Hurricane Ileana in EPAC Thread

[wxmann_91]

The UL anticyclone to the northeast should've induced a perfect outflow pattern for a strong hurricane... and hurricanes as powerful as Ileana usually don't get affected by dry air too much... perhaps its size was its downfall...and its speed (rapid movement into cooler waters).

[cycloneye]

WTPZ45 KNHC 241438
TCDEP5
HURRICANE ILEANA DISCUSSION NUMBER 13
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102006
800 AM PDT THU AUG 24 2006

INFRARED SATELLITE IMAGERY SHOWS THAT ILEANA IS NOW WEAKENING IN
EARNEST...WITH RAPIDLY WARMING CLOUD TOPS OVER THE NORTHERN
SEMICIRCLE. THE INITIAL INTENSITY IS SET AT 85 KT AND IS BASED ON
A COMPROMISE OF THE DVORAK CURRENT INTENSITY AND T NUMBERS FROM THE
VARIOUS AGENCIES. PROGRESSIVELY COOLER WATERS AND STABLE AIR ARE
EXPECTED TO RESULT IN FURTHER WEAKENING WITH ILEANA ULTIMATELY
BECOMING A REMNANT LOW BY DAY 4...IF NOT SOONER. THE OFFICIAL
INTENSITY FORECAST SHOWS WEAKENING A LITTLE FASTER THAN THE
PREVIOUS ADVISORY BASED ON THE AFOREMENTIONED DEGRADATION OF THE
CLOUD SIGNATURE.

ILEANA'S INITIAL MOTION IS ESTIMATED TO BE 300/9. GLOBAL MODELS
CONTINUE TO FORECAST A WEAKENING OF THE RIDGE OVER NORTHERN MEXICO.
ACCORDINGLY...ILEANA IS EXPECTED TO BE STEERED TOWARD THE NORTHWEST
OVER THE NEXT 2 DAYS WITH A GRADUAL DECREASE IN SPEED. THE CYCLONE
IS FORECAST TO BECOME INCREASINGLY SHALLOW BY DAY 3...RESULTING IN
A TURN TOWARD THE WEST. THE OFFICIAL TRACK FORECAST IS NEAR THE
DYNAMICAL MODEL CONSENSUS EARLY...AND THEN TRENDS TOWARD THE SHALLOW
BAM TRACK LATER IN THE FORECAST. THIS RESULTS IN AN OFFICIAL TRACK
SHIFTED SLIGHTLY TO THE NORTH AND A LITTLE FASTER THAN THE PREVIOUS
ONE BEYOND DAY 3.

FORECAST POSITIONS AND MAX WINDS

INITIAL 24/1500Z 20.5N 114.9W 85 KT
12HR VT 25/0000Z 21.2N 116.1W 75 KT
24HR VT 25/1200Z 21.9N 117.3W 60 KT
36HR VT 26/0000Z 22.4N 118.4W 50 KT
48HR VT 26/1200Z 22.8N 119.2W 40 KT
72HR VT 27/1200Z 23.0N 121.0W 30 KT
96HR VT 28/1200Z 23.0N 123.0W 25 KT...REMNANT LOW
120HR VT 29/1200Z 23.0N 126.0W 20 KT...REMNANT LOW

$$
FORECASTER RHOME/FRANKLIN

[AnnularCane]

Don't look now, but I think she's coming back!

[cycloneye]

355
WTPZ45 KNHC 251448
TCDEP5
HURRICANE ILEANA DISCUSSION NUMBER 17
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL EP102006
800 AM PDT FRI AUG 25 2006

ILEANA IS RETAINING GOOD STRUCTURE WITH A 20 NM WIDE EYE OBSERVED IN
INFRARED SATELLITE IMAGERY. HOWEVER...CLOUDS TOPS AROUND THE
CENTER CONTINUE TO GRADUALLY WARM AND DVORAK T NUMBERS ARE
DECREASING. THE INITIAL INTENSITY WILL BE LOWERED TO 70 KT...WHICH
IS AN AVERAGE OF THE DVORAK T AND CURRENT INTENSITY NUMBERS. THIS
AVERAGE IS TYPICALLY USED DURING THE WEAKENING PHASE WHEN CI
NUMBERS ARE CONSTRAINED BY DVORAK RULES. WITH VERY LITTLE VERTICAL
WIND SHEAR FORECAST...ILEANA MAY WEAKEN A LITTLE SLOWER THAN
INTENSITY GUIDANCE INDICATES FOR THE FIRST 12 TO 24 HOURS.
THEREAFTER...THE CYCLONE SHOULD STEADILY WEAKEN AS IT MOVES
OVER COOLER SSTS AND ENTRAINS DRY STABLE AIR. IT IS FORECAST
TO BECOME A REMNANT LOW IN ABOUT 3 DAYS.

THE HURRICANE HAS SLOWED CONSIDERABLY OVER THE PAST 6-12 HOURS AND
THE INITIAL MOTION IS ESTIMATED TO BE 300/4 KT. THE GFS WHICH
INITIALIZED THE HURRICANE FAR TOO WEAK....SEEMS UNREASONABLE WITH
ITS ALMOST IMMEDIATE SOUTHWESTWARD MOTION. THE REMAINDER OF THE
DYNAMICAL MODELS DEPICT A STRONGER SYSTEM THAT TRACKS SLOWLY
NORTHWEST DURING THE FIRST 24-36 HOURS. THE OFFICIAL TRACK FOLLOWS
THIS SCENARIO AND WAS ADJUSTED A LITTLE NORTHWARD. THE FORECAST
CONTINUES TO SHOW A WESTWARD BEND LATER IN THE PERIOD AS THE
CYCLONE WEAKENS AND BECOMES AN INCREASINGLY SHALLOW SYSTEM.

THE 12 FT SEA RADII WERE EXPANDED BASED ON EARLIER OBSERVATIONS
FROM TWO SHIPS OVER THE EASTERN SEMICIRCLE OF THE CIRCULATION.

FORECAST POSITIONS AND MAX WINDS

INITIAL 25/1500Z 21.6N 116.9W 70 KT
12HR VT 26/0000Z 21.9N 117.6W 65 KT
24HR VT 26/1200Z 22.1N 118.7W 55 KT
36HR VT 27/0000Z 22.2N 119.7W 40 KT
48HR VT 27/1200Z 22.2N 120.7W 30 KT
72HR VT 28/1200Z 22.0N 122.5W 25 KT...REMNANT LOW
96HR VT 29/1200Z 21.5N 124.5W 20 KT...REMNANT LOW
120HR VT 30/1200Z...DISSIPATED

$$
FORECASTER BROWN/BEVEN