000
AXPZ20 KNHC 171002
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1005 UTC FRI APR 17 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC. 
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              

THE ITCZ AXIS EXTENDS FROM 04N110W TO 02N118W TO 03N126W TO 
04N135W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM N OF THE 
AXIS BETWEEN 135W-138W...AND ALSO WITHIN 60 NM N OF THE AXIS 
BETWEEN 120W-125W.

A TROUGH EXTENDS FROM 08N90W TO 06N95W TO 04N100W. SCATTERED 
MODERATE CONVECTION IS WITHIN 60 NM N OF THE TROUGH BETWEEN 93W-
97W...AND WITHIN 30 NM OF TROUGH BETWEEN 97W-100W.

ALSO...AN AREA OF SCATTERED MODERATE AND ISOLATED STRONG 
CONVECTION IS FROM 09N TO 12N BETWEEN 121W AND 130W UNDER AN 
AREA OF UPPER LEVEL DIFFLUENCE.

...DISCUSSION... 

ALOFT...A MID/UPPER TROUGH IS OVER THE FAR EASTERN PORTION OF 
THE AREA SHIFTING QUICKLY EASTWARD FROM 17N109W TO 26N116W. 
BROAD ANTICYCLONIC FLOW COVERS THE AREA TO THE W AND SW OF THIS 
TROUGH WITH THE ASSOCIATED ANTICYLONE LOCATED NEAR 08N132W. A 
NARROW UPPER TROUGH IS APPROACHING THE FAR NW CORNER OF THE AREA 
AS A JET STREAM BRANCH RIDES UP ACROSS THE SOUTHERN PORTION OF 
THIS TROUGH...AND CUTS NW TO 27N140W...SEWD TO 25N130W 24N120W 
AND NEWD FROM THERE TO ACROSS NORTHERN MEXICO. STRONG SW WINDS 
ALONG AND NEAR THE JET STREAM ARE ADVECTING BROKEN TO OVERCAST 
MID/UPPER LEVEL CLOUDS OBSERVED WITHIN 540 NM SE AND S OF THE 
JET STREAM BRANCH ENE TO OVER THE WESTERN PORTION OF THE AREA 
FROM 16N TO 26N W OF 132W. THESE CLOUDS THIN OUT AS THEY REACH 
119W...THEN THICKEN AGAIN AS THEY APPROACH AND CROSS THROUGH THE 
MID/UPPER TROUGH MENTIONED ABOVE. 

OVER THE FAR EASTERN PORTION...AN INVERTED MID-LEVEL TROUGH IS 
NOTED MOVING WESTWARD ALONG A POSITION FROM 12N97W TO 05N101W TO 
02N102W. A SMALL UPPER ANTICYCLONE MOVING SW IS TO THE NE OF THE 
TROUGH NEAR 11N92W. DIFFLUENCE ALOFT BETWEEN THE ANTICYCLONE AND 
THE EASTERN PART OF THE TROUGH COMBINING WITH LOW-LEVEL 
CONVERGENCE NEAR THE SURFACE TROUGH ALONG 08N90W 06N95W TO 
04N100W IS HELPING TO GENERATE SCATTERED MODERATE CONVECTION AS  
DESCRIBED ABOVE UNDER ITCZ/MONSOON TROUGH. 
 
AT THE SURFACE...A NEARLY STATIONARY 1030 MB HIGH IS ANALYZED 
WELL N OF THE AREA AT 38N138W WITH A RIDGE SEWD TO 32N134W TO 
25N128W TO NEAR 21N115W. HIGH PRES COVERS THE AREA N OF 16N W OF 
114W. A TROUGH EXTENDS ALONG THE COAST OF CALIFORNIA. THE PRES 
GRADIENT BETWEEN THESE TWO FEATURES IS TIGHT ENOUGH TO SUPPORT 
FRESH NW-N WINDS WITHIN 60 NM OF THE COAST OF BAJA CALIFORNIA 
FROM 24N-28N. THESE WINDS WILL DIMINISH DURING THIS MORNING AS 
THE CULPRIT GRADIENT SLACKENS. THE RIDGE WILL SLOWLY WEAKEN AND 
SHIFT TO THE SW THROUGH THE END OF THE WEEK ALLOWING FOR TRADES 
TO DIMINISH.

E OF 110W...WINDS WILL MANAGE TO PULSE TO 15-20 KT THROUGH THE 
GULF OF PAPAGAYO DURING THE LATE NIGHT AND EARLY MORNING HOURS 
THROUGH EARLY SAT MORNING WHICH WILL TEMPORARILY BUILD SEAS TO 5-
7 FT. OTHERWISE LIGHT AND VARIABLE WINDS AND SEAS LESS THAN 8 FT 
WILL PREVAIL IN THE GULFS OF TEHUANTEPEC...FONSECA AND PANAMA... 
EXCEPT PULSING TO 15 KT JUST S OF THE ISTHMUS OF PANAMA DURING 
THE LATE NIGHT AND EARLY MORNING HOURS.

$$
AGUIRRE