|
Show Selection: |
| #293281 (Received by flhurricane at: 4:40 PM 03.Sep.2009) TCDAT1 TROPICAL DEPRESSION ERIKA DISCUSSION NUMBER 9 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062009 500 PM AST THU SEP 03 2009 THE CENTER OF ERIKA IS EXPOSED AS A LOW-LEVEL SWIRL MOVING OUT AHEAD OF THE WANING DEEP CONVECTION OVER THE LEEWARD ISLANDS. THE AIR FORCE RESERVE RECONNAISSANCE HURRICANE HUNTER AIRCRAFT FOUND A MINIMUM PRESSURE OF 1007 MB...BUT WERE UNABLE TO FIND ANY WINDS TO SUPPORT TROPICAL STORM STATUS. AS A RESULT...ERIKA IS DOWNGRADED TO A TROPICAL DEPRESSION ON THIS ADVISORY. THE INITIAL MOTION ESTIMATE IS 280/10...WELL TO THE SOUTH OF THE PREVIOUS OFFICIAL FORECAST TRACK AND THE MAJORITY OF ALL THE MODEL GUIDANCE. SINCE ERIKA SHOULD MOVE WITH THE LOW-LEVEL FLOW...THE SHALLOW BAM MODEL WAS FOLLOWED CLOSELY FOR THE NEW FORECAST TRACK. THIS FORECAST TURNS ERIKA TOWARD THE WEST-NORTHWEST...TAKING THE CYCLONE OR ITS REMNANT LOW SOUTH OF PUERTO RICO AND OVER HISPANIOLA ...WHERE THE LOW-LEVEL CENTER WILL LIKELY DISSIPATE OVER THE RUGGED TERRAIN IN 48 HOURS. THE OFFICIAL FORECAST ASSUMES THAT ERIKA WILL HAVE A DIFFICULT TIME SUSTAINING ANY DEEP CONVECTION AS IT MOVES INTO AN ENVIRONMENT OF INCREASING SHEAR AND DRY AIR IN THE LOWER TO MID-TROPOSPHERE. ERIKA IS MAINTAINED AS A TROPICAL DEPRESSION THROUGH 12 HOURS...AND IS FORECAST TO BE A REMNANT LOW BY 24 HOURS....ALTHOUGH THIS COULD OCCUR SOONER IF THE CONVECTION EAST OF THE LOW-LEVEL CENTER OVER THE LEEWARD ISLANDS CONTINUES TO WEAKEN. IT IS ALSO POSSIBLE THAT THE CENTER OF ERIKA COULD BECOME POORLY DEFINED AND THE CYCLONE COULD DEVOLVE INTO A TROPICAL WAVE AT ANY TIME. EVEN IF ERIKA LOSES TROPICAL CYCLONE STATUS...ITS REMNANTS COULD PRODUCE HEAVY RAINFALL OVER THE GREATER ANTILLES. FORECAST POSITIONS AND MAX WINDS INITIAL 03/2100Z 16.7N 65.3W 30 KT 12HR VT 04/0600Z 17.2N 66.8W 30 KT 24HR VT 04/1800Z 18.1N 68.6W 25 KT...REMNANT LOW 36HR VT 05/0600Z 18.9N 70.3W 20 KT...REMNANT LOW 48HR VT 05/1800Z 19.5N 72.2W 20 KT...DISSIPATING INLAND 72HR VT 06/1800Z...DISSIPATED $$ FORECASTER BRENNAN |
