000 FXUS63 KEAX 251729 AFDEAX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE KANSAS CITY/PLEASANT HILL MO 1229 PM CDT SUN MAY 25 2008 ...UPDATED AVIATION DISCUSSION... .DISCUSSION... /ISSUED 455 AM CDT SUN MAY 25 2008/ MINI CONVECTIVE SYSTEM OVER SOUTH CENTRAL KANSAS HAS PUT OUT AN OUTFLOW BOUNDARY. THIS BOUNDARY HAS CUT OFF ITS ENERGY/INFLOW AND SUBSEQUENT BACKBUILDING...AND SHOULD LEAD TO THE EVENTUAL END OF THE SYSTEM. MEANWHILE STEERING WINDS WILL CARRY IT TO THE NORTHEAST BUT IT MAY NOT HAVE ENOUGH ENERGY TO REMAIN INTACT INTO MY FORECAST AREA. HAVE THEREFORE DROPPED POPS THIS MORNING TO JUST SLIGHT CHANCE. GULF MOISTURE WILL CONTINUE TO FLOW INTO THE REGION TODAY...LEADING TO AN UNSTABLE AIRMASS. ANY LINGERING REMNANT OF A BOUNDARY SHOULD PROVIDE ENOUGH FOCUS FOR THUNDERSTORM DEVELOPMENT THIS AFTERNOON...AND HAVE HELD ON TO CHANCE POPS AT THAT TIME. A SURFACE BOUNDARY WILL WORK ITS WAY SOUTH INTO THE MIDWEST/CENTRAL PLAINS REGION LATER TODAY AND TONIGHT. A MODEST LOW LEVEL JET WILL DEVELOP...AND IN CONJUNCTION WITH AN EJECTING SHORTWAVE...WILL LIKELY LEAD TO AN MCS DEVELOPING OVER SOUTHEAST NEBRASKA THIS EVENING. THIS SYSTEM IS EXPECTED TO MOVE SOUTH INTO NORTHERN MISSOURI AND NORTHEAST KANSAS TONIGHT. THIS SYSTEM WILL CONTINUE TO MOVE SOUTHEAST INTO CENTRAL MISSOURI THROUGH THE NIGHT. HOW FAR SOUTH DEPENDS ON THE STRENGTH OF THE COLD POOL. THIS WILL ALSO PLAY INTO THE FORECAST FOR THE REST OF THE HOLIDAY WEEKEND. ANY THUNDERSTORMS TODAY AND TONIGHT WILL CONTAIN VERY HEAVY RAINFALL WITH PWATS WELL OVER ONE INCH/APPROACHING TWO INCHES PER NAM/GFS PROGS. NATIONAL EXCESSIVE RAINFALL PROG SHOWS BULLSEYE OVER NORTHEAST KANSAS/NORTHERN MISSOURI. RECENT HEAVY RAINFALL HAS PUSHED FLASH FLOOD GUIDANCE AND HEADWATER GUIDANCE VALUES TO AN INCH OR LESS ACROSS THIS SAME AREA. HAVE ISSUED A FLASH FLOOD WATCH FOR THE AREA GENERALLY NORTH OF A LINE FROM TONGANOXIE/LEAVENWORTH TO CHILLICOTHE AND MACON MISSOURI. DEPENDING ON THE EXPECTED SOUTHWARD EXTENT OF THE COLD POOL...LATER SHIFTS MAY NEED TO EXPAND WATCH AREA SOUTHWARD. THE EFFECTIVE SURFACE BOUNDARY...WHETHER THE COLD POOL OR ACTUAL FRONT WILL CONTINUE TO MOVE SOUTH MONDAY INTO TUESDAY. THIS BOUNDARY WILL ONCE AGAIN BE THE FOCUS FOR ORGANIZED CONVECTION...AND ANOTHER FLASH FLOOD WATCH MAY BE NEEDED FOR THE REST OF THE FORECAST AREA MONDAY NIGHT INTO TUESDAY IF THE BOUNDARY LINGERS ACROSS THIS FORECAST AREA. WITH FORECAST CAPE FROM 1500-3000 J/KG...ANY STRONG STORM DEVELOPING ACROSS THE AREA SUNDAY AND MONDAY WILL HAVE THE CHANCE OF REACHING SEVERE WIND/HAIL CRITERIA. COLDER AIR AND LOWER DEW POINTS FILTER IN BEHIND THE SURFACE BOUNDARY LATER TUESDAY AND ESPECIALLY WEDNESDAY INTO THURSDAY. HAVE THEREFORE ADJUSTED FORECAST TO ACCOUNT FOR THAT. NO CHANGES MADE PAST WEDNESDAY NIGHT. NRR && .AVIATION... FOR THE 18Z TAFS...WILL GO WITHOUT ANY THUNDERSTORMS THROUGH THE AFTERNOON AND EVENING PERIODS AS IT APPEARS THE BETTER CHANCES OF THUNDER WILL BE BOTH SOUTH AND NORTH OF THE TAF SITES. WILL KEEP AN EYE ON DEVELOPMENT AND AMEND IF NEED BE. WILL FOCUS THUNDERSTORM CHANCES ON THE MCS THAT IS EXPECTED TO BE ROLLING OUT OF KANSAS INTO NORTHWEST MISSOURI LATE TONIGHT. LOOKS LIKE THE MORE LIKELY AREA FOR THAT MCS WILL BE NORTH OF KANSAS CITY...BUT WITH POTENTIAL OF AN OUTFLOW BOUNDARY FROM THIS COMPLEX RIDING INTO THE KANSAS CITY AREA ON MONDAY MORNING...WILL GO WITH CATEGORICAL THUNDER AFTER DAYBREAK. PC && .EAX WATCHES/WARNINGS/ADVISORIES... MO...FLASH FLOOD WATCH FROM 7 PM SUNDAY TO 1 PM MONDAY FOR MOZ001-MOZ002-MOZ003-MOZ004-MOZ005-MOZ006-MOZ007-MOZ008- MOZ011-MOZ012-MOZ013-MOZ014-MOZ015-MOZ016-MOZ017-MOZ020- MOZ021-MOZ022-MOZ023-MOZ024-MOZ025-MOZ028-MOZ029. KS...FLASH FLOOD WATCH FROM 7 PM SUNDAY TO 1 PM MONDAY FOR KSZ025-KSZ102-KSZ103-KSZ104. $$