000 WTNT42 KNHC 112041 TCDAT2 HURRICANE BERTHA DISCUSSION NUMBER 35 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL022008 500 PM EDT FRI JUL 11 2008 AN AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT HAS BEEN INVESTIGATING BERTHA AND FOUND A 976 MB MINIMUM CENTRAL PRESSURE. THE MAXIMUM REPORTED WINDS AT FLIGHT LEVEL...700 MB...HAVE BEEN OF THE ORDER OF 90 TO 99 KNOTS IN NORTHEAST AND SOUTHEAST QUADRANTS RESPECTIVELY. MAXIMUM SFMR WINDS WERE 72 KNOTS BUT THE DATA WAS RAIN CONTAMINATED. A GOOD COMPROMISE BETWEEN THE TWO MEASUREMENTS FOR THE INITIAL INTENSITY IS 80 KNOTS. LATEST AMSU DATA SHOW THAT THE INNER WALL HAS BECOME A LITTLE BETTER DEFINED AND IS ALMOST CLOSED AGAIN...SO THE CHANGE FOR REINTENSIFICATION EXISTS. AT THIS TIME...THE INTENSITY FORECAST CALLS FOR NO SIGNIFICANT CHANGE IN STRENGTH IN THE NEXT DAY OR SO. THEREAFTER...BERTHA SHOULD BEGIN TO WEAKEN WHEN IT REACHES COOLER WATER AND HIGHER SHEAR. BERTHA HAS SLOWLY BEGAN TO MOVE TOWARD THE NORTH-NORTHWEST AT 4 KNOTS AROUND THE EDGE OF THE SUBTROPICAL RIDGE. THE SHORTWAVE CURRENTLY OVER THE EASTERN UNITED STATES COAST IS GOING TO BYPASS BERTHA AND WILL LEAVE THE HURRICANE EMBEDDED WITHIN VERY WEAK STEERING CURRENTS FOR A FEW DAYS. THE OFFICIAL FORECAST CALLS FOR A SLOW MOTION TO THE NORTH-NORTHWEST TONIGHT WITH A GRADUAL TURN TO THE NORTH AND THEN TO THE NORTH-NORTHEAST. LONG RANGE GLOBAL MODELS ARE SUGGESTING THAT BERTHA WILL CONTINUE WITHIN VERY WEAK STEERING CURRENTS AND I WILL NOT BE SURPRISED IF BERTHA KEEPS MEANDERING A LITTLE LONGER. IN FACT...SOME MODELS KEEP BERTHA LOOPING FOR SEVERAL DAYS. FORECAST POSITIONS AND MAX WINDS INITIAL 11/2100Z 29.1N 62.2W 80 KT 12HR VT 12/0600Z 29.5N 62.7W 80 KT 24HR VT 12/1800Z 30.2N 62.7W 80 KT 36HR VT 13/0600Z 30.6N 62.5W 75 KT 48HR VT 13/1800Z 31.5N 62.3W 70 KT 72HR VT 14/1800Z 32.5N 62.0W 65 KT 96HR VT 15/1800Z 34.0N 61.0W 60 KT 120HR VT 16/1800Z 35.0N 60.0W 55 KT $$ FORECASTER AVILA