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Hurricane OLAF (Text)

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HURRICANE OLAF DISCUSSION NUMBER   9
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
8 AM PDT SUN OCT 05 2003

OLAF HAS BECOME MUCH BETTER ORGANIZED DURING THE PAST SEVERAL HOURS. 
THE LOW-LEVEL CENTER IS NOW WELL EMBEDDED IN THE CONVECTION...AND
THE RADAR AT CUYUTLAN IS SHOWING A PARTIAL EYEWALL.  SATELLITE
INTENSITY ESTIMATES ARE 77 KT FROM TAFB...65 KT FROM SAB...AND 55
KT FROM AFWA.  BASED ON THIS...OLAF IS UPGRADED TO A 65 KT
HURRICANE.  CIRRUS OUTFLOW IS GOOD OVER THE WESTERN SEMICIRCLE AND
RESTRICTED ELSEWHERE...SUGGESTING THAT SOME EASTERLY SHEAR STILL
AFFECTS THE CYCLONE.
 
THE INITIAL MOTION IS 310/9.  OLAF IS SOUTH-SOUTHWEST OF A
MID/UPPER-LEVEL RIDGE OVER MAINLAND MEXICO...AND HURRICANE NORA IS
540 NM TO THE EAST-NORTHEAST.  AT FIRST GLANCE...THIS PATTERN
SHOULD CAUSE OLAF TO MOVE NORTHWESTWARD OR NORTH-NORTHWESTWARD. 
GUIDANCE GENERALLY AGREES WITH THIS...BUT THERE IS SOME SPREAD IN
BOTH SPEED AND DIRECTION CAUSED MAINLY BY DIFFERENCES IN HOW THE
MODELS HANDLE INTERACTION BETWEEN THE TWO CYCLONES.  THE UKMET AND
NOGAPS BOTH SHOW INTERACTION...WHILE THE GFS AND CANADIAN LOSE ONE
OF THE CYCLONES BEFORE INTERACTION CAN OCCUR.  THE OFFICIAL
FORECAST TRACK IS SIMILAR TO BUT FASTER THAN THE PREVIOUS
PACKAGE...CALLING FOR OLAF TO PARALLEL THE COAST.  HOWEVER...THE
FORECAST TRACK IS TO THE LEFT OF THE UKMET AND NOGAPS...AND IF
INTERACTION OCCURS IT MAY ALSO BE TOO SLOW.  THIS IS A LOW
CONFIDENCE TRACK FORECAST.
 
SHEAR IS DECREASING OVER OLAF...AND LARGE-SCALE GUIDANCE SUGGESTS
THAT THROUGH 72 HR THE CYCLONE WILL REMAIN IN A GENERALLY FAVORABLE
ENVIRONMENT TO THE EAST OF THE STRONG SOUTHWESTERLY FLOW AFFECTING
NORA.  THIS SHOULD ALLOW FOR SOME CONTINUED STRENGTHENING...
ASSUMING THAT INTERACTION WITH NORA AND WITH THE MEXICAN COAST DOES
NOT ADVERSELY AFFECT THE HURRICANE.  THE INTENSITY FORECAST WILL
CALL FOR STRENGTHENING FOR 48-72 HR...AND THEN KEEP A STEADY STATE
FOR THE REST OF THE PERIOD AS THE FORECAST SHEAR GRADUALLY
INCREASES.

EVEN THOUGH THE FORECAST TRACK KEEPS THE CENTER OFFSHORE... WARNINGS
HAVE BEEN ISSUED FOR THE MEXICAN COASTDUE TO THE PROXIMITY OF THE
TROPICAL STORM WINDS TO THE COAST AND THE SIGNIFICANT UNCERTAINTY
IN THE FORECAST TRACK.  ANY DEVIATION TO THE RIGHT OF THE FORECAST
TRACK COULD BRING THE CENTER ONSHORE.
 
FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      05/1500Z 17.1N 104.3W    65 KT
 12HR VT     06/0000Z 18.0N 105.1W    70 KT
 24HR VT     06/1200Z 18.9N 105.8W    75 KT
 36HR VT     07/0000Z 19.8N 106.4W    80 KT
 48HR VT     07/1200Z 20.8N 107.1W    85 KT
 72HR VT     08/1200Z 22.0N 108.0W    85 KT
 96HR VT     09/1200Z 23.5N 109.0W    85 KT
120HR VT     10/1200Z 25.0N 110.0W    85 KT
 
 
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