000 AXPZ20 KNHC 260926 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI SEP 26 2008 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 0915 UTC. ...TROPICAL WAVES... TROPICAL WAVE IS ALONG 86W N OF 06N MOVING W 10-15 KT. THERE HAS BEEN LITTLE EVIDENCE OF THIS FEATURE OVER THE PAST FEW DAYS...THEREFORE ITS CURRENT POSITION IS BASED ON FORWARD EXTRAPOLATION. THE INTERACTION WITH A DIFFLUENT UPPER PATTERN IS TRIGGERING SCATTERED TSTMS ACROSS THE N PORTION OF THE WAVE OVER CENTRAL AMERICA. TROPICAL WAVE IS ALONG 97W N OF 08N MOVING W 10 KT. A WEAK CIRCULATION IS LOCATED ALONG THE WAVE AXIS NEAR 15N...THOUGH IT IS POSSIBLY INDEPENDENT OF THE WAVE. SCATTERED SHOWERS AND TSTMS ARE WITHIN 90 NM W OF THE WEAK LOW. TROPICAL WAVE IS ALONG 109W FROM 06N TO 17N MOVING W 10 KT. SHORTWAVE IR IMAGES CONTINUE TO SHOW FAIRLY WELL DEFINED MID-LEVEL CYCLONIC TURNING ALONG OR JUST E OF THE WAVE AXIS NEAR 14N. HOWEVER...THERE DOES NOT APPEAR TO BE MUCH OF AN INFLUENCE AT THE SFC. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED E OF THE WAVE N OF 16N BETWEEN 100W AND 104W. GLOBAL MODELS HINT AT SOME WEAK SFC LOW PRESSURE DEVELOPMENT OVER THE NEXT COUPLE OF DAYS EITHER FROM THIS WAVE OR THE ONE BEHIND IT. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 12N86W TO 12N100W TO 10N115W TO 12N132W TO 09N140W. SCATTERED MODERATE TO STRONG CONVECTION IS FROM 10N TO 14N BETWEEN 130W AND 137W. ...DISCUSSION... W OF 110W... A 1009 MB LOW PRESSURE SYSTEM...ONCE AN AREA FOR CONCERN FOR TROPICAL DEVELOPMENT...IS TRACKING WSW AT 10 KT CURRENTLY CENTERED ABOUT 500 NM SW OF THE SRN TIP OF BAJA CALIFORNIA NEAR 16N115W. CONVECTION HAS ONCE AGAIN DIURNALLY REDEVELOPED WITHIN 240 NM W QUADRANT TONIGHT. A QSCAT PASS AT 0220 Z REVEALED 20 KT WINDS OVER MUCH OF THE NW SEMICIRCLE AND A JASON-1 ALTIMETER PASS AROUND 0100 Z SHOWED MAX SEAS NEAR 9 FT JUST W OF THE CENTER. THIS LOW IS EXPECTED TO CONTINUE ON ITS WSW PATH AND EVENTUALLY DEGENERATE COMPLETELY INTO A LOW-LEVEL SWIRL AS ITS ENCOUNTERS VERY STABLE AIR. ANOTHER LOW IS LOCATED NEAR 11N134W. CONVECTION HAS INCREASED SIGNIFICANTLY TONIGHT...BUT IT REMAINS EMBEDDED WITHIN THE ITCZ. THE TIGHTENED PRESSURE GRADIENT BETWEEN THIS LOW AND HIGH PRES N OF THE AREA IS PRODUCING 20 KT NE TRADES FROM 12N-18N W OF 128W. IN THE MID AND UPPER LEVELS...RIDGING EXTENDS SW FROM SOUTHERN MEXICO ALONG 21N105W 13N132W AND AN UPPER TROUGH IS WEAKENING ALONG 30N128W 14N137W. CONFLUENCE BETWEEN THESE FEATURES IS ENHANCING DRY AIR ALOFT. E OF 110W... A MID TO UPPER RIDGE OVER AND JUST W OF SOUTHERN MEXICO CONTINUES TO PROVIDE NE TO E SHEAR OVER THE TROPICAL WAVES LIMITING THE CHANCE OF ORGANIZATION. WATER VAPOR IMAGES REVEAL ABUNDANT HIGH LEVEL MOISTURE OVER THIS ENTIRE REGION BUT CONVECTION IS CONFINED N OF 13N BETWEEN 85W AND 104W...WHERE THE UPPER FLOW IS SLIGHTLY DIFFLUENT. GAP WINDS...THE COMBINATION OF HIGH PRES BUILDING S OVER MEXICO AND LOW PRES OVER THE SE CONUS WILL SET UP N WINDS OF 20-25 KT IN THE GULF OF TEHUANTEPEC FRI NIGHT THROUGH THE WEEKEND. $$ CANGIALOSI