653  
FXUS65 KSLC 221542  
AFDSLC  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SALT LAKE CITY UT  
942 AM MDT MON JUL 22 2019  
   
SYNOPSIS
 
A BROAD AREA OF HIGH PRESSURE ALOFT WILL REMAIN  
CENTERED NEAR THE FOUR CORNERS REGION THROUGH LATE IN THE WEEK.  
MONSOONAL MOISTURE WILL SPREAD NORTH ACROSS THE REGION BEGINNING  
TUESDAY, RESULTING IN AN INCREASE OF MAINLY AFTERNOON AND EVENING  
THUNDERSTORM ACTIVITY THROUGH LATE IN THE WEEK.  
 

 
   
DISCUSSION
 
MORNING WATER VAPOR AND H5 ANALYSIS DEPICT AN  
AMPLIFIED RIDGE ACROSS THE INTERMOUNTAIN REGION, WITH CENTER OF  
CIRCULATION CURRENTLY ORIENTED OVER THE 4-CORNERS REGION. A DEEP  
POOL OF SUB-TROP MOISTURE REMAINS IN PLACE OVER NORTHERN  
MEXICO/SOUTHERN ARIZONA, WITH TRENDS SLOWLY ADVECTING NORTH UP THE  
LOWER COLORADO VALLEY. THIS TREND WILL CONTINUE MOVING FORWARD  
WITH THE DEEP MOISTURE CONTINUING A NORTHWARD PUSH ALONG THE  
WESTERN PERIPHERY OF THE HIGH INTO EXTREME SOUTHERN/WESTERN UTAH  
AND NEVADA TUESDAY, PRIOR TO ENCOMPASSING THE MAJORITY OF THE  
AREA WEDNESDAY ON.  
 
IN THE NEAR TERM SENSIBLE WEATHER WILL REMAIN HOT AND DRY, WITH  
MAXES PUSHING INTO THE TRIPLE DIGITS ALONG THE WASATCH FRONT DURING  
PEAK HEATING TODAY THROUGH TUESDAY, WHILE ELSEWHERE TEMPS WILL BE  
RUNNING SOME 4-7 DEGREES ABOVE CLIMO. A HEAT ADVISORY REMAINS IN  
PLACE FOR THE WASATCH FRONT/NORTHWEST DESERTS, AS POOR OVERNIGHT  
RECOVERY WILL EXACERBATE CONDITIONS FOR THE HEAT SENSITIVE GROUPS.  
 
PRIMARY FORECAST PROBLEM THIS SHIFT WILL BE TO DELVE MORE INTO THE  
THE EXPECTED MOISTURE PUSH MOVING FORWARD. NO UPDATES MADE OR  
PLANNED THIS UPDATE.  
   
PREVIOUS DISCUSSION
 
BY WEDNESDAY/THURSDAY PWAT VALUES OF 1.00"  
OR MORE WILL COVER MUCH OF THE FORECAST AREA OUTSIDE OF THE  
UTAH/IDAHO BORDER REGION. THE NOW WELL PRIMED AIR MASS SHOULD  
SUPPORT TERRAIN-BASED CONVECTION, WITH THE POTENTIAL FOR LOCALLY  
HEAVY RAIN. DYNAMIC FORCING WOULD GREATLY ENHANCE PRECIP, THOUGH  
WITH THE STILL BROAD UPPER RIDGE IN PLACE CENTERED ON THE FOUR  
CORNERS REGION ANY VORTICITY LOBES ROTATING AROUND THE PERIMETER  
OF THE HIGH WILL LIKELY TRACK THROUGH NEVADA. EXTREME SOUTHWEST  
AND NORTHWEST UTAH MAY SEE ENHANCED DYNAMIC SUPPORT FROM THESE  
FEATURES, THOUGH THE BEST CHANCE WOULD COME AT THE END OF THE WEEK  
AS THE UPPER RIDGE BEGINS TO WEAKEN OVER THE REGION  
 

 
   
AVIATION
 
SOUTHEAST WINDS AT THE SLC TERMINAL ARE  
EXPECTED TO BECOME NORTHWEST BETWEEN 19-20Z TODAY. VFR CONDITIONS  
WILL PREVAIL THROUGH THE PERIOD.  
 

 
   
FIRE WEATHER
 
THE RIDGE OF HIGH PRESSURE HAS SET UP OVER THE  
FOUR CORNERS REGION WHICH WILL TAP DEEP MOISTURE OVER OLD MEXICO  
AND BRING IT NORTHWARD REACHING UTAH BY TUESDAY. INITIALLY THESE  
STORMS ARE EXPECTED TO BE DRY PRODUCING STRONG GUSTY WINDS BUT BY  
TUESDAY NIGHT MOISTURE WILL INCREASE AND MOST STORMS WILL BE  
PRODUCING RAIN. THE MOISTURE INFLUX PRODUCING WETTING RAINS IN  
MOST CASES WILL CONTINUE WEDNESDAY THROUGH THURSDAY ACROSS  
SOUTHERN AND CENTRAL UTAH WITH THE NORTHERN TIER MOST LIKELY  
REMAINING DRY. HOWEVER, A DISTURBANCE AT MID LEVELS MOVING AROUND  
THE HIGH IS EXPECTED TO MOVE INTO NORTHERN UTAH BY FRIDAY MORNING  
WHICH WILL GIVE NORTHERN UTAH THE BEST CHANCE FOR RAIN. A SHORT  
WAVE MOVING ACROSS THE NORTHERN ROCKIES WILL SQUASH THE HIGH AND  
BRING A DRIER WEST TO NORTHWEST FLOW ACROSS THE REGION BY SATURDAY  
AND SUNDAY, ALTHOUGH LINGERING THUNDERSTORMS ARE POSSIBLE OVER THE  
MOUNTAINS AND EASTERN ZONES.  
 

 
   
SLC WATCHES/WARNINGS/ADVISORIES
 
 
UT...HEAT ADVISORY UNTIL MIDNIGHT MDT TUESDAY NIGHT FOR UTZ002>005.  
 
WY...NONE.  

 
 

 
 
DISCUSSION/AVIATION...MERRILL/VERZELLA  
PREVIOUS DISCUSSION...CONGER/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  
 
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