000
AXPZ20 KNHC 170931
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON APR 16 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

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

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N90W TO 
04N106W AND THEN RESUMES FROM 04N111W TO 05N125W TO 04N140W. 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS WITHIN 90 
NM EITHER SIDE OF A LINE FROM 04N102W TO 00N100W. 

...DISCUSSION...

NEARLY STATIONARY 1027 MB HIGH PRES IS CENTERED NEAR 30N133W 
WITH A RIDGE EXTENDING SE TO NEAR 13N102W. THE PRES GRADIENT 
BETWEEN THIS RIDGING AND LOW PRES WITH TROUGHING OVER INTERIOR 
MEXICO HAS RELAXED A BIT OVER THE NW OLD MEXICO REGION ALLOWING 
FOR WINDS TO DIMINISH TO LESS THAN 20 KT OVER THE GULF OF 
CALIFORNIA. FRESH NW-N WINDS CONTINUE N OF 28N WITHIN 120 NM W 
OF THE BAJA CALIFORNIA PENINSULA AS INDICATED BY A 0412 UTC 
HIGH-RESOLUTION ASCAT SCATTEROMETER PASS AND BY SHIP WDF9316 
LOCATED NEAR 29N117W. THESE WINDS WILL DIMINISH DURING THE NEXT 
24 HOURS...MAKING A RETURN BY 48 HOURS AS NEW LOW PRES DEVELOPS 
OVER THE SOUTHWESTERN U.S.

A 0552 UTC ASCAT PASS SHOWED FRESH NE TRADES ACROSS THE WATERS 
FROM 06N TO 22N W OF 130W AND FROM 06N TO 16N BETWEEN 118W AND 
130W...BETWEEN THE RIDGING MENTIONED ABOVE AND LOWER PRES 
ASSOCIATED WITH THE ITCZ TO THE S. THESE TRADES WILL SHRINK IN 
COVERAGE TO THE AREA FROM 06N TO 23N W OF 128 BY 48 HOURS AS THE 
HIGH SHIFTS SLIGHTLY TO THE W TO NEAR 30N140W. 

NW SWELL OF 8-9 FT COVERS THE REMAINDER OF THE MAJORITY OF THE 
WATERS W OF 106W...WITH MERGING SW SWELL E OF 120W. THESE SEAS 
WILL GRADUALLY DECAY WHILE REACHING TO THE SE FROM W OF A LINE 
FROM 10N100W TO 00N92W BY LATE WED NIGHT.

BROAD LOW-LEVEL CONVERGENCE IS OCCURRING N OF THE ITCZ WITH 
SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WITHIN 30-60 
NM EITHER SIDE OF A LINE FROM 10N106W TO 06N114W TO 06N121W. 
SIMILAR ADDITIONAL CONVECTION IS WITHIN 120 NM W OF THE COAST OF 
SOUTH AMERICA FROM 01N TO 06N...AND ALSO WITHIN 30-60 NM EITHER 
SIDE OF A LINE FROM 08N77W TO 07N86W. THIS CONVECTION DEVELOPED 
OVER INLAND SECTIONS OF THE ADJACENT WATERS YESTERDAY EVENING 
BEFORE PROPAGATING OFFSHORE DURING THE OVERNIGHT HOURS.

GAP WINDS...MODEL GUIDANCE INDICATES THE POTENTIAL FOR 20-25 KT 
NORTHERLY WINDS IN THE GULF OF TEHUANTEPEC LATE TONIGHT THROUGH 
LATE WED NIGHT FROM DEVELOPING HIGH PRES OVER INTERIOR MEXICO 
AND LOW PRES IN THE EASTERN NORTH PACIFIC SW OF CENTRAL AMERICA.

$$
LEWITSKY