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Tropical Storm OLAF (Text)

ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM OLAF DISCUSSION NUMBER   3
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 PM PDT FRI OCT 03 2003
 
A BURST OF CONVECTION OBSCURED THE CENTER OF OLAF SHORTLY BEFORE
0000 UTC.  HOWEVER...UPPER-LEVEL NORTHEASTERLY SHEAR HAS ONCE AGAIN
CAUSED THE CENTER TO BE PARTIALLY EXPOSED.  THE SHIP REFERENCED IN
THE PREVIOUS DISCUSSION OBSERVED 44 KT AT 2100 UTC JUST SOUTHWEST
OF THE CENTER.  ON THIS BASES...THE INTENSITY IS INCREASED TO 45
KT. DVORAK SATELLITE INTENSITY ESTIMATES ARE LOWER AND ARE BETWEEN
30 AND 35 KT.
 
THE INITIAL MOTION IS NOW ESTIMATED TO BE 325/8. A WEAK RIDGE OVER
MEXICO SHOULD STEER OLAF TO THE NORTHWEST THROUGH THE NEXT 48
HOURS.  BEYOND 48 HOURS THE GFS BUILDS A STRONG RIDGE ALONG THE
COAST OF MAINLAND MEXICO AND IS THE WESTERN MOST OF THE GLOBAL
MODELS.  THE NOGAPS AND GFDL KEEP A WEAKER RIDGE OVER MEXICO AND
THEREFORE BRING OLAF MUCH CLOSER TO THE COAST... WITH THE GFDL
SHOWING LANDFALL IN ABOUT 72 HOURS.  IT SHOULD BE POINTED OUT THAT
THE 12Z UMKET DID NOT INITIALIZED THE TROPICAL CYCLONE.  THE
OFFICIAL FORECAST WAS ADJUSTED A LITTLE TO THE RIGHT OF THE
PREVIOUS FORECAST AND IS CLOSE TO THE GFS ENSEMBLE FORECAST.
 
SHIPS INTENSITY GUIDANCE INITIALIZED 14 KT OF SHEAR OVER THE
CYCLONE...THEN INDICATES IT SHOULD ABATE AROUND 48 HOURS. 
DESPITE THE CURRENT SHEAR THE INTENSITY FORECAST CALLS FOR SLOW
STRENGTHENING BUT NOT AS QUICKLY AS THE SHIPS GUIDANCE WHICH 
BRINGS OLAF TO A HURRICANE IN 36 HOURS.  THE GFDL STRENGTHENS THE
TROPICAL CYCLONE INTO A HURRICANE IN 12 HOURS WHICH SEEMS UNLIKELY.

FORECASTER BROWN/JARVINEN
  
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      04/0300Z 13.4N  99.9W    45 KT
 12HR VT     04/1200Z 14.1N 100.4W    50 KT
 24HR VT     05/0000Z 14.8N 100.9W    55 KT
 36HR VT     05/1200Z 15.4N 101.3W    60 KT
 48HR VT     06/0000Z 15.9N 101.8W    65 KT
 72HR VT     07/0000Z 16.7N 102.8W    75 KT
 96HR VT     08/0000Z 17.2N 103.6W    75 KT
120HR VT     09/0000Z 17.7N 104.8W    75 KT
 
 
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