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Tropical Storm OLAF


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TROPICAL STORM OLAF DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP182009
200 PM PDT THU OCT 01 2009
 
THE CYCLONE HAS BECOME A LITTLE BETTER ORGANIZED SINCE THIS 
MORNING WITH SEVERAL BANDS OF CONVECTION NOTED IN VISIBLE 
SATELLITE IMAGERY.  A 1702 UTC ASCAT PASS DETECTED AN AREA OF 
30-35 KT WINDS TO THE SOUTHEAST OF THE CENTER AND BASED ON THESE
DATA THE SYSTEM IS UPGRADED TO A TROPICAL STORM...THE FIFTEENTH 
OF THE 2009 EASTERN PACIFIC SEASON.  OLAF IS CURRENTLY OVER 27-28
DEGREE CELSIUS SSTS...BUT WATER TEMPERATURES GRADUALLY DECREASE
ALONG THE FORECAST TRACK.  ALSO...AS OLAF MOVES TOWARDS SLIGHTLY
HIGHER LATITUDES...IT IS EXPECTED TO ENCOUNTER INCREASING SOUTH-
SOUTHWESTERLY UPPER-LEVEL WINDS.  GIVEN THESE NEGATIVE
ENVIRONMENTAL FACTORS...ONLY A LITTLE ADDITIONAL STRENGTHENING IS
SHOWN IN THE OFFICIAL FORECAST.  THE NEW FORECAST IS IN GOOD
AGREEMENT WITH THE CONSENSUS OF THE INTENSITY GUIDANCE.  OLAF IS
EXPECTED TO WEAKEN TO A REMNANT LOW IN ABOUT 48 HOURS.

LATEST VISIBLE AND MICROWAVE SATELLITE IMAGERY SUGGEST THAT THE 
CENTER IS A LITTLE NORTHEAST OF THE EARLIER ESTIMATES.  THE
HIGHLY UNCERTAIN INITIAL MOTION ESTIMATE IS 300/5.  THE TRACK
GUIDANCE AND FORECAST REASONING HAS NOT CHANGED MUCH FROM THIS
MORNING.  OLAF IS EXPECTED TO TURN NORTHWARD AS A TROUGH ALONG THE
WEST COAST OF THE UNITED STATES WEAKENS THE RIDGE CURRENTLY TO THE
NORTH OF THE CYCLONE.  THERE REMAINS A LARGE SPREAD IN THE GUIDANCE
AS TO WHEN AND WHERE OLAF MAY TURN NORTHEASTWARD.  THE MODELS THAT
MAINTAIN A STRONGER...MORE VERTICALLY DEEP SYSTEM CONTINUE TO
ACCELERATE OLAF TOWARDS BAJA CALIFORNIA IN A COUPLE OF DAYS. 
THE OFFICIAL FORECAST CONTINUES TO LEAN TOWARD THE SOLUTION THAT
OLAF WILL WEAKEN AND BECOME A SHALLOWER SYSTEM.  THIS WOULD RESULT
IN LESS INFLUENCE FROM THE WEST COAST TROUGH...AND THEREFORE ONLY A
SLOW NORTHEASTWARD MOTION IS SHOWN IN THE LATTER PART OF THE
FORECAST.

FORECAST POSITIONS AND MAX WINDS
 
INITIAL      01/2100Z 19.4N 117.8W    35 KT
 12HR VT     02/0600Z 19.9N 118.8W    40 KT
 24HR VT     02/1800Z 20.4N 119.6W    35 KT
 36HR VT     03/0600Z 21.0N 120.0W    30 KT
 48HR VT     03/1800Z 22.0N 120.0W    25 KT...REMNANT LOW
 72HR VT     04/1800Z 23.5N 118.0W    20 KT...REMNANT LOW
 96HR VT     05/1800Z...DISSIPATED
 
$$
FORECASTER BROWN
 
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