| HOME | ARCHIVES | FORECASTS | IMAGERY | ABOUT NHC | RECONNAISSANCE |

---

Eastern Pacific Tropical Weather Discussion (Text)

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