000 WTPZ42 KNHC 200240 TCDEP2 TROPICAL STORM BEATRIZ DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP022011 800 PM PDT SUN JUN 19 2011 ENHANCED IR IMAGERY INDICATES THAT THE CONVECTIVE CLOUD PATTERN OF BEATRIZ IS GRADUALLY BECOMING BETTER ORGANIZED...WITH INCREASED EVIDENCE OF CURVED BANDS AND MORE SYMMETRY AROUND THE ESTIMATED CENTER. DVORAK INTENSITY ESTIMATES ARE 35 KT AND 45 KT FROM SAB AND TAFB RESPECTIVELY...AND THE CURRENT INTENSITY IS SET AT 40 KT. BEATRIZ WILL BE MOVING OVER A VERY WARM SEA SURFACE WITH HIGH OCEANIC HEAT CONTENT FOR THE NEXT 24 TO 36 HOURS WITH MODERATE EASTERLY SHEAR. THIS ENVIRONMENT SHOULD ALLOW THE SYSTEM TO BECOME A HURRICANE BY LATE TOMORROW AS INDICATED BY THE SHIPS...LGEM...AND GFDL HURRICANE MODEL GUIDANCE. THE OFFICIAL FORECAST IS SLIGHTLY ABOVE THESE MODELS SINCE THE SHIPS RAPID INTENSIFICATION INDEX SHOWS A SIGNIFICANT PROBABILITY OF AN INCREASE OF INTENSITY OF 25 TO 30 KT OVER THE NEXT 24 HOURS. BEYOND 48 HOURS...THE CYCLONE SHOULD ENCOUNTER SUBSTANTIALLY COOLER SEA SURFACE TEMPERATURES AND A MORE STABLE AIR MASS. THEREFORE BEATRIZ IS FORECAST TO WEAKEN TO A REMNANT LOW BY THE END OF THE FORECAST PERIOD. BASED ON A BLEND OF GEOSTATIONARY AND MICROWAVE SATELLITE FIXES THE INITIAL MOTION IS A RATHER UNCERTAIN 305/10. NO SIGNIFICANT CHANGES HAVE BEEN MADE TO THE TRACK FORECAST OR REASONING FROM THE PREVIOUS ADVISORY. A STRONG DEEP-LAYER TROUGH OVER WESTERN AND CENTRAL NORTH AMERICA SHOULD WEAKEN THE SUBTROPICAL RIDGE TO THE NORTH OF BEATRIZ AND CAUSE THE TROPICAL CYCLONE TO MOVE MORE TO THE RIGHT AT A DECREASED FORWARD SPEED OVER THE NEXT COUPLE OF DAYS. IN THE LATTER HALF OF THE FORECAST PERIOD THE TROUGH SHOULD LIFT OUT AND ALLOW SOME BUILDING OF A MID-LEVEL RIDGE TO THE NORTH OF BEATRIZ. THIS WOULD RESULT IN A MORE WESTWARD COURSE...ESPECIALLY AS THE CYCLONE WEAKENS AND BECOMES STEERED MORE BY THE LOW-LEVEL EASTERLY FLOW. THE OFFICIAL FORECAST IS ROUGHLY IN THE MIDDLE OF THE DYNAMICAL GUIDANCE. NO CHANGES TO THE WATCHES AND WARNINGS FOR THE COAST OF MEXICO ARE REQUIRED AT THIS TIME. ONE SHOULD NOT FOCUS ON THE EXACT FORECAST TRACK SINCE ONLY A SMALL DEVIATION FROM THIS FORECAST COULD BRING THE CENTER ACROSS THE COAST IN THE HURRICANE WARNING AREA. FORECAST POSITIONS AND MAX WINDS INIT 20/0300Z 14.9N 102.1W 40 KT 45 MPH 12H 20/1200Z 15.7N 102.8W 50 KT 60 MPH 24H 21/0000Z 16.9N 103.6W 60 KT 70 MPH 36H 21/1200Z 17.9N 104.3W 70 KT 80 MPH 48H 22/0000Z 18.8N 105.0W 70 KT 80 MPH 72H 23/0000Z 20.0N 108.0W 60 KT 70 MPH 96H 24/0000Z 20.0N 112.0W 40 KT 45 MPH 120H 25/0000Z 20.0N 116.0W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ FORECASTER PASCH/FRANKLIN