000 FXUS63 KDDC 050749 AFDDDC AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE DODGE CITY KS 249 AM CDT SUN JUL 5 2009 .DISCUSSION... DAYS 1-2... THE FORECAST CHALLENGE WILL BE TEMPERATURES AND CHANCES FOR EVENING THUNDERSTORMS. THE 00Z UA ANALYSIS SHOWED A 70 KNOT JET AT 250 MB EXTENDING FROM SOUTHEAST WYOMING INTO THE SOUTHERN GREAT LAKES. THIS PUT THE CENTRAL HIGH PLAINS UNDER THE RIGHT ENTRANCE REGION OF THE JET. THE COMBINATION OF THE JET AND A WEAK SHORTWAVE MOVING OUT OF THE CENTRAL ROCKIES BROUGHT WIDESPREAD SHOWERS AND THUNDERSTORMS TO EASTERN COLORADO DURING THE EVENING HOURS. AS OF EARLY THIS MORNING...THE AREA OF PRECIPITATION WAS DIMINISHING RAPIDLY AND AWOS OBS NOT INDICATING ANY PRECIPITATION FROM ECHOES MOVING OUT OF COLORADO INTO FAR SOUTHWEST KANSAS. WILL REMOVE THE SLIGHT CHANCE FOR THUNDERSTORMS FOR EARLY THIS MORNING OUT ALONG THE COLORADO BORDER. IN THE LOWER LEVELS...SURFACE HIGH PRESSURE OVER NORTHERN NEBRASKA WAS BRINGING EASTERLY UPSLOPE FLOW TO WESTERN KANSAS AND EASTERN COLORADO. WATER VAPOR LOOPS AND ANALYSIS SHOW SHORTWAVE DISTURBANCES OVER THE NORTHERN ROCKIES AND MOVING ONSHORE OVER NORTHERN CALIFORNIA. THE MODELS SHOW THESE DISTURBANCES RIDING OVER THE RIDGE AND MOVING SOUTHEAST INTO THE CENTRAL HIGH PLAINS THROUGH THE NEXT 24-48 HOURS. THUNDERSTORMS WILL BE FORMING WITH AFTERNOON HEATING ALONG THE EASTERN SLOPES OF COLORADO THE NEXT FEW DAY WITH THE SHORTWAVES HELPING FOCUS AND MOVE THE STORMS TO THE SOUTHEAST. MODEL SOUNDINGS AT POINTS IN SOUTHWEST KANSAS ARE NOT PARTICULARLY UNSTABLE TODAY AS THE GREATEST INSTABILITY WILL BE FARTHER WEST. AS LOW LEVEL MOIST FLOW CONTINUES INTO MONDAY BETTER INSTABILITY IS FORECAST TO DEVELOP OVER FAR WESTERN KANSAS. AT ANY RATE IT APPEARS THAT THE BEST CHANCE FOR THUNDERSTORMS WILL BE OVER WESTERN SECTIONS OF THE CWA BOTH TONIGHT AND MONDAY NIGHT. AM NOT SURE HOW FAR EAST ANY THUNDERSTORM CLUSTERS WILL MAKE IT GIVEN THE NORTHWEST COMPONENT TO THE UPPER FLOW AND LOW LEVEL MOIST FLOW BEING CONFINED TO THE WESTERN CWA. HAVE BACKED OFF A BIT ON POPS OVER EASTERN SECTIONS OF THE CWA MONDAY NIGHT BUT WILL STILL MAINTAIN SLIGHT CHANCE POPS. A COOL AIRMASS HAS SETTLED INTO WESTERN KANSAS BEHIND THE FRONT AND COLD AIR ADVECTION CONTINUES EARLY THIS MORNING. THAT AND SOME MID LEVEL CLOUDINESS COULD HOLD TEMPERATURES BACK A BIT TODAY AND HAVE DROPPED A FEW DEGREES OFF OF THE GOING FORECAST HIGHS. DAYS 3-7... MEDIUM RANGE MODELS ARE IN FAIR AGREEMENT INDICATING AN UPPER LEVEL RIDGE BUILDING AS IT TRANSITIONS EAST ACROSS THE ROCKIES TO BEGIN THE PERIOD TUESDAY. THIS RIDGE WILL CONTINUE TO BUILD AS IT MOVES INTO AND DOMINATES THE CENTRAL PLAINS THROUGH THURSDAY. AT THE SURFACE, A LEE SIDE TROUGH OF LOW PRESSURE WILL PERSIST NEAR OR ALONG THE COLORADO BORDER THROUGH THURSDAY AS WELL INFLUENCING A LOW LEVEL SOUTHERLY FLOW ACROSS SOUTHWEST KANSAS. THIS GENERAL OVERALL PATTERN WILL RESULT IN A GRADUAL WARMING TREND WITH TEMPERATURES CLIMBING TO ABOVE SEASONAL NORMS BY THURSDAY. FOR TUESDAY, TEMPERATURES WILL BE FAIRLY WARM WITH BOTH THE GFS AND ECMWF INDICATING TEMPERATURES AT H85 RANGING FROM THE MID 20S(C) IN EASTERN PORTIONS OF THE CWA TO NEAR 30C ALONG THE COLORADO BORDER. EXPECT HIGHS MAINLY IN THE 90S(F) ACROSS SOUTHWEST KANSAS TUESDAY WITH TEMPERATURES GRADUALLY WARMING TO NEAR TO JUST ABOVE 100F ACROSS MUCH OF THE FORECAST AREA BY THURSDAY. OTHERWISE, TRANQUIL CONDITIONS ARE EXPECTED. PLAN NO SIGNIFICANT CHANGES TO TEMPERATURES. && AVIATION... SURFACE HIGH PRESSURE ACROSS THE NORTHERN PLAINS WILL BEGIN TO SLOWLY MOVE SOUTH INTO CENTRAL AND EASTERN KANSAS TODAY. THIS WILL BRING ABOUT AN EASTERLY UPSLOPE FLOW ACROSS SOUTHWEST KANSAS EARLY THIS MORNING. COMBINED WITH HIGH RELATIVE HUMIDITIES, THIS WILL ALLOW AREAS OF LOW LEVEL STRATUS TO DEVELOP ACROSS PORTIONS OF WESTERN KANSAS BY DAY BREAK. AS A RESULT, MVFR CIGS/VSBYS WILL BE POSSIBLE IN THE VICINITY OF ALL TAF SITES EARLY THIS MORNING. CIGS AND VSBYS WILL BEGIN TO IMPROVE PRIMARILY AFTER 14Z WITH VFR CONDITIONS RETURNING BY EARLY AFTERNOON. && .PRELIMINARY POINT TEMPS/POPS... DDC 83 63 89 65 / 0 0 20 20 GCK 83 62 90 64 / 0 10 20 30 EHA 83 63 90 67 / 10 20 20 30 LBL 83 63 90 65 / 0 0 20 30 HYS 83 63 89 66 / 0 0 10 20 P28 86 66 89 66 / 0 0 10 10 && .DDC WATCHES/WARNINGS/ADVISORIES... NONE. && $$ FN02/32