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Eastern Pacific Tropical Weather Discussion (Text)

000
AXPZ20 KNHC 251603
TWDEP 

TROPICAL WEATHER DISCUSSION                                      
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1605 UTC SAT MAY 25 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH AXIS EXTENDS FROM 09N84W TO LOW PRES NEAR 09N88W 
1010 MB TO LOW PRES NEAR 09N97W 1010 MB TO LOW PRES NEAR 10N106W 
1009 MB. ITCZ AXIS CONTINUES FROM 10N106W TO 07N140W. SCATTERED 
MODERATE WITHIN EITHER SIDE OF AXIS BETWEEN 110W AND 125W.

...DISCUSSION...

AN UPPER TROUGH EXTENDS FROM THE SOUTHWEST UNITED STATES S 
TOWARD 14N110W. SOUTHERLY FLOW ALOFT IS VENTING ONGOING 
CONVECTION. MOST OF THIS IS SOUTH OF THE GULF OF 
TEHUANTEPEC...WHERE UPPER LEVEL OUTFLOW COMBINED WITH OVERNIGHT 
COASTAL IMPACTS HAVE GENERATED A WELL DEFINED LINE OF 
THUNDERSTORMS THAT EXTEND AS FAR SOUTH AS THE MONSOON TROUGH. 

ELSEWHERE STORNG HIGH PRES N OF THE AREA IS MAINTAIN MODERATE TO 
FRESH TRADE WINDS ACROSS MOST OF THE AREA W OF 110W.

LOOKING AHEAD...THERE CONTINUES TO BE LOW CONFIDENCE IN THE 
DEVELOPMENT OF THREE LOW PRES AREAS ALONG THE MONSOON TROUGH. 
THE GFS IS THE MOST AGGRESSIVE SHOWING TWIN TROPICAL CYCLONES 
EMERGING OUT OF THE ACTIVE MONSOON TROUGH AND MIGRATING NW TO N. 
ITS UNCLEAR WHETHER THIS IS FROM CONVECTIVE FEEBACK AS YET. THE 
EXTENDED FORECAST FOLLOWS THE MORE CONVSERVATIVE ECMWF 
INDICATING A SIMILAR PATTERN WITH TWIN LOW PRES SYSTEMS MOVING 
NW TO N...BUT FAVORING THE EASTERNMOST CYCLONE AND KEEPING 
CONDITIONS BELOW TROPICAL STORM STRENGTH. 

LONG PERIOD CROSS EQUATORIAL SW SWELLS AT 16-18 SECONDS DOMINATE 
MOST OF THE FORECAST WATERS E OF 115W...WHILE LONG PERIOD NW  
SWELLS ARE SPREADING ACROSS THE NRN PORTION. THESE SWELL EVENTS 
ARE FORECAST TO MERGE LATER TODAY. 

$$
CHRISTENSEN