000 WTNT45 KNHC 162030 TCDAT5 TROPICAL DEPRESSION ERIN DISCUSSION NUMBER 8 NWS NATIONAL HURRICANE CENTER MIAMI FL AL052013 500 PM AST FRI AUG 16 2013 THERE HAS BEEN LITTLE CHANGE IN THE STRUCTURE OF ERIN THROUGHOUT THE DAY. THE CLOUD PATTERN CONSISTS OF A WELL-DEFINED LOW-LEVEL SWIRL WITH SMALL PATCHES OF CONVECTION. SINCE THE SATELLITE APPEARANCE OF THE CYCLONE HAS NOT CHANGED MUCH...THE INITIAL INTENSITY IS HELD AT 30 KT. THE DEPRESSION CURRENTLY LIES OVER 25-26C WATERS AND IS EMBEDDED WITHIN A FAIRLY STABLE AIRMASS. EVEN THOUGH ERIN WILL BE MOVING OVER WARMER WATERS IN A COUPLE OF DAYS...WEST-SOUTHWESTERLY WIND SHEAR IS EXPECTED TO INCREASE WHILE THE SYSTEM REMAINS IN A STABLE ATMOSPHERE. THE NHC WIND SPEED FORECAST IS THE SAME AS BEFORE...AND KEEPS ERIN STEADY STATE THROUGHOUT THE FORECAST PERIOD. AS MENTIONED IN PREVIOUS DISCUSSIONS...ERIN COULD DEGENERATE TO A REMNANT LOW OR AN OPEN TROUGH DURING THE NEXT FEW DAYS...AS SHOWN BY SOME OF THE DYNAMICAL MODELS. ERIN REMAINS ON TRACK...AND IS STILL MOVING WEST-NORTHWESTWARD AT ABOUT 15 KT. A SLIGHTLY SLOWER MOTION TOWARD THE WEST-NORTHWEST OR NORTHWEST IS FORECAST THROUGH SATURDAY WHILE THE DEPRESSION FEELS SOME INFLUENCE FROM A WEAKNESS IN THE SUBTROPICAL RIDGE. A SLIGHT BEND TO THE LEFT IS PREDICTED ON SUNDAY AND MONDAY WHEN ERIN LIES ON THE SOUTH SIDE OF THE RIDGE AXIS. THEREAFTER...A TURN BACK TO THE NORTHWEST IS FORECAST AS ERIN...OR ITS REMNANTS...MOVES TOWARD ANOTHER WEAKNESS IN THE RIDGE. THE NHC TRACK FORECAST IS NUDGED NORTHWARD FOR THIS ADVISORY TO COME INTO BETTER AGREEMENT WITH THE LATEST GUIDANCE. FORECAST POSITIONS AND MAX WINDS INIT 16/2100Z 17.7N 33.3W 30 KT 35 MPH 12H 17/0600Z 18.8N 35.0W 30 KT 35 MPH 24H 17/1800Z 19.8N 37.1W 30 KT 35 MPH 36H 18/0600Z 20.4N 39.0W 30 KT 35 MPH 48H 18/1800Z 20.9N 41.0W 30 KT 35 MPH 72H 19/1800Z 22.7N 45.8W 30 KT 35 MPH 96H 20/1800Z 25.0N 50.5W 30 KT 35 MPH 120H 21/1800Z 28.0N 53.5W 30 KT 35 MPH $$ FORECASTER CANGIALOSI