000 FXUS65 KBOU 040941 AFDBOU AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DENVER CO 340 AM MDT SAT JUL 4 2009 .SHORT TERM...MOST OF THE CONVECTION IS DIMINISHING ATTM AS A WEAK FRONTAL BOUNDARY LAST EVENING SPARKED ADDITIONAL STORMS ALONG THE FRONT RANGE AROUND MIDNIGHT. UPSLOPE FLOW HAS DEEPENED TO AROUND 700MB...PER PLATTEVILLE PROFILER AND KFTG VAD WINDS. THIS HAS ALSO LED TO SOME STRATUS WHICH HAS DEVELOPED IN THE WAKE OF THE STORMS...MAINLY ALONG THE FOOTHILLS AND ACROSS DOUGLAS COUNTY. PRECIPITABLE WATER TRENDS ALSO HAVE INCREASED IN THE WAKE OF THE DEEPENING UPSLOPE FLOW AS VALUES ARE NOW AT/JUST ABOVE AN INCH BASED ON THE PW TRENDS FROM GPS. LOW LVL MOISTURE VALUES HAVE ALSO BEEN REPLENISHED WITH DEWPOINTS IN THE MID 50S TO LOWER 60S ACROSS ALL OF NERN CO. LOOKS LIKE WE'LL HAVE TO HOLD ONTO ISOLD POPS EVEN THIS MORNING AS CONTINUED SHOWERS ARE RE-GENERATING OVER THE NRN MOUNTAINS IN VICINITY OF THE 70KT JET STREAK RIDING ACROSS SRN WYOMING. APPEARS ANOTHER WAVE IS SITUATED ACROSS EASTERN NEVADA AND WESTERN UTAH WITH CONSIDERABLE AMOUNTS OF LIGHTNING STILL ONGOING AT THIS HOUR AND ANOTHER WAVE ACROSS SOUTHERN OREGON. THIS WILL LEAD TO ANOTHER ROUND OF STORMS FOR SATURDAY AFTN AND INTO THE EVENING HOURS ACROSS MUCH OF THE CWA...ESP MOUNTAINS AND ADJACENT PLAINS. FORECAST SOUNDINGS INDICATE CAPE VALUES OF 800-1200J/KG ACROSS THE FRONT RANGE GIVEN TEMPS IN THE UPPER 70S AND DEWPOINTS IN THE LOWER TO MID 50S. CAPES A BIT LOWER FURTHER EAST WITH A BIT MORE STABILITY IN PLACE. FREEZING LVLS ALSO A LOWER TODAY...WHILE EXITING 80KT JET STREAK WILL PUT NERN CO IN FAVORABLE ASCENT REGION OF JET. GIVEN DECENT 35-40KT MID LVL FLOW...EXPECT SOME STORMS MAY BECOME SEVERE THIS AFTN OVER THE FRONT RANGE WITH HAIL UP AROUND AN INCH IN DIAMTER AND DAMAGING WINDS. SPC HAS ALSO TARGETED HIS AREA AND LOOKS REASONABLE. GIVE PW VALUES OVER AN INCH THIS AFTN...HEAVY RAINERS AS WELL BUT STORM MOTIONS OF 10-15KT SHOULD BE ENOUGH TO KEEP STORMS MOVING. FLOOD POTENTIAL AREAS TO WATCH WILL BE DENVER COUNTY AND ALSO IN THE FORT MORGAN AREA...WHERE HEAVY RAINS YESTERDAY HAVE THE SOILS WELL SATURATED. .LONG TERM...AXIS OF THE 500MB RIDGE PROGGED OVER ERN UTAH/WRN WYOMING SUNDAY MORNING WITH NWLY MID-LVL FLOW OVER NERN COLORADO. MODELS SHOW A WEAK RIPPLE EMBEDDED WITHIN THE FLOW ROUNDING THE TOP OF THE RIDGE DROPS DOWN THE EAST SIDE OF THE RIDGE OVER NERN COLORADO DURING THE LATE MORNING AND AFTERNOON HOURS ON SUNDAY. MEANWHILE...A STRONG SFC HIGH SLIDING SEWRD OUT OF SOUTH DAKOTA AND ACROSS CNTRL NEBRASKA TURNS LOW-LEVEL FLOW S-SELY ON THE PLAINS OF ERN COLORADO. NAM AND TO LESSER EXTENT THE GFS SHOW THE FORMATION OF A DENVER CYCLONE JUST EAST OF THE METRO AREA AROUND MIDDAY. MODELS SHOW THE CYCLONE SHEARING APART DURING THE AFTERNOON AS BNDRY LAYER FLOW BACKS AROUND MORE TO AN ELY COMPONENT. LOW LEVEL FLOW DRIVES A THETA-E RIDGE UP INTO NERN COLORADO WITH THE HIGHER VALUES UP ALONG THE SRN FTHLS AND OVER THE PALMER DIVIDE. NAM INDICATES MID- AFTERNOON SFC BASED