000 WTNT43 KNHC 200839 TCDAT3 TROPICAL STORM CHRIS DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032012 500 AM AST WED JUN 20 2012 CHRIS CONTINUES TO PRODUCE A COMMA-SHAPED BAND OF HEAVY SHOWERS THAT IS WRAPPING AROUND THE NORTHERN AND EASTERN PORTION OF THE CIRCULATION. GIVEN THAT THE SATELLITE-OBSERVED STRUCTURE OF THE STORM HAS SHOWN LITTLE CHANGE AND DVORAK INTENSITY ESTIMATES ARE ALSO UNCHANGED SINCE THE PREVIOUS ADVISORY...THE CURRENT INTENSITY IS MAINTAINED AT 40 KT. CHRIS WILL BE MOVING OVER RELATIVELY COOL WATERS AND IN AN ENVIRONMENT OF MODERATE SHEAR FOR THE NEXT DAY OR SO...SO LITTLE CHANGE IN STRENGTH IS FORECAST FOR THE EARLY PART OF THE FORECAST PERIOD. BY 36 HOURS...THE GLOBAL MODELS INDICATE THAT THE CYCLONE WILL BECOME INVOLVED WITH A FRONTAL ZONE SO EXTRATROPICAL TRANSITION IS FORECAST TO OCCUR AROUND THAT TIME. SOME SLIGHT INTENSIFICATION DUE TO BAROCLINIC PROCESSES IS POSSIBLE WITHIN A COUPLE OF DAYS. HOWEVER...LATER IN THE FORECAST PERIOD... THE POST-TROPICAL CYCLONE IS FORECAST TO WEAKEN AND MERGE WITH ANOTHER EXTRATROPICAL CYCLONE OVER THE NORTH ATLANTIC. THE FORWARD MOTION HAS ACCELERATED TO 100/15. THE CYCLONE IS EMBEDDED WITHIN AN AMPLIFYING MID-TROPOSPHERIC TROUGH...AND A CLOSED LOW IS DEVELOPING OVER THE NORTHERN PORTION OF THIS TROUGH. CHRIS SHOULD ACCELERATE EASTWARD TO EAST-NORTHEASTWARD AROUND THE SOUTHERN PORTION OF THE LOW TODAY...AND AFTERWARDS THE POST-TROPICAL CYCLONE IS LIKELY TO CURVE CYCLONICALLY AROUND THE EASTERN AND NORTHERN PORTIONS OF THE LOW. THE OFFICIAL FORECAST IS FAIRLY CLOSE TO THE LATEST DYNAMICAL MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INIT 20/0900Z 38.2N 53.5W 40 KT 45 MPH 12H 20/1800Z 38.3N 50.4W 40 KT 45 MPH 24H 21/0600Z 39.6N 45.7W 40 KT 45 MPH 36H 21/1800Z 42.0N 42.7W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 22/0600Z 44.0N 43.0W 45 KT 50 MPH...POST-TROP/EXTRATROP 72H 23/0600Z 44.0N 45.5W 35 KT 40 MPH...POST-TROP/EXTRATROP 96H 24/0600Z...MERGED WITH ANOTHER EXTRATROPICAL LOW $$ FORECASTER PASCH