000
AXPZ20 KNHC 271556
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
ITCZ AXIS FROM 08N106W TO 07.5N116W TO 08N127W TO 06N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 150 
NM N OF AXIS BETWEEN 107W AND 128W.

...DISCUSSION...
AN UPPER CYCLONE WAS CENTERED OVER THE NE PACIFIC NEAR 48N134W 
WITH TROUGH AXIS EXTENDING S-SE TO NEAR 28N128W. A SHORT WAVE 
AND ASSOCIATED JET SEGMENT HAVE MOVED THROUGH WESTERN SIDE OF 
TROUGH AND INTO THE BASE OF TROUGH ALONG 134W. JUST SE OF THESE 
UPPER FEATURES LIES A LINGERING MID LEVEL TROUGH AXIS... 
EXTENDING FROM OFFSHORE OF BAJA CALIFORNIA W-SW TO A CUT OFF LOW 
E OF THE BIG ISLAND OF HAWAII NEAR 19N151W. THIS CUT OFF LOW IS 
BEING FORCED SE ATTM BY UPSTREAM ENERGY ACROSS THE CENTRAL 
PACIFIC...AND IS FORECAST TO MOVE SE TO ALONG 140W WITHIN 24 
HOURS. THIS WILL CREATE AN UNSTABLE ENVIRONMENT TO THE E AND SE 
OF THE LOW AS IT BEGINS TO INTERACT WITH ITCZ RELATED 
MOISTURE...AND GLOBAL MODELS DEVELOP SOME TYPE OF TROUGH OR 
PERTURBATION ALONG THE ITCZ BETWEEN 135W AND 140W WITHIN 24 
HOURS.

S OF THESE UPPER FEATURES...UPPER FLOW IS GENERALLY ZONAL...WITH 
BROAD CROSS EQUATORIAL RIDGING W OF 125W...AND BROAD TROUGHING 
BETWEEN 85W AND 125W. A WLY UPPER JET OF 85-125 KT IS PRESENT S 
OF THE CUT OFF LOW BETWEEN 140W AND 155W. 

AT LOWER LEVELS...A COLD FRONT SUPPORTED BY THE MEAN TROUGH HAS 
BEEN RELOCATED TO THE NW OF PREVIOUS POSITIONS...BASED ON 
OVERNIGHT ASCAT AND OSCAT PASSES...AND CURRENTLY EXTENDS FROM 
30N136W TO BEYOND 29N140W. SW TO W WINDS 20-25 KT ARE FOUND S OF 
THE FRONT TO 28N AND W OF 129W WHERE SEAS HAVE BUILT TO 10 FT IN 
NW SWELL. BEHIND THE FRONT W TO NW WINDS TO 20 KT PREVAIL WITH 
SEAS 8-11 FT IN NW SWELL. THE FRONT WILL BE FORCED SE OVER THE 
NEXT FEW DAYS AND GRADUALLY DISSIPATE...WITH ASSOCIATED NW SWELL 
PROPAGATING TOWARDS THE EQUATOR.

SE OF THE FRONT...A WEAKENING 1020 MB HIGH WAS CENTERED NEAR 
26.5N124W AND WILL DRIFT SE TO S OVER THE NEXT COUPLE OF DAYS 
AND GRADUALLY COLLAPSE. PRESENTLY...SUFFICIENT PRES GRADIENT 
EXISTS BETWEEN THE HIGH AND THE BAJA CALIFORNIA PENINSULA TO 
PRODUCE A NARROW ZONE OF 20 KT NW WINDS WITHIN 180 NM OF THE W 
COAST OF THE PENINSULA...WITH NW SWELL IS COMBINING WITH 
DEVELOPING WIND WAVE TO PRODUCE SEAS TO 10 FT. S OF THE 
HIGH...AN ELONGATED ZONE OF FRESH TRADEWINDS AROUND 20 KT 
PREVAILS FROM 08N TO 14N W OF 118W. MOISTURE CONVERGENCE 
ASSOCIATED WITH THE ITCZ IS OCCURRING ALONG THE S SIDE OF THIS 
ZONE OF FRESH TRADEWINDS...AND IS YIELDING AREAS OF MODERATE TO 
DEEP CONVECTION. LITTLE CHANGE IN THIS PATTER OF TRADEWINDS IS 
EXPECTED THROUGH TONIGHT UNTIL THE AFOREMENTIONED TROUGH OR WAVE 
DEVELOPS TOMORROW BETWEEN 135W AND 140W...WITH THE FRESH TRADES 
THEN EXPANDING N OF THIS FORECASTED FEATURE...TO NEAR 18N BY 
THU. 

LIGHT TO MODERATE WINDS PREVAIL E OF 105W...WITH GAP WIND FLOW 
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 AND WED...AND PRODUCE CONFUSED SEAS WITH A MIX OF 
NE...NW...AND SW SWELL W OF 120W BY WED NIGHT.

$$
STRIPLING