000 WTNT45 KNHC 260233 TCDAT5 TROPICAL DEPRESSION MATTHEW DISCUSSION NUMBER 11 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL152010 1000 PM CDT SAT SEP 25 2010 INFRARED IMAGERY SHOWS DEEP CONVECTION INCREASING AGAIN NEAR THE CENTER OF MATTHEW TONIGHT. THE INTENSITY IS HELD AT 30 KT BASED ON A 25-KT 10-MINUTE WIND FROM CIUDAD DEL CARMEN MEXICO NORTH OF THE CENTER AROUND 0000 UTC...AND THE CENTRAL PRESSURE OF 1001 MB IS BASED ON AN OBSERVATION FROM TIKAL GUATEMALA AS THE CENTER PASSED NEARBY. GRADUAL WEAKENING IS EXPECTED AS THE CYCLONE WILL REMAIN OVER LAND...WITH DISSIPATION EXPECTED BY 72 HOURS. SATELLITE IMAGERY AND SURFACE OBSERVATIONS SUGGEST THAT MATTHEW IS LOCATED FARTHER SOUTH AND WEST THAN PREVIOUSLY ESTIMATED...AND THE INITIAL MOTION IS 285/12. MATTHEW CONTINUES TO HAVE A LARGE CIRCULATION EMBEDDED WITHIN A LARGER REGION OF CYCLONIC FLOW THAT EXTENDS FROM THE EASTERN PACIFIC TO THE WESTERN CARIBBEAN. THE CYCLONE WILL BE MOVING INTO A REGION OF WEAK STEERING FLOW IN THE NEXT 12 TO 24 HOURS...AND THE FORWARD SPEED SHOULD SLOW DRAMATICALLY. BEYOND THAT TIME...A VERY SLOW SOUTHWARD OR SOUTHEASTWARD DRIFT SEEMS LIKELY AS WHAT IS LEFT OF MATTHEW ROTATES WITHIN THE LARGER CYCLONIC GYRE. THE OFFICIAL FORECAST HAS BEEN SHIFTED SOUTH AND WEST OF THE PREVIOUS ONE DUE TO THE INITIAL POSITION AND MOTION AND A SOUTHWARD TREND IN MUCH OF THE GUIDANCE FROM 24 TO 48 HOURS. TORRENTIAL RAINS WILL CONTINUE WITH MATTHEW AND ITS REMNANTS OVER THE NEXT SEVERAL DAYS. THERE WERE THREE OBSERVING SITES IN HONDURAS AND GUATEMALA THAT REPORTED BETWEEN 6.1 AND 7.3 INCHES OF RAIN IN THE 24-HOUR PERIOD ENDING AT 0000 UTC. FORECAST POSITIONS AND MAX WINDS INITIAL 26/0300Z 17.0N 91.0W 30 KT...INLAND 12HR VT 26/1200Z 17.4N 92.1W 25 KT...INLAND 24HR VT 27/0000Z 17.7N 92.6W 25 KT...POST-TROP/REMNT LOW 36HR VT 27/1200Z 17.5N 92.6W 20 KT...POST-TROP/REMNT LOW 48HR VT 28/0000Z 17.4N 92.5W 20 KT...POST-TROP/REMNT LOW 72HR VT 29/0000Z...DISSIPATED $$ FORECASTER BRENNAN