040 
 WTNT42 KNHC 182029
 TCDAT2
 HURRICANE BERTHA DISCUSSION NUMBER  63
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL022008
 500 PM EDT FRI JUL 18 2008
 
 SATELLITE IMAGES INDICATE THAT BERTHA IS NOW A HURRICANE AGAIN.  THE
 EYE HAS BECOME BETTER-DEFINED WITH DEEP CONVECTION INCREASING AROUND
 A CONSOLIDATING EYEWALL.  THE INITIAL INTENSITY IS RAISED TO 65 KT
 IN AGREEMENT WITH THE SATELLITE CLASSIFICATION FROM SAB.  BERTHA
 SHOULDN'T BE A HURRICANE FOR TOO LONG AS IT IS FORECAST TO BE OVER
 WATERS LESS THAN 70F BY THIS TIME TOMORROW.  A SLOW WEAKENING IS
 INDICATED...WHICH IS IN GOOD AGREEMENT WITH MOST GUIDANCE.  PHASE
 DIAGRAMS FROM FLORIDA STATE INDICATE THAT THE HURRICANE SHOULD
 BEGIN ITS EXTRATROPICAL TRANSITION IN A DAY OR SO...WITH THE
 PROCESS COMPLETE IN ABOUT 48 HR.  
  
 BERTHA CONTINUES MOVING TO THE NORTHEAST...NOW AT ABOUT 19 KT. THERE
 IS NO CHANGE TO THE SYNOPTIC REASONING. THE HURRICANE SHOULD
 ACCELERATE OUT TO SEA IN A WELL-DEFINED STEERING CURRENT BETWEEN A
 HIGH TO THE SOUTHEAST AND THE MIDDLE-LATITUDE WESTERLIES. MODEL
 GUIDANCE IS GENERALLY SHOWING GREATER INTERACTION THAN EARLIER WITH
 BERTHA AND AN APPROACHING TROUGH FROM NORTH AMERICA... RESULTING IN
 A SLIGHTLY MORE POLEWARD TRACK OF THE CYCLONE. THE OFFICIAL
 FORECAST IS SHIFTED WESTWARD TO ACCOUNT FOR THIS TREND AND LIES ON
 THE EASTERN SIDE OF THE GUIDANCE ENVELOPE. 
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      18/2100Z 37.6N  50.6W    65 KT
  12HR VT     19/0600Z 39.8N  48.2W    65 KT
  24HR VT     19/1800Z 42.9N  44.8W    60 KT
  36HR VT     20/0600Z 46.7N  40.6W    55 KT...BECOMING EXTRATROPICAL
  48HR VT     20/1800Z 51.5N  36.0W    50 KT...EXTRATROPICAL
  72HR VT     21/1800Z 61.0N  23.0W    50 KT...EXTRATROPICAL
  96HR VT     22/1800Z...ABSORBED
  
 $$
 FORECASTER BLAKE
  
 
Return to the Tropical Systems Page for BERTHA

Back to main Tropical Weather page







This page was last modified on: , 17 2014 - 1841 UTC
Send comments to: Ryan Lyman