000
AXPZ20 KNHC 301556
TWDEP 

TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT MAR 30 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1430 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
NO MONSOON TROUGH EVIDENT FOR 1200 UTC MAP. ITCZ EXTENDS FROM 
05N76W TO 00N84W TO 06N89W TO 01N120W TO BEYOND 01N140W.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 210 
NM N OF AXIS FROM 103W TO 120W. SCATTERED MODERATE TO STRONG 
CONVECTION NOTED FROM 01N TO 09N BETWEEN 120W AND 130W.

...DISCUSSION...
DEEP LAYERED CUT OFF CYCLONE N OF AREA SHIFTING SLOWLY NE... 
WITH CYCLONE CENTERED NEAR 35N132W AND SURFACE LOW ANALYZED AT 
1002 MB. LOW HAS BECOME OCCLUDED WITH COLD FRONT NOW WELL AHEAD 
OF SYSTEM...EXTENDING INTO AREA THROUGH 30N124W TO 21N138W. 
OVERNIGHT SCATTEROMETER PASSES SHOWED 25-30 KT OF NW TO W WINDS 
OCCURRING ACROSS THE S SEMICIRCLE OF LOW JUST SCRAPING N 
PORTIONS OF THE AREA N OF 29N...WITH SEAS THERE 10 TO 12 FT. 
OTHERWISE...SEAS TO 10 FT IN NW SWELL PREVAIL N OF 23N W OF 
127W. GLOBAL MODELS SHOW THIS CYCLONE SHIFTING NE DURING THE 
NEXT 48 HOURS AND QUICKLY WEAKENING AS IT NEARS THE NORTHERN 
COAST OF CALIFORNIA. IN ITS WAKE...ANOTHER DEEP LAYERED CYCLONE 
WILL MOVE FROM N OF THE HAWAIIAN ISLANDS TO NEAR 34N150W BY 
MONDAY MORNING...WITH AN ASSOCIATED COLD FRONT TO APPROACH NW 
PORTIONS OF THE AREA.

ELSEWHERE ALOFT...A RIDGE-TROUGH-RIDGE PATTERN PREVAILS THIS 
MORNING ACROSS THE DEEP TROPICS FROM THE CENTRAL PACIFIC S OF 
HAWAII TO SOUTH AMERICA...EXTENDING INTO THE SOUTHERN 
HEMISPHERE. THE DEEP LAYERED CYCLONE ABOVE EXTENDS AN UPPER 
TROUGH SW TO NEAR 18N140W. AN ASSOCIATED JET WITH CORE WITH 
SPEEDS UP TO 115 KT MOVES THROUGH BASE OF TROUGH NORTHEASTWARD 
ACROSS BAJA CALIFORNIA AND INTO NW MEXICO...TRANSPORTING AMPLE 
UPPER MOISTURE AND MULTI LAYERED MIDDLE AND HIGH CLOUDS. A BROAD 
MIDDLE TO UPPER TROUGH WAS CENTERED ALONG 122W S OF 07N AND 
AIDING IN PRODUCING INSTABILITY AND CONVECTION ALONG THE ITCZ 
OCCURRING ON BOTH SIDES OF THE EQUATOR W OF 115W. DOWNSTREAM AND 
E OF 110W...BROADSCALE UPPER CONFLUENCE WAS LEADING TO GENERALLY 
STABLE MIDDLE TO UPPER LEVEL CONDITIONS. 
 
ELSEWHERE AT THE LOWER LEVELS...A WEAK 1018 MB HIGH WAS CENTERED 
SE OF THE DEEP LAYERED CYCLONE...NEAR 25N118W. THIS WEAK HIGH 
WAS PRODUCING A MODEST PRES GRADIENT BETWEEN IT AND THE 
ITCZ...YIELDING MODERATE NE TO E TRADES 15-20 KT OCCURRING S OF 
13N AND W OF 106W PER OVERNIGHT SCATTEROMETER PASSES. SEAS WERE 
RUNNING 6 TO 9 FT THROUGH THIS ZONE IN MIXED SWELL. 

GULF OF PAPAGAYO...HIGH PRES ACROSS THE SW N ATLC BEHIND A 
CARIBBEAN COLD FRONT IS PRODUCING FRESH TO STRONG TRADEWINDS 
ACROSS THE CARIBBEAN...YIELDING A DOWNSTREAM PLUME OF STRONG NE 
TO E WINDS THROUGH THE GULF OF PAPAGAYO TO AS FAR W AS 92W THIS 
MORNING...BUT WILL GRADUALLY DIMINISH THROUGH LATE SUN AS THE SW 
N ATLC RIDGE WEAKENS AND MOVES E.

ELSEWHERE...LONG PERIOD MODERATE NWLY SWELL WILL CONTINUE TO 
PROPAGATE IN AND THROUGH MOST OF THE DISCUSSION AREA AND 
DOMINATE SEAS N OF 10N W OF 100W THROUGH THE WEEKEND.

$$
STRIPLING