000
WTPZ43 KNHC 132043
TCDEP3
 
TROPICAL STORM MANUEL DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP132013
200 PM PDT FRI SEP 13 2013

VISIBLE SATELLITE IMAGES SHOW THAT THE CYCLONE IS A LITTLE FARTHER
WEST THAN ESTIMATED EARLIER THIS MORNING...WITH A GROWING BALL OF
CONVECTION NEAR THE CENTER.  ASCAT DATA SUGGESTED THE MAXIMUM WINDS
WERE ABOUT 35 KT...AND THIS IS USED AS THE INITIAL INTENSITY. 
WHILE THE AREA OF TROPICAL-STORM-FORCE WINDS IS SMALL...THE
CIRCULATION OF MANUEL IS EMBEDDED WITHIN A MUCH LARGER CYCLONIC
GYRE THAT CONTAINS LOTS OF STRONG WINDS NOT DIRECTLY ASSOCIATED WITH
THE TROPICAL CYCLONE.  THIS STRUCTURE MAKES THE INTENSITY FORECAST
TRICKY SINCE OTHER ENVIRONMENTAL FACTORS SEEM CONDUCIVE FOR
STRENGTHENING. GIVEN THE RELATIVELY SMALL RADIUS OF MAXIMUM WINDS
FROM ASCAT...MANUEL SHOULD HAVE A GOOD CHANCE TO INTENSIFY...AND
THE NHC PREDICTION IS A LITTLE ABOVE THE CONSENSUS AT THE UPPER END
OF THE GUIDANCE SPECTRUM.  

INSTEAD OF A TURN TOWARD THE NORTH-NORTHWEST OCCURRING...IT SEEMS
LIKE MANUEL IS HEADING WEST-NORTHWESTWARD...295/5. MOST OF THE
GUIDANCE STILL SUGGEST THE STORM SHOULD TAKE A NORTHWARD TURN
RELATIVELY SOON DUE TO THE RIDGE WEAKENING OVER MEXICO. HOWEVER...
THE MODEL SPREAD HAS GROWN SINCE THE LAST ADVISORY...WITH THE
NORMALLY RELIABLE ECMWF A FAIR DISTANCE WEST OF THE MODEL
CONSENSUS. THIS IS NOT A HIGH CONFIDENCE FORECAST WITH THE GLOBAL
MODELS STRUGGLING TO RESOLVE THE INTERACTION OF THE RIDGE OVER
MEXICO...AN UPPER-LEVEL LOW...AND TROPICAL STORM INGRID. THE NEW
NHC TRACK FORECAST IS SHIFTED WESTWARD...ABOUT MIDWAY BETWEEN THE
ECMWF AND THE MODEL CONSENSUS...AND IT WOULD NOT BE VERY SURPRISING
IF FURTHER WESTWARD ADJUSTMENTS ARE REQUIRED.  

FORECAST POSITIONS AND MAX WINDS
 
INIT  13/2100Z 15.6N 102.1W   35 KT  40 MPH
 12H  14/0600Z 16.0N 102.3W   45 KT  50 MPH
 24H  14/1800Z 16.8N 102.4W   50 KT  60 MPH
 36H  15/0600Z 17.9N 102.7W   50 KT  60 MPH
 48H  15/1800Z 18.9N 103.2W   30 KT  35 MPH...INLAND
 72H  16/1800Z...DISSIPATED
 
$$
FORECASTER BLAKE