000  
FXUS65 KGJT 262019  
AFDGJT  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GRAND JUNCTION CO  
219 PM MDT MON JUN 26 2017  
   
UPDATE
 
 
ISSUED AT 207 PM MDT MON JUN 26 2017  
 
UPDATED NEAR TERM FORECAST TO INCLUDE ISOLATED THUNDER OVER SOME  
OF THE AREAS TERRAIN.  
 

 
   
SHORT TERM
 
(TODAY THROUGH TUESDAY)  
ISSUED AT 252 AM MDT MON JUN 26 2017  
 
LITTLE CHANGE AS FAR AS THE SHORT TERM PERIOD IS CONCERNED. HIGH  
PRESSURE REMAINS IN CONTROL BRINGING ANOTHER SUNNY AND WARM DAY TO  
EASTERN UTAH AND WESTERN COLORADO. ONCE AGAIN, A FEW SHOWERS AND  
THUNDERSTORMS ARE POSSIBLE OVER THE SAN JUANS BUT THE BEST  
INSTABILITY AND MOISTURE LOOKS TO BE JUST TO THE EAST OF OUR  
FORECAST AREA WHERE MORE WIDESPREAD CONVECTION IS EXPECTED. THE  
EASTERN UINTAS MAY ALSO SEE AN ODD SHOWER OR STORM THIS AFTERNOON  
BUT THESE WILL BE VERY ISOLATED IN NATURE. EXPECT SOME GUSTY WINDS  
TO MIX DOWN NEAR AND UNDER ANY CONVECTION. OUTSIDE OF THESE TWO  
AREAS, PLENTY OF SUN CONTINUES WITH A FEW CLOUDS THIS AFTERNOON.  
HIGH TEMPERATURES WILL INCREASE A FEW DEGREES COMPARED TO  
YESTERDAY.  
 
ON TUESDAY, THE TROUGH MENTIONED ABOVE WILL MOVE OVER THE CWA. A  
BIT MORE CONVECTION IS POSSIBLE WITH THE PASSAGE OF THIS  
DISTURBANCE BUT EVEN THE GFS, WHICH IS USUALLY VERY BULLISH WHEN  
IT COMES TO CONVECTION, HAS DOWNPLAYED PRECIPITATION. LOOKING  
ALOFT, THE NOSE OF THE UPPER LEVEL JET REMAINS NORTH OF OUR AREA  
AND DOES SUPPORT MORE PRECIPITATION FOR THE NORTHERN ROCKIES WHILE  
WE STAY FAIRLY DRY. AS THE TROUGH MOVES THROUGH, SOUNDINGS  
INDICATE GOOD MIXING TO 500MB, IF NOT HIGHER, WHERE WINDS OF 25 TO  
35 KTS CAN BE FOUND. THESE WILL LIKELY MIX TO THE SURFACE,  
ESPECIALLY UP NORTH, WHERE SOME GUSTIER WINDS ARE EXPECTED. WITH  
SUCH DRY CONDITIONS IN PLACE, CRITICAL FIRE WEATHER CONDITIONS NOW  
COME INTO PLAY. PLEASE SEE THE FIRE WEATHER DISCUSSION BELOW FOR  
MORE INFORMATION.  
   
LONG TERM
 
(TUESDAY NIGHT THROUGH SUNDAY)  
ISSUED AT 252 AM MDT MON JUN 26 2017  
 
THE SHORTWAVE TROUGH LOOKS TO MOVE THROUGH THE REGION THROUGH  
TUESDAY EVENING, USHERING IN A MODERATING SHOT OF COLDER AIR (WITH  
700MB TEMPERATURES DROPPING SOME 1 TO 3 DEGREES FROM MONDAY NIGHT TO  
THE 12 TO 16 DEGREES CELSIUS RANGE). THIS WILL ALLOW FOR DAYTIME  
HIGHS ON WEDNESDAY TO BE SLIGHTLY COOLER, THOUGH TEMPERATURES WILL  
STILL BE ABOVE NORMAL FOR THIS TIME OF YEAR. AS FAR AS FIRE WEATHER  
CONCERNS GO, IF THE TROUGH EXITS THE AREA ON TUESDAY AS ANTICIPATED,  
THE UPPER LEVEL GRADIENT WILL BEGIN TO LAX BEHIND THE TROUGH SO  
WHILE THE ATMOSPHERE WILL STILL REMAIN EXCEPTIONALLY DRY AS  
PRECIPITABLE WATER VALUES RANGE FROM 0.10 TO 0.30 INCHES, SURFACE  
WINDS DO NOT LOOK TO MEET CRITICAL FIRE WEATHER CRITERIA AT THIS  
TIME.  
 
