NORA #11 - DISCUSSION

[AussieMark]

000
WTPZ44 KNHC 040921
TCDEP4
HURRICANE NORA DISCUSSION NUMBER 11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2 AM PDT SAT OCT 04 2003

...CORRECTED INITIAL INTENSITY...

LATEST ENHANCED INFRARED IMAGERY DEPICTS BANDING EYE DEVELOPMENT.
DVORAK INTENSITY ESTIMATES ARE 77 KT FROM TAFB AND SAB...55 KT FROM
AFWA. WATER VAPOR IMAGERY REVEALS IMPROVED OUTFLOW OVER THE
NORTHERN HALF OF THE SYSTEM. BECAUSE OF THE SIGNIFICANT IMPROVEMENT
IN BANDING STRUCTURE...NORA IS INCREASED TO 75 KT.

THE INITIAL MOTION WAS ADJUSTED SLIGHTLY AND IS 300/6. THE FORECAST
TRACK GUIDANCE REMAINS SIMILAR TO THE PREVIOUS ADVISORY AS NORA IS
EXPECTED TO MOVE NORTHWEST AROUND A RIDGE OVER MEXICO INTO A
DEVELOPING WEAKNESS. A BLEND OF THE GFDL...NOGAPS...GFDN...AND
UKMET REMAINS THE BASIS OF THE FORECAST. THE GFS CONTINUES TO BE
THE WELL TO THE LEFT OF THE CONSENSUS. THE LATEST RUN SUGGESTS A
WEAKER TROPICAL CYCLONE TRACKING WITHIN THE STEERING FLOW OF A LOW
LEVEL RIDGE. A BAROCLINIC TROUGH STILL DEVELOPS JUST EAST OF 120W
CAUSING NORA TO SLOW CONSIDERABLY AND MOVE IN A MORE NORTHWARD
MOTION.

FURTHER INTENSIFICATION IS FORECAST THROUGH THE NEXT 24
HOURS...WHICH IS SIMILAR TO THE SHIPS. AFTERWARD...SOUTHWESTERLY
SHEAR...AND COOLER WATER SHOULD TRIGGER A WEAKENING TREND.


FORECASTER ROBERTS/AVILA

FORECAST POSITIONS AND MAX WINDS

INITIAL 04/0900Z 16.8N 111.3W 75 KT
12HR VT 04/1800Z 17.5N 111.9W 80 KT
24HR VT 05/0600Z 18.8N 112.8W 85 KT
36HR VT 05/1800Z 20.0N 113.5W 80 KT
48HR VT 06/0600Z 20.8N 113.9W 70 KT
72HR VT 07/0600Z 21.6N 114.1W 55 KT
96HR VT 08/0600Z 21.9N 114.1W 40 KT
120HR VT 09/0600Z 22.3N 114.0W 30 KT