347  
FXUS65 KBOU 150351  
AFDBOU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
951 PM MDT TUE AUG 14 2018  
   
UPDATE
 
 
ISSUED AT 945 PM MDT TUE AUG 14 2018  
 
THE LATE AFTERNOON AND EVENING STRONG TO SEVERE STORM ACTIVITY  
ALONG THE FRONT RANGE HAS DIMINISHED CONSIDERABLY WITH THE LAST  
REMAINING T-STORMS CONTINUING TO TRACK EAST-SOUTHEAST AWAY FROM  
THE DENVER METRO AREA INTO INCREASINGLY STABLE BOUNDARY LAYER AIR.  
ERUPTION OF TODAY'S HAIL AND HEAVY RAIN STORMS COINCIDED WITH THE  
PASSAGE OF A SHORTWAVE TROUGH WHICH GOES IR/WATER VAPOR IMAGERY  
NOW SHOW OVER FAR EASTERN COLORADO/NEBRASKA PANHANDLE. CLEARING,  
ALBEIT GRADUAL, IS NOW UNDERWAY, ALTHOUGH MID-LEVEL MOISTURE  
VISIBLE ON 6.19 AND 10.35UM GOES SAT LOOPS STREAMING UP FROM THE  
DESERT SOUTHWEST MAY KEEP AT LEAST HIGH CLOUD COVER AROUND  
THROUGH WEDNESDAY MORNING. IN ADDITION, LOW-LEVEL MOISTURE  
FEEDING UP INTO SOUTHEAST SECTIONS OF THE CWA MAY ONCE AGAIN  
RESULT IN PATCHY TO AREAS OF FOG TOWARDS DAWN. DO NOT BELIEVE THE  
FOG TONIGHT WILL EXTEND AS FAR WEST INTO PORTIONS OF THE I-25  
CORRIDOR AS IT DID LAST NIGHT. OTHER CHANGES TO TONIGHT'S  
FORECAST INCLUDE ONLY MINOR ADJUSTMENTS TO WIND AND TEMPERATURE  
FIELDS.  
 

 
   
SHORT TERM
 
(THIS EVENING THROUGH WEDNESDAY)  
ISSUED AT 222 PM MDT TUE AUG 14 2018  
 
THUNDERSTORMS WILL CONTINUE TO FORM OVER THE MOUNTAINS AND  
FOOTHILLS THIS AFTERNOON. ONCE THE URBAN CORRIDOR AND NEAR BY  
PLAINS DESTABILIZE MORE, THE STORMS WILL BE ABLE TO PROGRESS  
EASTWARD. LATEST RAP AND HRRR SHOWING CAPE OF 800-1400 J/KG IN THE  
FOOTHILLS AND ACROSS THE URBAN CORRIDOR LATE THIS AFTERNOON AND  
EVENING. THIS COMBINED WITH PRECIPITABLE WATER VALUES AROUND AN  
INCH AND LIFT FROM A TROUGH OVER MONTANA AND WYOMING IS EXPECTED  
TO PRODUCE SCATTERED THUNDERSTORMS OVER THE MOUNTAINS, FOOTHILLS,  
AND URBAN CORRIDOR. THE AIRMASS BECOMES MORE CAPPED AND MORE  
STABLE ACROSS THE EASTERN PLAINS. EXPECT STORMS TO DIE OFF AS THEY  
MOVE EAST OF THE URBAN CORRIDOR THIS EVENING.  
 
FOR WEDNESDAY, A BOUNDARY WILL BE OVER EASTERN COLORADO. TO THE  
WEST OF IT, MODELS INDICATE THERE WILL BE DRIER AIR. ALSO, MOST OF  
THE MODELS KEEP CONVECTION SOUTH OF I-70 WEDNESDAY. HOWEVER,  
THERE SHOULD BE ENOUGH CONVERGENCE ALONG THE BOUNDARY, MOISTURE,  
AND INSTABILITY TO PRODUCE A FEW STORMS. FLOW ALOFT WILL INCREASE  
AND PRODUCE BETTER SHEAR. THIS ALONG WITH CAPE OF 1000-1500 J/KG  
COULD PRODUCE A FEW SEVERE STORMS WEDNESDAY AFTERNOON OVER THE  
EASTERN PLAINS.  
   
LONG TERM
 
(WEDNESDAY NIGHT THROUGH TUESDAY)  
ISSUED AT 222 PM MDT TUE AUG 14 2018  
 
BY WEDNESDAY NIGHT THE UPPER RIDGE WILL BE OVER NEW MEXICO AND  
EXTEND EAST OVER THE GULF COAST. SPECIFIC HUMIDITY VALUES WILL  
INCREASE WITH PW VALUES REACHING TO ABOVE AN INCH BY LATE WEDNESDAY.  
FOR WEDNESDAY NIGHT STORMS WILL MAINLY BE FOCUSED OVER THE HIGHER  
TERRAIN OF THE PALMER DIVIDE WITH SOME CELLS BEING ABLE TO MOVE OVER  
THE PLAINS WITH THE BREAKDOWN AND NORTHERN MOVEMENT OF THE SURFACE  
LOW. THESE STORMS WILL MAINLY BE CAPABLE OF GUSTY WINDS AND SMALL  
HAIL.  
 
