000
AXPZ20 KNHC 281554
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAR 28 2012

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
ITCZ AXIS FROM 08N107W TO 04N124W TO 06N132W. SCATTERED MODERATE 
WITHIN 90 NM OF AXIS BETWEEN 110W AND 116W. 

...DISCUSSION...
BROAD AND ENERGETIC UPPER LEVEL TROUGH ACROSS NE PACIFIC 
SHIFTING E INTO W COAST OF U.S. WITH BASE EXTENDING FROM 36N125W 
TO 29N132W. A MIDDLE TO UPPER LEVEL LOW WAS CUT OFF FROM MEAN 
FLOW NEAR 18N144W...AND WAS BERING FORCED SLOWLY SE DUE TO VERY 
BROAD RIDGE ALOFT BUILDING INTO THE CENTRAL PACIFIC BEHIND THE W 
COAST TROUGH. THIS LOW WAS INTERACTING WITH ZONE OF ABUNDANT 
LLVL MOISTURE TRAPPED N OF THE ITCZ TO PRODUCE SCATTERED TO 
LOCALLY NUMEROUS MODERATE TO STRONG CONVECTION FROM 08N TO 17N W 
OF 130W...AND HAS AIDED IN THE FORMATION OF TWO LLVL TROUGHS IN 
THIS VICINITY. OTHERWISE...ZONAL FLOW ALOFT PREVAILS ACROSS THE 
AREA S OF 20N TO 105W. A TROPICAL JET STREAK OF 85-110 KT WAS S 
OF THE CUT OFF LOW BETWEEN 135W AND 155W. E OF 105W...A BROAD 
UPPER TROUGH HAS EVOLVED...CENTERED ALONG 94W/95W. 

AT LOW LEVELS...A DISSIPATING COLD FRONT HAS STALLED ACROSS THE 
NW PORTION OF THE AREA FROM 30N128W TO 26N140W. WINDS HAVE 
DIMINISHED TO 15 KT OR LESS ON BOTH SIDES OF THE FRONT. HOWEVER 
LARGE NW SWELLS ASSOCIATED WITH THIS FRONTAL SYSTEM CONTINUE TO 
PROPAGATE SOUTHEASTWARD...WITH SEAS 8 TO 13 FT ACROSS MUCH OF 
THE NW PART OF THE AREA. THE FRONT WILL DISSIPATE BY THIS 
EVENING AS THE SWELLS MOVE SE AND INTO THE COASTS OF SOUTHERN 
CALIFORNIA AND BAJA CALIFORNIA NORTE. 

WEAK HIGH PRES LOCATED SE OF THIS FRONT WAS CENTERED ON A 1020 
MB HIGH NEAR 26N124W. SUFFICIENT PRES GRADIENT EXISTS ALONG THE 
W COAST OF THE BAJA CALIFORNIA PENINSULA TO PRODUCE NWLY WINDS 
20 KT N OF 27N AND WITHIN 120 NM OF THE W COAST. TO THE S OF THE 
HIGH...FRESH NELY TRADEWINDS WERE DEPICTED BY OVERNIGHT 
SCATTEROMETER PASSES GENERALLY FROM 06N TO 16N W OF 120W...WHERE 
SEAS WERE RUNNING 9 TO 11 FT IN MIXED NE AND NW SWELL. THESE 
FRESH TRADES WILL PERSIST THROUGH THU AND CONTINUE TO INITIATE 
STRONG CONVECTION W OF 135W AS THE ASSOCIATED MOISTURE CONTINUES 
TO INTERACT WITH THE CUT OFF LOW. NW SWELL WILL MERGE WITH SW 
SWELL FROM THE SOUTHERN HEMISPHERE THIS EVENING AND TONIGHT TO 
PRODUCE A CONFUSED SEA STATE.

EAST OF 110W...SURFACE WINDS REMAIN LIGHT TO MODERATE...WITH GAP 
WIND FLOW EXITING CENTRAL AMERICA INCREASING TO NEAR 20 KT ONLY 
DURING THE LATE NIGHT AND EARLY MORNING HOURS. A NEW PULSE OF 
STRONG SW SWELL WILL REACH THE CENTRAL AMERICAN COASTLINES ON 
THU TO PRODUCE MODERATE SIZED...BUT POWERFUL AND DANGEROUS SURF 
ALONG THE LOCAL REEFS AND BEACHES. 

$$
STRIPLING