Tropical Storm LANE

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TROPICAL STORM LANE DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP122012
200 AM PDT SUN SEP 16 2012
 
LANE HAS BEEN MAINTAINING A BALL OF COLD-TOPPED CONVECTION
TONIGHT...BUT IS LARGELY ABSENT SIGNIFICANT BANDING FEATURES.
WHILE A 0506 UTC ASCAT PASS SUGGESTS THAT THE LOW-LEVEL CENTER IS
EMBEDDED WITHIN THE CONVECTIVE MASS...MICROWAVE IMAGES WOULD PLACE
THE CENTER CLOSER TO THE EDGE.  SATELLLITE CLASSIFICATIONS HAVE
INCREASED TO A CONSENSUS T3.0/45 KT FROM TAFB AND SAB.  HOWEVER...
SEVERAL BELIEVABLE 45-50 KT WIND VECTORS WERE PRESENT IN THE
EARLIER ASCAT PASS...AND BASED ON THIS...THE INITIAL INTENSITY IS
INCREASED TO 50 KT.
 
THE DISAGREEMENT BETWEEN MICROWAVE AND ASCAT CENTER FIXES MAKES THE
INITIAL MOTION ESTIMATE RATHER UNCERTAIN.  A BLEND OF THESE
ESTIMATES SUGGESTS A GENERALLY WESTWARD TRACK OF 280/06. LANE IS
NEARING THE SOUTHWESTERN EDGE OF A WEAK MID-LEVEL RIDGE SOUTH OF
BAJA CALIFORNIA WHICH HAS BEEN ERODED BY A LARGE CUT-OFF LOW OVER
SUBTROPICAL PACIFIC NEAR 34N 137W.  GLOBAL MODELS SHOW LANE QUICKLY
GAINING LATITUDE DURING THE NEXT COUPLE OF DAYS AS IT MOVES INTO
THE WEAKNESS CREATED BY THIS CUT-OFF FEATURE.  AFTER 72 HOURS...THE
TRACK SHOULD BEND TOWARD THE WEST AS LANE WEAKENS AND GRADUALLY
BECOMES A SHALLOW CYCLONE.  THE NHC TRACK FORECAST IS SIMILAR TO THE
PREVIOUS ONE AND IS WEIGHTED TOWARD THE GFS/ECMWF MODELS...ON THE
LEFT SIDE OF THE GUIDANCE ENVELOPE THROUGH 48 HOURS.  THEREAFTER...
THE TRACK FORECAST IS CLOSE TO THE MULTI-MODEL CONSENSUS TVCE.
 
LANE HAS A LIMITED WINDOW OF OPPORTUNITY FOR STRENGTHENING. THE
SHEAR IS EXPECTED TO BE LOW AND THE WATERS WARM FOR ANOTHER 36-48
HOURS.  AFTER THAT TIME...THE MORE POLEWARD MOTION OF THE CYCLONE
SHOULD CAUSE IT TO REACH A SHARP BOUNDARY OF SSTS.  SOUTHWESTERLY
SHEAR IS ALSO LIKELY TO SIGNIFICANTLY INCREASE IN ASSOCIATION WITH
AN UPPER-LEVEL TROUGH TO THE NORTHWEST OF THE CYCLONE.  GIVEN THE
CURRENT INTENSIFICATION TREND...THE INTENSITY FORECAST UP TO 72 HR
HAS BEEN ADJUSTED HIGHER EARLY IN THE FORECAST PERIOD IN BEST
AGREEMENT WITH THE LGEM AND FSU SUPERENSEMBLE OUTPUT.  AFTER THAT
TIME...IT IS UNCHANGED FROM THE PREVIOUS ADVISORY.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  16/0900Z 13.3N 124.5W   50 KT  60 MPH
 12H  16/1800Z 14.0N 125.4W   60 KT  70 MPH
 24H  17/0600Z 14.9N 126.5W   65 KT  75 MPH
 36H  17/1800Z 16.2N 127.5W   70 KT  80 MPH
 48H  18/0600Z 17.8N 128.4W   60 KT  70 MPH
 72H  19/0600Z 20.0N 130.3W   40 KT  45 MPH
 96H  20/0600Z 20.0N 132.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  21/0600Z 19.5N 137.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 
$$
FORECASTER KIMBERLAIN
 
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