000
AXPZ20 KNHC 301649
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 30 2007

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.

...SPECIAL FEATURES...
TROPICAL DEPRESSION ALVIN AT 13.4N 114.6W AT 1500 UTC MOVING WNW 
AT 3 KT WITH 1005 MB CENTRAL PRESSURE.  MAXIMUM SUSTAINED WIND 
30 GUSTS TO 40 KT.  CONVECTION WITH ALVIN DECREASED CONSIDERABLY 
AND RESTRICTED TO SRN SEMICIRCLE.  UNFAVORABLE UPPER LEVEL FLOW 
IS CURTAILING ITS DEVELOPMENT.

TROPICAL STORM BARBARA AT 14.2N 97.3W AT 1500 UTC IS STATIONARY. 
CENTRAL PRESSURE IS 1006 MB WITH MAXIMUM SUSTAINED WIND OF 30 
GUSTS TO 40 KT.  NUMEROUS MODERATE TO STRONG CONVECTION WITHIN 
180 NM OF CENTER.  SEE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/ 
WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS.

...ITCZ...
ITCZ AXIS ALONG 114N92W  10N103W  7N120W  7N136W  6N140W.  
SCATTERED TO NUMEROUS MODERATE TO STRONG WITHIN 120 NM N OF AXIS 
E OF 92W.  SCATTERED MODERATE ISOLATED STRONG WITHIN 90 NM S OF 
AXIS FROM 115W TO 122W.

...DISCUSSION...
VERY SHARP DEEP LAYER LONGWAVE TROUGH 32N137W TO 21N140W BRINGS 
95 KT JET CORE INTO NW CORNER OF E PAC ALONG WITH ABUNDANT 
MOISTURE WHICH RACES ALONG ON W SIDE OF DOWNSTREAM RIDGE INTO 
SRN BAJA CALIFORNIA PENINSULA.  UPPER ANTICYCLONE AT 16N110W
PULLING ITS SUPPORT FROM NOW T.D. ALVIN DISTURBING ITS OUTER 
FLOW AND MAKING IT LOSE INTENSITY.  

RIDGE ALOFT EXTEND N FROM CIRCULATION ALONG 115W ACROSS BAJA 
PENINSULA INTO SW U.S.  VERY DRY AIR MASS UNDER RIDGE FROM 
16N-23N BETWEEN E OF 125W.  

DOWNSTREAM UPPER TROUGH WITH AXIS ALONG 95W COMBINES WITH RIDGE 
TO FORM AREA OF UPPER DIFFLUENCE ABOVE T.S BARBARA ENHANCING ITS 
INTENSIFICATION LIKELY TO HURRICANE LEVEL WITHIN 72 HRS. 

AT THE SURFACE...
WEAK HIGH PRES CENTER 1021 MB AT 34N133W HAS RIDGE EXTENDING TO  
18N108W AND CONTINUE KEEPING LIGHT NE TRADES ACROSS E PAC.  ELY 
TRACK OF HIGH PRES WILL EVENTUALLY INCREASE NW WIND ALONG BAJA 
CALIFORNIA COAST WITHIN 36-48 HRS.    

$$
WALLY BARNES