000WTNT43 KNHC 060500TCDAT3HURRICANE MICHAEL SPECIAL DISCUSSION NUMBER 12NWS NATIONAL HURRICANE CENTER MIAMI FL AL132012100 AM AST THU SEP 06 2012MICHAEL HAS RAPIDLY INTENSIFIED WITH A SMALL WELL-DEFINED EYEBECOMING EVIDENT IN RECENT SATELLITE IMAGERY. THE INITIAL WINDSPEED IS SET TO 90 KT...IN LINE WITH SPECIAL 0415 UTC DVORAKCLASSIFICATIONS FROM TAFB AND SAB. THE INTENSITY FORECAST HAS BEENADJUSTED UPWARD FOR THE FIRST FEW DAYS OF THE PERIOD...AND ISCLOSEST TO THE EXPERIMENTAL GFDL AND HWRF MODELS BASED OFF OF THEECMWF FIELDS. THE FORECAST IS THEN BLENDED BACK TO THE PREVIOUS ONEBY DAY 5. NO CHANGES TO THE TRACK FORECAST WERE REQUIRED...AND ONLYSMALL ADJUSTMENTS TO THE WIND RADII WERE REQUIRED THROUGH 36 H.FORECAST POSITIONS AND MAX WINDSINIT 06/0500Z 29.4N 42.0W 90 KT 105 MPH 12H 06/1200Z 29.8N 41.7W 100 KT 115 MPH 24H 07/0000Z 30.5N 41.5W 100 KT 115 MPH 36H 07/1200Z 31.0N 41.6W 100 KT 115 MPH 48H 08/0000Z 31.5N 42.0W 100 KT 115 MPH 72H 09/0000Z 32.7N 43.0W 95 KT 110 MPH 96H 10/0000Z 34.0N 44.5W 80 KT 90 MPH120H 11/0000Z 35.5N 46.0W 65 KT 75 MPH$$FORECASTER BLAKE/BRENNAN
000WTNT43 KNHC 061439TCDAT3HURRICANE MICHAEL DISCUSSION NUMBER 14NWS NATIONAL HURRICANE CENTER MIAMI FL AL1320121100 AM AST THU SEP 06 2012THERE HAS BEEN LITTLE CHANGE IN THE CLOUD PATTERN OF MICHAEL THISMORNING...WITH ONLY SLIGHT WARMING OF THE EYE EVIDENT IN ENHANCEDINFRARED IMAGERY. A COMPROMISE OF THE DVORAK SUBJECTIVE INTENSITYESTIMATES AND THE UW-CIMSS OBJECTIVE ADT VALUE IS THE BASISFOR MAINTAINING AN INITIAL INTENSITY OF 100 KT. THERE IS ARELATIVELY SMALL WINDOW OF OPPORTUNITY FOR THE CYCLONE TOSTRENGTHEN A BIT MORE BEFORE THE UPPER-LEVEL WIND ENVIRONMENTBECOMES LESS FAVORABLE. GRADUAL WEAKENING WILL BE EITHER DUE TO AMID- TO UPPER-LEVEL MID-LATITUDE TROUGH APPROACHING FROM THENORTHWEST...OR THE RATHER LARGE OUTFLOW ASSOCIATED WITH HURRICANELESLIE. THE NHC INTENSITY FORECAST IS SIMILAR TO THE PREVIOUSADVISORY AND IS BASED PRIMARILY ON A BLEND OF THE IVCN CONSENSUSAND THE FLORIDA STATE UNIVERSITY SUPERENSEMBLE. OF COURSE...THEINTENSITY FORECAST IS HIGHLY DEPENDENT ON HOW BOTH HURRICANES TRACKWITH TIME.THE INITIAL MOTION ESTIMATE IS 040/6. THE LARGE-SCALE MODELS SHOW ATURN TO THE NORTH AND THE NORTH-NORTHWEST OCCURRING DURING THE NEXT24-36 HOURS IN RESPONSE TO A DEEPENING MID- TO UPPER- LEVEL LOW. SUBSEQUENTLY...AN INCREASING SPREAD IN THE GFS AND ECMWFSOLUTIONS...RIGHT AND LEFT OUTLIERS RESPECTIVELY...STILL EXISTSBEYOND THE 48 HOUR PERIOD. THE ECMWF SHOWS MORE INFLUENCE FROM AMID-LATITUDE RIDGE NORTHWEST OF THE CYCLONE...WHILE THE GFSINDICATES MORE RESPONSE TO A MID- TO UPPER LEVEL TROUGH. THEOFFICIAL TRACK FORECAST PHILOSOPHY IS SIMILAR TO THE PREVIOUS ONEAND SIDES WITH THE TVCA CONSENSUS...WHICH BASICALLY IS BETWEEN THEECMWF AND GFS SOLUTIONS.FORECAST POSITIONS AND MAX WINDSINIT 06/1500Z 30.1N 41.3W 100 KT 115 MPH 12H 07/0000Z 30.6N 41.1W 105 KT 120 MPH 24H 07/1200Z 31.2N 41.4W 100 KT 115 MPH 36H 08/0000Z 31.9N 42.0W 95 KT 110 MPH 48H 08/1200Z 32.4N 42.9W 90 KT 105 MPH 72H 09/1200Z 33.4N 44.0W 80 KT 90 MPH 96H 10/1200Z 35.2N 45.4W 70 KT 80 MPH120H 11/1200Z 38.0N 47.0W 60 KT 70 MPH$$FORECASTER ROBERTS