000 AXPZ20 KNHC 040930 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC FRI APR 04 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. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 8N82W 2N94W 2N110W 3N125W 4N140W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM N OF THE AXIS BETWEEN 85W AND 89W. SCATTERED MODERATE ISOLATED STRONG WITHIN 210 NM N OF AXIS BETWEEN 91W AND 94W. ...DISCUSSION... W OF 115W... HAVING BROKEN AWAY FROM THE MAIN BELT OF WESTERLIES TO THE N... A LARGE AND DEEP MID- TO UPPER-LEVEL CYCLONE NW OF THE AREA IS DRIFTING SOUTHWARD ALONG 148W. THE PRESSURE GRADIENT BETWEEN THE CYCLONES ASSOCIATED GALE CENTER NEAR 28N147W AND HIGH PRESSURE OFF THE CALIFORNIA COAST IS LEADING TO SE WINDS OF UP TO 20 KT GENERALLY N OF 25N AND W OF 136W. THE SELY FLOW HAS NOT LASTED LONG ENOUGH YET TO HAVE AN IMPACT ON THE OCEAN SURFACE...BUT SEAS STILL REMAIN NEAR 8 FT OVER THE FAR NW IN LONG PERIOD NW SWELL ASSOCIATED WITH THE LAST GALE CENTER. OVER THE NEXT FEW DAYS MODEL GUIDANCE INDICATES THE NEW GALE CENTER SHOULD SINK FARTHER SOUTH AND STALL BEFORE WEAKENING AND DRIFTING NE LATE IN THE WEEKEND. DURING THIS TIME...A CONTINUED SELY FLOW OF 20 TO PERHAPS 25 KT SHOULD PREVAIL BETWEEN 20N AND 25N AND W OF 134W ...WHICH SHOULD EVENTUALLY RESULT IN 8 TO 11 FT SEAS IN SE WIND WAVES. IN ADDITION...THE EASTERN END OF A STATIONARY FRONT ASSOCIATED WITH THIS FEATURE SHOULD EXTEND INTO THIS SAME AREA...ACCOMPANIED BY OVERRUNNING CLOUDS AND PERHAPS SOME LIGHT PRECIPITATION. TO THE SOUTH...AN INCREASINGLY TIGHTER PRESSURE GRADIENT BETWEEN ROUGHLY 10N AND 20N W OF ABOUT 115W SHOULD RESULT IN A SUBTLE INCREASE TO THE TRADES ACROSS THIS BELT. IN GENERAL...NE TO E WINDS OF 20 TO PERHAPS 25 KT CAN BE EXPECTED ACROSS THIS AREA BY THIS WEEKEND...WITH SEAS BUILDING UP TO 8 OR 9 FT IN ISOLATED SPOTS IN A MIXTURE OF OLD NW SWELL AND NEWLY-GENERATED NE WIND WAVES. E OF 115W... IN THE WAKE OF A SHORTWAVE PUSHING INTO THE SW CONUS...HIGH PRESSURE ARCS SE FROM OFFSHORE THE CALIFORNIA COAST TO SOUTH OF THE BAJA PENINSULA. THE ENHANCED PRESSURE GRADIENT ACROSS THIS AREA HAS LED TO BRISK NW TO N WINDS OF 20 KT DIRECTLY OFFSHORE THE SOUTHERN AND CENTRAL BAJA WEST COAST. INDICATIONS ARE THAT THESE WIND SHOULD THIS SAME NW TO N FLOW SHOULD CONTINUE INTO THE WEEKEND...WITH NW WINDS ALSO OCCASIONALLY PEAKING AROUND 20 KT IN THE SOUTHERN GULF OF CALIFORNIA. THESE FAIRLY LONG-LIVED NW WINDS SHOULD HELP SEAS MATURE TO 8 FT BOTH W OF THE SOUTHERN AND CENTRAL BAJA PENINSULA AND S OF 23N E OF 110W FRI AND SAT BEFORE GRADUALLY SUBSIDING. ELSEWHERE...A RATHER LARGE MID- TO UPPER-LEVEL ANTICYCLONE CENTERED A FEW HUNDRED MILES SOUTH OF THE BAJA PENINSULA HAS SHIFTED W SINCE YESTERDAY...THANKS TO SOME FAIRLY SUBSTANTIAL HEIGHT FALLS OVER MEXICO AND THE GULF OF MEXICO. MODERATE TO STRONG SUBSIDENCE UNDERNEATH THE RIDGE CONTINUES TO INHIBIT ANY SIGNIFICANT CONVECTION S OF 20N E OF 120W NOT TO MENTION MUCH IN THE WAY OF CLOUD COVER. THE ONE EXCEPTION IS FARTHER E...WHERE AN UPPER TROUGH OVER THE W CARIBBEAN EXTENDS SOUTHWESTWARD INTO THE TROPICAL EAST PACIFIC E OF ABOUT 90W. THE UPPER-LEVEL DIFFLUENT FLOW IS HELPING TO IGNITE SCATTERED MODERATE CONVECTION NEAR AND N OF THE ITCZ. FINALLY...LONG PERIOD SW SWELL WITH ORIGINS FROM THE SOUTHERN HEMISPHERE CONTINUES TO ARRIVE ACROSS THE EQUATOR TO MEXICO AND CENTRAL AMERICA. HOWEVER...THE SWELL IS SUBSIDING AND WAVE HEIGHTS OF 6 TO 7 FT ARE MOST COMMON ACROSS MUCH OF THIS AREA...WITH 3 TO 5 FT SEAS CLOSER TO THE MEXICAN AND CENTRAL AMERICAN COASTS. $$ KIMBERLAIN