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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
140 PM MDT MON SEP 22 2014

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 140 PM MDT MON SEP 22 2014

UPPER LOW WILL MOVE ACROSS WYOMING THROUGH TONIGHT AS THE
SOUTHERN EXTENT OF THE LOW SWEEPS ACROSS NORTHERN COLORADO. THERE
IS A 60KT JET STREAK ASSOCIATED WITH THE WAVE ACROSS NORTHWEST
COLORADO AND THIS IS AIDING THUNDERSTORM DEVELOPMENT EARLY THIS
AFTERNOON. MODEL QG FIELDS SHOWING WEAK ASCENT THROUGH THIS
EVENING THEN GRADUALLY SUBSIDENCE MOVES IN LATER TONIGHT AND
TUESDAY AS AIRMASS DRIES.

A LINE OF SHOWERS AND THUNDERSTORMS ARE MOVING INTO THE FRONT
RANGE EARLY THIS AFTERNOON AND WILL CONTINUE TO SPREAD EASTWARD
ONTO THE PLAINS DURING THE AFTERNOON. STORMS WILL GATHER STRENGTH
AS THEY MOVE EASTWARD INTO AREA WITH BETTER SHEAR AND MOISTURE.
GIVEN DEWPOINTS NOW IN THE 50S ACROSS MUCH OF THE PLAINS...SURFACE
BASED CAPES INCREASING TO 1000-1500J/KG. STILL A GRADUAL LACK OF
STRONG HEATING WILL KEEP MOST STORMS UNDER SEVERE LIMITS.
HOWEVER...GIVEN BETTER SHEAR PROFILE FURTHER EAST...MIGHT SEE AN
ISOLATED SEVERE STORM.

BEHIND THE TROF LATER TNT...A BIT OF MOUNTAIN WAVE DEVELOPS WITH
SOME DOWNSLOPE WINDS DEVELOP OVER THE FRONT RANGE. WILL INDICATED
SOME CLOUDS AND WINDS WITH THIS FEATURE. FOR TUESDAY
AFTERNOON...LIMITED MOISTURE AND INSTABILITY MAY BE ENOUGH TO
DEVELOP A FEW SHOWERS OVER MOUNTAINS AND HIGHER TERRAIN.
TEMPERATURES WILL BE WARMER ON TUESDAY WITH MORE SUNSHINE
AVAILABLE. 

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 140 PM MDT MON SEP 22 2014

UPPER TROUGH CONTINUES TO SLIDE EAST AWAY FROM THE 
COLORADO FRONT RANGE TUESDAY NIGHT AS AN UPPER RIDGE BUILDS TO OUR 
SOUTHWEST. A DRIER AND WARMER NORTHWEST FLOW ALOFT MOVES OVER THE 
AREA OVERNIGHT AND WEDNESDAY AS THE UPPER RIDGE REACHES 
NORTHEASTWARD ACROSS COLORADO AND NORTHERN GREAT PLAINS. THERE IS 
STILL AN OUTSIDE CHANCE THAT STRONG DAYTIME HEATING AND A MODESTLY  
MOIST SELY LOW-LEVEL FLOW COULD SPARK A FEW STRAY SHOWERS OR T-
STORMS OVER THE HIGHER TERRAIN IN JEFFERSON...DOUGLAS...PARK AND 
SUMMIT COUNTIES LATE ON WEDNESDAY. OTHERWISE A DRY AND VERY WARM DAY 
ON TAP FOR EVERYWHERE ELSE. TEMPERATURE GUIDANCE INDICATES HIGHS 
GENERALLY 6-12F ABOVE AVERAGE ON WEDNESDAY. CAN/T ARGUE WITH THAT. 
THE UNSEASONABLY WARM AND DRY WEATHER IS LIKELY TO PERSIST THROUGH 
THURSDAY AS THE CORE OF A 591 DECAMETER HIGH TRACKS NORTHEASTWARD 
ACRS THE STATE. THURSDAY APPEARS EVEN DRIER AND SLIGHTLY WARMER 
ACCORDING TO THE GFS AND ECMWF WITH STRONG MID-LEVEL SUBSIDENCE. 
WHEREAS THE NAM SHOWS THIS WARM CORE RIDGE CLOSING OFF NORTHEAST OF 
COLORADO DURING THE DAY. THIS OPENS THE DOOR TO A BATCH OF 
SUBTROPICAL MOISTURE POOLING OVER ERN ARIZONA/WRN NEW MEXICO. NAM 
SHOWS SOME OF THIS MOISTURE MEANDERING NWRD UP ALONG THE SPINE OF 
THE ROCKIES AND OVER SWRN PORTION OF THE FCST AREA BY THURSDAY 
AFTERNOON. NAM INDICATES POCKETS OF LIGHT QPF IN THIS AREA. THE 
LATEST RUN OF THE CANADIAN MODEL LOOKS ABOUT THE SAME...ALTHOUGH IT 
KEEPS THE PRECIP SOUTH OF THE CWA ON THURSDAY. 

