000
WTPZ45 KNHC 040259
TCDEP5
 
TROPICAL DEPRESSION JOHN DISCUSSION NUMBER   6
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP102012
800 PM PDT MON SEP 03 2012
 
THE CENTER OF JOHN REMAINS DEVOID OF DEEP CONVECTION...AND WHAT DEEP
CONVECTION REMAINS HAS BEEN SHUNTED TO THE SOUTHWEST BY STRONG
NORTHEASTERLY WIND SHEAR.  A BLEND OF THE LATEST SATELLITE
INTENSITY ESTIMATES WITH RECENT UW-CIMSS ADT VALUES IS THE BASIS
FOR LOWERING THE INITIAL INTENSITY TO 30 KT.  JOHN IS NEARING THE
26C-ISOTHERM...AND SHOULD REACH A SHARP GRADIENT OF DECREASING SEA
SURFACE TEMPERATURES IN 12-24 HOURS.  AN INCREASINGLY STABLE
THERMODYNAMIC ENVIRONMENT AND A CONTINUATION OF AT LEAST MODERATE
NORTHEASTERLY SHEAR SHOULD MEAN A QUICK DEMISE OF JOHN.  THE NEW
NHC INTENSITY FORECAST SHOWS STEADY WEAKENING IN BASIC AGREEMENT
WITH THE LATEST SHIPS AND LGEM GUIDANCE. JOHN IS FORECAST TO BECOME
A REMNANT LOW IN 36 HOURS...IF NOT SOONER.
 
THE INITIAL MOTION ESTIMATE IS 305/11...THOUGH RECENT CENTER FIXES
SUGGEST A SOMEWHAT SLOWER FORWARD SPEED.  THE LARGE-SCALE MODELS
SHOW JOHN DECELERATING ON A WEST-NORTHWESTWARD TO NORTHWESTWARD
COURSE OVER THE NEXT COUPLE OF DAYS...AROUND THE SOUTHWESTERN
PERIPHERY OF A MID-LEVEL RIDGE OVER THE SOUTHWESTERN UNITED STATES.
ONCE THE CYCLONE DECOUPLES AND BECOMES SHALLOW...ITS FORWARD MOTION
SHOULD SLOW FURTHER AND THE TRACK SHOULD BEND TOWARD THE NORTH OR
POSSIBLY THE NORTHEAST.  THE NHC TRACK FORECAST IS A HAIR TO THE
RIGHT OF THE PREVIOUS ONE FOR THE FIRST COUPLE OF DAYS...AND THEN
MORE SO BEYOND 72 HOURS.  THIS IS IN GOOD AGREEMENT WITH THE
MULTI-MODEL CONSENSUS TVCE.
 
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/0300Z 21.7N 114.6W   30 KT  35 MPH
 12H  04/1200Z 22.7N 116.0W   30 KT  35 MPH
 24H  05/0000Z 23.9N 117.6W   25 KT  30 MPH
 36H  05/1200Z 25.0N 119.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  06/0000Z 25.8N 120.4W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  07/0000Z 27.0N 121.0W   15 KT  15 MPH...POST-TROP/REMNT LOW
 96H  08/0000Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN