|
Show Selection: |
| #519735 (Received by flhurricane at: 4:35 PM 20.Jun.2012) TCDAT3 TROPICAL STORM CHRIS DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032012 500 PM AST WED JUN 20 2012 ALTHOUGH ONLY A FEW BANDING FEATURES ARE SEEN IN INFRARED SATELLITE PICTURES...VISIBLE IMAGERY SHOWS SEVERAL BANDS OF SHOWERS ROTATING AROUND THE CENTER. IN FACT...A RECENT SSMI MICROWAVE IMAGE REVEALED A RING OF CONVECTION THAT WRAPPED A LITTLE MORE THAN HALFWAY AROUND THE CENTER. AN ASCAT PASS THAT ARRIVED SHORTLY AFTER THE RELEASE OF THE PREVIOUS ADVISORY HAD A COUPLE 40-KT WIND VECTORS OVER THE SOUTHEASTERN QUADRANT. GIVEN THE LOW BIAS OF THAT INSTRUMENT AND THE IMPROVED STRUCTURE IN MICROWAVE IMAGERY SINCE THAT TIME...THE INITIAL INTENSITY IS INCREASED TO 50 KT. IT IS DOUBTFUL THAT CHRIS WILL STRENGTHEN ANY FURTHER AS A TROPICAL CYCLONE SINCE IT WILL BE MOVING OVER COLDER WATER WITHIN 12 HOURS. THE GLOBAL MODELS CONTINUE TO PREDICT THAT THE CYCLONE WILL MAINTAIN ITS INTENSITY OR PERHAPS STRENGTHEN A LITTLE AS A BAROCLINIC SYSTEM ON THURSDAY. AFTER 36 HOURS...GRADUAL WEAKENING IS EXPECTED...AND THE SYSTEM IS LIKELY TO MERGE WITH A LARGER EXTRATROPICAL LOW IN ABOUT 3 DAYS. CHRIS IS MOVING EASTWARD OR 085 DEGREES AT 18 KT. THE CYCLONE SHOULD TURN NORTHEASTWARD...THEN NORTHWARD AS AN UPPER-LEVEL TROUGH TO ITS NORTHWEST CUTS OFF. THE POST-TROPICAL CYCLONE IS FORECAST TO ROTATE CYCLONICALLY AROUND THE UPPER-LOW BEFORE THE MERGER TAKES PLACE. FORECAST POSITIONS AND MAX WINDS INIT 20/2100Z 38.5N 49.0W 50 KT 60 MPH 12H 21/0600Z 39.4N 45.8W 50 KT 60 MPH 24H 21/1800Z 41.7N 42.9W 50 KT 60 MPH...POST-TROPICAL 36H 22/0600Z 44.3N 42.7W 45 KT 50 MPH...POST-TROP/EXTRATROP 48H 22/1800Z 44.2N 44.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 72H 23/1800Z 42.5N 43.5W 30 KT 35 MPH...POST-TROP/EXTRATROP 96H 24/1800Z...DISSIPATED $$ FORECASTER BROWN |
