000
AXPZ20 KNHC 181611 RRA
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1605 UTC THU JUL 18 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 
1545 UTC.

...TROPICAL WAVES...                                            
A TROPICAL WAVE EXTENDS FROM 18N107W TO 13N108W MOVING W AT 10-
15 KT. A 1009 MB LOW IS EMBEDDED ON THE BASE OF THE WAVE AXIS AT 
13N108W. THE WAVE COINCIDES WITH A BULGE OF MOISTURE PRESENT IN 
TOTAL PRECIPITABLE WATER IMAGERY. SCATTERED MODERATE CONVECTION 
IS S OF THE LOW FROM 10N TO 13N BETWEEN 106W AND 110W. ISOLATED 
MODERATE CONVECTION IS WITHIN 90 NM OF THE REMAINDER OF THE WAVE 
AXIS. GLOBAL MODELS SUGGEST THAT THE WAVE WILL GRADUALLY LOSE 
ITS SURFACE IDENTITY AS IT TRACKS WESTWARD THROUGH THE NEXT 
COUPLE OF DAYS.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...        
MONSOON TROUGH AXIS EXTENDS FROM 09N80W TO 07N100W TO 13N108W TO 
10N126W. ITCZ AXIS FROM 10N126W TO 12N136W. SCATTERED TO 
NUMEROUS STRONG FROM 03N TO 09N E OF 80W. SCATTERED MODERATE TO 
ISOLATED STRONG WITHIN 120 NM OF MONSOOON TROUGH BETWEEN 85W AND 
96W. SCATTERED MODERATE FROM 10N TO 13N BETWEEN 106W AND 110W. 
SCATTERED MODERATE FROM 07N TO 12N BETWEEN 120W AND 124W. 

...DISCUSSION...                                            

IN THE UPPER LEVELS... 

AN UPPER LEVEL LOW IS CENTERED WELL N OF THE AREA NEAR 44N138W. 
ANOTHER UPPER LEVEL LOW IS CENTERED OVER NW MEXICO NEAR 31N108W 
PRODUCING SCATTERED MODERATE CONVECTION INLAND N OF 25N BETWEEN 
104W AND 110W. A THIRD UPPER LEVEL LOW IS OVER THE TROPICS NEAR 
02S97W.    

AT THE SURFACE... A RIDGE EXTENDS SE FROM A 1026 MB HIGH N OF 
THE AREA AT 36N138W TO 25N120W. IN THE TROPICS... A SURFACE 
TROUGH EXTENDS FROM 15N136W TO 10N140W. NE WINDS 20 TO 25 KT 
WITH SEAS 8 TO 9 FT ARE FROM 13N TO 18N BETWEEN 134W AND 140W. 
THESE WINDS AND SEAS WILL MOVE W OUT OF THE ARE IN 24 HOURS. 

20 KT GAP WINDS ARE PRESENTLY SPREADING OVER THE GULF OF 
PAPAGAYO TODAY...AND WILL AGAIN FRI MORNING. 

20 KT GAP WINDS ARE PRESENTLY SPREADING OVER THE GULF OF 
TEHUANTEPEC TODAY AND WILL DEMINISH WITHIN 12 HOURS. 

LONG PERIOD CROSS EQUATORIAL SOUTHWESTERLY SWELLS RESULTING IN 
COMBINED SEAS TO 8 FT ARE OVER A PORTION OF THE FORECAST WATERS 
S OF LINE FROM 00N100W TO 10N110W TO 00S130W. THIS SWELL WILL 
PERSIST FOR THE NEXT 24 TO 36 HOURS AND THEN SUBSIDE. 
ELSEWHERE...A SET OF LONG PERIOD SW SWELLS WITH WAVE PERIOD OF 
19 TO 21 SECONDS IS REACHING MOST OF THE MEXICAN COAST AND WILL 
AFFECT MOST OF THE COAST OF CENTRAL AMERICA TODAY THROUGH SAT 
WITH ROUGH SURF CONDITIONS AND DANGEROUS RIP CURRENTS. 
  
$$ 
FORMOSA