000 AXPZ20 KNHC 060939 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU JAN 06 2011 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 0900 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS IS CENTERED ALONG 05N80W TO 08N96W TO 05N109W TO 09N118W TO 10N129W TO 08N140W. NO SIGNIFICANT CONVECTION. ...DISCUSSION... A FILLING 1016 MB LOW PRES IS CENTERED NEAR 28N129W. A RIDGE EXTENDS FROM A 1025 MB HIGH PRESSURE CENTERED N OF THE AREA NEAR 40W128W TO W OF THE AREA NEAR 22N145W. THE PRESSURE GRADIENT BETWEEN THIS RIDGE AND THE LOW IS CREATING FRESH NE WINDS TO 20 KT W OF THE LOW AS INDICATED BY RECENT WINDSAT PASS. THIS LOW WILL DISSIPATE WITHIN THE NEXT 24 TO 30 HOURS WITH ASSOCIATED WINDS DIMINISHING BELOW 20 KT. THE PRESSURE GRADIENT BETWEEN THE RIDGE MENTIONED ABOVE AND LOWER PRESSURE ASSOCIATED WITH THE ITCZ IS MAINTAINING A SMALL AREA OF 20 KT TRADES FROM 14N TO 18N W OF 135W. AS THE ITCZ SHIFTS TO A POSITION SLIGHTLY FURTHER S OVER THE NEXT 24 HOURS...THE PRESSURE GRADIENT WILL RELAX ENOUGH TO DIMINISH TRADES BELOW 20 KT. EVEN THOUGH THE TRADES DIMINISH BELOW 20 KT...LINGERING NW SWELLS WITH SEAS OF 8-10 FT WILL PREVAIL OVER MUCH OF THE AREA W OF 100W. AS THE LOW PRESSURE CENTER MENTIONED IN THE PREVIOUS PARAGRAPH FILLS...RIDGING WILL BUILD OVER THE EASTERN PART OF THE AREA N OF 20N. THIS WILL TIGHTEN THE PRESSURE GRADIENT W OF BAJA CALIFORNIA...AND INCREASE WINDS TO 20 KT WITHIN 90 NM OF THE BAJA CALIFORNIA COAST BY LATE FRI NIGHT. STRONG HIGH PRESSURE OVER THE GREAT BASIN REGION COMBINED WITH LOW PRESSURE OVER SW MEXICO IS CREATING A PRESSURE GRADIENT WHICH IS SUPPORTING NW WINDS OF 20-25 KT OVER THE GULF OF CALIFORNIA. AS THE HIGH PRESSURE OVER THE GREAT BASIN REGION WEAKENS OVER THE NEXT 48 HOURS...THE PRESSURE GRADIENT WILL RELAX AND 20 KT WINDS OVER THE GULF OF CALIFORNIA WILL DECREASE FROM N TO S. A TROUGH EXTENDS FROM 15N117W TO 09N120W. LATEST ASCAT PASS AND SATELLITE IMAGERY INDICATES FRESH TO STRONG NE WINDS AND ACTIVE CONVECTION PREVAIL TO THE WEST OF THE TROUGH AXIS. THIS TROUGH WILL DISSIPATE AND ASSOCIATES WINDS WILL DIMINISH WITHIN 48 HOURS. A STATIONARY 1009 MB LOW IS OVER THE FAR EASTERN PORTION OF THE AREA NEAR 05N78W...THERE IS NO SIGNIFICANT CONVECTION OR WINDS ASSOCIATED WITH THIS LOW. GAP WINDS... A COLD FRONT OVER THE GULF OF MEXICO WILL CONTINUE MOVING EASTWARD PAST THE BAY OF CAMPECHE TODAY. DENSER AIR BEHIND THIS FRONT WILL FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC TODAY...WITH N WINDS INCREASING TO 20 KT THIS AFTERNOON...THEN INCREASING TO 30 KT LATE TONIGHT/EARLY FRI. THERE IS A PROGRESSIVE UPPER LEVEL LEVEL PATTERN WHICH WILL QUICKLY SHIFT THE COLD HIGH PRESSURE IN THE WAKE OF THE FRONT INTO THE CENTRAL GULF OF MEXICO FRI NIGHT. THIS WILL RESULT IN SE RETURN FLOW DEVELOPING OVER THE WESTERN GULF OF MEXICO...AND DIMINISH THE WINDS FUNNELING THROUGH THE CHIVELA PASS. AS A RESULT...WINDS ARE EXPECTED TO DIMINISH BELOW 20 KT FRI NIGHT...WITH A SMALL AREA OF 8 FT NE SWELL LINGERING SW OF THE GULF OF TEHUANTEPEC. WINDS OVER GULF OF PAPAGAYO REMAIN IN THE 20 KT RANGE. TRADES WILL DIMINISH OVER THE WESTERN CARIBBEAN TODAY. THIS WILL DECREASE THE WINDS FUNNELING THROUGH THE CENTRAL AMERICA PASSES...AND WINDS OVER THE GULF OF PAPAGAYO WILL DIMINISH BELOW 20 KT BY THIS AFTERNOON. AS THE COLD FRONT CURRENTLY OVER THE GULF OF MEXICO CONTINUES MOVING EASTWARD INTO THE WESTERN CARIBBEAN...WINDS FUNNELING THROUGH THE CENTRAL AMERICA PASSES WILL ONCE AGAIN INCREASE...WITH WINDS INCREASING TO 20 KT OVER THE GULF OF PAPAGAYO LATE FRI NIGHT. $$ AL