000
AXPZ20 KNHC 132130
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE AUG 13 2013

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.

...SPECIAL FEATURE...                                        
ANIMATED VISUAL SATELLITE IMAGERY SHOWS MULTIPLE WEAK MID-LEVEL 
VORTICES ALONG A TROUGH AXIS EXTENDING FROM 13N136W TO 17N132W. 
CONVECTION ASSOCIATED WITH THIS DISTURBANCE HAS BECOME MORE 
DISORGANIZED OVER THE PAST 6-12 HOURS. SEA-HEIGHT ALTIMITER DATA 
FROM THE PAST 12 HOURS INDICATES WW3 SEAS BASED ON GFS MODEL ARE 
ABOUT 1-2 FT TOO HIGH AND SCATTEROMETER DATA SHOWS WINDS ARE 
GENERALLY 20 KT OR LESS IN THE N SEMICIRCLE OF THE ILL-DEFINED 
LOW. BASED ON THIS INFORMATION...IT IS BECOMING MORE LIKELY THAT 
THIS DISTURBANCE WILL FAIL TO INTENSIFY SIGNIFICANTLY BEFORE IT 
CROSSES 140W AND MOVES INTO THE CENTRAL PACIFIC. IN THE MEANTIME 
THERE IS A MEDIUM CHANCE OF INTENSIFYING INTO A TROPICAL CYCLONE 
OVER THE NEXT 48 HOURS AS IT TRACKS WESTWARD. 

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
THE MONSOON TROUGH EXTENDS FROM 10N85W TO 10N111W TO A 1008 MB 
LOW PRES NEAR 07N118W. ITCZ EXTENDS W OF THE LOW FROM 07N118W TO 
08N128W THEN RESUMES FROM 12N137W TO 11N140W. SCATTERED MODERATE 
CONVECTION IS WITHIN 90 NM S OF THE AXIS BETWEEN 101W AND 107W. 

...DISCUSSION...                                                 
 
BROAD UPPER RIDGE EXTENDS W-SW FROM NORTHERN MEXICO TO 22N140W. 
DEEP LAYER MOISTURE IS TRAPPED WELL S OF THE RIDGE S OF 18N 
EXCEPT FOR MID-LEVEL MOISTURE EXTRUSION ALONG 115W NORTHWARD TO 
CENTRAL BAJA CALIFORNIA. 

A 1022 MB SURFACE HIGH IS ANALYZED NEAR 31N135W WITH A RIDGE 
EXTENDING SE TO 23N118W. WEAK PRES GRADIENT BETWEEN THIS HIGH 
AND A TROUGH NEAR THE SIERRA MADRES OCCIDENTALES IS PRODUCING 
NNW WINDS TO 20 KT ALONG AND OFFSHORE OF THE W COAST OF BAJA 
CALIFORNIA WITH SEAS TO 5-6 FT. THE HIGH IS EXPECTED TO WEAKEN 
SLIGHTLY AS IT SHIFTS W-SW TO NEAR 29N139W WED.
 
PRES GRADIENT BETWEEN THE HIGH AND THE CONVERGENCE ZONE BOUNDARY 
CONTINUES TO SUPPORT FRESH TRADE WINDS WITHIN 450-500 NM N OF A 
LINE FROM 18N122W TO 12N140W...WITH HIGHEST WINDS IN THE N SEMI-
CIRCLE OF THE SPECIAL FEATURE MENTIONED ABOVE CENTERED NEAR 13N 
135W. THE TROUGH IS FORECAST TO CONTINUE WESTWARD AND MOVE W OF 
THE DISCUSSION AREA BY EARLY THU.

$$ 
MUNDELL