000
AXPZ20 KNHC 280301
TWDEP 

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

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 04N120W TO 
05N130W THEN FROM 08N133W TO 07N140W. ISOLATED MODERATE 
CONVECTION IS FROM 07N TO 10N BETWEEN 133W AND 140W.

...DISCUSSION...
AN UPPER LEVEL CYCLONE IS CENTERED OVER THE NE PACIFIC NEAR 
51N136W WITH THE ASSOCIATED TROUGH AXIS EXTENDING S-SE TO NEAR 
28N130W. A SHORTWAVE AND ASSOCIATED JET SEGMENT IS CURRENTLY 
RIDING THE SOUTHWESTERN PERIPHERY OF THE TROUGH AND INTO THE 
BASE OF THE TROUGH ALONG 135W. TO THE SOUTHEAST OF THESE UPPER 
LEVEL FEATURES LIES LINGERING MID-LEVEL TROUGHING...EXTENDING 
FROM OFFSHORE OF BAJA CALIFORNIA W-SW TO A CUT-OFF UPPER LEVEL 
LOW E-SE OF THE BIG ISLAND OF HAWAII NEAR 19N145W. THIS CUT-OFF 
LOW IS BEING FORCED SE BY UPSTREAM ENERGY ACROSS THE CENTRAL 
PACIFIC...AND IS FORECAST TO MOVE SE TO ALONG 140W WITHIN THE 
NEXT 24 TO 36 HOURS. THIS IS EXPECTED TO CREATE AN UNSTABLE 
ENVIRONMENT ON THE EASTERN PERIPHERY OF THE LOW AS IT INTERACTS 
WITH ITCZ RELATED MOISTURE. GLOBAL MODELS DEVELOP SURFACE 
TROUGHING ALONG THE ITCZ BETWEEN 135W AND 140W BY WEDNESDAY.

SOUTH OF THESE UPPER LEVEL FEATURES...FLOW ALOFT IS GENERALLY 
ZONAL...WITH BROAD CROSS EQUATORIAL RIDGING W OF 115W AND BROAD 
TROUGHING BETWEEN 85W AND 115W. A WESTERLY UPPER LEVEL JET OF 
90-130 KT IS PRESENT S OF THE CUT-OFF LOW FROM 10N TO 16N 
BETWEEN 125W AND 160W. 

AT THE LOWER LEVELS...A COLD FRONT SUPPORTED BY THE MEAN TROUGH 
IS ANALYZED INTO THE DISCUSSION AREA NEAR 32N129W EXTENDING SW 
TO BEYOND 27N140W. SW TO W WINDS OF 20 KT ARE FOUND WITHIN 60 NM 
EITHER SIDE OF A LINE FROM 30N132W TO 28N134W WITH SEAS 8 TO 11 
FT IN NW SWELL. WITH THE FRONTAL PASSAGE...WINDS DIMINISH BELOW 
20 KT HOWEVER SEAS REMAIN IN THE RANGE OF 8 TO 14 FT IN NW 
SWELL. THE FRONT IS FORECAST TO MOVE E-SE OVER THE NEXT 48 HOURS 
AND GRADUALLY DISSIPATE...WITH THE ASSOCIATED NW SWELL 
PROPAGATING TOWARDS THE EQUATOR.

SE OF THE FRONT...A WEAKENING 1020 MB HIGH IS CENTERED NEAR 
26N124W AND IS EXPECTED TO REMAIN NEARLY STATIONARY OVER THE 
NEXT FEW DAYS AND GRADUALLY MERGE WESTWARD OVER THE UPCOMING 
WEEKEND BY A STRONGER CENTRAL PACIFIC HIGH MOVING EAST. 
PRESENTLY...SUFFICIENT PRESSURE GRADIENT EXISTS BETWEEN THE HIGH 
AND THE BAJA CALIFORNIA PENINSULA TO PRODUCE A NARROW ZONE OF 20 
KT NW WINDS WITHIN 120 NM OF THE W COAST OF THE PENINSULA. NW 
SWELL IS COMBINING WITH DEVELOPING WIND WAVES TO PRODUCE SEAS TO 
8 FT. SOUTH OF THE HIGH...AN ELONGATED ZONE OF FRESH TRADEWINDS 
OF 20 KT PREVAILS FROM 07N TO 14N W OF 118W. LOW-LEVEL MOISTURE 
CONVERGENCE ASSOCIATED WITH THE ITCZ IS OCCURRING ALONG THE 
SOUTHERN SIDE OF THIS ZONE OF FRESH TRADEWINDS...AND IS YIELDING 
AREAS OF ISOLATED MODERATE CONVECTION FROM 08N TO 16N W OF 133W. 
THE AREA OF TRADEWINDS WILL GRADUALLY EXPAND NORTHWARD TO 18N W 
OF 124W THROUGH THE NEXT 36 TO 48 HOURS WITH THE ADDITION OF THE 
PREVIOUSLY MENTIONED SURFACE TROUGH FEATURE FORECAST TO DEVELOP 
WEDNESDAY BETWEEN 135W AND 140W. 

LIGHT TO MODERATE WINDS PREVAIL E OF 110W...WITH GAP WIND FLOW 
THROUGH THE GULF OF PAPAGAYO EXPECTED TO PULSE TO AROUND 20 KT 
DURING THE OVERNIGHT AND EARLY MORNING HOURS THE NEXT FEW DAYS. 
A STRONG PULSE OF SW SWELL WILL BEGIN TO MOVE FROM THE SOUTHERN 
HEMISPHERE AND CROSS THE EQUATOR OVERNIGHT INTO WEDNESDAY 
PRODUCING CONFUSED SEAS WITH A MIX OF NE...SW...AND NW SWELL W 
OF 120W BY LATE WEDNESDAY.

$$
HUFFMAN