000
WTNT44 KNHC 110251
TCDAT4
 
TROPICAL STORM HUMBERTO DISCUSSION NUMBER  10
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL092013
1100 PM AST TUE SEP 10 2013
 
AN EYE HAS BEEN SHOWING UP INTERMITTENTLY THIS EVENING IN
HUMBERTO...BUT HAS NOT PERSISTED.  MOREOVER...THE DEEP CONVECTION
HAS BEEN SOMEWHAT ASYMMETRIC AND IS NOT MAINTAINING A CENTRAL DENSE
OVERCAST CONTINUOUSLY.  DVORAK CURRENT INTENSITY ESTIMATES FROM
TAFB AND SAB HAVE REMAINED THE SAME OVER THE LAST SIX
HOURS...AVERAGING AT 60 KT...WHILE ADT AND CIMSS AMSU SUGGEST A
SUBSTANTIALLY WEAKER CYCLONE.  IN DEFERENCE TO THE SUBJECTIVE
DVORAK ANALYSES AND THE INTERMITTENT EYE...THE INITIAL INTENSITY
REMAINS 60 KT.  WHILE NO NEW ASCAT OBSERVATIONS WERE AVAILABLE...A
2240Z CIRA AMSU SIZE ANALYSIS SUGGESTED A SLIGHTLY LARGER RADIUS OF
TROPICAL STORM FORCE WINDS...WHICH HAS BEEN SO ADJUSTED.

HUMBERTO SHOULD STILL REACH HURRICANE INTENSITY...AS IT HAS ABOUT
24-36 HOURS TO GO WHILE TRAVERSING LUKEWARM WATER AND AN
ENVIRONMENT OF LOW VERTICAL WIND SHEAR.  BUT IN ABOUT 36-48
HOURS...THE VERTICAL SHEAR SHOULD INCREASE SUBSTANTIALLY DUE TO
HUMBERTO APPROACHING CLOSER TO A LARGE UPPER-LEVEL TROUGH...WHILE
AT THE SAME TIME THE SSTS SHOULD DROP TO A COOLISH 25-26C. 
GRADUAL...IF NOT RAPID...WEAKENING SHOULD OCCUR BETWEEN DAYS 2 AND
4.  THE INTENSITY GUIDANCE IS RATHER TIGHTLY CLUSTERED AND THE NHC
PREDICTION MIRRORS THIS AND IS JUST SLIGHTLY LOWER THAN THE
PREVIOUS ADVISORY.

HUMBERTO IS MOVING AT ABOUT 6 KT TOWARD 315 DEGREES...PRIMARILY DUE
TO THE INFLUENCE OF A MID-LAYER RIDGE TO ITS NORTHEAST.  WITH THE
RIDGE WEAKENING...THE CYCLONE SHOULD TURN NORTHWARD IN ABOUT A DAY
AND CONTINUE THIS MOTION FOR ANOTHER DAY OR SO.  AROUND DAY
3...HUMBERTO SHOULD TURN AGAIN...THIS TIME TOWARD THE WEST...AS A
STRONGER DEEP-LAYER RIDGE BUILDS IN NEAR THE AZORES.  THE TRACK
FORECAST IS BASED UPON A BLEND OF THE GFS...ECMWF...AND FIM GLOBAL
MODELS...AND IS NEARLY IDENTICAL TO THE PREVIOUS ADVISORY THROUGH
48 HOURS AND THEN SLIGHTLY SOUTH THEREAFTER.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  11/0300Z 15.4N  28.4W   60 KT  70 MPH
 12H  11/1200Z 16.4N  28.9W   65 KT  75 MPH
 24H  12/0000Z 18.3N  29.1W   70 KT  80 MPH
 36H  12/1200Z 20.2N  29.4W   75 KT  85 MPH
 48H  13/0000Z 21.7N  29.9W   70 KT  80 MPH
 72H  14/0000Z 23.5N  32.5W   60 KT  70 MPH
 96H  15/0000Z 24.0N  37.5W   45 KT  50 MPH
120H  16/0000Z 24.5N  43.0W   40 KT  45 MPH
 
$$
FORECASTER LANDSEA