000
AXPZ20 KNHC 262146
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN AUG 26 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 
2045 UTC.

...SPECIAL FEATURE...

A SURFACE LOW PRESSURE IS ANALYZED ALONG THE MONSOON TROUGH AXIS 
NEAR 13.5N102W WITH AN ESTIMATED PRESSURE OF 1007 MB...MOVING 
WNW AT 10 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
NOTED WITHIN 150 NM N QUADRANT OF LOW PRES. THIS SYSTEM FORMED A 
COUPLE OF DAYS AGO ALONG THE MONSOON TROUGH SOUTH OF THE GULF OF 
TEHUANTEPEC AS A TROPICAL WAVE MIGRATED INTO THE AREA AND 
INTERACTED WITH THE MONSOON TROUGH. ENVIRONMENTAL CONDITIONS ARE 
CONDUCIVE FOR ADDITIONAL DEVELOPMENT DURING THE NEXT COUPLE OF 
DAYS. THIS SYSTEM HAS A MEDIUM CHANCE OF BECOMING A TROPICAL 
CYCLONE DURING THE NEXT 48 HOURS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

MONSOON TROUGH AXIS EXTENDS FROM 14N91W TO 1007 MB LOW PRES AT 
13.5N102W TO 10N115W TO 1010 MB LOW PRES AT 11N126W TO 09N140. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 07 
TO 12N BETWEEN 82W AND 95W AND FROM 10N TO 12N BETWEEN 101W AND 
110W. SCATTERED MODERATE CONVECTION IS FROM 08N TO 11N BETWEEN 
110W AND 120W AND WITHIN 150 NM NW QUADRANT OF LOW PRES NEAR 
11N126W.

...DISCUSSION...

AN UPPER ANTICYCLONE REMAINS ANCHORED NEAR 25N112W WITH A RIDGE 
EXTENDING ACROSS THE N WATERS TO NEAR 22N135W. ANOTHER RIDGE 
EXTENDS SE FROM THE SAME ANTICYCLONE TO NEAR 19N108W AND IS 
HELPING TO INDUCE SOME SHOWER/TSTM ACTIVITY S OF BAJA CALIFORNIA 
PARTICULARLY FROM 18N TO 22N E OF 110W. MODERATE TO STRONG 
SUBSIDENCE AND IMPLIED DRY AIR MASS CAN BE FOUND N OF 15N W OF 
120W. A DIFFLUENT PATTERN ALOFT IS SUPPORTING THE AREAS OF 
CONVECTION ALONG THE MONSOON TROUGH. 

SCATTEROMETER DATA PROVIDED OBSERVATIONS OF FRESH TO STRONG S TO 
SW FLOW SOUTH OF THE MONSOON TROUGH...COVERING THE REGION FROM 
06N TO 11N BETWEEN 102W AND 120W. 

MODEL CONSENSUS BETWEEN THE GFS...ECMWF...AND UKMET SHOWS THAT 
THE LOW PRES NEAR 13.5N102W WILL DEEPEN GRADUALLY OVER THE NEXT 
COUPLE OF DAYS AS IT MOVES WEST-NORTHWESTWARD AT ABOUT 10 KT.  
MODELS ALSO INDICATE WINDS REACHING 20 TO 25 KT ON THE SE SIDE 
OF THE LOW...AND WITH SEAS BUILDING TO AROUND 8 TO 10 FT.  

FURTHER WEST...DISSIPATING SURFACE LOWS...ANALYZED 1011 MB ON 
THE 1800 UTC SURFACE MAP...ARE NOTED NEAR 18N115W AND NEAR 
15N114W. ANOTHER 1010 MB LOW PRES IS ALONG THE MONSOON TROUGH 
NEAR 11N126W. 

LONG PERIOD CROSS EQUATORIAL SWELLS ARE CURRENTLY OBSERVED IN 
THE WATERS S OF 10N BETWEEN 95W AND 115W. THESE SWELLS ARE 
EXPECTED TO PROPAGATE N AND COMBINE WITH FRESH SWELLS GENERATED 
S OF THE DEEPENING LOW...FROM ROUGHLY FROM 05N TO 11N BETWEEN 
100W AND 124W BY MON.

$$
GR/EC