FOR THURSDAY, THE PARENT UPPER LEVEL LOW RESPONSIBLE FOR THE  
AFOREMENTIONED EMBEDDED TROUGH WILL DRIFT TO THE EAST WHICH WILL  
LEAVE OUR FORECAST AREA IN NORTHWESTERLY FLOW THROUGH THE FIRST HALF  
OF THE WEEKEND AS A TRANSITIONAL RIDGE OF HIGH PRESSURE BUILDS TO  
THE SOUTH. SATURDAY EVENING AND BEYOND, A PACIFIC TROUGH LOOKS TO  
DIG INTO THE GREAT BASIN WITH SOUTHWESTERLY FLOW INCREASING ACROSS  
EASTERN UTAH AND WESTERN COLORADO. AS THE PREVIOUS FORECASTER  
MENTIONED, NO INDICATION THAT THE DRY SPELL WILL END ANYTIME SOON  
WHICH PAIRS WELL WITH THE CLIMATE PREDICTION CENTER'S 6 TO 10 DAY  
OUTLOOK WHICH SHOWS ODDS FAVORING WARMER AND DRIER CONDITIONS  
PERSISTING THROUGH THE END OF THE PERIOD.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)  
ISSUED AT 1041 AM MDT MON JUN 26 2017  
 
VFR CONDITIONS WILL CONTINUE THROUGH THE FORECAST PERIOD. A WEAK  
FRONTAL BOUNDARY WILL PASS ON TUESDAY AFTERNOON BRINGING A SLIGHT  
UPTICK IN WESTERLY WINDS AT ALL TERMINAL LOCATIONS.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 252 AM MDT MON JUN 26 2017  
 
AS THE TROUGH MOVES OVER THE AREA TUESDAY, DECENT MIXING UP TO AT  
LEAST 500MB WILL ALLOW SOME STRONGER WINDS TO REACH THE SURFACE.  
FOR THE MOMENT, OUR NORTHERN ZONES LOOK TO GET THE STRONGER WINDS  
AND WITH DRY CONDITIONS CONTINUING AND VERY DRY FUELS, CRITICAL  
FIRE WEATHER CONDITIONS WILL LIKELY BE MET TUESDAY. LATEST MODEL  
RUNS INDICATED THE GRAND VALLEY AND AREAS OF EASTERN UTAH POSSIBLY  
GETTING SOME GUSTIER WINDS TOO. HOWEVER, MOS GUIDANCE DOESN'T  
SUPPORT THESE WINDS WHILE SOUNDINGS CERTAINLY LEND THEMSELVES TO  
THE CHANCE OF IT HAPPENING. VERY BORDERLINE AT THE MOMENT AND WITH  
CONFIDENCE WAVERING BETWEEN MEDIUM TO MEDIUM HIGH, WILL KEEP THE  
WATCHES GOING ALLOWING ANOTHER MODEL RUN TO COME IN AND SEE HOW  
WINDS ARE LOOKING.  
 
ON WEDNESDAY, A SECOND, STRONGER JET STREAK IS PROGGED TO MOVE  
OVER EASTERN UTAH AND COLORADO AND IF MIXING REMAINS GOOD, THESE  
HIGHER WIND SPEEDS MAY BE TAPPED AND REACH THE SURFACE CAUSING  
ANOTHER DAY OF CRITICAL FIRE WEATHER. A FEW MORE MODEL RUNS WILL  
CERTAINLY HELP IN THIS REGARD, TOO.  
 

 
   
GJT WATCHES/WARNINGS/ADVISORIES
 
 
CO...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING  
FOR COZ200-202.  
 
UT...NONE.  

 
 

 
 
UPDATE...LARRY  
SHORT TERM...TGR  
LONG TERM...MMS  
AVIATION...MAC  
FIRE WEATHER...TGR  
 
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