** WTPZ41 KNHC 182041 *** TCDEP1 TROPICAL STORM SERGIO DISCUSSION NUMBER 21 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP212006 100 PM PST SAT NOV 18 2006 DESPITE MODERATE SOUTHWESTERLY SHEAR...SERGIO IS MAINTAINING DEEP CONVECTION OVER THE CENTER OF ITS CIRCULATION TODAY. DVORAK CURRENT INTENSITY ESTIMATES ARE 3.0 AND 3.5. ASSUMING THAT SERGIO'S POSITION IS ON THE PERIPHERY OF THE CONVECTION...THE INTENSITY IS ANALYZED TO REMAIN 45 KT AT THE LOW END OF THE DVORAK ESTIMATES. SERGIO REMAINS OVER QUITE WARM WATER AND A CONDUCIVE DIVERGENT FLOW ALOFT. HOWEVER...AS THE SHEAR IS PREDICTED BY ALL GLOBAL MODELS TO INCREASE TO AT LEAST 30 KT IN THE NEXT 36 TO 48 HOURS...GRADUAL WEAKENING IS FORECAST. THE INTENSITY PREDICTION IS NEAR THE STATISTICAL SHIPS AND FSU SUPER-ENSEMBLE MODELS...BUT IS SLIGHTLY ABOVE THAT FORECAST IN THE LAST ADVISORY. SERGIO IS MOVING 310/6 ALONG THE SOUTHEASTERN PERIPHERY OF A DEEP LAYER RIDGE. IF THE VERTICAL SHEAR WEAKENS THE CYCLONE TO A SHALLOWER SYSTEM...THEN THE CYCLONE SHOULD BEGIN TO MOVE WEST-NORTHWESTWARD WITHIN THE LOW-LEVEL FLOW. THE TRACK FORECAST IS BASED UPON THE MODEL CONSENSUS MINUS THE GFDL...WHICH HAS AN UNREALISTIC INITIAL LOOP. A 1320 UTC QUIKSCAT PASS ALLOWED FOR A CONTRACTION OF THE GALE FORCE WIND RADII TO BE ANALYZED. FORECAST POSITIONS AND MAX WINDS INITIAL 18/2100Z 15.6N 104.7W 45 KT 12HR VT 19/0600Z 16.0N 105.5W 45 KT 24HR VT 19/1800Z 16.5N 106.2W 40 KT 36HR VT 20/0600Z 16.8N 107.2W 35 KT 48HR VT 20/1800Z 17.1N 108.5W 30 KT 72HR VT 21/1800Z 17.5N 111.0W 20 KT...REMNANT LOW $$ FORECASTER AVILA/LANDSEA ** WTPZ21 KNHC 182042 *** TCMEP1 TROPICAL STORM SERGIO FORECAST/ADVISORY NUMBER 21 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP212006 2100 UTC SAT NOV 18 2006 INTERESTS ALONG THE SOUTHWESTERN COAST OF MEXICO SHOULD MONITOR THE PROGRESS OF SERGIO. TROPICAL STORM CENTER LOCATED NEAR 15.6N 104.7W AT 18/2100Z POSITION ACCURATE WITHIN 25 NM PRESENT MOVEMENT TOWARD THE NORTHWEST OR 310 DEGREES AT 6 KT ESTIMATED MINIMUM CENTRAL PRESSURE 1000 MB MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. 34 KT....... 50NE 30SE 0SW 50NW. 12 FT SEAS.. 75NE 75SE 60SW 75NW. WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT. REPEAT...CENTER LOCATED NEAR 15.6N 104.7W AT 18/2100Z AT 18/1800Z CENTER WAS LOCATED NEAR 15.4N 104.4W FORECAST VALID 19/0600Z 16.0N 105.5W MAX WIND 45 KT...GUSTS 55 KT. 34 KT... 50NE 30SE 0SW 50NW. FORECAST VALID 19/1800Z 16.5N 106.2W MAX WIND 40 KT...GUSTS 50 KT. 34 KT... 50NE 30SE 0SW 50NW. FORECAST VALID 20/0600Z 16.8N 107.2W MAX WIND 35 KT...GUSTS 45 KT. 34 KT... 40NE 0SE 0SW 0NW. FORECAST VALID 20/1800Z 17.1N 108.5W MAX WIND 30 KT...GUSTS 40 KT. FORECAST VALID 21/1800Z 17.5N 111.0W...REMNANT LOW MAX WIND 20 KT...GUSTS 25 KT. EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 200 NM ON DAY 4 AND 250 NM ON DAY 5...AND FOR INTENSITY NEAR 20 KT EACH DAY REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 15.6N 104.7W NEXT ADVISORY AT 19/0300Z $$ FORECASTER AVILA/LANDSEA