000
AXPZ20 KNHC 261553
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...SPECIAL FEATURE...

A SURFACE LOW PRESSURE IS ANALYZED ALONG THE MONSOON TROUGH AXIS 
NEAR 12N102W WITH AN ESTIMATED PRESSURE OF 1007 MB...MOVING WNW 
AT 12 KT. SCATTERED MODERATE CONVECTION FROM 90 NM TO 150 NM N 
OF LOW. THIS LOW PRES FORMED A COUPLE OF DAYS AGO ALONG THE 
MONSOON TROF SOUTH OF THE GULF OF TEHUANTEPEC...AS A TROPICAL 
WAVE MIGRATED INTO THE AREA AND INTERACTED WITH THE MONSOON 
TROF. CONTINUED DEVELOPMENT IS POSSIBLE DURING THE NEXT COUPLE 
OF DAYS AND TROPICAL CYCLONE FORMATION IS POSSIBLE.

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

THE MONSOON TROUGH FROM 11N86W TO 1007 MB LOW PRES AT 12N102W TO 
13N107W TO 11N124W TO 07N137W THEN ITCZ TO BEYOND 08N140.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 08N TO AXIS 
BETWEEN 106W AND 126W.

...DISCUSSION...

MODERATE TO FRESH SW FLOW TO THE SOUTH OF THE MONSOON TROF IS 
SUPPORTING THE AREAS OF CONVECTION BETWEEN 106W AND 116W. A WEAK 
MID LEVEL TROUGH NEAR 85W IS AIDING MORE MODEST CONVECTION ALONG 
THE MONSOON TROUGH...IN PART LEFTOVER FROM OVERNIGHT COASTAL 
CONVECTION FROM 07N TO THE TROUGH AXIS FROM COSTA RICA TO 95W. 
AN UPPER ANTICYCLONE REMAINS ANCHORED NEAR 25N112W...AND NE TO E 
FLOW ON THE S SIDE OF THIS SYSTEM IS PROVIDING MODERATE SHEAR 
ACROSS THE AREAS OF CONVECTION. 

MODEL CONSENSUS BETWEEN THE GFS...ECMWF...AND UKMET SHOWS THE 
LOW NEAR 12N102W WILL DEEPEN GRADUALLY OVER THE NEXT 48 TO 72 
HOURS AND DRIFT NW TO 15N110W...BEFORE SHIFTING MORE NW THROUGH 
NEXT WEEK. MODELS ALSO INDICATE WINDS REACHING 20 TO 25 KT ON 
THE S SIDE OF THE LOW...AND WITH SEAS BUILDING TO AT LEAST 8 FT. 
A WEAKER LOW MAY FORM ALONG THE COAST OF NORTHERN CENTRAL 
AMERICA AND SOUTHERN MEXICO THROUGH THIS SAME TIME 
PERIOD...ALONG THE MONSOON TROF WHICH WILL BOWING NORTHWARD AND 
PARALLELING THE COAST THROUGH ROUGHLY 15N...BEFORE EXTENDING 
WESTWARD TOWARD THE MORE DEVELOPED LOW NEAR 15N110W. 

FURTHER WEST...A DISSIPATING SURFACE LOW IS CENTERED NEAR 
15N115W. AN UPPER LOW IS SITUATED NEAR 18N127W...AIDING 
CONVECTION ALONG THE MONSOON TROUGH BETWEEN 118W AND 126W. 
ALTIMETER DATA FROM AROUND 08 UTC SHOWED SEAS TO 8 FT LIKELY IN 
LONG PERIOD CROSS EQUATORIAL SWELLS DEPICTED IN MWW3...ECWAVE 
AND UKWAVE S OF 09N BETWEEN 92W AND 115W. THESE SWELLS ARE 
EXPECTED TO PROPAGATE N AND COMBINE WITH FRESH SWELLS GENERATED 
S OF THE DEEPENING LOW...FROM ROUGHLY 08N TO 12N BETWEEN 100W 
AND 120W BY MON.

$$
CHRISTENSEN