000
AXPZ20 KNHC 090218
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC THU APR 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY  
THROUGH 0100 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
          
THE ITCZ AXIS WAS ANALYZED FROM 02N95W TO 03N112W TO 03N125W TO 
04N131W TO 04N140W. SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION WAS N OF THE AXIS TO 08N BETWEEN 105W-112W. 

...DISCUSSION... 

A SURFACE RIDGE AXIS EXTENDS FROM A 1022 MB HIGH CENTER NEAR 
32N125W THROUGH 27N124W TO 14N107W. RECENT ASCAT DATA SHOWS 
TRADE WINDS ARE A MODERATE TO FRESH BREEZE SW OF THE RIDGE AXIS. 
THE SUBTROPICAL HIGH IS EXPECTED TO WEAKEN FURTHER AND SHIFT SE 
AS A PROGRESSIVE COLD FRONT NW OF THE AREA ENCROACHES UPON IT. 
THIS SHOULD KEEP TRADE WINDS BELOW THE ADVISORY CRITERIA OF 20-
25 KT THROUGH THE END OF THE FORECAST PERIOD FRIDAY AFTERNOON. 
WINDS SHOULD REMAIN A SOLID FRESH BREEZE IN THE MAIN TRADE WIND 
BELT N OF THE ITCZ AND HELP MAINTAIN SEAS TO 9 FT OVER WATERS W 
OF 120W THROUGH EARLY FRI WHERE NW...NE AND SW SWELL ARE 
COMBINING. SEAS ARE EXPECTED TO DIMINISH BELOW 8 FT BY FRI 
EVENING.

THE COLD FRONT ENCROACHING ON THE SUBTROPICAL HIGH IS FORECAST 
TO REACH THE NW FORECAST WATERS THU. SW WINDS TO ADVISORY 
CRITERIA ARE EXPECTED WITHIN 90 NM AHEAD OF THE FRONT. SEAS WILL 
SLOWLY BUILD ABOVE 8 FT BEHIND THE FRONT OVERNIGHT THU NIGHT. 
ALOFT...THE TROUGH SUPPORTING THIS COLD FRONT IS EXPECTED TO CUT 
OFF FROM THE NORTHERN STREAM BY THU NIGHT. A DEEP LAYERED LOW 
WILL MOVE INTO WATERS N OF 30N BETWEEN 130W-135W ON FRI. WINDS W 
OF THE LOW WILL INCREASE TO A STRONG BREEZE AS SEAS BUILD AS 
HIGH AS 15 FT. 

SPLIT FLOW OVER THE CENTRAL PACIFIC HAS DIRECTED A 100 KT 
SOUTHWESTERLY JET ACROSS THE AREA FROM 16N140W TO GUAYMAS 
MEXICO. THIS JET IS PROPELLING TROPICAL MOISTURE ALOFT ACROSS 
THE FORECAST AREA. MULTI-LEVEL CLOUDINESS WITH SOME EMBEDDED 
SHOWERS CAN PRIMARILY BE FOUND WITHIN 450 NM SE OF THE JET AXIS. 
THIS PATTERN IS EXPECTED TO CHANGE LITTLE OVER THE NEXT TWO DAYS.

GAP WINDS...                                                    
GULF OF PAPAGAYO...THE PRESSURE GRADIENT BETWEEN RIDGING OVER 
THE WESTERN CARIBBEAN AND THE ITCZ TO THE SW IS STRONG ENOUGH TO 
SUPPORT A PULSING FRESH TO STRONG NE BREEZE IN THE GULF OF 
PAPAGAYO WITH THE ASSISTANCE OF NOCTURNAL DRAINAGE FLOW. THE 
WINDS ARE BELOW ADVISORY CRITERIA AT THE MOMENT...BUT ARE 
EXPECTED TO RETURN IN THE MORNING HOURS THU. WINDS WILL DROP OFF 
AGAIN THU AFTERNOON AND RETURN TO ADVISORY CRITERIA FRI 
MORNING...EXCEPT HUG CLOSER TO THE COAST...BEFORE DROPPING OFF 
AGAIN FRI AFTERNOON. 

$$
SCHAUER