Show Selection: |
#106009 (Received by flhurricane at: 4:55 AM 25.Aug.2006) TCDAT4 TROPICAL STORM DEBBY DISCUSSION NUMBER 15 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL042006 500 AM EDT FRI AUG 25 2006 THE DEEP CONVECTION HAS DECREASED BUT THE CLOUD PATTERN STILL REMAINS WELL-ORGANIZED AND HAS NOT CHANGED SIGNIFICANTLY DURING THE PAST FEW HOURS. A TRIMM PASS OVER DEBBY SHOWED THAT THE CYCLONE IS NOT VERTICALLY ALIGNED AND THE LOW- AND MIDDLE-LEVEL CENTERS ARE A LITTLE BIT DISPLACED. THIS IS CONSISTENT WITH THE CURRENT SOUTHEASTERLY SHEAR AFFECTING THE CYCLONE. INITIAL INTENSITY IS KEPT AT 45 KNOTS AS IN THE PREVIOUS ADVISORY BASED ON QUIKSCAT...BUT DVORAK T-NUMBERS SUGGEST A WEAKER SYSTEM. DEBBY IS ABOUT TO MOVE OVER WARMER WATERS AND THAT COULD HELP THE CYCLONE TO STRENGTHEN A LITTLE...BUT NOT AS MUCH AS THE GFDL AND THE SUPERENSEMBLE MODELS THAT MAKE DEBBY A MUCH STRONGER SYSTEM AFTER RECURVATURE. DEBBY CONTINUES TO MOVE TOWARD THE WEST-NORTHWEST AT 16 KNOTS AROUND THE PERIPHERY OF THE SUBTROPICAL RIDGE. THE CYCLONE WILL LIKELY REACH A WEAKNESS CAUSED BY AN APPROACHING TROUGH AND RECURVATURE SHOULD OCCUR IN ABOUT 48 TO 72 HOURS. THEREAFTER...DEBBY SHOULD MOVE TO THE NORTHEAST WITH A GRADUAL INCREASE IN FORWARD SPEED AND BECOME EXTRATROPICAL OR ABSORBED BY A LARGER FRONTAL LOW. THE OFFICIAL FORECAST IS CONSISTENT WITH THE TRACK GUIDANCE WHICH IN FACT...CONTINUES TO BE TIGHTLY CLUSTERED. THIS INCREASES THE CONFIDENCE IN THE FORECAST. FORECAST POSITIONS AND MAX WINDS INITIAL 25/0900Z 22.9N 42.3W 45 KT 12HR VT 25/1800Z 24.1N 44.6W 45 KT 24HR VT 26/0600Z 25.8N 47.3W 45 KT 36HR VT 26/1800Z 28.0N 49.5W 50 KT 48HR VT 27/0600Z 30.0N 50.5W 55 KT 72HR VT 28/0600Z 33.5N 50.0W 55 KT 96HR VT 29/0600Z 39.0N 43.0W 55 KT...BECOMING-EXTRATROPICAL 120HR VT 30/0600Z 45.0N 35.0W 55 KT...EXTRATROPICAL |