|
Show Selection: |
| #531092 (Received by flhurricane at: 4:44 AM 02.Aug.2012) TCDAT5 TROPICAL DEPRESSION FIVE DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL AL052012 500 AM AST THU AUG 02 2012 THUNDERSTORM ACTIVITY ASSOCIATED WITH THE DEPRESSION HAS GENERALLY DIMINISHED DURING THE LAST SEVERAL HOURS...WITH DEEP CONVECTION NOW CONFINED TO THE SOUTH OF THE LOW-LEVEL CENTER. ALTHOUGH DVORAK T-NUMBERS HAVE DECREASED TO 1.5 AND 1.0 FROM TAFB AND SAB...THE INITIAL INTENSITY IS HELD AT 30 KT. THERE IS A POSSIBILITY THAT THE DEPRESSION COULD DEGENERATE INTO A REMNANT LOW OR TROPICAL WAVE LATER TODAY IF THE CURRENT WEAKENING TREND CONTINUES. IF THIS IS THE CASE...THEN ADJUSTMENTS TO THE TROPICAL STORM WATCH MAY BE NECESSARY. LATEST FIXES SUGGEST THAT THE DEPRESSION HAS INCREASED ITS FORWARD SPEED...WITH THE INITIAL MOTION ESTIMATE NOW 280/18. LARGE-SCALE MODELS AGREE THAT THE DEPRESSION WILL MOVE QUICKLY WESTWARD OR WEST- NORTHWESTWARD ON THE SOUTH SIDE OF A LOW- TO MID-LEVEL RIDGE DURING THE NEXT SEVERAL DAYS. LATER IN THE FORECAST PERIOD...THE SPREAD IN THE GUIDANCE INCREASES...WITH THE UKMET SHOWING A MORE NORTHWESTWARD TRACK AS THE CYCLONE RESPONDS TO A WEAKNESS TO THE NORTH. THE ECMWF/GFS SOLUTIONS SHOW A STRONGER RIDGE AND MAINTAIN A WESTWARD HEADING. THE NEW NHC TRACK FORECAST IS ADJUSTED SLIGHTLY SOUTHWARD THROUGHOUT THE FORECAST PERIOD...WITH MORE WEIGHT GIVEN TO THE MORE RELIABLE ECMWF/GFS OUTPUT ON DAYS 4-5. UW-CIMSS AND SHIPS ANALYSES INDICATE 20 KT OF WESTERLY SHEAR... ASSOCIATED WITH AN UPPER-LEVEL TROUGH TO THE NORTH...AFFECTING THE CYCLONE. THE GUIDANCE SHOWS A CONTINUATION OF THIS SHEAR OVER THE DEPRESSION THROUGH THE NEXT COUPLE OF DAYS...ESPECIALLY SINCE THE SYSTEM WILL BE MOVING INTO AN ENVIRONMENT CHARACTERIZED BY STRONG LOW- TO MID-LEVEL EASTERLY FLOW AND WEAKER FLOW ALOFT. ASSUMING THE SYSTEM SURVIVES...GLOBAL MODELS SHOW A MORE FAVORABLE ENVIRONMENT OVER THE WESTERN CARIBBEAN IN 4-5 DAYS...WHERE INTENSIFICATION COULD OCCUR. GIVEN THE CURRENT TREND...THE NHC INTENSITY FORECAST IS REDUCED...ESPECIALLY EARLY IN THE FORECAST PERIOD...AND IS LINE WITH THE LATEST SHIPS/LGEM OUTPUT. FORECAST POSITIONS AND MAX WINDS INIT 02/0900Z 12.8N 52.6W 30 KT 35 MPH 12H 02/1800Z 13.3N 55.2W 30 KT 35 MPH 24H 03/0600Z 13.7N 58.5W 30 KT 35 MPH 36H 03/1800Z 14.0N 61.6W 35 KT 40 MPH 48H 04/0600Z 14.6N 64.9W 40 KT 45 MPH 72H 05/0600Z 15.7N 71.3W 45 KT 50 MPH 96H 06/0600Z 16.7N 76.7W 50 KT 60 MPH 120H 07/0600Z 18.0N 80.5W 60 KT 70 MPH $$ FORECASTER KIMBERLAIN/AVILA |
