000
AXPZ20 KNHC 061508
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU SEP 06 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 13N104W TO 
09N121W WITH A BREAK THEN ITCZ AXIS EXTENDS FROM 05N123W TO 
BEYOND 07N140W.  SCATTERED MODERATE CONVECTION EXISTS WITHIN 
180 NM OF AXIS FROM 110W TO 121W.

...DISCUSSION...
THE PACIFIC IS EXCEEDINGLY QUIET FOR EARLY SEPTEMBER.  THE TWO 
REMNANT LOWS OF ILEANA AND JOHN ARE STILL SPINNING...BUT HAVE 
NOW DROPPED BELOW THE 25 KT THRESHOLD NEEDED FOR INCLUSION IN 
THE HIGH SEAS FORECAST.  THESE DYING VORTICES HAVE NO 
SIGNIFICANT DEEP CONVECTION AND ARE NO THREAT FOR BECOMING 
TROPICAL CYCLONES AGAIN.  A WEAK TROUGH OF LOW PRESSURE EXISTS 
ALONG 05N122W TO 11N120W BETWEEN THE MONSOON TROUGH TO THE EAST 
AND THE ITCZ TO THE WEST.  HOWEVER...THIS HAS MINIMAL VORTICITY 
AND CONVECTION ASSOCIATED WITH IT.  IT IS EXPECTED TO MOVE 
WESTWARD AT 10 TO 15 KT WITH LITTLE CHANGE.

THERE APPEARS TO BE NO CHANCE FOR TROPICAL CYCLOGENESIS DURING 
THE NEXT TWO DAYS.  OUT TO FIVE DAYS...ONLY THE NOGAPS GLOBAL 
MODEL DEPICTS ANY SYSTEMS DEVELOPING...WHICH SPINS UP TWO OR 
EVEN THREE CYCLONES ALONG THE MONSOON TROUGH.  HOWEVER...SUCH A 
SCENARIO APPEARS TO BE UNLIKELY.  THE GRIDDED FORECASTS WILL BE 
A BLEND OF THE GFS AND ECMWF GLOBAL MODELS AND ASSOCIATED 
WAVEWATCH MODELS...WHICH HAVE NO TROPICAL CYCLONES IN THE NEXT 
SEVERAL DAYS.

THERE ARE NO GAP WIND EVENTS CURRENTLY OCCURRING OR LIKELY TO 
OCCUR DURING THE NEXT SEVERAL DAYS.

THE ONLY FEATURE MENTIONED IN THE HIGH SEAS FORECAST ARE SOME 8 
FT SOUTHEASTERLY SWELLS IN THE SOUTH CENTRAL AREA OF 
RESPONSIBILITY.  THESE WILL REMAIN FAIRLY STEADY STATE OVER THE 
NEXT TWO DAYS.  NO LONG PERIOD HIGH WAVEHEIGHT SWELL EVENTS 
APPEAR TO BE LIKELY FOR AT LEAST THE NEXT WEEK.

IN THE UPPER LEVELS...AN ANTICYCLONE CENTERED OVER NORTHERN 
MEXICO AND TEXAS IS FORCING PRIMARILY SOUTHEASTERLY FLOW OVER 
THE WATERS SOUTH OF MEXICO.  A WEAK UPPER LEVEL TROUGH EXTENDS 
FROM 05N127W TO 15N123W TO 19N117W...WHICH MAY BE ENHANCING SOME 
OF THE DEEP CONVECTION ASSOCIATED WITH THE MONSOON TROUGH.

$$
CHRIS LANDSEA