FOR THURSDAY AND FRIDAY THE UPPER RIDGE WILL RETROGRADE BACK TO THE  
WEST AND NORTH IN COLORADO. THIS WILL HELP TO BRING INCREASED NW  
FLOW OVER THE STATE. A COLD FRONT WILL PUSH THROUGH OVER THE NE  
PLAINS THURSDAY AFTERNOON THAT COULD PRODUCE ENOUGH CIN AROUND PEAK  
HEATING TIME TO INHIBIT MUCH CONVECTIVE POTENTIAL OUTSIDE OF THE  
HIGHER ELEVATIONS OF THE MOUNTAINS AND FOOTHILLS. TEMPERATURES  
THURSDAY WILL BE HOVERING JUST AROUND NORMAL FOR THIS TIME OF YEAR  
WITH HIGHS IN THE MID TO UPPER 80S. FOR FRIDAY, SOME FOG COULD BE  
POSSIBLE OVER THE PLAINS DURING THE EARLY MORNING HOURS AS MOISTURE  
WILL BE HIGH AND TEMPERATURES SLIGHTLY COOLER IN THE POST FRONTAL  
AIRMASS. BY THE LATE MORNING HOURS A DISTURBANCE EMBEDDED IN THE NW  
FLOW ALOFT WILL MOVE OVER HELPING TO INTRODUCE LIFT FOR STORM  
DEVELOPMENT ACROSS THE PLAINS BY THE LATE AFTERNOON HOURS.  
INSTABILITY IS BETTER OVER THE FAR EASTERN PLAINS AFTER CONVECTIVE  
INITIATION WITH CAPE IN THE 1000-1500 J/KG WITH JUST AROUND 500 OVER  
THE URBAN CORRIDOR ACCORDING TO THE GFS. PW VALUES REMAIN OVER AN  
INCH WITH STEERING FLOW ONLY 10-15 KTS. THIS INDICATES THAT ANY  
STORMS THAT DO FORM WILL BE SLOWER MOVING AND COULD PRODUCE A QUICK  
HALF INCH IN LESS THAN 30 MINUTES UNDER THE STRONGER CELLS. FRIDAY  
WILL BE SLIGHTLY WARMER THAN THURSDAY WITH HIGHS IN THE UPPER 80S.  
 
FOR THE WEEKEND AND INTO THE START OF NEXT WEEK THE UPPER RIDGE WILL  
FULLY TRANSITION TO OVER THE WESTERN CONUS LEAVING COLORADO IN  
INCREASED NW FLOW. THIS WILL ALLOW FOR THE INFLUX OF UPPER WAVES AND  
FRONTS TO BRING COOLER AIR AND INCREASED CHANCES OF SHOWERS AND  
THUNDERSTORMS TO THE REGION. THE FIRST SHORTWAVE WILL MOVE THROUGH  
SATURDAY INTO SUNDAY BRINGING STORMS SATURDAY LATE AFTERNOON AND  
EVENING CAPABLE OF BRIEF HEAVY RAIN AND SMALL HAIL. AS THE SHORTWAVE  
MOVED OVER FORCING COULD CONTINUE STORMS OVERNIGHT INTO SUNDAY. A  
COLD FRONT IS SET TO MOVE OUT OF WY INTO CO MONDAY USHERING IN  
CONTINUED COOLER TEMPERATURES WITH HIGHS POSSIBLY IN THE 70S BY  
MONDAY.  
 

 
   
AVIATION
 
(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)  
ISSUED AT 945 PM MDT TUE AUG 14 2018  
 
STORMS FOR THE MOST PART HAVE MOVED EAST OF THE DENVER METRO AREA  
AND CEILINGS HAVE BEGUN TO RISE WITH THE DEVELOPMENT OF A DRYING  
SOUTH-SOUTHWEST DRAINAGE WIND OF 5-12KTS. CAN'T RULE OUT A STRAY  
RAIN SHOWER AT ANY ONE OF THE DENVER AREA TERMINALS BEFORE 06Z  
TONIGHT, THEN GRADUAL CLEARING THEREAFTER. RESTRICTIONS DUE TO FOG  
ARE NOT EXPECTED TONIGHT.  
 

 
   
BOU WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
UPDATE...BAKER  
SHORT TERM...MEIER  
LONG TERM...BOWEN  
AVIATION...BAKER  
 
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