS AT THE KSLC TERMINAL ARE EXPECTED TO REMAIN  
AT VFR THROUGH THE EVENING. NORTH WINDS IN PLACE ARE EXPECTED TO  
SHIFT TO THE SOUTH BETWEEN 03-04Z, WITH A SMALL CHANCE THAT NEARBY  
SHOWERS CREATE GUSTY ERRATIC WINDS BEFORE 03Z.  
 

 
   
FIRE WEATHER
 
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS WILL  
OCCUR OVER THE EASTERN AND SOUTHERN PORTIONS OF FIRE DISTRICT THIS  
EVENING AND THEN MAINLY OVER SOUTHERN UTAH WEDNESDAY AND THURSDAY.  
MOISTURE WILL SPREAD NORTHWARD FRIDAY INTO NORTHERN UTAH AND THERE  
COULD BE DRY LIGHTNING ALONG THE LEADING EDGE OF THIS MOISTURE,  
BUT LOOKS TO BE BRIEF IF IT DOES OCCUR. ELEVATED RH VALUES WILL  
REMAIN OVER THE SOUTH THROUGH THE FORECAST PERIOD. HOWEVER, MIN  
RH VALUES HAVE DROPPED INTO THE LOWER TEENS ACROSS NORTHWEST DESERTS  
TODAY AND THIS SHOULD SPREAD INTO THE NORTHERN PORTIONS OF THE  
WESTERN VALLEYS WEDNESDAY AND POSSIBLY INTO THURSDAY. RH VALUES  
ARE EXPECTED TO COME UP THROUGH THE WEEKEND.  
 

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

 
 

 
 
SHORT TERM...STRUTHWOLF  
LONG TERM...VERZELLA  
AVIATION...DEWEY  
FIRE WEATHER...STRUTHWOLF  
 
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  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab UT Page
The Nexlab ID Page
The Nexlab WY Page Main Text Page