000
AXPZ20 KNHC 252142
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI AUG 24 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS EXTENDS FROM 11N86W TO 1008 MB LOW PRES AT 
11N99W TO 12N110W TO 10N120W TO 11N130W TO 11N 140W. SCATTERED 
MODERATE ISOLATED STRONG CONVECTION FROM 06N TO 10N BETWEEN 80W 
AND 94W. SCATTERED MODERATE CONVECTION WITHIN 120 NM S OF TROUGH 
AXIS BETWEEN 113W AND 121W...AND FROM 07N TO 11N BETWEEN 121W 
AND 128W.

...DISCUSSION...

E OF 110W...A 1008 MB LOW PRES AREA IS CENTERED ALONG MONSOON 
NEAR 11N99W. CONVECTIVE BANDS ARE BUILDING WITHIN 90 NM OF THE 
CENTER OF THE LOW ACROSS THE NORTHERN SEMICIRCLE. THIS SYSTEM 
WILL TRACK WNW AT 20 TO 25 KT THROUGH SUN...AND WEAKEN SLIGHTLY. 
AN ASCAT PASS FROM AROUND 17 UTC SHOWED SW WINDS TO 20 KT 
CONVERGING INTO THE LOW. ANOTHER LOW PRES AREA WITH AN ESTIMATED 
MSLP AROUND 1010 MB IS CENTERED NEAR 15N114W AT THE BASE OF A 
TROUGH EXTENDING TO THE GULF OF CALIFORNIA. THIS LOW IS BECOMING 
MORE DIFFUSE AND WILL DISSIPATE THROUGH SUN. THE MODERATE TO 
FRESH SW FLOW INTO THE MONSOON TROUGH IS SUPPORTING THE CLUSTERS 
OF CONVECTION AROUND THE LOW PRES AREA. NE FLOW ALOFT ROUNDING 
THE BASE OF A PERSISTENT UPPER ANTICYCLONE CENTERED OVER CENTRAL 
BAJA IS PROVIDING SHEAR OF THIS CONVECTION AND LIMITING 
INTENSITY.

W OF 110W...A WEAK LOW TO MID LEVEL TROUGH/TROPICAL WAVE IS 
LOCATED FROM 15N126W TO 11N127W. THIS IS ENHANCING SCATTERED 
MODERATE CONVECTION ALONG THE MONSOON TROUGH AXIS W OF PRIMARILY 
BETWEEN 120W AND 125W. GFS AND ECMWF GUIDANCE SHOWS A WEAK 
SURFACE LOW FORMING ALONG THE MONSOON TROUGH NEAR 120W OVER THE 
NEXT 24 TO 48 HOURS...LIKELY IN RESPONSE TO THE LOWER TO MID 
LEVEL TROUGH. BESIDES SUPPORTING THE EPISODIC CONVECTION THE 
MAIN SENSIBLE WEATHER IMPACT WILL BE TO MAINTAIN MODERATE TO 
FRESH TRADE WIND FLOW BETWEEN THE LOWER PRES AND WEAK SURFACE 
RIDGING ALONG 30N. A COLD FRONT APPROACHING 30N W OF 130W SUN 
NIGHT WILL WEAKEN INTO A TROUGH THROUGH MON NIGHT THEN 
DISSIPATE. THIS TROUGH WILL DISRUPT THE SUBTROPICAL RIDGE ACROSS 
NORTHERN PORTIONS AND MAINTAIN LIGHT TO MODERATE WINDS N OF 20N 
THROUGH TUE.

CROSS-EQUATORIAL SOUTHERLY SWELL WILL GRADUALLY BUILD TO AROUND 8
FT THROUGH SAT...THEN A SURGE OF SW SWELL ARRIVING SAT NIGHT WILL
PUSH SEA HEIGHTS TO 8-9 FT S OF 08N BETWEEN 95W AND 115W SUN AND 
MON...WHILE WINDS S OF THE MONSOON TROUGH REMAIN 20 KT OR LESS.

$$
CHRISTENSEN