[Tropical] Tropical Cyclone Discussion

EMWIN Server emwin at nashvilleweather.net
Sat Sep 18 21:38:35 CDT 2004


WTNT42 KNHC 190238
TCDAT2
HURRICANE KARL DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
11 PM EDT SAT SEP 18 2004

KARL HAS WOBBLED A LITTLE TO THE LEFT OF THE PREVIOUS TRACK
DIRECTION AND IS CURRENTLY MOVING AT 290/10. THE FORECAST REASONING
IS THE SAME AS THE PREVIOUS ADVISORY. THE RIDGE TO THE NORTH OF
KARL IS FORECAST TO GRADUALLY BE ERODED BY AN APPROACHING
AMPLIFYING SHORT WAVE TROUGH IN THE WESTERLIES. THIS WILL ALLOW
KARL TO MOVE AROUND THE WESTERN PERIPHERY OF THE ERODED RIDGE AND
THEN MOVE NORTH TO NORTHEASTWARD BY DAY 4 OR 5. THE OFFICIAL TRACK
FORECAST FOLLOWS A CONSENSUS OF THE GUIDANCE.

DVORAK INTENSITY ESTIMATES ARE 102/102/90 KT FROM TAFB/SAB/KGWC.
THE INITIAL INTENSITY IS SET AT 100 KT.  THIS MAKES KARL THE FIFTH
MAJOR HURRICANE OF THE 2004 ATLANTIC HURRICANE SEASON.  INFRARED
SATELLITE IMAGERY HAS SHOWN THAT THE EYE DIAMETER HAS GOTTEN
SMALLER DURING THE PAST SIX HOURS...SUGGESTING THAT THE STORM IS
STRENGTHENING...WHICH THE INTENSITY ESTIMATES ABOVE CONFIRM.  A
2357Z MICROWAVE SATELLITE IMAGE ALSO GAVE SUPPORTING EVIDENCE FOR
THIS...SHOWING A DOUBLE EYEWALL WITH THE INNER EYE JUST ABOUT TO
COLLAPSE AND DISAPPEAR.  THE EYEWALL REPLACEMENT CYCLE SCENARIO
REQUIRES THE WIND SPEED TO DECREASE AS THE OUTER EYE BECOMES
DOMINANT AND REPLACES THE DISAPPEARING INNER ONE.  THIS IS
REFLECTED IN THE INTENSITY FORECAST AT THE 12 HOUR TIME FRAME.
SURPRISINGLY THE GFDL INTENSITY GUIDANCE DOES HAVE THIS
SCENARIO...WHICH THE SHIPS DOES NOT.  BOTH THE GFDL AND SHIPS HAVE
KARL BACK TO MAJOR HURRICANE INTENSITY AT THE 12 TO 24 HOUR TIME
FRAME.  ADDITIONAL EYEWALL REPLACEMENT CYCLES ARE POSSIBLE.

FORECASTER JARVINEN

FORECAST POSITIONS AND MAX WINDS

INITIAL      19/0300Z 16.2N  41.3W   100 KT
 12HR VT     19/1200Z 16.6N  42.8W    90 KT
 24HR VT     20/0000Z 17.4N  44.8W   105 KT
 36HR VT     20/1200Z 18.2N  46.7W   110 KT
 48HR VT     21/0000Z 19.3N  48.1W   115 KT
 72HR VT     22/0000Z 23.0N  49.4W   115 KT
 96HR VT     23/0000Z 28.0N  48.0W   100 KT
120HR VT     24/0000Z 34.0N  44.0W    85 KT


$$
This weather bulletin was brought to you by:
www.nashvilleweather.net




More information about the Tropical mailing list