000
AXPZ20 KNHC 091523
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC SAT MAY 09 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 
1500 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE ITCZ AXIS IS FROM 05N93W TO 05N105W TO 03N115W TO 07N125W 
THEN RESUMES W OF A SURFACE TROUGH FROM 07N128W TO 04N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED FROM 03N 
TO 07N E OF 85W TO THE COAST OF COLOMBIA...AND FROM 08N TO 10N 
BETWEEN 131W AND 137W. SCATTERED MODERATE CONVECTION IS WITHIN 
90 NM S OF AXIS BETWEEN 93W AND 96W. SIMILAR CONVECTION IS FROM 
01.5N TO 03N BETWEEN 103W AND 107.

...DISCUSSION...

ALOFT...AN UPPER-LEVEL LOW IS SPINNING OVER THE FOUR CORNER WITH 
A TROUGH EXTENDING SW ACROSS THE BAJA CALIFORNIA PENINSULA. A 90-
100 KT JETSTREAM ROUNDS THE BASE OF THE TROUGH AND CROSSES 
CENTRAL BAJA CALIFORNIA INTO NW MEXICO. ANOTHER UPPER-LEVEL 
TROUGH HAS ENTERED THE NW CORNER OF THE FORECAST AREA. IN 
BETWEEN...A RIDGE IS NOTED. A LARGE UPPER ANTICYCLONE REMAINS 
CENTERED OVER THE TROPICS NEAR 08N105W WITH AN UPPER RIDGE 
EXTENDING NORTHWARD ACROSS CENTRAL MEXICO INTO THE GULF OF 
MEXICO. UPPER DIFFLUENCE ASSOCIATED WITH THIS ANTICYCLONE IS 
HELPING TO SUPPORT THE CONVECTION W OF 115W PREVIOUSLY 
DESCRIBED. AN UPPER-LEVEL TROUGH FROM THE SW CARIBBEAN ENTERS 
THE TROPICAL EPAC THROUGH WESTERN PANAMA TO A BASE NEAR THE 
EQUATOR. SOME CONVECTIVE ACTIVITY IS NOTED ON EITHER SIDE OF THE 
TROUGH N OF 03N E OF 85W. 

AT THE SURFACE...1027 MB HIGH PRES IS CENTERED NEAR 33N136W WITH 
A RIDGE AXIS EXTENDING SE TO NEAR THE REVILLAGIGEDO ISLANDS.  
THE PRES GRADIENT SW OF THE RIDGE IS SUPPORTING 20-25 KT NE-E 
TRADES ACROSS THE WATERS FROM 10N TO 18N W OF 116W. 
SCATTEROMETER DATA CONFIRMED THE PRESENCE OF THESE WINDS. THE 
ASSOCIATED FRESH NE SWELL IS MIXING WITH LONG PERIOD S AND NW 
SWELL RESULTING IN COMBINED SEAS OF 8-12 FT BASED ON A COUPLE OF 
ALTIMETER PASSES. THE PRES GRADIENT WILL GRADUALLY RELAX THROUGH 
SUN NIGHT AS THE HIGH PRES WILL BE ABSORBED BY A STRONGER ONE 
CURRENTLY LOCATED NEAR 38N155W. THE AERIAL EXTENT AND STRENGTH 
OF THE TRADES WILL DECREASE TO A SMALLER AREA FROM 07N TO 13N W 
OF 132W BY EARLY MON MORNING. THE ENHANCED SEAS OF 7-9 FT WILL 
GRADUALLY SUBSIDE TO 6-7 FT LATE WED. MEANWHILE THE GRADIENT NE 
OF THIS RIDGE IS SUPPORTING NW WINDS OF 20-25 KT ALONG THE 
PACIFIC COAST OF THE BAJA PENINSULA...PARTICULARLY FROM 23N TO 
27N. BY THIS EVENING...THESE FRESH TO STRONG WINDS ARE EXPECTED 
TO AFFECT MAINLY THE WATERS N OF 25N CONTINUING THROUGH THE 
OVERNIGHT HOURS.

A TROUGH IS ANALYZED FROM 12N124W TO 05N126W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WHERE THE TROUGH MEETS THE 
ITCZ AND MAINLY FROM 05N TO 08N BETWEEN 125W AND 129W. SIMILAR 
CONVECTION IS ALSO OBSERVED WITHIN 150 NM E OF TROUGH AXIS FROM 
09N TO 11N.
 
LONG PERIOD SOUTHERLY SWELL WILL CONTINUE TO AFFECT THE WATERS S 
OF A LINE FROM 03.4S95W TO 03N110W TO 03N117W TO 00N135W WITH 
COMBINED SEAS OF 8-11 FT ACCORDING TO AN ALTIMETER PASS. THE 
HIGHEST SEAS CAN BE FOUND S OF THE EQUATOR W OF 110W. RE-
ENFORCING S SWELL WILL ARRIVE ON SUN WITH SEAS OF 8-10 FT 
BUILDING ACROSS THE TROPICAL WATERS S OF 03N BETWEEN 93W AND 
120W BY MON MORNING.
  
GULF OF PAPAGAYO...WINDS WILL PULSE TO FRESH TO STRONG LEVELS 
OVER AND JUST SW OF THE GULF DURING THE LATE NIGHT AND EARLY 
MORNING HOURS EACH DAY THROUGH MON.

$$ 
GR