000 AXPZ20 KNHC 290327 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE MAY 29 2007 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 0315 UTC. ...SPECIAL FEATURES... TROPICAL STORM ALVIN AT 12.6N 113.7W AT 0300 UTC WITH ESTIMATED CENTRAL PRES OF 1004 MB MOVING W SW OR 245 DEG AT 5 KT. NUMEROUS MODERATE TO STRONG CONVECTION NOTED WITHIN 30 NM N SEMICIRCLE AND WITHIN 75 NM S SEMICIRCLE OF CENTER. SCATTERED MODERATE ISOLATED STRONG IS NOTED IN BANDS ELSEWHERE WITHIN 150 NM OVER NW SEMICIRCLE AND WITHIN 120 NM OVER SE SEMICIRCLE. FAVORABLE WATER TEMPERATURES SUPPORT FOR ALVIN TO STRENGTHEN SLIGHTLY OVER THE NEXT FEW DAYS. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE AXIS 11N85W 12N99W 6N113W 7N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 60 NM 11N95W AND WITHIN 90 NM OF LINE 13N99W 10N103W AND LINE 9N105W 9N111W AND LINE 7N124W 7N131W. ...DISCUSSION... AN UPPER ANTICYCLONE IS ESTIMATED NEAR 13N107W. A SECOND UPPER ANTICYCLONE IS NEAR 9N135W. THE COMBINED RIDGE CRESTS ALONG POINTS 18N140W 28N125W 25N109W. AN UPPER TROUGH IS OBSERVED NW OF THE RIDGE ALONG 32N120W THROUGH A WEAK UPPER CYCLONE AT 29N134W THEN CONTAINING SW TO BEYOND 22N140W. AN UPPER MOISTURE PLUME LIES ALONG THE W PERIPHERY OF THE RIDGE ROUGHLY WITHIN 120 NM EITHER SIDE OF LINE 13N140W 22N130W 25N115W. OTHERWISE DRY UPPER AIR IS TRAPPED UNDER THE RIDGE. UPPER DIFFLUENCE IS ENHANCING ALONG 12N BETWEEN 94W AND 116W. SOME OF THE RESULTANT DEBRIS MOISTURE IS ADVECTED S ACROSS THE EQUATOR BETWEEN 109W AND 118W. SOME OF THE MOISTURE SPREADS N BUT EVAPORATES IN THE UPPER DRY AIR ALONG 21N. AN UPPER TROUGH EXTENDS S ACROSS OLD MEXICO ALONG 31N102W 19N97W. AN UPPER ANTICYCLONE IS S OTHER TROUGH BASE NEAR 13N95W WITH A RIDGE EXTENDING E ACROSS CENTRAL AMERICA TO A SHARP CREST NEAR 15N83W. AN OTHER UPPER ANTICYCLONE IS OVER THE E CARIBBEAN NEAR 12N108W WITH A RIDGE W TO NEAR 12N74W. A BROAD TROUGH LIES BETWEEN THESE UPPER RIDGES OVER THE CENTRAL CARIBBEAN EXTENDING S INTO THE E PAC NEAR 8N78W. SCATTERED CONVECTION WAS ENHANCED MON AFTERNOON OVER THE SW CARIBBEAN AND THE ASSOCIATED DEBRIS MOISTURE IS ADVECTED S OVER THE E PAC S OF 12N E OF 88W. AT THE SURFACE... RIDGE EXTENDS INTO DISCUSSION AREA ALONG 32N141W 20N110W. A LOW LEVEL TROUGH IS EMBEDDED IN THE ITCZ NEAR 8N125W. $$ NELSON