Hurricane KARL

ZCZC MIATCDAT2 ALL
TTAA00 KNHC DDHHMM
HURRICANE KARL DISCUSSION NUMBER  17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
5 PM EDT MON SEP 20 2004
 
CONVECTION HAS BECOME MORE INTENSE AROUND KARL'S EYEWALL THIS
AFTERNOON WITH THE EYE BECOMING A BIT BETTER-DEFINED.  HOWEVER A
1657 UTC AMSU-B MICROWAVE PASS SHOWED THE EYEWALL WAS STILL OPEN
SOUTH.  IN ADDITION...SATELLITE ESTIMATES HAVEN'T CHANGED MUCH
SINCE THIS MORNING AND THE INTENSITY IS BEING HELD AT 105 KT. 
MODEST SOUTHWESTERLY SHEAR WILL BE STEADY OR DECREASING FOR THE
NEXT 24 HOURS...PROVIDING A WINDOW OF OPPORTUNITY FOR KARL TO
REINTENSIFY.  SSTS ARE ALSO INCREASING UP TO NEAR 84F IN ITS PATH. 
THE OFFICIAL INTENSITY FORECAST IS SIMILAR TO PREVIOUS CALLING FOR
MAXIMUM INTENSITY NEAR THE CYCLONE'S RECURVATURE POINT.  WEAKENING
IS FORECAST AFTER 48 HOURS UNDER DECREASING SSTS AND INCREASING
SHEAR.  MODEL GUIDANCE SUGGESTS THAT EXTRATROPICAL TRANSITION WILL
BEGIN AROUND 96 HOURS THEN FORMING A STRONG EXTRATROPICAL CYCLONE IN
ABOUT 5 DAYS OVER THE NORTH ATLANTIC.

KARL HAS MADE THE EXPECTED TURN TO THE NW... NOW MOVING 305/10 KT. 
THERE HAS BEEN NO CHANGE TO THE SYNOPTIC REASONING OF THE PREVIOUS
FORECAST WITH A STRONG MID-LATITUDE TROUGH FORECAST TO DIG ALONG
55W AHEAD OF THE CYCLONE.  MODEL GUIDANCE REMAINS TIGHTLY CLUSTERED
ON RECURVATURE IN ABOUT 36 HOURS AROUND 50W.  THE FORECAST TRACK IS
SIMILAR TO THE PREVIOUS PACKAGE BETWEEN CONU AND THE GFS. 

12 FT SEAS RADII HAVE BEEN SLIGHTLY MODIFIED AFTER CONSULTATION WITH
THE ATLANTIC FORECASTER IN TAFB.  
 
FORECASTER BLAKE/LAWRENCE
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      20/2100Z 18.6N  47.1W   105 KT
 12HR VT     21/0600Z 19.8N  48.2W   110 KT
 24HR VT     21/1800Z 21.8N  49.6W   115 KT
 36HR VT     22/0600Z 24.1N  50.1W   120 KT
 48HR VT     22/1800Z 27.0N  49.5W   120 KT
 72HR VT     23/1800Z 34.0N  45.5W   100 KT
 96HR VT     24/1800Z 43.0N  43.5W    80 KT...EXTRATROPICAL
120HR VT     25/1800Z 49.0N  44.0W    65 KT...EXTRATROPICAL
 
 
$$
NNNN