000 AXPZ20 KNHC 300317 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE JUN 30 2009 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 WAVE... TROPICAL WAVE IS ALONG 88W N OF 07N MOVING W 10-15 KT. A WEAK AREA OF LOW PRES HAS FORMED ALONG THE AXIS NEAR 09N...NEAR THE INTERSECTION OF THE ITCZ. CONVECTION NEAR THE WAVE HAS DISSIPATED AND IS NOW MAINLY WITHIN THE ITCZ AND OVER CENTRAL AMERICA WHERE LOCAL EFFECTS AND UPPER DIFFLUENCE ARE PROVIDING AN ENHANCEMENT. ...ITCZ... ITCZ IS CENTERED ALONG 08N84W 10N103W 08N115W 12N134W 10N140W. SCATTERED MODERATE CONVECTION IS FROM 04N TO 08N E OF 92W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 07N TO 12N BETWEEN 107W AND 117W. NUMEROUS MODERATE SCATTERED STRONG CONVECTION IS FROM 05N TO 12N W OF 137W. ...DISCUSSION... SUBTROPICS... LIGHT SFC WINDS EXIST ACROSS THE SUBTROPICS DUE TO A WEAK HIGH SITUATED NEAR 24N126W. LATEST QUIKSCAT AND ASCAT PASSES CONFIRM THAT NW WINDS HAVE DIMINISHED BELOW 20 KT NEAR THE BAJA COAST. WINDS MAY OCCASIONALLY PULSE TO NEAR 20 KT IN THAT REGION OVER THE NEXT COUPLE OF DAYS FORCED BY LOCAL TERRAIN VARIATIONS OVER THE PENINSULA AND A MODERATE PRESSURE GRADIENT BETWEEN THE HIGH AND LOW PRES TROUGHING N OF THE AREA. DESPITE THE OVERALL LIGHT FLOW...SEAS ARE ELEVATED TO 6-9 FT DUE PRIMARILY TO N SWELL PROPAGATING S FROM GALE FORCE WINDS OFF THE N CALIFORNIA COAST. THESE SWELLS ARE EXPECTED TO DIMINISH TO LESS THAN 8 FT BY WED. ALOFT...TROUGHING HAS BROADENED ACROSS THE AREA BASICALLY ENCOMPASSING THE ZONE W OF 120W WITH THE AXIS EXTENDING FROM 30N137W TO A LOW NEAR 26N129W TO 20N124W. RIDGING HOLDS E OF 120W ANCHORED BY A HIGH CENTER NEAR THE MEXICO/NEW MEXICO BORDER. ABUNDANT DRY AIR IS NOTED ACROSS MUCH OF THE AREA LIMITING THE DEVELOPMENT OF SIGNIFICANT CLOUDINESS. A FEW SHORTWAVE TROUGHS ARE EXPECTED TO MAINTAIN THE BROAD TROUGH W OF 120W-125W OVER THE NEXT FEW DAYS WITH EACH SYSTEM LIKELY BRINGING A SLIGHT INCREASE IN MOISTURE. TROPICS... THE TROPICS REMAIN QUIET ACROSS THE EAST PACIFIC AS THERE ARE NO WELL DEFINED AREAS OF SFC LOW PRESSURE. CONVECTION IS SPREAD OUT ACROSS THE ENTIRE BELT MAINLY NEAR THE ITCZ...AS OUTLINED ABOVE. THERE ARE A COUPLE OF OTHER WEATHER FEATURES PROVIDING ENHANCEMENT TO THE CONVECTION OR WINDS. ONE OF THESE IS THE TROPICAL WAVE DISCUSSED ABOVE. THE OTHER IS A SFC TROUGH ALONG 17N133W 10N140W. THIS TROUGH HAS TIGHTENED THE PRESSURE GRADIENT PRODUCING NE 20 KT WINDS W OF THE AXIS...AS INDICATED BY AN EARLIER QUIKSCAT PASS. THIS FEATURE IS EXPECTED TO MOVE NW AND WEAKEN ALLOWING THE ENHANCED AREA OF WINDS TO DIMINISH WITHIN THE NEXT 12-24 HOURS. ASSOCIATED LOW-LEVEL CONVERGENCE IS GENERATING NUMEROUS MODERATE SCATTERED STRONG CONVECTION WITHIN 300 NM W AND 180 NM E OF THE AXIS. CROSS-EQUATORIAL SLY WINDS ARE NEAR 20 KT NEAR THE AFOREMENTIONED SFC TROUGH S OF 06N W OF 125W WITH SEAS TO NEAR 8 FT WITH SW SWELL. THESE WINDS AND SEA CONDITIONS ARE EXPECTED TO PERSIST OVER THE NEXT COUPLE OF DAYS AS THE PRESSURE GRADIENT REMAINS TIGHT BETWEEN THE SRN HEMISPHERE SUBTROPICAL RIDGE AND THE ITCZ. $$ CANGIALOSI