Tropical Depression IRWIN
ZCZC MIATCDEP1 ALL
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TROPICAL DEPRESSION IRWIN DISCUSSION NUMBER 43
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112011
200 PM PDT SUN OCT 16 2011
ALL OF THE DEEP CONVECTION HAS ONCE AGAIN VANISHED...LEAVING IRWIN
AS A LOW-LEVEL CLOUD SWIRL. GIVEN THE CURRENT PRESENTATION OF THE
CYCLONE AND THE LATEST SATELLITE CLASSIFICATIONS...THE INITIAL WIND
SPEED IS LOWERED TO 25 KT. CONTINUED DRY AIR ENTRAINMENT AND AN
INCREASE IN EASTERLY SHEAR SHOULD CAUSE IRWIN TO BECOME A REMNANT
LOW IN 24 TO 36 HOURS...IF NOT SOONER. THE NHC FORECAST IS LOWERED
FROM THE PREVIOUS ONE...AND NOW SHOWS IRWIN DISSIPATING IN THREE TO
FOUR DAYS...IN AGREEMENT WITH THE GLOBAL MODEL GUIDANCE.
NOW THAT THE LOW-LEVEL CENTER IS EASY TO LOCATE...THERE IS MORE
CONFIDENCE IN THE LATEST 12-HOUR INITIAL MOTION ESTIMATE OF 225/4.
HOWEVER...THE LAST FEW VISIBLE IMAGES SUGGEST THAT IRWIN MAY BE
MOVING A LITTLE MORE WESTWARD. THE TRACK FORECAST REASONING IS
UNCHANGED. IRWIN...OR ITS REMNANTS...IS EXPECTED TO MOVE SLOWLY
WESTWARD OR WEST-NORTHWESTWARD FOR THE NEXT DAY OR SO.
THEREAFTER...THE WEAK SYSTEM COULD CURVE TO THE SOUTHEAST
BEFORE IT DISSIPATES.
FORECAST POSITIONS AND MAX WINDS
INIT 16/2100Z 13.6N 108.1W 25 KT 30 MPH
12H 17/0600Z 13.8N 108.6W 25 KT 30 MPH
24H 17/1800Z 14.1N 109.2W 25 KT 30 MPH
36H 18/0600Z 14.2N 109.6W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 18/1800Z 14.0N 109.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
72H 19/1800Z 13.4N 108.8W 20 KT 25 MPH...POST-TROP/REMNT LOW
96H 20/1800Z...DISSIPATED
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FORECASTER CANGIALOSI
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