CAPE VALUES UP AROUND 2500 J/KG ACROSS ERN DOUGLAS AND ELBERT COUNTIES. WHEREAS CAPE VALUES NOT AS HIGH ON THE GFS...THE MODEL DOES SHOW A FINGER OF ELEVATED CAPE EXTENDING NWRD ACROSS ERN ARAPAHOE...LINCOLN...WASHINGTON AND LOGAN COUNTIES ABOUT THE TIME THE SHORTWAVE PASSES BY. BOTH MODELS INDICATE INITIAL STORM DEVELOPMENT ACROSS THE NERN CORNER OF THE STATE DURING THE MORNING HOURS. BY AFTERNOON...NEW STORM GROWTH APPEARS TO SHIFT WESTWARD TO AREAS OVER AND NEAR THE FRONT RANGE AND ACROSS THE PALMER DIVIDE WITH THE REINFORCED MOIST UPSLOPE FLOW. NAM QPF FIELDS INDICATE THE GREATER PCPN AMOUNTS OVER THE PALMER DIVIDE SOUTH/SOUTHEAST OF DENVER WHERE THE BEST INSTABILITY...VERTICAL SHEAR AND MOISTURE ALL COME TOGETHER. WITH NWLY TRANSPORT WINDS...SUSPECT WE/LL SEE A DROP OFF IN T-STORM FORMATION/COVERAGE UP TOWARDS THE WYOMING BORDER AS MODELS SHOW WEAK SUBSIDENCE AND DRIER AIR MOVING IN AT MID-LEVELS ON THE BACK SIDE OF THE PASSING SHORTWAVE. SPC CONVECTIVE OUTLOOK HAS MOST OF ERN COLORADO UNDER A SLIGHT RISK ON SUNDAY. CAN/T ARGUE WITH THAT. ALTHOUGH SUSPECT LARGE HAIL AND DAMAGING T-STORM WINDS WILL BE MAIN THREAT...AND MAINLY SOUTH AND EAST OF THE DENVER METRO AREA. SCATTERED CONVECTION EXPECTED TO LINGER INTO THE EVENING BUT AS DRIER AIR AND SUBSIDENCE SPREADS IN FM THE NORTHWEST SHOULD SEE STORM ACTIVITY PRETTY MUCH WINDING DOWN BY MIDNIGHT...UNLIKE WHAT WE/LL SEEN THE PAST FEW NIGHTS. BY MONDAY...AIRMASS CONTINUES TO WARM AND STABILIZE ALOFT AS THE UPPER RIDGE CURRENTLY OUT WEST AMPLIFIES AND SHIFTS EASTWARD. Q-G VERTICAL MOTION FIELDS INDICATE INCREASING SUBSIDENCE IN THE 700-500 MB LAYER FOR MOST OF THE DAY. HOWEVER...MODELS CONTINUE TO SHOW LOW-LEVEL MOISTURE BEING TRANSPORTED NWRD INTO NERN COLORADO...WITH MID/LATE AFTERNOON CAPES IN THE 1000-2000 J/KG RANGE. EVEN WITH A RELATIVELY STRONG MID-LEVEL INVERSION IN PLACE...LOW POPS STILL IN ORDER WITH BEST CHANCE FOR MEASURABLE PCPN EAST OF A FORT MORGAN TO ELBERT LINE. LOOK FOR TEMPERATURES ON MONDAY TO BE 5-10F ABOVE THOSE ON SUNDAY. TUESDAY THROUGH THURSDAY...MID-LEVELS LOOK EVEN DRIER AND MORE STABLE AS THE UPPER RIDGE MIGRATES ACROSS THE STATE. TEMPERATURES ALOFT ALSO CONTINUE TO WARM WITH THE FCSTD 700 MB TEMP OVER DENVER AROUND 16C ON TUESDAY...19C ON WEDNESDAY AND AROUND 20C ON THURSDAY. THEREFORE SHOULD SEE A PERIOD OF LOW TO MID 90S ON THE PLAINS AND 60S TO LOWER 80E IN THE HIGH COUNTRY. ANY STORMS THAT MANAGE TO FORM LATE IN THE DAY WILL PROBABLY BE HIGH BASED AND PRODUCE MAINLY GUSTY MICROBURST WINDS AND ONLY A BRIEF RAINFALL. BY FRIDAY MAY SEE BIT OF AN INCREASE IN T-STORM ACTIVITY AS THE PLUME OF MONSOONAL MOISTURE BECOMES RE-ESTABLISHED OVER NEW MEXICO AND ERN COLORADO. && .AVIATION...VARYING IFR/MVFR CIGS EARLY THIS AM...ESP IN/NR FOOTHILLS AND DOUGLAS COUNTY. EXPECT THUNDERSTORMS TO DEVELOP THIS AFTN...MAINLY IN THE 20-01Z TIME FRAME. SURFACE WINDS WILL SHIFT N-NE BY AFTN AS HIGH PRESSURE BUILDS SOUTHWARD FROM WYOMING. && .BOU WATCHES/WARNINGS/ADVISORIES...NONE. $$ ENTREKIN/BAKER