ON FRIDAY...THE UPPER RIDGE CLOSES OFF AS IT CONTINUES ITS 
NORTHEASTWARD MIGRATION OVER THE NRN GREAT PLAINS/SRN CENTRAL 
CANADA. FLOW ALOFT OVER COLORADO BECOME PREDOMINANTLY SWLY IN 
ADVANCE OF A DEEPENING UPPER TROUGH PLOWING INTO THE WEST COAST. GFS 
SHOWS SUBTROPICAL MOISTURE POOLED OVER ARIZONA/NEW MEXICO AT THAT 
TIME SPREADING NWRD OVER ERN UTAH AND WRN/SWRN COLORADO DURING THE 
DAY. WHILE AREAS EAST OF THE MTNS APPEAR TO REMAIN DRY. MODEL 
GUIDANCE CONTINUES AN UPWARD TREND IN TEMPERATURES ON FRIDAY. 
HOWEVER SHOULD THIS MOISTURE/CLOUD COVER ARRIVE EARLIER THAN 
PREDICTED...TEMPS MAY NOT GET AS WARM AS THOSE ON THURSDAY. 

OVER THE WEEKEND...MOISTURE SPREADS NORTHWARD FROM THE DESERT 
SOUTHWEST IN ADVANCE OF A DEEP UPPER TROUGH WHICH THE GFS SHOWS 
CLOSING OFF OVER SRN IDAHO/NRN UTAH BY SUNDAY. EARLIER MODEL RUNS 
SHOWED THIS HAPPENING FARTHER SOUTH OVER SOUTH CENTRAL PORTIONS OF 
THE GREAT BASIN AND ABOUT 12 HRS EARLIER. AT ANY RATE...DURING THE 
WEEKEND SHOULD SEE A GRADUAL TREND TOWARDS COOLER AND WET CONDITIONS 
BEGINNING IN THE MTNS AND HIGH VALLEYS ON SATURDAY AND OUT ACRS THE 
PLAINS OF NERN COLORADO ON SUNDAY. BY EARLY NEXT WEEK...MODELS SHOW 
THE CLOSED UPPER LOW LIFTING NERWD OVER THE NRN ROCKIES/NRN GREAT 
PLAINS WHICH POSITIONS A SWATH OF DRY...STABLE AIR OVER OUR FCST 
AREA. DETAILS REMAIN FUZZY THAT FAR OUT. SO WILL GO WITH A SLIGHT 
CHANCE OF PRECIP MAINLY FOR THE MTNS AND HANG ONTO THE NEAR SEASONAL 
TEMPERATURES OFFERED BY MODEL GUIDANCE.

&&

.AVIATION...(FOR THE TAFS THROUGH 00Z TUESDAY LATE AFTERNOON)
ISSUED AT 140 PM MDT MON SEP 22 2014

EXPECT SCATTERED SHOWERS AND THUNDERSTORMS OVER TERMINALS THROUGH
LATE AFTERNOON...THEN DIMINISHING CHANCES BY EARLY EVENING.
CURRENT SOUTHEAST WINDS WILL BECOME VARIABLE AND GUSTY WITH
SHOWERS...BEFORE SHIFTING EAST AND SOUTHEAST THIS EVENING.

&&

.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...ENTREKIN
LONG TERM...BAKER
AVIATION...ENTREKIN

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