000
AXPZ20 KNHC 120948
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC TUE MAY 12 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...ITCZ...
AXIS ALONG 08N78W TO 09N100W TO 06N127W TO 05N140W.  ISOLATED 
MODERATE TO STRONG CONVECTION WITHIN 90 NM S OF AXIS E OF 115W.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 60 NM OF 
AXIS FROM 122W TO 130W.  ISOLATED MODERATE CONVECTION WITHIN 90 
NM OF AXIS W OF 138W.

...DISCUSSION...
LARGE AMPLITUDE UPPER LEVEL TROUGH FROM 32N122W TO WEAK CYCLONE 
AT 01N104W BRINGS ABUNDANT TROPICAL MOISTURE FROM LOW LATITUDES 
UP NORTH TO S HALF OF BAJA CALIFORNIA AND NW MEXICO.  BROAD AND 
HEALTHY RIDGE CENTERED AT 15N103W BRINGS SWATH OF MOISTURE E 
INTO CENTRAL MEXICO FEEDING IT TO THERMAL LOW PRES TO ENHANCE 
CONVECTION WITH THE AID OF DAYTIME HEAT. 

WEAKENING SURFACE HIGH PRES 1026 MB AT 34N136W HAS RIDGE EXTEND 
N OF 15N W OF 105W.  RIDGE DRIFTING E INCREASING STRONG WINDS 
ALONG CALIFORNIA COAST TO GALE FORCE WITHIN 24 HRS AND CAUSE 
ANOTHER EPISODE OF N SWELL ENCROACHING INTO E PAC BASIN N OF 26N 
E OF 120W. 

WEAK SURFACE TROUGH ALONG 124W FROM 04N TO 11N HAS SCATTERED 
CONVECTION ALONG ITCZ BUT SUSTAINS LITTLE CHANCE OF ANY FURTHER 
DEVELOPMENT AS IT MOVES W INTO AREA OF DRY AIR MASS AND 
UNFAVORABLE UPPER ENVIRONMENT.

$$
WALLY BARNES