000 AXPZ20 KNHC 080930 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SUN NOV 08 2009 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 0730 UTC. ...TROPICAL LOWS... THE 1008 MB LOW PRES SYSTEM CENTERED NEAR 13N90W IS SLOWLY MOVING N SLOWLY IN RESPONSE TO THE UPPER TROUGH IMMEDIATELY TO ITS W WHICH HAS BEEN CONTRIBUTING BOTH SOUTHWESTERLY WIND SHEAR AND DRY AIR...WHICH IS BEING ENTRAINED BY THE LOW...FOR OVER A DAY. THIS PERSISTENT SYSTEM IS FINALLY EXPECTED TO DISSIPATE TO A TROUGH OVER THE NEXT 24 HOURS WITHIN THIS HOSTILE ENVIRONMENT. IN THE MEANTIME...SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IS DISPLACED FROM THE LOW LEVEL CENTER AND IS FOUND MAINLY OVER LAND WITHIN 150 NM NE QUADRANT. THE ASCAT PASS FROM 0304 UTC SHOWED SOUTHERLY WINDS IN THE 20 TO 25 KT RANGE WITHIN 90 NM E SEMICIRCLE OF THE LOW. THE 1009 MB LOW PRES SYSTEM CENTERED NEAR 11N118W HAS WEAKENED OVER THE LAST 24 HOURS AS THE SOUTHWEST TO WESTERLY UPPER JET TO ITS N HAS BEGUN TO SINK SOUTHWARD...PROVIDING 20 TO 30 KT OF SHEAR OVER THE SYSTEM. CONVECTION HAS ONCE AGAIN INCREASED DURING THE OVERNIGHT HOURS WITH THE SYSTEM...BUT IS DISPLACED BETWEEN 120 NM AND 240 NM E OF THE LOW CENTER DUE TO THE SHEAR ALOFT. THIS LOW IS ALSO EXPECTED TO DISSIPATE TO A TROUGH LATER TODAY. ...ITCZ... THE ITCZ AXIS EXTENDS ALONG 08N78W TO 11N87W TO 07N95W TO 11N115W TO 08N140W. SCATTERED MODERATE CONVECTION LIES IN THE GULF OF PANAMA WITHIN 45 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 78W AND 80W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION CAN BE FOUND WITHIN 120 NM N OF THE ITCZ AXIS W OF 137W. ...DISCUSSION... AN UPPER LOW LIES OVER WEST TEXAS AND HAS A 50 TO 70 KT WESTERLY UPPER JET EXTENDING FROM ITS SOUTHERN EDGE ALONG 22N TO 122W WHERE IT TAKES A SOUTHERLY TURN ON THE LEADING EDGE OF AN UPPER TROUGH TO NEAR 12N138W. THE UPPER LEVEL DIFFLUENCE ASSOCIATED WITH THE REAR RIGHT QUADRANT OF THE JET IS SUPPORTING SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WITHIN 120 NM N OF THE ITCZ AXIS W OF 137W. CIRRUS EXTENDING FROM THIS AREA OF CONVECTION CAN BE FOUND ALONG THE JET AXIS W OF 125W. THIS JET IS INHIBITING DEEP CONVECTION N OF 15N WHERE A BROKEN STRATOCUMULUS FIELD CAN BE FOUND. A HIGH PRES RIDGE STEMMING FROM A 1026 MB HIGH NEAR 33N136W DOMINATES NORTH WATERS AT THE SURFACE. THIS HIGH PRES SYSTEM IS PART OF A LARGER NORTH PACIFIC RIDGE THAT IS CURRENTLY BEING COMPROMISED BY A COLD FRONT WELL NORTH OF THE FORECAST AREA. WHILE THIS FRONT IS EXPECTED TO DISSIPATE AS IT REACHES FORECAST WATERS TUE...LONG PERIOD NW SWELL FROM THE SYSTEM HAS ALREADY PUSHED INTO N WATERS WITH SIGNIFICANT WAVE HEIGHTS TO 18 FT. THIS SWELL WILL SPREAD SE THROUGH THE FORECAST AREA W OF 105W OVER THE NEXT FEW DAYS...WITH MAXIMUM WAVE HEIGHTS OVER N WATERS SUBSIDING TO THE 10 TO 14 FT RANGE MON EVENING. THE SE PROGRESSION OF THE COLD FRONT N OF FORECAST WATERS WILL WEAKEN THE SURFACE HIGH PRES AHEAD OF IT AND FORCE THE HIGH CENTER SE. EASTERLY TRADE WINDS WILL PERSIST THROUGH THE FORECAST PERIOD ON THE S SIDE OF THE RIDGE AXIS AND W OF THE AFOREMENTIONED LOW PRES SYSTEM NEAR 11N118W. QUIKSCAT PASSES FROM 0222 AND 0404 UTC SHOW A BROAD AREA OF NE WINDS IN THE 15 TO 25 KT RANGE HERE. AN UPPER ANTICYCLONE IS OVER THE SW CARIBBEAN NEAR 13N76W WITH A RIDGE EXTENDING W TO NEAR 13N85W. THE UPPER LEVEL FLOW IS DIFFLUENT OVER THE GULF OF PANAMA BETWEEN THIS RIDGE AXIS AND A NORTHEASTERLY UPPER JET OVER COLOMBIA...ALLOWING FOR SCATTERED MODERATE CONVECTION IN THE GULF OF PANAMA WITHIN 45 NM EITHER SIDE OF THE ITCZ AXIS BETWEEN 78W AND 80W. LITTLE CHANGE IS EXPECTED IN THIS PATTERN OVER THE NEXT FEW DAYS. GAP WINDS... THE 0304 UTC ASCAT PASS SHOWED N WINDS IN THE 20 TO 25 KT RANGE LINGERING IN THE GULF OF TEHUANTEPEC. WINDS ARE EXPECTED TO DIMINISH BELOW 20 KT THIS AFTERNOON...BUT THIS SHOULD BE A SHORT REPRIEVE. NORTH WINDS ARE EXPECTED TO ONCE AGAIN FUNNEL THROUGH THE ISTHMUS OF TEHUANTEPEC OVERNIGHT MON NIGHT AS A COLD FRONT PASSES SOUTH THROUGH NE MEXICO AND THE WESTERN GULF OF MEXICO ON THE WESTERN SIDE OF HURRICANE IDA. IT SHOULD BE NOTED THAT THERE IS CONSIDERABLE UNCERTAINTY IN THE TIMING AND STRENGTH OF THE GAP WINDS IN THE GULF OF TEHUANTEPEC DUE TO THE UNCERTAINTY IN THE TRACK AND INTENSITY OF IDA. INTERESTS IN THE VICINITY OF THE GULF OF TEHUANTEPEC SHOULD MONITOR THE HIGH SEAS FORECAST THE NEXT FEW DAYS AS MANY OF THE FORECAST MODELS SHOW WINDS INCREASING AGAIN TO GALE STRENGTH BY TUE. $$ SCHAUER