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000
AXPZ20 KNHC 182124
TWDEP

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT MAY 18 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH
2100 UTC.

...SPECIAL FEATURES...

THE 1007 MB REMNANTS OF ALVIN ARE CENTERED NEAR 12N117W...MOVING
W AT 10 KT. NUMEROUS MODERATE TO STRONG CONVECTION IS WITHIN 240
NM IN THE E QUADRANT. SCATTERED MODERATE AND ISOLATED STRONG
CONVECTION IS ELSEWHERE FROM 12N TO 16N BETWEEN 111W AND 117W. A
1650 UTC ASCAT PASS WENT OVER THE E SEMICIRCLE OF THE LOW AND
INDICATED 20 TO 30 KT WINDS WITHIN 210 NM IN THE NE SEMICIRCLE
OF THE LOW...EXCEPT WITHIN 150 NM IN THE SE QUADRANT. A 1922 UTC
ALTIMETER PASS WENT RIGHT OVER THIS SAME AREA AND IT MEASURED SEAS
OF 8-11 FT. THE LOW IS EXPECTED TO CONTINUE ON A WESTWARD TRACK
OVER THE NEXT FEW DAYS. IT WILL HAVE A BRIEF WINDOW OF
OPPORTUNITY TO BECOME BETTER ORGANIZED BEFORE WEAKENING...AND IT
HAS A MEDIUM CHANCE OF REGENERATING INTO A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 09N86W TO 1011 MB
LOW PRES NEAR 06N101W TO 1007 MB LOW PRES...THE REMNANTS OF
ALVIN...NEAR 12N118W TO 09N125W. THE ITCZ AXIS EXTENDS FROM
09N125W TO 05N140W. SCATTERED MODERATE CONVECTION IS FROM 05N TO
07N BETWEEN 80W AND 85W...WITHIN 180 NM S OF THE MONSOON TROUGH
BETWEEN 92W AND 103W...WITHIN 120 NM EITHER SIDE OF THE MONSOON
TROUGH BETWEEN 120W AND 124W...AND ALSO FROM 06N TO 08N BETWEEN
129W AND 134W.

...DISCUSSION...

1029 MB SUBTROPICAL HIGH PRES IS ANALYZED NEAR 35N135W WITH A
RIDGE EXTENDING SE THROUGH 32N128W TO 21N110W. MAINLY MODERATE N
THROUGH E WINDS ARE FOUND UNDER THIS RIDGE ACROSS THE WATERS N
OF 18N W OF 110W. WINDS ARE EXPECTED TO INCREASE OFF OF THE
CALIFORNIA COAST TONIGHT THROUGH MON AS THE PRES GRADIENT
TIGHTENS THERE BETWEEN THE HIGH AND TROUGHING OVER INTERIOR
CALIFORNIA. THESE WINDS WILL SEND A NW SWELL S TO 29N BETWEEN
118W AND 123W BY SUN AFTERNOON...THEN TO 28N BETWEEN 119W AND
127W BY MON AFTERNOON.

MODERATE TO FRESH TRADE WINDS ARE PRESENT IN THE W CENTRAL
WATERS AND 8-9 FT SEAS IN MIXED NE WIND WAVES AND LONG PERIOD SW
SWELL COVER THE AREA W OF A LINE FROM 18N140W TO 12N127W TO
06N140W. THESE WINDS WILL DIMINISH DURING THE NEXT 24 HOURS AS
THE PRES GRADIENT WEAKENS...ALLOWING FOR SEAS TO SUBSIDE TO LESS
THAN 8 FT BY SUN MORNING.

CROSS-EQUATORIAL SOUTHWESTERLY SWELL IS MAINTAINING 8-9 FT SEAS IN
THE S CENTRAL WATERS S OF 06N BETWEEN 100W AND 125W. THE
COVERAGE AND HEIGHT OF THESE SEAS WILL NOT VARY MUCH THROUGH THE
NEXT 24-48 HOURS.

WEAK 1011 MB LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR
06N101W. ASSOCIATED CONVECTION IS DESCRIBED IN THE SECTION
ABOVE. NO SIGNIFICANT DEVELOPMENT OF THIS LOW IS ANTICIPATED AS
IT MOVES TO THE W-NW AROUND 10 KT DURING THE NEXT FEW DAYS.

OTHERWISE...MAINLY LIGHT AND VARIABLE WINDS COVER THE E PACIFIC
GULF AREAS WITH LITTLE CHANGE EXPECTED.

$$
LEWITSKY