Eastern Pacific Tropical Weather Discussion

000
AXPZ20 KNHC 200228
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC MON MAY 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0230 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W TO 09N86W TO 08N92W 
TO 09N99W. THE ITCZ AXIS EXTENDS FROM 09N99W TO 10N119W...THEN 
RESUMES FROM 10N125W TO 08N131W TO 07N140W. SCATTERED MODERATE 
AND ISOLATED STRONG CONVECTION IS FROM 06N TO 09N BETWEEN 86W 
AND 96W.

SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS ALSO WITHIN 
300 NM E OF A LINE FROM 16N119W TO 09N125W...IN ASSOCIATED WITH 
THE REMNANTS OF ALVIN.

...DISCUSSION...                                                

1034 MB SURFACE HIGH PRES IS POSITIONED WELL N OF THE AREA NEAR 
44N132W WITH A RIDGE AXIS EXTENDING S-SE OF THE HIGH THROUGH 
32N132W TO 17N110W. THIS RIDGING COMBINED WITH TROUGHING OVER 
INTERIOR CALIFORNIA IS PRODUCING GALE FORCE WINDS FROM THE 
REDWOOD COAST OF CALIFORNIA S TO THE CHANNEL ISLANDS. THESE 
WINDS ARE GENERATING SEAS OF 8-11 FT WHICH ARE PROPAGATING INTO 
THE DISCUSSION WATERS N OF 27N BETWEEN 117W AND 126W. THESE SEA 
HEIGHTS WILL ENCOMPASS THE WATERS N OF 28N BETWEEN 120W AND 128W 
BY MON EVENING...WITH LITTLE CHANGE IN COVERAGE FROM THAT POINT 
THROUGH TUE EVENING.

THE REMNANTS OF ALVIN...IN THE FORM OF A 1010 MB LOW AND 
ATTENDANT TROUGH...EXTEND FROM 15N122W TO 13N122W TO 07N124W. 
EARLIER SCATTEROMETER DATA INDICATED FRESH TO STRONG WINDS IN 
THE N QUADRANT OF THE LOW CENTERED NEAR 13N122W. EARLIER 
ALTIMETER PASSES ALSO INDICATED 9-11 FT SEAS IN THE N QUADRANT 
AS WELL. MODERATE TO FRESH WINDS ARE NEARBY IN THE W CENTRAL 
WATERS FROM 09N TO 20N W OF 126W WHERE SEAS OF 8-10 FT IN MIXED 
NE AND SW SWELL ARE PRESENT. THE LOW IS FORECAST TO DISSIPATE 
DURING THE NEXT 24 HOURS WITH THE REMAINING TROUGH CONTINUING 
WESTWARD...EXTENDING FROM 15N125W TO 11N126W TO 08N128W BY TUE 
EVENING. WINDS WILL DIMINISH TO 20 KT OR LESS ACROSS THE BOARD 
IN THIS AREA BY MON EVENING...WHILE LINGERING SEAS OF 8-9 FT 
WILL REMAIN W OF THE TROUGH THROUGH 48 HOURS.

ALOFT...A TROPICAL MOISTURE PLUME APPROXIMATELY 390 NM WIDE 
EXTENDS FROM THE DEEP TROPICS FROM 05N TO 12N W OF 120W...THEN 
CONTINUES TO THE NE TO ACROSS THE SOUTHERN TIP OF THE BAJA 
CALIFORNIA PENINSULA TO ACROSS CENTRAL MEXICO. DRY AND STABLE 
AIR IS PRESENT ACROSS THE WATERS N OF THIS PLUME...EXCEPT W OF 
132W WHERE ADDITIONAL TROPICAL MOISTURE S OF HAWAII IS ADVECTING 
INTO THE DISCUSSION WATERS. ELSEWHERE...MOISTURE ALONG THE 
MONSOON TROUGH AS IS DESCRIBED IN THE CONVECTION SECTION 
CONTINUES TO FAN OUT WHILE MOVING WESTWARD TO 110W AROUND AN 
UPPER ANTICYCLONE CENTERED OVER THE GULF OF TEHUANTEPEC AREA.

$$
LEWITSKY