461  
FXUS65 KFGZ 161203  
AFDFGZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE FLAGSTAFF AZ  
503 AM MST MON JUL 16 2018  
   
SYNOPSIS
 
THE MONSOON WEATHER PATTERN WILL CONTINUE OVER ARIZONA  
THIS WEEK, WITH DAILY ROUNDS OF SHOWERS AND THUNDERSTORMS. THE  
MAIN THREAT WITH STORMS TODAY WILL BE HEAVY RAINFALL AND LOCALIZED  
FLOODING.  
 

 
   
DISCUSSION
 
AT 430 AM - MOSTLY CLOUDY SKIES PERSIST ACROSS  
NORTHERN ARIZONA AS DEBRIS CLOUDINESS FROM SUNDAY'S STORMS HAS  
BEEN SLOW TO DISSIPATE. THERE ARE ALSO SOME SCATTERED SHOWERS  
ACROSS YAVAPAI AND COCONINO COUNTIES. THE MID LEVEL RIDGE AXIS  
STRETCHES FROM THE PACIFIC INTO SOUTHERN UT/CO WHICH PLACES OUR  
AREA IN AN EASTERLY STEERING FLOW. OVERALL, THE PATTERN IS SIMILAR  
TO WHAT WAS IN PLACE YESTERDAY WHEN SEVERAL AREAS OF STORMS  
DEVELOPED CONTAINING TORRENTIAL RAINFALL RATES OF 2+ INCHES IN  
UNDER AN HOUR. HOWEVER, THE DAY BEGAN FAIRLY SUNNY WHICH ALLOWED  
RAPID DESTABILIZATION. TODAY - IT LOOKS LIKE CLOUDS MAY BE SLOWER  
TO DIMINISH SO STORMS WILL PROBABLY DEVELOP LATER INTO THE  
AFTERNOON AND MOVE OFF TO THE WEST AROUND 10 MPH. WITH MORE  
UNCERTAINTY IN CLOUD COVER AND SURFACE HEATING TODAY, WE HELD OFF  
ON A FLASH FLOOD WATCH. IF IT BECOMES APPARENT THAT CLOUDS WILL  
DISSIPATE THROUGH THE MORNING, A WATCH MAY BE ISSUED SO STAY ALERT  
FOR THAT.  
 
TUESDAY THROUGH THURSDAY - HIGH PRESSURE STRENGTHENS AND BECOMES  
CENTERED OVER SOUTHERN UTAH. PRECIPITABLE WATER VALUES STAY ABOUT  
THE SAME FROM THE MOGOLLON RIM SOUTHWARD BUT DROP A BIT IN  
NORTHEAST ARIZONA. THE MID LEVELS LOOK SOMEWHAT DRIER SO WHILE WE  
EXPECT DAILY ROUNDS OF SCATTERED STORMS, COVERAGE SHOULD BE  
SOMEWHAT LOWER ESPECIALLY IN NORTHEAST ARIZONA. RAINFALL  
EFFICIENCY IN THE STORMS WILL ALSO BE LESS DUE TO DRIER MID  
LEVELS, SO THE FLASH FLOOD THREAT WON'T BE QUITE AS HIGH.  
 
FRIDAY THROUGH SUNDAY - THE RIDGE IS FORECAST TO REMAIN STRONG AND  
SHIFT INTO NEW MEXICO. MODELS ARE FORECASTING WARMER DAYTIME  
TEMPERATURES AND FOR ENOUGH MOISTURE FOR SCATTERED STORMS TO  
CONTINUE.  

 
   
AVIATION...FOR THE 12Z PACKAGE
 
EXPECT MOSTLY VFR CONDITIONS AND  
LIGHT WINDS ACROSS NORTHERN ARIZONA. SCATTERED -SHRA/-TSRA ONGOING  
SOUTH OF A LINE FROM KGCN TO KRQE THIS MORNING. SCATTERED  
-SHRA/-TSRA WILL BEGIN OVER HIGHER TERRAIN AFTER 18Z BECOMING WIDE  
SPREAD IN THE AFTERNOON AND DIMINISHING AFTER 02Z. LOCAL MVFR/IFR  
CONDITIONS WITH GUSTY, ERRATIC WINDS NEAR THE SHOWERS AND  
THUNDERSTORMS. AVIATION DISCUSSION NOT UPDATED FOR TAF  
AMENDMENTS.  
 

 
   
FIRE WEATHER
 
SCATTERED TO NUMEROUS THUNDERSTORMS WITH A THREAT OF  
HEAVY RAIN EACH AFTERNOON/EVENING WILL CONTINUE THROUGH FRIDAY.  
MOISTURE BEGINS TO DECREASE BY THE WEEKEND IN TO NEXT WEEK WITH  
THUNDERSTORM COVERAGE BECOMING MORE ISOLATED. GUSTY AND ERRATIC  
WINDS MAY DEVELOP NEAR THUNDERSTORMS.  
 

 
   
FGZ WATCHES/WARNINGS/ADVISORIES
 
NONE.  
 

 
 

 
 
PUBLIC...JJ  
AVIATION...ET  
FIRE WEATHER...ET  
 
FOR NORTHERN ARIZONA WEATHER INFORMATION VISIT  
WEATHER.GOV/FLAGSTAFF  
 
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