000 WTPZ42 KNHC 212047 TCDEP2 TROPICAL DEPRESSION TWO-E DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL EP022012 200 PM PDT MON MAY 21 2012 A 1640 UTC ASCAT PASS HAS MADE THE CENTER OF THE DEPRESSION MORE READILY APPARENT...AND THE INITIAL POSITION IS A BIT OF A NORTHWARD ADJUSTMENT. THE ASCAT DATA IS ALSO SHOWING WINDS NO HIGHER THAN 25-30 KT...SO THE CYCLONE IS BEING MAINTAINED AS A 30-KT DEPRESSION. THE ADJUSTMENT OF THE CENTER LOCATION HAS RESULTED IN A LONG-TERM MOTION OF 290/5 KT. THERE IS RELATIVELY LITTLE CHANGE TO THE TRACK FORECAST THROUGH THE FIRST 72 HOURS. THE TRACK GUIDANCE REMAINS IN GOOD AGREEMENT ON A NORTHWESTWARD TO NORTHWARD TURN AS A WEAKNESS IN THE MID-LEVEL RIDGE DEVELOPS OVER MEXICO. THERE IS CONSIDERABLE CHANGE IN THE MODELS ON DAYS 4 AND 5...WITH THE 12Z GFS AND ECMWF SUGGESTING THAT THE CYCLONE MAY NOT BE FULLY PICKED UP BY A DEEPENING LONGWAVE TROUGH OVER THE WESTERN UNITED STATES...AND INSTEAD SLOWS DOWN AND STALLS VERY NEAR THE MEXICAN COAST. THE GFDL AND HWRF CONTINUE TO SHOW THE SYSTEM PLOWING NORTHEASTWARD ACROSS MEXICO...AND THOSE SOLUTIONS ARE DISREGARDED. THE NHC TRACK FORECAST SHOWS THE CYCLONE DECELERATING AS IT APPROACHES THE COAST OF MEXICO...ENDING UP ALONG THE COAST ON DAY 5. DEEP CONVECTION APPEARS TO BE CONSOLIDATING AROUND THE LOW-LEVEL CENTER...AND THE ANTICIPATED INTENSIFICATION OF THE DEPRESSION MAY BEGIN SOON. IN FACT...THE SHIPS RAPID INTENSIFICATION INDEX HAS INCREASED TO 56 PERCENT FOR THE 25-KT THRESHOLD AND 40 PERCENT FOR THE 30-KT THRESHOLD DUE TO THE SEEMINGLY CONDUCIVE ENVIRONMENT OF LOW VERTICAL WIND SHEAR AND WARM SEA-SURFACE TEMPERATURES. THE NHC FORECAST THEREFORE INDICATES THE DEPRESSION BECOMING A HURRICANE BY 36 HOURS...WHICH IS CLOSE TO WHAT IS SHOWN BY SHIPS AND HWRF. THE CYCLONE SHOULD REACH ITS PEAK INTENSITY AROUND 72 HOURS...BUT THERE IS A LOT OF UNCERTAINTY ON DAYS 4 AND 5. THE STATISTICAL GUIDANCE SHOWS THE CYCLONE WEAKENING AS IT APPROACHES THE COAST OF MEXICO...WHICH IS ALSO SUPPORTED IN SOME FASHION BY THE GFS AND ECMWF MODELS. THE OFFICIAL FORECAST FOLLOWS THIS TREND AND NOW INDICATES THAT THE SYSTEM MAY NOT EVEN BE A HURRICANE ON DAY 5. BUT...AS ALREADY STATED...THERE IS A LOT OF UNCERTAINTY. USERS ARE REMINDED NOT TO FOCUS ON THE EXACT TRACK FORECAST... ESPECIALLY AT DAYS 4 AND 5 WHERE AVERAGE NHC TRACK FORECAST ERRORS ARE 175 TO 225 MILES. FORECAST POSITIONS AND MAX WINDS INIT 21/2100Z 9.6N 101.0W 30 KT 35 MPH 12H 22/0600Z 10.2N 102.0W 40 KT 45 MPH 24H 22/1800Z 11.3N 103.5W 50 KT 60 MPH 36H 23/0600Z 12.4N 104.8W 65 KT 75 MPH 48H 23/1800Z 13.6N 105.4W 70 KT 80 MPH 72H 24/1800Z 15.5N 105.0W 80 KT 90 MPH 96H 25/1800Z 17.0N 104.0W 65 KT 75 MPH 120H 26/1800Z 18.0N 102.5W 60 KT 70 MPH...ON THE COAST OF MEXICO $$ FORECASTER BERG