000
AXPZ20 KNHC 011547
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON JUN 01 2009

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...
AXIS ALONG 09N78W TO 10N95W TO 08N105W TO 07N120W TO 07N140W.  
ISOLATED MODERATE CONVECTION WITHIN 90 NM N OF AXIS E OF 84W AND 
WITHIN 60 NM OF 06N92W.  SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 360 NM N OF AXIS W OF 124W.

...DISCUSSION...
DEEP LAYER CYCLONIC CIRCULATION N OF AREA SUPPORTS OCCLUDED 1009 
MB SURFACE LOW PRES AT 37N133W.  ASSOCIATED WEAKENING STATIONARY 
FRONT EXTENDS FROM 30N130W TO 25N140W BECOMING DIFFUSING UPON 
LOSING ITS UPPER SUPPORT.  NW SWELL ASSOCIATED WITH LOW PRES 
HAVE NOW SUBSIDED BELOW 8 FT. 

UPPER TROUGH RUNS FROM 32N125W TO DEVELOPING CYCLONE AT 16N140W 
WITH 75 KT JET CORE ADVECTING PLENTY OF TROPICAL MOISTURE INTO E 
PAC S OF 20N FEEDING ITCZ CONVECTION MAINLY W OF 120W.  

LOW PRES 1006 MB OVER CENTRAL MEXICO SUPPORT NW-SE TROUGH WHICH  
TIGHTENS PRES GRADIENT PRODUCING FRESH NW BREEZE ALONG W COAST 
OF BAJA CALIFORNIA EXPECTED TO LAST THROUGH FORECAST PERIOD.   
PROLONGED DURATION OF WINDS LIKELY INCREASE SEAS TO 8 FT.

SURFACE TROUGH EXTENDS FROM 12N97W THROUGH 1010 MB LOW PRES 
CENTERED AT 09N100W THEN TO 06N103W.  SURFACE WINDS REACHING 20 
KT WITHIN 120 NM ON SE QUADRANT OF CENTER CONVERGE RESULTING IN 
SCATTERED MODERATE CONVECTION ALSO SUPPORTED BY UPPER LEVEL 
DIVERGENCE AND DEEP LAYER MOISTURE.  HOWEVER...WESTERLY FLOW 
ALOFT W OF LOW PRES IS ADVECTING DRY AIR TOWARD SYSTEM AND 
OUTFLOW PATTERN SHOULD BE TURNING MORE ADVERSE TO ANY FURTHER 
DEVELOPMENT.  LOW PRES FORECAST TO WEAKEN FURTHER AND BECOME 
DIFFUSE WITHIN NEXT 24 HR.  MODEL GUIDANCE CONTINUE WITH MAINLY 
A WESTWARD TRACK.  AT THIS POINT DEVELOPMENT OF SYSTEM...IF 
ANY...IS EXPECTED TO BE SLOW AND MINIMAL.

FARTHER W...WEAK SURFACE TROUGH ALONG 136W MAINTAINS TIGHT 
GRADIENT WITH HIGH PRES BEHIND STATIONARY FRONT IN NW CORNER OF 
E PAC KEEPING FRESH TRADES FROM 08N-13N W OF 132W.  TROUGH MOVES 
OUT OF BASIN WITHIN 36 HR.  

ENHANCED EASTERLY TRADE WINDS IN WESTERN CARIBBEAN SEEP INTO E 
PAC ACROSS GULF OF PAPAGAYO INCREASING TO REACH FRESH BREEZE 
LASTING THROUGH FORECAST PERIOD.

$$
WALLY BARNES