000
AXPZ20 KNHC 272116
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC TUE MAR 27 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 08N108W TO 
07N120W TO 09N130W TO 07N140W. ISOLATED MODERATE CONVECTION IS 
FROM 06N TO 09N BETWEEN 116W AND 122W.

...DISCUSSION...
AN UPPER LEVEL CYCLONE IS CENTERED OVER THE NE PACIFIC NEAR 
50N136W WITH THE ASSOCIATED TROUGH AXIS EXTENDING S-SE TO NEAR 
29N130W. A SHORTWAVE AND ASSOCIATED JET SEGMENT IS CURRENTLY 
RIDING THE SOUTHWESTERN PERIPHERY OF THE TROUGH AND INTO THE 
BASE OF THE TROUGH ALONG 133W. 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 19N146W. 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 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 APPEAR TO 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 32N130W EXTENDING SW 
TO BEYOND 28N140W. SW TO W WINDS OF 20 KT ARE FOUND WITHIN 120 
NM E OF THE FRONT N OF 28N WITH SEAS TO 10 FT IN NW SWELL. WITH 
FRONTAL PASSAGE...WINDS DIMINISH BELOW 20 KT HOWEVER SEAS REMAIN 
IN THE RANGE OF 8 TO 12 FT IN NW SWELL. THE FRONT IS FORECAST TO 
MOVE SE OVER THE NEXT FEW DAYS AND GRADUALLY DISSIPATE...WITH 
THE ASSOCIATED NW SWELL PROPAGATING TOWARDS THE EQUATOR.

SE OF THE FRONT...A WEAKENING 1021 MB HIGH IS CENTERED NEAR 
26N124W AND IS EXPECTED TO REMAIN NEARLY STATIONARY OVER THE 
NEXT FEW DAYS AND GRADUALLY MERGE WESTWARD OVER THE 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 WAVE TO PRODUCE SEAS TO 9 FT. 
SOUTH OF THE HIGH...AN ELONGATED ZONE OF FRESH TRADEWINDS OF 20 
KT PREVAILS FROM 07N TO 14N W OF 118W. 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. THE AREA OF TRADEWINDS WILL 
GRADUALLY EXPAND NORTHWARD TO 17N W OF 125W 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 TONIGHT INTO WEDNESDAY 
PRODUCING CONFUSED SEAS WITH A MIX OF NE...SW...AND NW SWELL W 
OF 120W BY LATE WEDNESDAY.

$$
HUFFMAN