000
AXPZ20 KNHC 162150
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE APR 16 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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH 08N81W TO 08N92W TO 06N96W THEN ITCZ TO 6N112W TO 
07N118W TO 1011 MB LOW PRES AT 06N120W TO 04N125W TO 06N133W TO 05N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM OF AXIS 
FROM 104W TO 115W AND WITHIN 240 NM OF AXIS FROM 115W TO 123W.

...DISCUSSION... 
UPPER LEVEL CYCLONIC CIRCULATION AT 29N140W EXTEND ALONG 140W TO 00N.
VERY DRY AIR MASS W OF AXIS WILL BE INTRUDING INTO BASIN LATER IN THE 
FORECAST PERIOD...BUT 80 KT JET CORE ADVECTS PLENTY OF TROPICAL 
MOISTURE N AND NE OVER DOWNSTREAM RIDGE CREST E OF 140W.  RIDGE WELL 
ANCHORED BY ANTICYCLONE AT 06N116W AND ALMOST ON TOP OF SURFACE LOW 
PRES 1011 MB AT 06N120W.  MODERATE TO STRONG DIVERGENT FLOW RIGHT ABOVE
LOW PRES AND ABUNDANT AVAILABLE TROPICAL MOISTURE ALONG ITCZ ENABLES 
SYSTEM TO PRODUCE BROKEN TO OVERCAST MULTI-LAYERED CLOUDS WITH SCATTERED
CONVECTION WITHIN 240 NM OF ITCZ FROM 115W TO 123W.  

SECOND UPPER LEVEL TROUGH...ALONG 98W S OF CENTRAL MEXICO...KEEPS DRY
AIR MASS E OF 102W.  

...ELSEWHERE AT THE LOWER LEVELS...
WEAK DISSIPATING COLD FRONT ALONG 29N/30N E OF 130W USHERS BROAD HEALTHY
SURFACE HIGH PRES 1037 MB INTO REGION JUST N OF BASIN.  MODERATE TO 
FRESH BREEZE ALONG W COAST OF BAJA CALIFORNIA PENINSULA N OF FRONT. 
LONG PERIOD 8-12 FT N SWELL N OF 24N W OF 116W SPREADS S AND SUBSIDES 
THROUGH FORECAST PERIOD.  DECAYED 10 FT SWELLS REACH 10N BY THU.  

...OUTLOOK...
CURRENT NW SWELL DECAY TO 8 FT AND DECREASE IN COVERAGE AS IT SPREADS S.

WINDS INCREASE OVER GULF OF CALIFORNIA FRI AS HIGH PRES PUSHES EASTWARD
WITH FRESH TO STRONG NW BREEZE BUILDING SEAS TO 8 FT.   

$$
WALLY BARNES