000
AXPZ20 KNHC 090921
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON SEP 09 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...TROPICAL WAVES... 

THE SOUTHERN EXTENT OF WEAK TROPICAL WAVE IS FORECAST TO MOVE 
OFF THE COAST OF GUATEMALA LATE TONIGHT. THIS POORLY DEFINED 
WAVE IS MOVING THROUGH AN ALREADY ABUNDANT AREA OF MOISTURE AND 
IS HELPING TO FIRE OFF NEW CONVECTION OVER GUATEMALA...THE 
YUCATAN AND FAR SE MEXICO...INCLUDING THE GULF OF TEHUANTEPEC 
AND ADJACENT WATERS.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH AXIS EXTENDS FROM 08N78W THROUGH INTERIOR 
CENTRAL AMERICA TO 16N95W TO 14N115W TO LOW PRES NEAR 12N132W TO 
11N140W. NO ITCZ IS PRESENT E OF 140W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION IS WITHIN 90 NM OF GUATEMALA AND 
MEXICO BETWEEN 91W AND 96W...AND WITHIN 120 NM S OF THE MONSOON 
TROUGH BETWEEN 107W AND 112W.

SCATTERED MODERATE CONVECTION IS FROM 02N TO 06N E OF 79W...AND 
ALSO FROM 20N TO 23N BETWEEN 107W AND 109W.

...DISCUSSION... 

A COMPLEX ARRANGEMENT OF ANTICYCLONES ALOFT IS MAINTAINING A DRY 
SUBSIDING AND STABLE AIR MASS W OF A LINE FROM 23N110W TO 
10N120W TO 12N140W. A SMALL AND WEAKER ANTICYCLONE FORMING AT    
18N103W IS ADVECTING ABUNDANT TROPICAL MOISTURE ALOFT INTO THE 
NE PACIFIC FROM 08N TO 20N BETWEEN 95W AND 120W. ELSEWHERE AT 
THE UPPER LEVELS...MAINLY ZONAL NE TO E FLOW DOMINATES THE BASIN.

AT THE SURFACE...1024 MB HIGH PRES IS CENTERED WELL N OF THE 
DISCUSSION WATERS NEAR 43N136W AND EXTENDS A BROAD RIDGE THROUGH 
32N136W THEN SE TO 23N125W. THE REMNANTS OF LORENA TO THE SE... 
IN THE FORM OF A TROUGH AT 03 UTC...HAVE SINCE DISSIPATED. ONLY 
ISOLATED TO WIDELY SCATTERED SHOWERS REMAIN SW OF THE BAJA 
CALIFORNIA PENINSULA.

WEAK 1012 MB LOW PRES IS EMBEDDED IN THE MONSOON TROUGH NEAR 
12N132W. A RECENT ALTIMETER PASS SHOWED 4 TO 6 FT SEAS NEAR THIS 
LOW WITH ONLY LIGHT TO MODERATE WINDS IN THE VICINITY. THIS LOW 
IS FORECAST TO GRADUALLY MOVE W THROUGH THE NEXT 24 TO 48 HOURS.

MAINLY LIGHT TO MODERATE WINDS AND 3 TO 6 FT SEAS DOMINATE THE 
BASIN...EXCEPT S OF THE MONSOON TROUGH IN THE CENTRAL WATERS 
WHERE WINDS HAVE INCREASED TO FRESH LEVELS BUILDING SEAS TO 8 FT 
FROM 12N TO 14N BETWEEN 103W AND 106W. THESE CONDITIONS WILL 
PERSIST THROUGH TODAY WITH LITTLE CHANGE...HOWEVER BY TONIGHT 
CROSS-EQUATORIAL SWELL WILL BREACH THE EQUATOR COVERING THE 
WATERS S OF 02N BETWEEN 106W AND 120W. THIS SWELL WILL MERGE 
WITH THE AREA OF SEAS S OF THE MONSOON TROUGH...WITH 8 TO 10 FT 
SEAS COVERING THE MAJORITY OF THE AREA S OF 13N/14N BETWEEN 95W 
AND 120W BY LATE TUE NIGHT.

$$
LEWITSKY