000
AXPZ20 KNHC 030230
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC FRI APR 03 2015

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY  
THROUGH 0215 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
            
THE ITCZ WAS ANALYZED FROM 07N86W TO 04N100W TO 03N127W...THEN  
RESUMES FROM 04N136W TO 04N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION OBSERVED S OF THE ITCZ WITHIN 90 NM OF 
08.5N91W AND OVER AND TO THE N OF THE ITCZ WITHIN 90 NM EITHER 
SIDE OF A LINE FROM 08N91W TO 03N107W. ISOLATED MODERATE 
OCCASIONALLY STRONG CLUSTERS WERE OBSERVED FROM 03-13N BETWEEN 
98-140W.

A SURFACE TROUGH EXTENDS SW OFF THE COAST OF COLOMBIA FROM  
05N77W TO 02N81W...BUT CURRENTLY LACKS SIGNIFICANT CONVECTION.
 
...DISCUSSION... 
  
ALOFT...AN UPPER LEVEL SHORT WAVE TROUGH HAS MOVED OVER THE NW 
PORTION OF THE DISCUSSION AREA WITH MEAN AXIS FROM 32N136W TO 
13N134W. AN UPPER ANTICYCLONE IS OVER NW COLOMBIA WITH AN UPPER 
RIDGE EXTENDING NW TO A CREST AT 32N123W. A 180 NM WIDE BAND OF 
UPPER MOISTURE IS STREAMING E FROM 29N137W TO ACROSS THE 
NORTHERN BAJA CALIFORNIA PENINSULA AND GULF OF CALIFORNIA...AND CONTINUES
E ACROSS NEW MEXICO AND ARIZONA.     
UPPER DEBRIS MOISTURE...MOSTLY FROM FORMER CONVECTION...CONTINUES 
ACROSS THE DISCUSSION AREA FROM 
07-28N BETWEEN 121W-109W. SOME OF THIS MOISTURE TURNS E ACROSS 
THE UPPER RIDGE OVER THE SOUTHERN BAJA PENINSULA AND THE SOUTHERN
HALF OF THE GULF OF CALIFORNIA...AND CONTINUES 
E ACROSS NORTHERN MEXICO.   
 
AT THE LOW LEVELS A SURFACE RIDGE EXTENDS FROM 32N132W TO  
14N97W. THE PRESSURE GRADIENT E OF THE RIDGE IS SUPPORTING 
NORTHERLY 20-25 KT WINDS ACROSS THE DISCUSSION AREA FROM 29-32N  
BETWEEN 118-129W...WITH COMBINED SEAS OF 9-12 FT. A RECENT 
ALTIMETER PASS MEASURED SEAS OF 7-11 FT ALONG THE NW COAST OF 
THE BAJA CALIFORNIA PENINSULA IN AN AREA OF 15 KT NW WINDS. THE 
GRADIENT WILL GRADUALLY RELAX ON FRI WITH WINDS DIMINISHING TO 
20 KT OR LESS ON FRI EVENING. THE GRADIENT SW OF THE RIDGE IS 
ALSO RELAXING...BUT NE 20-25 KT TRADES STILL CONTINUE ACROSS THE 
DISCUSSION AREA FROM 19-24N W OF 137W WITH SEAS OF 7-10 FT. LONG 
PERIOD NW SWELL IS PROPAGATING SE ACROSS THE OPEN PACIFIC WATERS 
W OF 85W AND MIXING WITH LONG PERIOD CROSS-EQUATORIAL SOUTHERLY 
SWELL...AND ADDITIONALLY MIXING NE TRADE SWELL ACROSS THE WATERS 
SW OF THE SURFACE RIDGE. COMBINED SEAS OF 7-9 FT ARE OBSERVED 
ELSEWHERE WITHIN THE AREA BOUNDED BY A LINE FROM 30N132W TO 
30N115W TO 17N140W TO 27N140W TO 30N132W. THESE SWELLS WILL 
GRADUALLY SUBSIDE ON FRI AND SAT. HOWEVER SEAS TO 8 FT WILL 
RETURN ALONG THE NW COAST OF THE BAJA PENINSULA ON SUN AND SUN 
NIGHT...THEN SUBSIDE TO 4-6 FT ON MON. 

GULF OF PAPAGAYO...EXPECT NOCTURNAL DRAINAGE OF ENE 20-25 KT  
WINDS TONIGHT INTO EARLY FRI MORNING...AND ON FRI NIGHT INTO SAT 
MORNING. GUIDANCE SUGGESTS A SIGNIFICANT DRAINAGE EVENT WILL 
OCCUR ON SAT AND SUN NIGHTS WITH THE WESTERN EXTENT REACHING 
NEAR 11N92W AT SUNRISE ON MON...WITH SEAS BUILDING TO 9 FT. MON 
NIGHTS EVENT WILL NO BE AS STRONG AS SUN NIGHTS AND TUE NIGHTS 
EVENT WILL BE MINIMAL AGAIN.
 
GULF OF TEHUANTEPEC...EXPECT NORTHERLY 20-25 KT WINDS TO SURGE  
THROUGH THE ISTHMUS OF TEHUANTEPEC LATE FRI NIGHT...GRADUALLY 
INCREASE THROUGHOUT THE DAY ON SAT REACHING MINIMAL GALE FORCE 
ON SAT NIGHT THROUGH SUNRISE ON SUN.  

$$ 
NELSON