000
AXPZ20 KNHC 220249
TWDEP 

TROPICAL WEATHER DISCUSSION                                   
NWS NATIONAL HURRICANE CENTER MIAMI FL                        
0405 UTC FRI MAR 22 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 
0200 UTC.

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

MONSOON TROUGH EXTENDS ACROSS THE GULF OF PANAMA TO 08N82W THEN 
CONTINUES TO 02N95W TO 04N104W TO 02N117W. ITCZ AXIS FROM 
02N117W TO 01N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED FROM 04N TO 06N BETWEEN 82W AND 85W. 
SCATTERED MODERATE CONVECTION IS NEAR 03N96W AND FROM 04N TO 06N 
BETWEEN 116W AND 123W. 

...DISCUSSION... 

AS IT IS NORMAL FOR THIS TIME OF THE YEAR...THE NE PACIFIC 
REGION IS RELATIVELY QUIET. THERE ARE NO GALE FORCE WINDS...NO 
GAP WIND EVENTS AND NO ACTIVE COLD FRONTS. CONVECTION IS LIMITED 
AND IS MAINLY ASSOCIATED WITH THE MONSOON TROUGH E OF 90W. 
SEVERAL SCATTEROMETER PASSES SHOWED MAINLY LIGHT WINDS E OF 110W 
WITH SEAS GENERALLY UNDER 6 FT. 

W OF 110W...A STRONG HIGH PRESSURE 1034 MB IS CENTERED WELL N OF 
THE AREA NEAR 41N135W WITH RIDGE EXTENDING SE TO NEAR 12N110W. 
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 IS RESULTING 
IN A FRESH TO STRONG N-NW BREEZE OVER THE NE FORECAST WATERS OFF 
BAJA CALIFORNIA NORTE...WITH GALE CONDITIONS DEVELOPING N OF THE 
FORECAST REGION. THIS WEATHER PATTERN WILL PERSIST OVER THE NEXT 
24 HOURS WITH WINDS DIMINISHING BELOW 20 KT OVER THE N-CENTRAL 
WATERS BY 48 HOURS AS HIGH PRES WEAKENS.

SEAS WILL BUILD TO 10 FT IN N-NW SWELL BY EARLY FRI MORNING AND 
WILL BUILD BRIEFLY TO 13 FEET FRI NIGHT IN THE NE WATERS BEFORE 
SEAS START TO SUBSIDE THIS WEEKEND. A NEW SURGE OF LONG-PERIOD 
NW SWELL WILL REACH THE FAR NW WATERS LATER TONIGHT...WITH 
COMBINED SEAS AROUND 8 FT MOVING INTO THE AREA. THIS SWELL EVENT 
WILL ALSO OVERLAP WITH THE AREA OF N-NW SWELL OVER THE NE WATERS 
OVERNIGHT FRI NIGHT. IN ADDITION...A NEW CROSS-EQUATORIAL SW 
SWELL TRAIN WITH PERIODS IN EXCESS OF 20 SECONDS WILL PROPAGATE 
NORTHEASTWARD REACHING THE COAST OF MUCH OF CENTRAL AMERICA AND 
MAINLAND MEXICO BY FRI AFTERNOON AND BAJA CALIFORNIA OVERNIGHT 
FRI NIGHT.

VISIBLE SATELLITE IMAGERY SHOWS A SWIRL OF LOW CLOUDS MOVING SW 
ACROSS THE W WATERS AND A 1015 MB LOW PRES IS ANALYZED ON THE 
0000 UTC SURFACE MAP NEAR 19N133.5W. MODEL GUIDANCE INDICATES A 
WEAK TROUGH...LIKELY ASSOCIATED WITH THIS FEATURE...MOVING WWD 
AROUND THE SOUTHERN PERIPHERY OF THE RIDGE.

OTHER THAN THE AFOREMENTIONED AREAS...MAINLY BENIGN CONDITIONS 
WILL PREVAIL...WITH WINDS AND SEAS BELOW ADVISORY CRITERIA 
THROUGH THE FORECAST PERIOD. 

$$
GR