512  
FXUS65 KSLC 251025  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
425 AM MDT SUN AUG 25 2019  
   
SYNOPSIS
 
A COUPLE OF WEATHER DISTURBANCES MOVING THROUGH THE  
NORTHERN ROCKIES TODAY WILL NUDGE A DRY FRONT ACROSS NORTHERN AND  
CENTRAL UTAH. COOLER TEMPERATURES WILL FOLLOW THE FRONT FOR THE  
EARLY PART OF THE WEEK. A PLUME OF MOISTURE WILL MAKE A BRIEF RETURN  
MIDWEEK.  
 

 
   
SHORT TERM (THROUGH 00Z THURSDAY)
 
THE LARGE SCALE PATTERN THIS  
MORNING CONSISTS OF A BROAD RIDGE CENTERED NEAR 145W WITH A WEST-  
NORTHWESTERLY FLOW ALOFT EXTENDING INTO UTAH. A COUPLE OF SHORTWAVE  
DISTURBANCES, ONE CURRENTLY OVER THE NORTHERN ROCKIES AND ANOTHER  
OVER THE PACIFIC NORTHWEST, ARE EMBEDDED WITHIN A MEAN TROUGH WHICH  
IS MOVING ACROSS THE NORTHWESTERN CONUS. PRECIPITABLE WATER VALUES  
REMAIN GENERALLY IN THE 0.6-0.75 INCH RANGE ACROSS MOST VALLEYS.  
SKIES ARE MOSTLY CLEAR THIS MORNING WITH JUST A FEW PATCHES OF HIGH  
CLOUDS DRIFTING THROUGH CENTRAL UTAH.  
 
THE AFOREMENTIONED DISTURBANCES WILL PUSH A DRY COLD FRONT THROUGH  
NORTHERN UTAH TODAY, WITH THE FRONT STALLING OUT OVER CENTRAL UTAH  
THIS EVENING. WINDS WILL INCREASE ON BOTH SIDES OF THE FRONT, BUT  
ESPECIALLY ACROSS PORTIONS OF NORTHERN UTAH AND THE NORTHEASTERN  
THROUGH EAST-CENTRAL VALLEYS GIVEN A WESTERLY MSLP GRADIENT AND 20-  
35KT 700MB FLOW THIS AFTERNOON. ALTHOUGH AFTERNOON MAX TEMPERATURES  
ARE NOT EXPECTED TO CHANGE SIGNIFICANTLY FROM YESTERDAY'S VALUES,  
OVERNIGHT MINS TONIGHT AND AFTERNOON MAXES TOMORROW WILL BE  
NOTICEABLY COOLER ACROSS NORTHERN UTAH AND SOUTHWEST WYOMING.  
 
THE RIDGE WILL SHIFT EASTWARD THROUGH THE EARLY PART OF THE WEEK AND  
RE-CENTER ITSELF OVER ARIZONA BY MIDWEEK. A SOUTHERLY FLOW ALONG THE  
CA/AZ BORDER AND THROUGH SOUTHERN NEVADA WILL DRAW EXISTING MOISTURE  
FROM OVER AND AROUND THE GULF OF CALIFORNIA AND BRING IT NORTHWARD  
AND INTO SOUTHERN UTAH BY WEDNESDAY. THIS MOISTURE IS EXPECTED TO  
LEAD TO A RETURN OF CONVECTIVE ACTIVITY AROUND MIDWEEK.  
   
LONG TERM (AFTER 00Z THURSDAY)
 
BY THURSDAY, THE RIDGE AXIS IS  
EXPECTED TO MOVE BACK OVER UTAH, RESULTING IN A LIGHT AND GENERALLY  
WESTERLY FLOW ALOFT. THIS SHOULD CUT OFF THE MOISTURE TAP, BUT  
MOISTURE LINGERING OVER THE FORECAST AREA WILL RESULT IN SOME  
AFTERNOON/EVENING CONVECTION OVER THE HIGHER TERRAIN FOR THE LATTER  
PART OF THE UPCOMING WORK WEEK.  
 
A WEAK TROUGH MOVING OVER THE RIDGE IS PROGGED TO FLATTEN IT  
THURSDAY NIGHT INTO EARLY FRIDAY. BEHIND THE EXITING WAVE, GLOBAL  
MODELS INDICATE THE RIDGE WILL REAMPLIFY, WITH THE AXIS MOVING WEST  
OF THE FORECAST AREA. THIS ORIENTATION OF THE RIDGE WOULD DRY OUT  
THE AIRMASS OVER THE AREA, RESULTING IN DECREASING CHANCES OF  
CONVECTION OVER THE WEEKEND. THE INFLUENCE OF THE RIDGE SHOULD KEEP  
TEMPERATURES NEAR TO JUST ABOVE SEASONAL NORMALS THROUGH THE LONG  
TERM PERIOD.  
 

 
   
AVIATION
 
THE SLC TERMINAL WILL SEE VFR CONDITIONS THROUGHOUT THE  
DAY WITH MOSTLY CLEAR SKIES. SOUTHEAST WINDS ARE EXPECTED TO SHIFT  
TO THE NORTHWEST WITH THE PASSAGE OF A DRY COLD FRONT BETWEEN 17Z  
AND 19Z.  
 

 
   
FIRE WEATHER
 
A DRY COLD FRONT WILL PUSH THROUGH NORTHERN UTAH  
TODAY BEFORE STALLING OVER CENTRAL UTAH AS A TROUGH CROSSES THE  
NORTHERN ROCKIES. WINDS WILL INCREASE NEAR THE FRONT WHICH, COMBINED  
WITH LOW HUMIDITIES IN PLACE, WILL LEAD TO HAZARDOUS FIRE WEATHER  
CONDITIONS TODAY. LOCALIZED AREAS OF GUSTY WINDS WILL CONTINUE  
TOMORROW ACROSS PORTIONS OF EASTERN UTAH WHICH WILL CONTINUE TO  
PRODUCE ISOLATED HAZARDOUS FIRE WEATHER CONDITIONS. THE COLD FRONT  
WILL BRING COOLER TEMPERATURES TO NORTHERN UTAH LATER TODAY THROUGH  
MONDAY. HIGH PRESSURE WILL THEN BUILD OVER THE AREA MIDWEEK, BUT  
MOISTURE WILL INCREASE FROM THE SOUTH LEADING TO THE RETURN OF  
THUNDERSTORM ACTIVITY.  
 

 
   
SLC WATCHES/WARNINGS/ADVISORIES
 
 
UT...RED FLAG WARNING FROM 11 AM TO 10 PM MDT SUNDAY FOR UTZ478>484-  
488-489.  
 
WY...RED FLAG WARNING FROM 10 AM TO 8 PM MDT SUNDAY FOR WYZ277.  
 

 
 

 
 
CHENG/TRAPHAGAN  
 
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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