000 WTPZ43 KNHC 031448 TCDEP3 TROPICAL STORM POLO DISCUSSION NUMBER 4 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP182008 700 AM PST MON NOV 03 2008 POLO IS A MIDGET TROPICAL CYCLONE...WITH A RATHER TINY AREA OF TROPICAL STORM FORCE WINDS. WHILE AN EYE-LIKE FEATURE HAS BEEN EVIDENT IN THE GEOSTATIONARY SATELLITE IMAGERY...CLOUD-TOP TEMPERATURES HAVE WARMED AND DVORAK INTENSITY ESTIMATES FROM TAFB AND SAB REMAIN UNCHANGED AT A 2.5 CI NUMBER. WINDS IN SUCH SMALL SYSTEMS COULD BE HIGHER THAN INDICATED FROM DVORAK...BUT IN THE ABSENCE OF IN-SITU OBSERVATIONS...THE INITIAL INTENSITY WILL REMAIN 35 KT. POLO IS MOVING AT 270 DEGREES AT 10 KT...UNDER THE INFLUENCE OF A MID TO LOW-LEVEL RIDGE TO ITS NORTHWEST. A WEAKNESS DEVELOPS IN THE RIDGE IN ABOUT ONE TO TWO DAYS...AND THE MODEL GUIDANCE RESPONDS BY BENDING THE CYCLONE'S TRACK TOWARD THE WEST-NORTHWEST OR NORTHWEST. AT THE LONG-LEAD...THE TRACK MODELS DIVERGE WITH THE GLOBAL MODELS SHOWING A WEAKENING CYCLONE STAIR-STEPPING BACK TOWARD THE WEST...WHILE THE GFDL AND HWRF HURRICANE MODELS RECURVE A STRONGER POLO BACK TO THE NORTH-NORTHEAST THROUGH THE WEAKNESS IN THE RIDGE. GIVEN THAT ALL OF THE MODELS SHOW A SUBSTANTIAL INCREASE IN VERTICAL SHEAR IN ABOUT 48-60 HOURS...THE FORECAST TRACK LEANS TOWARD THE GLOBAL MODEL CONSENSUS OF A WEAKENING TROPICAL CYCLONE AND IS A BIT WEST OF THE PREVIOUS ADVISORY. THE INTENSITY FORECAST IS...PERHAPS AS USUAL...NOT STRAIGHTFORWARD. THE LOW VERTICAL SHEAR...DIVERGENT FLOW ALOFT...AND WARM SSTS WOULD SUGGEST ROBUST INTENSIFICATION IN THE NEXT TWO DAYS. BUT THE UNCONDUCIVE THERMODYNAMICAL ENVIRONMENT AND RATHER MEAGER CONVECTION WOULD SUGGEST OTHERWISE. THE FORECAST INTENSITY SLOWLY BRINGS THE WINDS UP THROUGH 48 HOURS...STRONGER THAN THE STATISTICAL MODELS...BUT WEAKER THAN THE GFDL AND HWRF MODELS. AFTER TWO DAYS...THE INCREASED VERTICAL SHEAR SHOULD INDUCE WEAKENING AND THE PREDICTED INTENSITY IS CLOSE TO THE MODEL CONSENSUS. FORECAST POSITIONS AND MAX WINDS INITIAL 03/1500Z 8.8N 113.2W 35 KT 12HR VT 04/0000Z 8.9N 114.8W 40 KT 24HR VT 04/1200Z 9.4N 116.8W 45 KT 36HR VT 05/0000Z 10.4N 118.6W 50 KT 48HR VT 05/1200Z 11.3N 120.3W 55 KT 72HR VT 06/1200Z 12.5N 122.5W 50 KT 96HR VT 07/1200Z 13.5N 125.0W 40 KT 120HR VT 08/1200Z 14.0N 128.0W 30 KT $$ FORECASTER LANDSEA/PASCH