157  
FXUS65 KGJT 151140  
AFDGJT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND JUNCTION CO  
540 AM MDT MON AUG 15 2022  
   
SHORT TERM
 
(TODAY THROUGH TUESDAY)  
ISSUED AT 417 AM MDT MON AUG 15 2022  
 
THE PLUME OF DEEPEST MONSOON MOISTURE SHIFTED OVER NORTHEAST UTAH  
AND NORTHWEST COLORADO TODAY IN RESPONSE TO A MID-LEVEL SHORT WAVE  
TROUGH WHICH TRACKED EASTWARD ACROSS UTAH. THIS DISTURBANCE  
EXTENDED FROM KRWL SOUTHWEST TO A SHALLOW LOW CENTERED OVER KPGA  
EARLY THIS MORNING. A FEW SHOWERS LINGERED BENEATH THE TROUGH IN A  
BAND WHICH EXTENDED FROM KEEO SOUTHWEST TO KCNY WHICH INCLUDED A  
PORTION OF THE GRAND VALLEY.  
 
THE TROUGH CONTINUES TO TRACK SOUTHEASTWARD TODAY DRIVING THE HIGH  
LOCATED OVER THE SOUTHERN PLAINS FARTHER SOUTH. THIS WILL CAUSE  
THE PLUME OF DEEPEST MOISTURE TO SHIFT SOUTHWARD SHIFTING ITS AXIS  
OVER SOUTHEAST UTAH AND WEST-CENTRAL COLORADO. ACCORDING TO  
CLIMATOLOGICAL NORMS, MOISTURE LEVELS IN THE PLUME ARE PROJECTED  
TO RANGE FROM 150 TO 200 PERCENT OF NORMAL, AND AT THOSE LEVELS  
SUGGEST THE POTENTIAL FOR EXCESSIVE RAINFALL, ESPECIALLY IN AN  
ENVIRONMENT WHERE STEERING WINDS ARE LIGHT. HOWEVER, ONE  
SIGNIFICANT MITIGATING FACTOR IS CLOUD COVER, WHICH MODELS  
SUGGESTED WILL BE PRETTY EXPANSIVE. THIS SEEMED REASONABLE GIVEN  
THE MID-LEVEL TROUGH OVERHEAD AND THE MESOSCALE CONVECTIVE VORTEX  
UPSTREAM OVER ARIZONA. GIVEN ANTECEDENT MOISTURE FROM YESTERDAY'S  
RAIN COMBINED WITH PRECIPITABLE WATER LEVELS WELL ABOVE NORMAL,  
GAVE CAREFUL CONSIDERATION TO ISSUING A FLOOD WATCH FOR SOUTHEAST  
UTAH AND MUCH OF WEST-CENTRAL COLORADO. HOWEVER, JUST COULDN'T  
FIND THE CONFIDENCE TO PULL THE TRIGGER GIVEN THE CLOUDIER  
FORECAST. HOWEVER, DID HOIST A FLASH FLOOD WATCH FOR THE GRIZZLY  
CREEK BURN SCAR AS RAIN GAUGES AROUND THE SITE PICKED UP FROM 1  
TO 3 INCHES OF RAINFALL YESTERDAY, SO IT REALLY WOULDN'T TAKE MUCH  
TO GET IT FLOWING TODAY. IN CONTRAST, DRYING FLOW FROM THE  
NORTHWEST OVER THE NORTHERNMOST ZONES SHOULD BRING MORE ISOLATED  
ACTIVITY TO THOSE AREAS.  
 
DEEP MOISTURE AND PERSISTENT WEAK TROUGHINESS OVERHEAD FAVORS  
SHOWERS AND THUNDERSTORMS LINGERING OVERNIGHT, MAINLY FOR THE  
SOUTHERN TWO-THIRDS OF THE FORECAST AREA. LITTLE CHANGES ON  
TUESDAY AS THE LARGE SCALE PATTERN CONTINUES TO FEATURE HIGH  
PRESSURE OVER THE SOUTHERN PLAINS AND A RIDGE OF HIGH PRESSURE  
OVER THE GREAT BASIN AND INTERMOUNTAIN WEST WITH A WEAK TROUGH  
BETWEEN THE TWO STALLED OVERHEAD. AS RESULT, EXPECT ANOTHER ROUND  
OF SHOWERS AND THUNDERSTORMS, FAVORING THE CENTRAL AND SOUTHERN  
MOUNTAINS AND ADJACENT VALLEYS.  
 
