000 AXPZ20 KNHC 102138 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU JAN 10 2013 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 06N78W TO 05N90W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 05N90W TO 05N110W TO 08N122W TO 06N130W TO 07N140W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM EITHER SIDE OF THE ITCZ BETWEEN 117W AND 120W...AND ALSO WITHIN 150 NM S OF THE ITCZ BETWEEN 123W AND 126W. ...DISCUSSION... AT THE UPPER LEVELS...AN UPPER SHORTWAVE TROUGH IS MOVING ACROSS THE WESTERN SEABOARD OF THE CONUS WITH THE TROUGH CONTINUING S INTO THE DISCUSSION AREA THROUGH 32N119W TO 29N130W. AN UPPER LEVEL ANTICYCLONE IS OVER THE DEEP TROPICS AT 08N116W WITH A SHORTWAVE RIDGE EXTENDING NW TO A CREST AT 30N140W...AND A SECOND RIDGE EXTENDING NE TO A CREST OVER EASTERN NEW MEXICO. THE PREVIOUSLY MENTIONED UPPER TROUGH IS ERODING THE RIDGE BETWEEN THE TWO CRESTS. AN UPPER CYCLONE NE OF THE BIG ISLAND OF HAWAII AT 26N151W HAS AN UPPER TROUGH EXTENDING E TO SE ACROSS THE DISCUSSION AREA FROM 27N140W TO 18N128W. THIS PATTERN SETS UP A LARGE AREA OF UPPER DIFFLUENCE WHICH EXTENDS S OVER THE ITCZ CONVECTION PREVIOUSLY MENTIONED. THE RESULTANT DEBRIS MOISTURE IS ADVECTED NE UNDER THE WESTERN RIDGE...BECOMING ORGANIZED INTO A TROPICAL PLUME WHICH CONTINUES NE ACROSS EXTREME SOUTHERN CALIFORNIA...THE ENTIRE BAJA CALIFORNIA PENINSULA...THE GULF OF CALIFORNIA...AND NW MEXICO. THIS MOISTURE IS FEEDING INTO A DEEP LAYERED CYCLONE OVER NE TEXAS AND SE OKLAHOMA. THE CYCLONE HAS AN UPPER TROUGH EXTENDING S ACROSS THE FAR WESTERN GULF OF MEXICO ALONG 95W TO A BASE OVER THE TROPICAL PACIFIC AT 10N104W. A BROAD UPPER RIDGE EXTENDS NW FROM WESTERN ECUADOR TO AN ILL-DEFINED CREST OVER HONDURAS. THESE TWO UPPER FEATURES COMBINE TO DRY OUT THE UPPER LEVELS S OF 20N E OF 110W...EXCEPT FOR A NARROW MOISTURE PLUME PRECEDING THE UPPER TROUGH ACROSS SE MEXICO AND GUATEMALA...WITHIN 360 NM E OF THE TROUGH AXIS LOCATION. AT THE LOW LEVELS...A WEAKENING SURFACE COLD FRONT FROM NEAR TIJUANA MEXICO THROUGH 26N123W TO 24N121W IS BEING SUPPORTED BY THE FIRST MENTIONED UPPER TROUGH OVER THE FAR NORTHERN WATERS. NE-E WINDS AT 20-30 KT WITH SEAS 8-15 FT IN NE SWELL IS NOTED W AND NW OF THE FRONT. TRADES ARE AT 20-25 KT ALONG WITH SEAS OF 8-12 FT IN MIXED NE AND NW SWELL FROM 09-24N W OF 129W. A CONGLOMERATION OF NE AND NW SWELL OF 8-9 FT IS PROPAGATING S ACROSS THE REMAINDER OF THE AREA W OF A LINE FROM 24N129W TO 17N120W TO 04N110W TO 00N130W. THE FRONT WILL DEGENERATE INTO A REMNANT SHEAR LINE BY FRI AFTERNOON WITH NE-E WINDS AT 25-30 KT COVERING THE AREA FROM 18N TO 27N W OF 130W ALONG WITH SEAS UP TO 16 FT IN MAINLY NE SWELL. THE NE AND NW SWELL WILL COVER THE WATERS W AND NW OF A LINE FROM 23N110W TO 10N113W TO 00N140W BY SAT AFTERNOON...WITH THE HIGHEST SEAS OUTSIDE OF ANY ENHANCED TRADES UP TO 13 FT JUST W OF THE BAJA CALIFORNIA PENINSULA BY THEN. GULF OF CALIFORNIA...CURRENT MODEL GUIDANCE IS NOT AS AGGRESSIVE AS PREVIOUS MODEL RUNS AND SUGGESTS THAT THE SW-W WINDS WILL INCREASE ONLY TO 20-25 KT N OF 29.5N AS THE WEAKENING FRONT PASSES THROUGH THE AREA. NW WINDS BEHIND THE FRONT WILL THEN DIMINISH TO 15-20 KT BY FRI AFTERNOON AS THE PRES GRADIENT RELAXES OVER NW MEXICO. GAP WINDS...THE GULF OF PAPAGAYO WILL PULSE ON A DIURNAL CYCLE THE NEXT FEW DAYS WITH NE-E WINDS AT 20-25 KT ACROSS THE WATERS E OF 91W PRIMARILY DURING THE LATE NIGHT AND EARLY MORNING HOURS. MEANWHILE...RELATIVELY TRANQUIL CONDITIONS...WINDS 20 KT OR LESS AND SEAS OF 2-4 FT...OCCASIONALLY UP TO 6 FT DURING PEAK DRAINAGE FLOW...ARE EXPECTED IN THE VICINITY OF THE GULF OF TEHUANTEPEC THROUGH EARLY NEXT WEEK. $$ LEWITSKY