Image Department Meteorology
Meteorology_Home Weather_Server News/Seminars
People
Research
Academics Application Contact_Us

Hawaiian_Weather
US_Mainland_Weather
Tropical_Weather
Satellite_Imagery
Radar_Imagery
Marine
Numerical_Models
LAPS
Forecasts
Observations
Archive
Links Disclaimer
Space
SOEST_Home
University_of_Hawaii_Home

 388 
 WTNT43 KNHC 260848
 TCDAT3
 TROPICAL DEPRESSION EIGHT DISCUSSION NUMBER   3
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL082009
 500 AM AST SAT SEP 26 2009
  
 WHILE DEEP CONVECTION HAS INCREASED OVER THE PAST FEW HOURS...
 GEOSTATIONARY IMAGERY AND AN AMSR-E PASS FROM AROUND 0400 UTC
 SUGGEST THAT THE LOW-LEVEL CENTER IS LOCATED ON THE SOUTHWESTERN
 EDGE OF THE CONVECTION. THIS STRUCTURE IS LIKELY DUE TO THE 10-15
 KT OF SOUTHWESTERLY SHEAR ANALYZED OVER THE CYCLONE BY UW-CIMSS AND
 THE SHIPS MODEL. DVORAK CI-NUMBERS WERE 1.5 AND 2.0 FROM SAB AND
 TAFB...RESPECTIVELY...AND THE INITIAL INTENSITY IS HELD AT 30 KT
 FOR THIS ADVISORY. CONDITIONS WILL BE ONLY MARGINALLY FAVORABLE FOR
 INTENSIFICATION OVER THE NEXT 2-3 DAYS. SSTS WILL BE 26-27C...AND
 THE SHIPS MODEL SHOWS THE SHEAR DECREASING BELOW 15 KT ONLY FOR A
 BRIEF PERIOD FROM 12 TO 24 HOURS. GIVEN THIS...THE OFFICIAL
 FORECAST HOLDS THE INTENSITY AT 30 KT THROUGH 24 HOURS AND THEN
 SHOWS A GRADUAL WEAKENING. HOWEVER...IT IS POSSIBLE THAT THE SYSTEM
 COULD BRIEFLY REACH TROPICAL STORM STATUS DURING THE NEXT DAY OR
 SO. 
  
 THE INITIAL MOTION ESTIMATE IS 300/12...A LITTLE TO THE LEFT OF THE
 PREVIOUS ADVISORY. MOST OF THE TRACK GUIDANCE INDICATES THAT THE
 CYCLONE WILL ROUND THE WESTERN EDGE OF THE SUBTROPICAL RIDGE AND
 TURN TOWARD THE NORTHWEST OVER THE NEXT COUPLE OF DAYS. BEYOND THAT
 TIME...THE GFS...NOGAPS AND HWRF SHOW THE DEPRESSION OR ITS REMNANTS
 TURNING NORTHWARD AHEAD OF A FRONT...WHILE THE UKMET...ECMWF...AND
 THE MEDIUM BAM SUGGEST THAT WHAT IS LEFT OF THE CYCLONE WILL TURN
 WESTWARD. THE OFFICIAL FORECAST IS SOUTH OF THE PREVIOUS ONE FOR
 THE FIRST 24 HOURS DUE TO THE INITIAL MOTION...AND IS AN UPDATE OF
 THE PREVIOUS FORECAST BEYOND THAT TIME. AT DAY 3 ONLY A SLOW
 NORTHWESTWARD MOTION IS INDICATED DUE TO THE LARGE SPREAD IN THE
 GUIDANCE.
 
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      26/0900Z 17.6N  33.8W    30 KT
  12HR VT     26/1800Z 18.7N  35.3W    30 KT
  24HR VT     27/0600Z 20.2N  36.9W    30 KT
  36HR VT     27/1800Z 21.6N  38.1W    25 KT
  48HR VT     28/0600Z 23.1N  39.3W    25 KT
  72HR VT     29/0600Z 24.5N  40.5W    20 KT...REMNANT LOW
  96HR VT     30/0600Z...DISSIPATED
  
 $$
 FORECASTER BRENNAN
  
 
Return to the Tropical Systems Page for EIGHT

Back to main Tropical Weather page




This page is maintained voluntarily by the MKWC and the UHMET faculty, staff, and students.
It was last modified on: Thu, Jul 23 2020 - 2003 UTC
Send comments to: Ryan Lyman