000
AXPZ20 KNHC 181549
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC THU JUN 18 2015

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 1545 UTC. 
 
...TROPICAL WAVES...

A TROPICAL WAVE IS ANALYZED N OF 07N ALONG 80W BUT IS CURRENTLY
ENHANCING CONVECTION ONLY OVER THE SW CARIBBEAN. 

A TROPICAL WAVE EXTENDS TO THE N OF 10N BETWEEN 96-97W AND HAS 
BEEN PROGRESSING W AT 10-15 KT OVER THE PAST 24 HOURS. CURRENTLY 
ISOLATED MODERATE TO STRONG CONVECTION IS OBSERVED N OF 13N 
BETWEEN 92-98W INCLUDING THE GULF OF TEHUANTEPEC. 
  
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

SCATTEROMETER DATA INDICATES THAT THE ITCZ FORMS NEAR 10N86W  
AND EXTENDS SW TO 08N94W...THEN TURNS W TO 09N110W...THEN SW TO 
02N130W...THEN W AGAIN TO BEYOND 02N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS OBSERVED ALONG THE ITCZ WITHIN 90 
NM EITHER SIDE OF A LINE FROM 10.5N86W TO 08N93W TO 10.5N106W... 
WITHIN 240 NM EITHER SIDE OF A LINE FROM 11N110W TO 02N123W... 
AND WITHIN 60 NM EITHER SIDE OF A LINE FROM 02N135W TO 02N140W. 
ISOLATED MODERATE AND STRONG CONVECTION IS NOTED WELL S OF THE 
ITCZ WITHIN 90 NM EITHER SIDE OF A LINE FROM 04N77W TO 03N90W TO 
05N110W.

...DISCUSSION...

AN UPPER ANTICYCLONE IS CENTERED NEAR 30N122W AND ANOTHER NEAR  
17N114W WITH THEIR ANTICYCLONIC ENVELOPE DOMINATING THE 
DISCUSSION AREA N OF 15N W OF 105W WITH ASSOCIATED SUBSIDENCE 
SUPPRESSING CONVECTION. AN UPPER CYCLONE IS NOTED OVER THE DEEP 
TROPICS AT 08N130W WITH ONLY A FEW TSTMS OBSERVED WITHIN 300 NM 
OF THE CYCLONE. AN UPPER CYCLONE IS NOTED OVER THE YUCATAN 
PENINSULA WITH AN UPPER TROUGH EXTENDING SW TO 13N103W TO 
00N105W. AN ILL-DEFINED UPPER RIDGE IS NOTED E OF THIS TROUGH 
EXTENDING W FROM COLOMBIA TO NEAR 11N95W WITH ASSOCIATED UPPER 
DIFFLUENCE ENHANCING CONVECTION ALONG THE ITCZ AS PREVIOUSLY 
DESCRIBED. UPPER DEBRIS MOISTURE FROM THE CONVECTION E OF 90W IS 
ADVECTED NE ACROSS CENTRAL AMERICA S OF 13N AND ACROSS THE SW 
CARIBBEAN. THE DEBRIS MOISTURE FROM THE CONVECTION BETWEEN 100-
128W IS ADVECTED S ACROSS THE EQUATOR.
     
AT THE LOW LEVELS A RIDGE EXTENDS FROM 33N140W TO 14N95W. THE  
PRESSURE GRADIENT S OF THE RIDGE AND N OF THE ITCZ IS 
MAINTAINING MODERATE TRADES. THE TRADE WIND SWELL IS MIXING WITH 
LONG PERIOD CROSS-EQUATORIAL SOUTHERLY SWELL RESULTING IN 
COMBINED SEAS 7-10 FT ACROSS THE TROPICAL WATERS S OF LINE FROM 
14N128W TO 12N97W TO 03.4S91W. EXPECT THE SOUTHERLY SWELL TO 
SUBSIDE OVER THE NEXT FEW DAYS. 

GULF OF PAPAGAYO...EXPECT NE 20-25 KT NOCTURNAL PULSES WITH THE  
WESTERLY EXTENT REACHING NEAR 10N91W. THE RESULTANT ENE SWELL 
WILL PROPAGATE W AND MIX WITH LONG PERIOD CROSS-EQUATORIAL SW 
SWELL WITH COMBINED SEAS OF 6-8 FT ALONG A SWATCH FROM 08.5-
11.5N BETWEEN 88-103W. 

$$ 
NELSON