Hurricane BERTHA

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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
 
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