522 
 WTNT44 KNHC 122034
 TCDAT4
  
 HURRICANE HUMBERTO DISCUSSION NUMBER  17
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092013
 500 PM AST THU SEP 12 2013
  
 THE EYE IS NO LONGER APPARENT ON SATELLITE IMAGES...AND THERE
 CONTINUES TO BE SOME EVIDENCE OF SOUTHWESTERLY SHEAR OVER THE
 HURRICANE. DVORAK-BASED CURRENT INTENSITY ESTIMATES FROM TAFB AND
 SAB HAVE NOT YET DECREASED...SO THE ADVISORY INTENSITY IS KEPT AT
 75 KT. HUMBERTO SHOULD BE IN AN ENVIRONMENT OF MODERATE TO STRONG
 WEST-SOUTHWESTERLY SHEAR AND MARGINAL SEA SURFACE TEMPERATURES FOR
 THE NEXT COUPLE OF DAYS...AND WEAKENING SHOULD OCCUR DURING THAT
 TIME FRAME. LATER ON...THE TROPICAL CYCLONE IS LIKELY TO TRAVERSE
 WARMER WATERS WEST OF 40W LONGITUDE AND THE SHEAR IS FORECAST TO
 RELAX A LITTLE. THUS...THE OFFICIAL WIND SPEED FORECAST HINTS AT
 SOME RE-STRENGTHENING BY LATE IN PERIOD. THIS IS IN GOOD AGREEMENT
 WITH THE LATEST LGEM GUIDANCE. IT SHOULD BE NOTED THAT THE GLOBAL
 MODELS SUGGEST THAT HUMBERTO COULD BE EVEN STRONGER THAN INDICATED
 HERE AT DAYS 4-5.
 
 THE NORTHWARD MOTION CONTINUES...AT 350/12 KT. A LARGE MID-
 TROPOSPHERIC HIGH PRESSURE AREA CENTERED NORTH OF THE AZORES SHOULD
 CAUSE HUMBERTO TO TURN TOWARD THE NORTHWEST AND THEN THE WEST-
 NORTHWEST OVER THE NEXT SEVERAL DAYS. LATER IN THE FORECAST
 PERIOD...THE TROPICAL CYCLONE IS EXPECTED TO TURN BACK TO THE RIGHT
 WITHIN THE FLOW BETWEEN THE HIGH AND A MID-TROPOSPHERIC TROUGH
 MOVING EASTWARD FROM THE NORTHEASTERN U.S. AND ATLANTIC CANADA. THE
 NEW TRACK GUIDANCE...ESPECIALLY THE ECMWF...AND THE OFFICIAL
 FORECAST...ARE A LITTLE FASTER THAN THE PREVIOUS ONES. THE NHC
 TRACK FORECAST FOR THIS ADVISORY IS SIMILAR TO THE MODEL CONSENSUS
 AND ESSENTIALLY SPLITS THE DIFFERENCE BETWEEN THE GFS AND THE
 ECMWF.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  12/2100Z 23.1N  29.2W   75 KT  85 MPH
  12H  13/0600Z 24.1N  30.3W   70 KT  80 MPH
  24H  13/1800Z 25.2N  32.0W   65 KT  75 MPH
  36H  14/0600Z 26.0N  34.2W   55 KT  65 MPH
  48H  14/1800Z 26.8N  36.5W   45 KT  50 MPH
  72H  15/1800Z 28.8N  40.8W   45 KT  50 MPH
  96H  16/1800Z 30.5N  43.5W   45 KT  50 MPH
 120H  17/1800Z 33.0N  45.0W   50 KT  60 MPH
  
 $$
 FORECASTER PASCH