INCREASED CLOUDS ARE EXPECTED TO BRING COOLER TEMPERATURES TO THE  
REGION TODAY AND TOMORROW. LATEST GUIDANCE SUGGESTED HIGHS WILL  
DIP CLOSE TO 10 DEGREES FOR MOST LOCATIONS TODAY WITH READINGS  
COMING IN ROUGHLY 3 TO 5 DEGREES BELOW NORMAL.  
   
LONG TERM
 
(TUESDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 417 AM MDT MON AUG 15 2022  
 
THE RIDGE OF HIGH PRESSURE WILL PERSIST OVER THE GREAT BASIN  
REGION AT MIDWEEK. THE BEST MOISTURE WILL REMAIN SOUTH OF  
INTERSTATE 70 WHICH WILL KEEP AN ELEVATED THREAT EXCESSIVE  
RAINFALL FROM SCATTERED TO NUMEROUS THUNDERSTORMS. THERE WILL BE  
A DECREASING TREND IN COVERAGE AND INTENSITY ON WEDNESDAY AS THE  
MONSOONAL PLUME WEAKENS AND SHIFTS TO THE WEST OF THE FORECAST  
AREA. ELSEWHERE, WEAK NORTHERLY FLOW WILL KEEP CONDITIONS DRIER  
ACROSS THE NORTH WITH A SLIGHT CHANCE OF LATE-DAY SHOWERS AND  
THUNDERSTORMS THROUGH THE MID-WEEK PERIOD. CONFIDENCE DECREASES BY  
LATE IN THE WEEK AS ENSEMBLE FORECASTS SHIFT THE RIDGE OF HIGH  
PRESSURE EAST ACROSS THE FORECAST AREA. DIVERGENCE IN ENSEMBLE  
MEMBERS WAS EVIDENT REGARDING THE TIMING OF THIS EASTWARD  
PROGRESSION. HOWEVER, THE TREND INDICATED AN UPTICK IN SHOWER AND  
THUNDERSTORM COVERAGE AND INTENSITY AS THE PLUME OF MONSOONAL  
MOISTURE SHIFTS BACK TO THE EAST AND ACROSS THE FORECAST AREA  
LATER IN THE WEEK AND INTO THE WEEKEND. MEANWHILE, HIGH  
TEMPERATURES WILL REMAIN NEAR OR SLIGHTLY BELOW NORMAL THROUGH  
THE LONG TERM FORECAST PERIOD.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)  
ISSUED AT 540 AM MDT MON AUG 15 2022  
 
LINGERING MOISTURE WILL FUEL ANOTHER ROUND OF SHOWERS AND  
THUNDERSTORMS WHICH BRINGS THE LIKELIHOOD OF SOME ACTIVITY MOVING  
OVER ALL TAF SITES EXCEPT KVEL AND KHDN THIS AFTERNOON AND  
EVENING. THERE'S A GOOD CHANCE THAT CELLS COULD DRIVE VISIBILITY  
INTO THE MVFR RANGE AND CEILINGS MAY BRIEFLY FALL BELOW ILS  
BREAKPOINTS AT KRIL, KEGE AND KASE. THERE'S LITTLE TO SUGGEST  
THAT OVERNIGHT STORMS WON'T OCCUR AGAIN TONIGHT AT TAF SITES  
ALONG AND SOUTH OF THE I-70 CORRIDOR.  
 

 
   
GJT WATCHES/WARNINGS/ADVISORIES
 
 
CO...FLASH FLOOD WATCH FROM 1 PM MDT THIS AFTERNOON THROUGH THIS  
EVENING FOR COZ008-010-013.  
 
UT...NONE.  
 

 
 

 
 
SHORT TERM...NL  
LONG TERM...MPM/NL  
AVIATION...NL  
 
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