000
AXPZ20 KNHC 100906
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC WED JUL 10 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ANALYZED OVER SOUTHERN MEXICO AROUND 92W/94W 
MOVING INTO THE ISTHMUS OF TEHUANTEPEC. THIS HAS BEEN INCREASING 
THE PRESSURE GRADIENT ACROSS THE ISTHMUS OF TEHUANTEPEC ALLOWING 
MODERATE TO FRESH NORTHERLY GAP FLOW INTO THE GULF OF 
TEHUANTEPEC. SEAS WILL BUILD TO 8 FT THIS MORNING IN THE 
NORTHERLY FLOW...MIXING WITH LONGER PERIOD SWELL FROM THE SOUTH. 
CONVERGENCE OF THE NORTHERLY WINDS IS ALSO AIDING MODEST 
CONVECTION ALONG AND WITHIN 180 NM N OF THE MONSOON TROUGH 
BETWEEN 95W AND 100W. THE WAVE WILL PASS W OF THE ISTHMUS AND 
WEAKEN...ALLOWING THE WINDS TO DIMINISH. SEAS WILL SUBSIDE 
ACCORDINGLY THROUGH LATE TODAY.
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...   
     
THE MONSOON TROUGH FROM 08N78W TO 10N89W TO 07N98W TO LOW PRES 
NEAR 08N110W 1012 MB TO 07N115W. THE ITCZ EXTENDS FROM 07N115W 
TO 06N125W TO 10N140W. SCATTERED MODERATE ISOLATED CONVECTION 
OBSERVED WITHIN 180 NM S OF MONSOON TROUGH AXIS E OF 80W. 
SCATTERED MODERATE CONVECTION OBSERVED WITHIN 180 NM N OF 
MONSOON TROUGH AXIS BETWEEN 95W AND 100W. SCATTERED MODERATE 
OBSERVED WITHIN 180 NM N OF AXIS BETWEEN 115W AND 118W. 

...DISCUSSION... 

A PAIR OF ASCAT PASSES AND AN ALTIMETER PASS OVER THE PAST 12 
HOURS CONFIRM THERE IS NO LONGER ANY EVIDENCE OF THE REMNANT LOW 
OF THE PREVIOUS TROPICAL CYCLONE ERICK OFF THE SOUTHERN BAJA 
PENINSULA. IN FACT WINDS ARE HARDLY BREAKING 10 KT OVER MUCH OF 
THE AREA N OF 20N E OF 120W...BUT RESIDUAL SWELL IS KEEPING SEAS 
UP TO 6 FT. 
 
NEARBY OVER THE GULF OF CALIFORNIA...A LARGE AREA OF 
THUNDERSTORMS ARE NOTED OVER THE MEXICAN STATE OF SONORA THIS 
MORNING...MOVING INTO THE NORTHERN GULF OF CALIFORNIA. 
DIVERGENCE ALOFT BETWEEN A PAIR OF UPPER CYCLONES...ONE OVER 
28N108W IN NW MEXICO AND ANOTHER WEAKENING UPPER CYCLONE 
OFFSHORE OVER 25N121W...SOUTH OF AN UPPER RIDGE EXTENDING FROM 
NEW MEXICO TO NORTHERN BAJA. 

GULF OF PAPAGAYO...A PULSE OF MODERATE TO FRESH GAP WINDS IS 
NOTED ON A 0230 UTC ASCAT PASS. THESE WINDS ARE ENHANCED BY 
SHORT WAVE RIDGING IN THE WAKE OF A TROPICAL WAVE THAT MOVED 
THROUGH NORTHERN CENTRAL AMERICA YESTERDAY. THE WINDS WILL 
DIMINISH THROUGH EARLY AFTERNOON AS THE TROPICAL WAVE WEAKENS. 

WEAK PERTURBATIONS REMAIN ALONG OR N OF THE ITCZ W OF 120W. AN 
ASCAT PASS FROM 06 UTC ILLUMINATED A SHARP SURFACE TROUGH ALONG 
135W FROM 11N TO 15N. THIS AND MORE SUBTLE CIRCULATIONS ARE 
REMNANTS OF A SURGE OF 15 TO 20 KT SOUTHERLY FLOW CROSSING THE 
EQUATOR INTO ITCZ/MONSOON TROUGH A COUPLE OF DAYS AGO. GLOBAL 
MODELS SHOW THESE WEAK AND SHORT LIVED CIRCULATIONS ALONG THE 
ITCZ DISSIPATING LATER TODAY. 

SOUTHERLY CROSS EQUATORIAL SWELL IS MAINTAINING COMBINED SEAS OF 
6-9 FT ACROSS THE TROPICAL WATERS TO 12N BETWEEN 80W AND 110W. 
THE LONG PERIOD SWELL IS EXPECTED TO DECAY BELOW 8 FT TONIGHT.  
 
$$ 
CHRISTENSEN