|
Show Selection: |
| #201427 (Received by flhurricane at: 4:55 AM 17.Jul.2008) TCDAT2 TROPICAL STORM BERTHA DISCUSSION NUMBER 57 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008 500 AM EDT THU JUL 17 2008 NORTHWESTERLY SHEAR APPEARS TO BE TAKING ITS TOLL ON BERTHA AS THE REMAINING THUNDERSTORM ACTIVITY IS LIMITED TO THE EAST AND SOUTHEAST OF THE CENTER. THE LATEST DVORAK INTENSITY ESTIMATES ARE 45 KT AND A RECENT ASCAT PASS SUGGESTS THAT BERTHA'S WINDS HAVE INDEED DECREASED. THE INITIAL INTENSITY IS LOWERED TO PERHAPS A GENEROUS 50 KT. ALTHOUGH BERTHA IS FORECAST TO MOVE OVER SLIGHTLY WARMER WATERS TODAY...CONTINUED SHEAR SHOULD MEAN LITTLE CHANGE IN INTENSITY. IN FACT...NO CHANGE IN INTENSITY IS PREDICTED THROUGHOUT THE FORECAST PERIOD AND THIS IS IN LINE WITH THE LATEST SHIPS AND LGEM GUIDANCE. BERTHA IS STILL MOVING SOUTHEASTWARD WITH AN INITIAL MOTION ESTIMATE OF 140/9. WATER VAPOR IMAGERY INDICATES THAT THE UPPER-LEVEL LOW IS BEGINNING TO MOVE NORTHWARD AND BERTHA SHOULD TURN EASTWARD AROUND THE SOUTHWESTERN PERIPHERY OF THE LOW DURING THE NEXT 6-12 HOURS. THEREAFTER....BERTHA SHOULD GRADUALLY ACCELERATE NORTHEASTWARD. THE NEW FORECAST IS ADJUSTED A LITTLE SOUTH OF THE PREVIOUS TRACK DURING THE FIRST 24 HOURS...OTHERWISE IT IS VERY SIMILAR TO THE PREVIOUS ADVISORY. BERTHA SHOULD BECOME EXTRATROPICAL IN 3-4 DAYS AND COULD GET ABSORBED BY A LARGER EXTRATROPICAL LOW IN ABOUT 5 DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 17/0900Z 34.5N 59.2W 50 KT 12HR VT 17/1800Z 34.0N 58.0W 45 KT 24HR VT 18/0600Z 34.5N 55.7W 45 KT 36HR VT 18/1800Z 36.3N 53.2W 45 KT 48HR VT 19/0600Z 38.4N 50.2W 45 KT 72HR VT 20/0600Z 43.1N 44.3W 45 KT...BECOMING EXTRATROPICAL 96HR VT 21/0600Z 49.0N 37.0W 45 KT...EXTRATROPICAL 120HR VT 22/0600Z 56.0N 27.5W 45 KT...EXTRATROPICAL $$ FORECASTER BROWN |
