349 
 WTNT42 KNHC 151441
 TCDAT2
  
 TROPICAL STORM GERT DISCUSSION NUMBER   7
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL072011
 1100 AM AST MON AUG 15 2011
  
 THE PRESENTATION OF GERT IN DOPPLER RADAR IMAGERY FROM BERMUDA 
 HAS INDICATED BRIEF PERIODIC TIGHTENING OF THE INNER CORE
 CIRCULATION...INCLUDING A SMALL 6-8 NMI DIAMETER EYE-LIKE
 FEATURE...ONLY TO HAVE THE CONVECTION WEAKEN OR DISSIPATE 
 DUE TO INTRUSIONS OF DRY AIR. AN AIR FORCE RESERVE RECON AIRCRAFT
 INVESTIGATING THE CYCLONE HAS FOUND MAXIMUM 850 MB FLIGHT-LEVEL
 WINDS OF 53 KT AND A FEW UNCONTAMINATED 49-51 KT SFMR WINDS IN 
 THE EASTERN SEMICIRCLE...ACCOMPANIED BY A MINIMUM PRESSURE OF NEAR
 1000 MB. BASED ON THIS INFORMATION...THE INTENSITY IS SET AT 50 KT
 FOR THIS ADVISORY.
 
 THE INITIAL MOTION ESTIMATE IS 010/10 KT. THERE IS NO CHANGE TO THE
 PREVIOUS FORECAST REASONING. GERT HAS BEEN MOVING NORTHWARD THROUGH
 A BREAK IN THE SUBTROPICAL RIDGE AND HAS NOW REACHED THE AXIS OF
 THE EAST-WEST ORIENTED RIDGE THAT LIES ALONG 32N LATITUDE. AS THE
 LARGE FULL LATITUDE TROUGH CURRENTLY MOVING OFF THE U.S. EAST COAST
 CONTINUES ITS EASTWARD PROGRESS...GERT SHOULD GRADUALLY ACCELERATE
 AND TURN TOWARD THE NORTH-NORTHEAST LATER TODAY AND TOWARD THE
 NORTHEAST BY LATE TONIGHT OR TUESDAY. THE OFFICIAL TRACK FORECAST
 IS A LITTLE TO THE RIGHT OF THE PREVIOUS TRACK AND IS A BLEND OF
 THE ECMWF AND GFS MODEL SOLUTIONS.
  
 SOME FURTHER INTENSIFICATION OF GERT IS POSSIBLE DURING THE NEXT 24
 HOURS AS THE CYCLONE REMAINS OVER RELATIVELY WARM WATER AND BENEATH
 AN UPPER-LEVEL ANTICYCLONE. HOWEVER...GERT IS A SMALLER THAN AVERAGE
 SIZE TROPICAL CYCLONE...WHICH MEANS IT WILL BE SUSCEPTIBLE TO
 INTRUSIONS OF DRY AIR AND SLIGHT INCREASES IN VERTICAL SHEAR. AS A
 RESULT...THE INTENSITY FORECAST IS BEING HELD JUST BELOW HURRICANE
 STRENGTH. BY 24 HOURS...GERT WILL BE MOVING OVER SEA-SURFACE
 TEMPERATURES COOLER THAN 26C...AND OVER WATER COOLER THAN 20C BY 48
 HOURS. AS A RESULT...GRADUAL WEAKENING IS EXPECTED AFTER 24 HOURS
 AND EXTRATROPICAL TRANSITION IS EXPECTED TO OCCUR BY 48 HOURS WHEN
 THE CYCLONE BEGINS TO MERGE WITH A FRONTAL SYSTEM AND ALSO BEGINS
 TO FEEL THE EFFECTS OF STRONG SOUTHWESTERLY UPPER-LEVEL WIND SHEAR.
 THE INTENSITY FORECAST IS SIMILAR TO THE PREVIOUS ADVISORY AND
 CLOSELY FOLLOWS THE SHIPS AND LGEM MODEL SOLUTIONS. EXTRATROPICAL
 INTENSITY FORECASTS WERE PROVIDED BY THE NOAA OCEAN PREDICTION
 CENTER.
  
 THE BERMUDA WEATHER SERVICE HAS DISCONTINUED THE TROPICAL STORM
 WARNING FOR BERMUDA.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  15/1500Z 32.0N  63.2W   50 KT  60 MPH
  12H  16/0000Z 34.3N  62.0W   55 KT  65 MPH
  24H  16/1200Z 37.8N  59.0W   60 KT  70 MPH
  36H  17/0000Z 40.8N  54.6W   55 KT  65 MPH
  48H  17/1200Z 43.4N  48.5W   45 KT  50 MPH...POST-TROP/EXTRATROP
  72H  18/1200Z 48.5N  33.5W   40 KT  45 MPH...POST-TROP/EXTRATROP
  96H  19/1200Z...DISSIPATED
  
 $$
 FORECASTER STEWART