000 AXPZ20 KNHC 202227 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT JUN 20 2009 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2115 UTC. ...SPECIAL FEATURES... LEFT BEHIND IN THE WAKE OF AN ADVANCING TROPICAL WAVE DISCUSSED BELOW...A 1007 MB SURFACE LOW HAS BEEN ANALYZED NEAR 14.5N 98.5W DRIFTING WNW. BROAD CYCLONIC TURNING CAN BE SEEN IN SATELLITE IMAGERY IN THE MID LEVEL CLOUDS...IN THE EASTERN END OF A MONSOON LIKE CIRCULATION REMAINING AFTER THE DEVELOPMENT AND DEPARTURE OF TROPICAL DEPRESSION ONE. RAINBANDS HAVE BEGUN TO DEVELOP THIS AFTERNOON SURROUNDING THIS LOW...AND THE OVERALL STRUCTURE OF THIS FEATURE IS SLOWLY IMPROVING. AN UPPER LEVEL ANTICYCLONE RESIDES OVER THIS REGION...AND IS PROVIDING AN ENVIRONMENT FAVORABLE FOR CONTINUED DEEP CONVECTION. GLOBAL MODELS GENERALLY AGREE ON SOME SLOW GRADUAL ORGANIZATION OF THIS SYSTEM...AND THERE IS A MODERATE CHANCE THAT IT COULD BECOME THE SECOND TROPICAL CYCLONE OF THE EASTERN PACIFIC SEASON DURING THE FEW DAYS. A SECOND SURFACE LOW...1009 MB...HAS LINGERED ACROSS THE EAST CENTRAL PACIFIC THE PAST FEW DAYS...CURRENTLY NEAR 09N 130W... AND WAS MOVING SLOWLY NORTHEAST DURING THE PAST 24 HOURS. ISOLATED CLUSTERS OF DEEP CONVECTION HAVE CONTINUED TO FLARE ON AND OFF THE PAST 24 HOURS NEAR THIS LOW...WHICH REMAINS ANCHORED IN THE ITCZ. THIS SYSTEM IS UNDERNEATH THE SW PERIPHERY OF AN UPPER LEVEL HIGH...AND SHEAR IS WEAK. GLOBAL MODELS GENERALLY MOVE THIS SYSTEM TO THE NE DURING THE NEXT FEW DAYS AND SUGGEST SOME CHANCE FOR VERY SLOW AND MODEST WEAKENING...AND THERE IS A LOW CHANCE OF THIS DEVELOPING INTO A TROPICAL CYCLONE DURING THE NEXT 48 HOURS. ...TROPICAL WAVES... A TROPICAL WAVE WAS ANALYZED ALONG 107W...AND ESTIMATED TO BE MOVING W 10 TO 15 KT. THE WAVE POSITION IS BASED ON MOTION CONTINUITY. SATELLITE WINDS. AN AREA OF CONVECTION DEVELOPED NEAR THE WAVE AXIS WITH SCATTERED MODERATE TO STRONG CONVECTION EARLIER TODAY...BUT HAS SINCE WEAKENED QUICKLY. ...ITCZ... THE ITCZ AXIS WAS ALONG 08N75W TO 07.5N77W TO 10N85W TO 10N89W TO 12N96W...THEN RESUMED 14N101W TO 14N107W TO 09.5114W TO 08N121W TO 09N130W TO 05N140W. SCATTERED MODERATE TO STRONG WITHIN 120 NM OF AXIS BETWEEN 86W AND COAST OF COLOMBIA. SCATTERED MODERATE TO STRONG WITHIN 240 NM OF AXIS BETWEEN 89W AND 97W. SCATTERED MODERATE WITHIN 180 NM OF AXIS BETWEEN 101W AND 106W. SCATTERED MODERATE ISOLATED STRONG WITHIN 60 NM N AND 120 NM S OF AXIS FROM 107W TO 128W. SCATTERED MODERATE WITHIN 60 NM OF AXIS FROM 132W TO 137W. ...DISCUSSION... MIDDLE AND UPPER RIDGE IS NORTH OF 20N WEST OF 125W. RIDGE IS FORECAST TO WEAKEN THROUGH THE NEXT COUPLE OF DAYS AND BY MONDAY THIS AREA WILL BE PART OF A BROAD TROUGH THAT DEVELOPS OVER THE NORTHERN PART OF THE AREA. THE AREA IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS WITH OVERCAST TO BROKEN STRATOCUMULUS IN THE LOWER LEVELS. WELL DEFINED SHORTWAVE IS OVER THE NORTHEAST PART OF THE PACIFIC OCEAN AREA. THE TROUGH IS NORTH OF 25N FROM 105W TO 120W. THE AREA IS DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS. IN THE LOWER LEVELS MOSTLY OVERCAST STRATOCUMULUS IS OBSERVED. THE TROUGH EXTENDS SOUTH OF 25N IN A WEAKER FORM AND COVERS A BROAD AREA NORTH OF THE ITCZ FROM ABOUT 110W TO 125W. DIFFLUENT UPPER FLOW EAST OF BOTH THE STRONG AND WEAK PART OF THE TROUGH COUPLED WITH SOUTHERLY FLOW IS ADVECTING A MOISTURE PLUME FROM THE ITCZ NORTHWARD OVER A BROAD AREA EAST OF A LINE FROM NEAR 32N105W TO 25N105W TO THE ITCZ NEAR 122W. OVER THE PACIFIC PART OF THIS AREA A LARGE UPPER DIFFLUENCE AREA WITH MULTI LEVEL CLOUDS AND EMBEDDED AREAS OF CONVECTION EXTENDS TO 85W. THE MOISTURE PLUME IS MUCH NARROWER OVER MEXICO AND DRY AIR IS ADVECTION FROM THE GULF OF MEXICO NORTH OF 20N. THE PLUME OVER MEXICO IS ONLY ABOUT 200 NM WIDE. A MODERATE SURFACE RIDGE IS NORTH OF 22N WEST OF 130W WITH A WEAKER RIDGE ELSEWHERE NORTH OF 14N WEST OF 112W. ELSEWHERE EXCEPT AS MENTIONED ABOVE A BROAD W TO E TROUGH IS ANALYZED AT THE SURFACE ALONG ABOUT 13-14N...WITH MODERATE TO FRESH ANTICYCLONIC FLOW TO THE SOUTH OF THIS TROUGH...PRODUCING SEAS IN THE 6 TO 8 FT RANGE...AND YIELDING CONVERGENCE THAT WILL MAINTAIN ACTIVE CONVECTION ACROSS THE REGION BETWEEN 85W AND 110W FOR THE NEXT 24 HOURS. $$ STRIPLING