000
AXPZ20 KNHC 101603
TWDEP 

TROPICAL WEATHER DISCUSSION      
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU MAY 10 2012

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...MONSOON 
TROUGH FROM 07N78W TO 05N83W TO 09N117W TO 07N129W THEN  ITCZ TO 
06N135W TO 04N140W.  SCATTERED MODERATE ISOLATED STRONG WITHIN 
240 NM FROM 84W TO 116W.

...DISCUSSION...
DEEP LAYER CYCLONE AT 29N148W APPROACHES W BOUNDARY OF BASIN 
PUSHING DOWNSTREAM BROAD UPPER LEVEL RIDGE EASTWARD.  TROUGH 
WILL INTRODUCE DRY AIR MASS OVER WESTERN PORTION DISPLACING 
MOISTURE NOW HEADING INTO W COAST...MOST OF IT N OF 30W.  
DYNAMIC MODEL GUIDANCE HOLDS RIDGE AXIS ALONG 120W SHIFTING 
INCOMING CYCLONE NE...EVENTUALLY FLATTENING RIDGE CREST AND 
ESTABLISHING ZONAL FLOW N OF 18N ACROSS ENTIRE BASIN.  

SECOND UPPER LEVEL CYCLONE OVER NORTHERN MEXICO KEEPS DRY AIR 
MASS N OF 20N E OF 125W.  CYCLONE ALSO FORCED NE BY DISPLACED 
RIDGE WITH ATTENDANT UPPER LEVEL TROUGH FROM CYCLONE TO 20N120W 
GETS FLATTENED.  MOISTURE PLUME SE OF TROUGH RIDING A 55 KT JET 
CORE INTO CENTRAL MEXICO DRIES UP AS TROUGH WEAKENS.  WEAK UPPER 
LEVEL ANTICYCLONE AT 10N99W PROVIDES MODERATE DIVERGENCE ALOFT 
FOR TROPICAL MOISTURE AND SCATTERED CONVECTION FROM 94W TO 116W 
ALONG ITCZ AXIS.    

...ELSEWHERE AT THE LOWER LEVELS...
HIGH PRES CENTER 1036 MB WELL N OF AREA HAS RIDGE EXTENDING TO 
15N115W.  PRES GRADIENT RELAXES AS RIDGE DISPLACES NORTHEASTWARD
BUT ALLOWS SHORT-LIVED INTRUSION OF 10 FT NE SWELLS PRODUCED 
ALONG COAST OF NORTHERN CALIFORNIA INTO NW CORNER OF BASIN N OF 
27N W OF 125W TODAY DECAYING TO 8 FT BY SAT.  

$$
WALLY BARNES