000
AXPZ20 KNHC 232205
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
2205 UTC TUE APR 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

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

MONSOON TROUGH AXIS EXTENDS FROM COLOMBIA NEAR 07N75W TO 03N78W  
TO 06N87W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 
08.5N106W TO LOW PRES NEAR 07N112W 1010 MB TO 06N136W TO BEYOND 
05N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 
150 NM N AND 180 NM S OF AXIS BETWEEN 90W AND 114W...WHILE 
NUMEROUS MODERATE TO STRONG CONVECTION WAS NOTED FROM 09N TO 13N 
BETWEEN 103W AND 108W. SCATTERED MODERATE TO STRONG CONVECTION 
ALSO NOTED WITHIN 180 NM S AND 120 NM N OF AXIS BETWEEN 118W AND 
134W.
         
...DISCUSSION... 

AS IS TYPICAL FOR THIS TIME OF THE YEAR...THE NORTHEASTERN 
PACIFIC IS RELATIVELY QUIET WEATHER-WISE. CURRENTLY...THERE ARE 
NO GALES...NO GAP WINDS EVENTS AND NO ACTIVE COLD FRONTS ACROSS 
THE REGION. GLOBAL MODEL GUIDANCE SHOWS VERY LITTLE SIGNIFICANT 
CHANGES ON THE SHORT-TERM HORIZON. 

WINDS ARE EXPECTED TO REMAIN BELOW 25 KT OVER THE ENTIRE 
FORECAST AREA THROUGH AT LEAST THU MORNING. HOWEVER...A BROAD 
AREA OF N TO NE WINDS OCCURRING WELL OFF THE CALIFORNIA COAST 
WILL STRENGTHEN TONIGHT THROUGH WED TO GENERATE NE SWELL THAT 
WILL PROPAGATE INTO NE PORTIONS...RAISING SEAS 8-9 FT BETWEEN 
128W AND 135WN BY WED MORNING AND SHIFTING SLIGHTLY W THROUGH 
THU. 

HIGH PRESSURE REMAINS WELL N OF THE AREA...WITH A 1037 MB HIGH 
CENTER LOCATED NEAR 48N136W...AND EXTENDS A RIDGE SOUTHWARD INTO 
THE NW PORTION OF THE DISCUSSION AREA...BETWEEN 125W AND THE 
HAWAIIAN ISLANDS. AN AREA OF MODERATE NE TRADE WINDS IS NOTED 
PER THE MOST RECENT SCATTEROMETER DATA ON THE SOUTHERN PERIPHERY 
OF THE RIDGE AND N OF THE ITCZ AXIS...PARTICULARLY FROM 06N TO 
16N W OF 130W.

A WEAK 1010 MB LOW PRES IS ANALYZED ALONG THE ITCZ AXIS NEAR 
07N112W. SCATTERED TO NUMEROUS DEEP CONVECTION DESCRIBED ABOVE 
IS OCCURRING TO THE N AND NE OF THE LOW...WITHIN AN AREA OF HIGH 
LOW LEVEL MOISTURE CONTENT DIFFLUENCE ALOFT. THE LOW IS EXPECTED 
TO SHIFT SLOWLY W DURING THE NEXT DAY OR SO AND DISSIPATE.
                                             
ALOFT...A RIDGE/TROUGH/RIDGE PATTERN DOMINATES THE N WATERS WITH 
A CUT-OFF LOW NEAR 29N1270W SHIFTING SLOWLY E. THE SURFACE 
REFLECTION OF THIS LOW AND RESULTANT TROUGHING WILL WEAKEN THE 
SUBTROPICAL RIDGE OVER N WATERS...KEEPING WINDS THERE LIGHT. AN 
UPPER RIDGE AXIS EXTENDS FROM COLOMBIA ALL THE WAY NORTHWESTWARD 
ACROSS CENTRAL AMERICA AND MEXICO. THIS RIDGE IS AIDING IN 
PROMOTING UPPER SPEED DIVERGENCE W OF THE RIDGE AXIS...WHICH IS 
MAINTAINING CONVECTION NEAR THE ITCZ AXIS. 

FIRES OCCURRING INLAND FROM SOUTHERN MEXICO INTO NW NICARAGUA 
ARE CREATING PATCHY SMOKE THAT IS MOVING W AND SW AND OVER THE 
ADJACENT OFFSHORE WATERS...AND RESTRICTING VISIBILITIES BELOW 5 
MILES ACROSS ISOLATED AREAS. THESE CONDITIONS WILL LIKELY 
CONTINUE OVER THE NEXT FEW DAYS.

$$
STRIPLING