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

 407 
 WTPZ44 KNHC 271440
 TCDEP4
 TROPICAL STORM IRWIN DISCUSSION NUMBER   8
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 8 AM PDT SAT AUG 27 2005
  
 A SMALL CLUSTER OF DEEP CONVECTION HAS PERSISTED JUST WEST OF THE
 EXPOSED LOW-LEVEL CIRCULATION CENTER...WHICH IS JUST ENOUGH TO KEEP
 IRWIN A 35-KT TROPICAL STORM. MODERATE EAST-SOUTHEASTERLY
 UPPER-LEVEL SHEAR IS EXPECTED TO PERSIST FOR THE NEXT 96 HOURS...
 WITH SOME RELAXATION OF THE SHEAR EXPECTED AFTER THAT. GIVEN THAT
 IRWIN IS FORECAST TO REMAIN OVER 26-27C SSTS THROUGHOUT THE
 FORECAST PERIOD...THERE MAY BE ENOUGH INTERMITTENT BURSTS OF DEEP
 CONVECTION NEAR THE CENTER TO KEEP THIS SYSTEM GOING AS A MINIMAL
 TROPICAL CYCLONE. THIS IS CONSISTENT WITH THE SHIPS MODEL...WHICH
 ONLY WEAKENS IRWIN TO 25 KT IN 120 HOURS BENEATH 12 KT OF SHEAR.
  
 THE INITIAL MOTION REMAINS AT 270/9. THE GENERAL MOTION SHOULD BE
 WESTWARD AS IRWIN IS STEERED BY THE DEEP-LAYER EASTERLY FLOW ON THE
 SOUTH SIDE OF A STRONG MID-LEVEL SUBTROPICAL RIDGE THAT EXTENDS
 FROM MEXICO WESTWARD TO THE NORTH OF IRWIN. THIS MOTION IS
 SUPPORTED BY THE CONSENSUS OF THE NHC MODEL GUIDANCE. HOWEVER...
 IRWIN IS EXPECTED TO REMAIN OVER OR VERY NEAR SSTS WARM ENOUGH TO
 SUPPORT THE OCCASIONAL DEVELOPMENT OF DEEP CONVECTION. THIS
 INTERMITTENT STRENGTHENING OF THE VERTICAL CIRCULATION IN
 CONJUNCTION WITH SOUTHEAST TO EAST-SOUTHEASTERLY UPPER-LEVEL SHEAR
 MAY RESULT IN OCCASIONAL WOBBLES TO THE RIGHT...OR NORTH...OF THE
 MEAN WESTERLY FORECAST TRACK INDICATED IN THE OFFICIAL ADVISORY.
  
 FORECASTER STEWART
 
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      27/1500Z 17.4N 112.6W    35 KT
  12HR VT     28/0000Z 17.4N 114.0W    35 KT
  24HR VT     28/1200Z 17.5N 115.9W    35 KT
  36HR VT     29/0000Z 17.6N 117.7W    35 KT
  48HR VT     29/1200Z 17.7N 119.1W    35 KT
  72HR VT     30/1200Z 17.6N 122.0W    30 KT
  96HR VT     31/1200Z 17.5N 126.0W    25 KT
 120HR VT     01/1200Z 17.5N 130.0W    25 KT
  
 $$
 
Return to the Tropical Systems Page for IRWIN

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