000
AXPZ20 KNHC 200329
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE MAY 20 2008

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY
THROUGH 0300 UTC.

...TROPICAL WAVES...
TROPICAL WAVE ALONG 93W FROM 05N-12N MOVING W 15 KT WITH 
ISOLATED CONVECTION WITHIN 90 NM N OF ITCZ.  LITTLE DEVELOPMENT 
EXPECTED OF SYSTEM AS UPPER ENVIRONMENT DOES NOT LOOK FAVORABLE 
WITHIN NEXT 24-36 HRS. 

...ITCZ ALONG...
9N84W TO 07N91W TO 12N102W TO 11N110W TO 12N118W TO 05N140W.  
SCATTERED MODERATE CONVECTION WITHIN 120 NM OF AXIS E OF 91W.  
SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 90 NM N OF 
AXIS AND 210 S OF AXIS FROM 112W-124W.

...DISCUSSION...
MID TO UPPER LEVEL TROUGH EXTENDS FROM 32N134W TO CYCLONIC 
VORTEX AT 25N139W THEN W OF AREA AT 17N140W.  LARGE SWATH OF 
TRPCL MOISTURE 6-8 DEG WIDE ADVECTED N-NE BY WEAKENING 70 KT JET 
STREAM FROM 08N140W TO 32N129W.  NARROW RIDGE DOWNSTREAM WITH 
ANTICYCLONE NEAR 12N122W SITS AHEAD ON PATH OF WEAK SURFACE 
TROUGH PRODUCING UPPER LEVEL DIFFLUENCE AND ENHANCING SCATTERED 
DEEP CONVECTION ALONG INTERSECTION OF ITCZ AND TROUGH.  NO 
ORGANIZED CONVECTION OBSERVED AT THIS TIME...BUT STRENGTHENING 
IS PROBABLE DUE TO THE FAVORABLE CONDITIONS ALOFT. 

MID TO UPPER LEVEL TROUGH EXTENDS FROM CYCLONIC VORTEX AT 
26N107W TO 13N115W.  MODERATE TO STRONG SUBSIDENCE AROUND BASE 
OF TROUGH CAUSING DRY AIR MASS FROM RIDGE AXIS AT 123W TO W 
COAST OF MEXICO.  JUST S OF TROUGH BASE...WEAK DEFORMATION ZONE 
AT THE WRN EDGE OF CARIBBEAN RIDGE SUPPLIES GOOD DIFFLUENCE 
ALOFT ENOUGH TO ENHANCE DEEP CONVECTION ALONG SURFACE TROUGH 
ALONG 106W FROM 06N-15N.  NO ORGANIZATION OBSERVED AT THIS 
TIME...BUT STRENGTHENING IS PROBABLE DUE TO THE FAVORABLE 
CONDITIONS ALOFT. 

ELSEWHERE AT THE SURFACE...
WEAK HIGH PRES CENTER 1021 MB AT 30N140W HAS RIDGE EXTENDING TO 
17N106W.  WITH HIGH PRES DISSIPATING WITHIN 24 HRS AS STRONG 
COLD FRONT ENTER NW CORNER OF BASIN WITH STRONG NLY WINDS AND 
LONG PERIOD LARGE SWELLS N OF 25N E OF 128W BY END OF FORECAST 
PERIOD.    

$$
WALLY BARNES