000 AXPZ20 KNHC 261514 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN SEP 26 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...SPECIAL FEATURE... EAST SHEAR OVER THE LOW PRES SYSTEM NEAR 15N108W IS DISPLACING THE CONVECTION WITH THE LOW TO WITHIN 180 NM OF ITS W SEMICIRCLE. EASTERLY SHEAR IS EXPECTED TO CONTINUE TO TAKE ITS TOLL ON THE SYSTEM OVER THE NEXT 24 HOURS...BUT THEN AN ANTICYCLONE IS EXPECTED TO SHIFT SW OVER THE NEARLY STATIONARY AREA OF LOW PRES AT THE SURFACE WHICH WOULD MAKE CONDITIONS MORE FAVORABLE FOR THE SYSTEM TO POSSIBLY BECOME A TROPICAL CYCLONE WITHIN THE NEXT 48 HOURS. PLEASE SEE THE LATEST TROPICAL WEATHER OUTLOOK FROM THE NATIONAL HURRICANE CENTER FOR MORE DETAILS. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE IS ANALYZED 12N95W TO 08N110W TO 11N120W THEN RESUMES AT 12N125W TO 10N140W. NO SIGNIFICANT CONVECTION IS NOTED. ...DISCUSSION... E OF 115W.... AN UPPER-LEVEL ANTICYCLONE IS CENTERED OVER CENTRAL MEXICO NEAR 21N99W AND A RIDGE EXTENDS FROM THIS ANTICYCLONE TO ANOTHER ANTICYCLONE NEAR 29N123W. EAST WINDS ON THE SOUTH SIDE OF THIS RIDGE ARE RESPONSIBLE FOR THE EASTERLY SHEAR OVER THE SURFACE LOW AT 15N108W AS DESCRIBED ABOVE. TROUGHING ALOFT ASSOCIATED WITH AN UPPER LOW MOVING SOUTHWARD INTO NW MEXICO EXTENDS FROM THE LOW TO JUST N OF THE RIDGE AXIS ALONG 109W. UPPER LEVEL DIFFLUENCE BETWEEN THE SE SIDE OF THE TROUGH AXIS AND THE ANTICYCLONE TO THE E IS ENHANCING CONVECTION NEAR THE MOUTH OF THE GULF OF CALIFORNIA WITHIN 120 NM OF THE COAST OF MAINLAND MEXICO FROM 21N TO 25N. THIS UPPER LOW IS FORECAST TO SHIFT W TO THE NORTHERN BAJA AS THE RIDGE ALOFT CONSOLIDATES TO ITS S OVER THE NEXT FEW DAYS NEAR THE SURFACE LOW DESCRIBED ABOVE. THIS PATTERN IS FORECAST TO ALLOW FOR SOME INTENSIFICATION OF THE LOW PRES SYSTEM AND...ALONG WITH THE WESTWARD MOVEMENT OF THE REMNANTS OF MATTHEW THROUGH SOUTHERN MEXICO...WILL ENHANCE SW SURFACE FLOW E OF THE SURFACE LOW FROM ROUGHLY 05N TO 15N...WITH WINDS REACHING AS HIGH AS 30 KT. SEAS WILL BUILD ACCORDINGLY... REACHING AS HIGH AS 11 FT OFF THE CENTRAL AMERICAN COAST BY MID WEEK. THE 0338 UTC ASCAT PASS ALREADY SHOWS AN AREA OF S TO SW WINDS OFF THE COAST OF NICARAGUA AND COSTA RICA IN THE 25-30 KT RANGE. SCATTERED MODERATE CONVECTION CAN BE FOUND N OF 09N BETWEEN 86W AND 90W AND FROM 08N TO 10N BETWEEN 91W AND 100W WITH SIMILAR CONVECTION NOTED FROM 12N TO 14N BETWEEN 95W AND 100W. W OF 115... CONVECTION REMAINS ANEMIC HERE DUE A LACK OF DEEP LAYER MOISTURE...WITH THE BULK OF THE E PAC MOSITURE TRAPPED E OF 115W. A QUASI-STATIONARY 1011 MB SURFACE LOW PRES SYSTEM IS NOTED ALONG THE ITCZ NEAR 12N135W. AN ASCAT PASS FROM 0520Z SHOWED WINDS REMAIN LESS THAN 20 KT NEAR THIS LOW. FURTHER SOUTH...CROSS-EQUATORIAL SWELL IS EXPECTED TO GRADUALLY RAISE SEAS ABOVE 8 FT OVER FAR SW WATERS S OF 10N AND W OF 130W BEGINNING OVERNIGHT TONIGHT. MEANWHILE...15-17 SECOND PERIOD SWELL IS PUSHING INTO THE NW PORTION OF THE DISCUSSION AREA FROM THE N CENTRAL ATLANTIC. SEAS ARE CURRENTLY AS HIGH AS 12 FT WITH THIS SWELL TRAIN. THE FORECAST CALLS FOR NW SWELL OF 10 TO 13 FT TO SPREAD SE THROUGH THE AREA...REACHING THE SOUTHERN TIP OF THE BAJA PENINSULA TUE. $$ SCHAUER/CHRISTENSEN