000
AXPZ20 KNHC 231607
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC FRI AUG 23 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.
                                    
...SPECIAL FEATURE...                                            
TROPICAL STORM IVO CENTERED NEAR 18.7N 112.4W 1000 MB AT 1500 
UTC AUG 23 MOVING N OR 360 DEG AT 5 KT. MAXIMUM SUSTAINED WINDS 
35 KT GUSTS 45 KT. NUMEROUS MODERATE TO STRONG CONVECTION FROM 
16N TO 20N BETWEEN 107W AND 118W. SEE LATEST NHC FORECAST/ 
ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ24 KNHC FOR MORE 
DETAILS. 

IVO IS EXPECTED TO INTENSIFY SLIGHTLY DURING THE NEXT 24-36 
HOURS BEFORE IT ENCOUNTERS COLDER WATER W OF BAJA CALIFORNIA AND 
CAUSE IT TO WEAKEN INTO A REMNANT LOW. A LONG FETCH OF SW WINDS 
ASSOCIATED WITH THE TROPICAL CYCLONE IS ALLOWING COMBINED SEAS 
TO BUILD TO 15 FT SE OF THE CENTER. WW3 WAVE FORECAST BASED ON 
THE GFS MODEL SHOWS HIGH SEAS REACHING WELL NORTHWARD INTO THE 
GULF OF CALIFORNIA SAT NIGHT AND SUN...THE RESULT OF S-SE WINDS 
EXTENDING THE FETCH OF SW SWELL UNUSUALLY FAR NORTHWARD. A SMALL 
DEVIATION IN WIND DIRECTION OR RAPID WEAKENING WILL CAUSE HIGH 
SEAS TO BARELY REACH N OF 24N...SO FORECAST IS HIGHLY VARIABLE 
IN THIS REGION...EITHER GREATER THAN 10 FT OR LESS THAN 3 FT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...       
DISCONTINUOUS MONSOON TROUGH EXTENDS FROM 09N79W TO 08N83W TO 
10N89W TO 07N98W TO 07N110W...THEN RESUMES FROM 16N118W TO LOW 
PRES NEAR 13N125W 1007 MB TO 13N133W TO 11N140W. NUMEROUS 
MODERATE TO STRONG CONVECTION FROM 09N TO 14N BETWEEN 92W AND 
96W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 60 NM 
EITHER SIDE OF TROUGH BETWEEN 122W AND 128W.

...DISCUSSION... ACTIVE MONSOON TROUGH REACHING ACROSS THE 
ENTIRE BASIN REMAINS PRIMARY SURFACE FEATURE. SUBTROPICAL HIGH 
CENTERED NEAR 31N143W EXTENDS MODERATELY WEAK RIDGE E-SE TO 21N 
120W. WEAK PRES GRADIENT S OF THE RIDGE IS SUPPORTING GENTLE TO 
MODERATE E-NE TRADES NORTH OF THE MONSOON TROUGH WHILE MODERATE 
TO FRESH SW WINDS PERSIST S OF THE TROUGH...AND EXTEND FAR WEST 
TO AROUND 130W. A TROPICAL WAVE MOVING THROUGH THE W CARIBBEAN 
MAY INDUCE ENHANCED WINDS THROUGH THE CHIVELA PASS INTO THE GULF 
OF TEHUANTEPEC AS FRESH NORTHERLY WINDS TONIGHT AND SAT...WITH 
SEAS BUILDING TO 6-7 FT BY SAT MORNING.
 
$$
MUNDELL