000 AXPZ20 KNHC 211509 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU MAR 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 08N83W TO 02N120W WHERE LOW LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS TO BEYOND 01N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 150 NM S OF THE AXIS BETWEEN 83W AND 92W. ISOLATED MODERATE CONVECTION WAS NOTED WITHIN 240 NM N OF THE AXIS BETWEEN 103W AND 125W. SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 180 NM N OF THE AXIS BETWEEN 125W AND 132W. ...DISCUSSION... HIGH PRESSURE 1031 MB IS CENTERED WELL N OF THE AREA NEAR 41N137W WITH RIDGE EXTENDING SE TO NEAR 12N108W. WITH THE HIGH PRESSURE CENTERED WELL N OF THE AREA...THE PRESSURE GRADIENT BETWEEN THE HIGH AND THE ITCZ OVER WESTERN WATERS IS WEAK AND IS SUPPORTING MAINLY MODERATE TRADES. THE PRESSURE GRADIENT HAS TIGHTENED BETWEEN THE RIDGE AND LOWER PRESSURE OVER MEXICO AND THE SW UNITED STATES. THIS HAS PRODUCED A FRESH TO STRONG N-NW BREEZE OVER THE NE FORECAST WATERS OFF BAJA CALIFORNIA NORTE...WITH GALE CONDITIONS DEVELOPING N OF THE AREA. SEAS WILL BUILD TO 10 FT IN N-NW SWELL BY EARLY FRI MORNING AND WILL BUILD BRIEFLY TO 13 FEET LATE FRI NIGHT IN THE NE WATERS BEFORE SEAS START TO SUBSIDE THIS WEEKEND. A NEW SURGE OF LONG-PERIOD NW SWELL WILL MOVE INTO NW WATERS ON FRI...WITH COMBINED SEAS AROUND 8 FT MOVING INTO THE AREA. THIS SWELL WILL ALSO OVERLAP WITH THE AREA OF N-NW SWELL OVER THE NE WATERS OVERNIGHT FRI NIGHT. OTHER THAN THESE AREAS...MAINLY BENIGN CONDITIONS WILL PREVAIL...WITH WINDS AND SEAS BELOW ADVISORY CRITERIA THROUGH THE FORECAST PERIOD. $$ AL