000
AXPZ20 KNHC 210240
TWDEP 

TROPICAL WEATHER DISCUSSION                                
NWS NATIONAL HURRICANE CENTER MIAMI FL                          
0405 UTC TUE MAY 21 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0215 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 07N78W TO 10N104W TO 
11N123W. THE ITCZ AXIS EXTENDS FROM 09N129W TO 06N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF 
THE MONSOON TROUGH BETWEEN 80W AND 92W...WITHIN 100 NM S OF THE 
MONSOON TROUGH BETWEEN 96W AND 99W AND WITHIN 140 NM EITHER SIDE 
OF THE MONSOON TROUGH BETWEEN 110W AND 121W.

...DISCUSSION... 

THE 1010 MB LOW REMNANT OF ALVIN IS CENTERED NEAR 12N126W ALONG 
A NORTH-SOUTH ORIENTATED TROUGH THAT EXTENDS FROM 10N127W TO 
14N126W. THE MOST RECENT ASCAT PASS PROVIDED OBSERVATIONS OF 20-
25 KT WINDS WITHIN 120 NM N SEMICIRCLE OF LOW CENTER. THIS 
SYSTEM IS GENERATING MAXIMUM SEAS OF 10 FT. A BROAD MIX OF SWELL 
IS MAINTAINING SEAS UP TO 10 FT ELSEWHERE FROM 11N-16N BETWEEN 
122W-130W. MARINE GUIDANCE SUGGESTS THAT THE REMNANT LOW OF 
ALVIN WILL CONTINUE TO MOVE MAINLY WESTWARD DURING THE NEXT 48 
HOURS WITH AN AREA OF FRESH WINDS WITHIN ABOUT 120 NM TO THE N 
OF THE LOW CENTER.  

A 1044 MB HIGH PRES LOCATED N OF AREA NEAR 50N148W EXTENDS A 
RIDGE SE TO NEAR 20N111W. PRESSURE GRADIENT TIGHTENS ON THE EAST 
SIDE OF THE RIDGE PRODUCING NW WINDS OF 10-15 KT ALONG THE 
ENTIRE WESTERN SHORE OF THE BAJA CALIFORNIA PENINSULA WITH SEAS 
OF 4-6 FT. A SURGE OF NORTHERLY WINDS AT 15-20 KT CONTINUES 
ACROSS THE N-CENTRAL PACIFIC WATERS...ROUGHLY N OF 29N BETWEEN 
120W AND 128W WITH SEAS TO 8 FT PRIMARILY IN N SWELL. THESE 
NORTHERLY WINDS ARE EXPECTED TO INCREASE TO 20-25 KT EARLY ON 
WED AND UP TO 30 KT FROM WED AFTERNOON TO EARLY THU AS HIGH PRES 
N OF AREA INTENSIFIES. 

$$
NR/MKH