ZCZC MIATCDEP1 ALL TTAA00 KNHC DDHHMM TROPICAL DEPRESSION SERGIO DISCUSSION NUMBER 28 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP212006 700 AM PST MON NOV 20 2006 CONVENTIONAL SATELLITE IMAGERY SHOWS PULSATING CONVECTION ACROSS THE EASTERN SEMICIRCLE OF SERGIO. THE PROXIMITY OF THE DEEP CONVECTION TO THE CYCLONE'S CENTER YIELDED 1200 UTC DVORAK ESTIMATES FROM BOTH TAFB AND AFWA OF 45 KT AND 35 KT FROM SAB. SINCE THEN...THE CONVECTION HAS PULLED FURTHER AWAY FROM THE CENTER ONCE AGAIN. EARLY VISIBLE IMAGERY INDICATES A DISORGANIZED CLOUD PATTERN AND PROVIDES LITTLE ADDITIONAL ASSISTANCE IN DISCERNING THE CENTER. MY FIRST INCLINATION WAS TO BRING SERGIO BACK TO A TROPICAL STORM... HOWEVER DUE TO THE WEAKENING CONVECTION AND LACK OF AN ORGANIZED CENTER...THE INITIAL INTENSITY WILL REMAIN AT 30 KT. SOUTHWESTERLY SHEAR AROUND 30 TO 35 KT IS CURRENTLY AFFECTING THE CYCLONE AND IS FORECAST TO CONTINUE BUT BE SOMEWHAT MORE RELAXED. EVEN IF THE SHEAR DECREASES SIGNIFICANTLY AS INDICATED BY THE EXPERIMENTAL SHIPS MODEL...WHICH REDUCES THE AREA THAT COMPUTES THE SHEAR...IT WILL BE DIFFICULT FOR THE CIRCULATION TO RE-CONSOLIDATE. THE INITIAL MOTION IS ESTIMATED AT 255/3. SERGIO IS CURRENTLY LOCATED TO THE SOUTH OF A LOW- TO MID-LEVEL RIDGE AND TO THE NORTHEAST OF A LOW-LEVEL DISTURBANCE. OVER THE NEXT COUPLE OF DAYS THE RIDGE IS EXPECTED TO MIGRATE EASTWARD AND THE LOW-LEVEL DISTURBANCE...WEST OF SERGIO...SHOULD CONTINUE WESTWARD. THE OFFICIAL FORECAST ANTICIPATES THAT SERGIO WILL REMAIN A SHALLOW SYSTEM AND TAKES THE CYCLONE ON A GENERAL WESTWARD MOTION UNTIL DISSIPATION OCCURS. THE OFFICIAL FORECAST IS A LITTLE NORTH OF THE PREVIOUS TRACK AND FOLLOWS CLOSELY WITH THE MODEL CONSENSUS BUT SLOWER. FIRST LIGHT VISIBLE IMAGERY SUGGESTS THAT THE CENTER HAS BECOME EVEN FURTHER DETACHED FROM THE CONVECTION THAN INDICATED...BUT I WILL WAIT UNTIL THE NEXT ADVISORY TO DETERMINE IF SIGNIFICANT CHANGES... SUCH AS DISSIPATING THE SYSTEM SOONER THAN INDICATED...ARE WARRANTED. FORECAST POSITIONS AND MAX WINDS INITIAL 20/1500Z 14.9N 107.2W 30 KT 12HR VT 21/0000Z 15.1N 107.7W 30 KT 24HR VT 21/1200Z 15.4N 109.0W 30 KT 36HR VT 22/0000Z 15.8N 110.8W 25 KT...REMNANT LOW 48HR VT 22/1200Z 16.0N 112.5W 20 KT...REMNANT LOW 72HR VT 23/1200Z...DISSIPATED $$ FORECASTER MAINELLI NNNN
Alternate Formats
About Alternates -
E-Mail Advisories -
RSS Feeds
Cyclone Forecasts
Latest Advisory -
Past Advisories -
About Advisories
Marine Forecasts
Latest Products -
About Marine Products
Tools & Data
Satellite Imagery -
US Weather Radar -
Aircraft Recon -
Local Data Archive -
Forecast Verification -
Deadliest/Costliest/Most Intense
Learn About Hurricanes
Storm Names
Wind Scale -
Prepare -
Climatology -
NHC Glossary -
NHC Acronyms -
Frequently Asked Questions -
AOML Hurricane-Research Division
About Us
About NHC -
Mission/Vision -
Other NCEP Centers -
NHC Staff -
Visitor Information -
NHC Library
NOAA/
National Weather Service
National Centers for Environmental Prediction
National Hurricane Center
11691 SW 17th Street
Miami, Florida, 33165-2149 USA
nhcwebmaster@noaa.gov
Disclaimer
Privacy Policy
Credits
About Us
Glossary
Career Opportunities
Page last modified: Monday, 20-Nov-2006 14:50:04 UTC