000
AXPZ20 KNHC 111009
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN MAY 11 2008

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...
ITCZ AXIS CENTERED ALONG 7N77W TO 10N110W TO 5N120W TO 6N130W TO 
4N140W.  SCATTERED MODERATE TO STRONG CONVECTION WITHIN 180 NM N 
OF AXIS FROM 91W-95W AND WITHIN 90 NM N OF AXIS FROM 134W-140W.

...DISCUSSION...
MID/UPPER LEVEL CUT-OFF CYCLONIC VORTEX AT 28N129W WITH TROUGH 
EXTENDING FROM 32N127W TO 22N140W.  VERY DRY AIR MASS NW OF 
TROUGH AXIS DUE TO STRONG SUBSIDENCE.  SUBTROPICAL JET STREAM 85 
KT ON SE QUADRANT OF VORTEX ADVECTING LARGE AMOUNT OF TRPCL 
MOISTURE DEBRIS FROM ITCZ DEEP CONVECTION.  SWATH OF WATER- 
LADEN AIR HEADS NE TOWARDS S BAJA CALIFORNIA AND NW MEXICO.  

BROAD ANTICYCLONE WELL ANCHORED OVER BAY OF CAMPECHE AT 20N91W 
HAS HEALTHY RIDGE EXTEND W TO 110W AND EASTWARD TO WRN 
CARIBBEAN.  VERY DRY AIR MASS UNDER RIDGE COVERAGE DUE TO 
MODERATE TO STRONG SUBSIDENCE.  TAIL END OF UPPER LEVEL LONG 
WAVE TROUGH WITH AXIS FROM 22N62W TO PANAMA COVERS SE PART OF 
ERN CARIBBEAN WITH WEAK JET CORE OF 45 KT.  MOISTURE SWATH OVER 
NRN PORTIONS OF SOUTH AMERICA...WINDWARD ISLANDS AND TROPICAL 
ATLC.  VERY DRY IN NRN HALF OF CARIBBEAN INFLUENCED BY RIDGE 
OVER BAY OF CAMPECHE. 

AT THE SURFACE...
HIGH PRES 1030 MB AT 34N144W HAS RIDGE EXTEND SE TO 20N110W 
FORCING LONG-FETCHED STRONG NLY WINDS AND LARGE N SWELLS ALONG 
BAJA CALIFORNIA COAST BUILDING DURING NEXT 48 HRS. 

FRESH NE TRADES N OF 08N W OF 130W EXPECTED TO CONTINUE THROUGH 
FORECAST PERIOD.  MINOR CROSS EQUATORIAL INCURSION OF 8 FT SWELL 
LIKELY TO SUBSIDE WITHIN NEXT 12 HRS.

$$
WALLY BARNES