000 AXPZ20 KNHC 020249 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC THU AUG 02 2012 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0100 UTC. ...TROPICAL WAVES... A TROPICAL WAVE LIES ALONG 97W N FROM 07N TO 13N AND IS MOVING W AT 5-10 KT. THERE IS NO EVIDENCE OF WINDS ABOVE A MODERATE BREEZE ASSOCIATED WITH THIS WAVE. CONVECTION IS LIMITED TO THE S END OF THE WAVE WITH SCATTERED MODERATE CONVECTION FOUND WITHIN 150 NM E OF THE WAVE FROM 07N TO 09N. THIS WAVE LIES IN AN AREA OF RELATIVELY LOW PRECIPITABLE WATER VALUES AND FAIRLY SUBSIDENT MID TO UPPER FLOW ON THE EAST SIDE OF AN UPPER ANTICYCLONE CENTERED NEAR 15N108W. MOISTURE WILL CONTINUE TO BE A LIMITING FACTOR FOR THIS WAVE. IT IS FORECAST TO WEAKEN AS IT CONTINUES WESTWARD. A BETTER DEFINED TROPICAL WAVE IS NOTED ALONG 113W FROM 10N TO 17N. THIS WAVE IS MOVING W AROUND 10 KT. THE 1650 UTC ASCAT PASS SHOWED CYCLONIC TURNING OF THE FRESH WINDS ALONG THE WAVE AXIS FROM 12N TO 15N. WINDS ARE FORECAST TO DIMINISH OVERNIGHT TONIGHT NEAR THE WAVE AS THE SUBTROPICAL HIGH SHIFTS NW AND THE PRES GRADIENT WEAKENS. HOWEVER...THE LOW LEVEL CIRCULATION IS EXPECTED TO HOLD TOGETHER AS IT MOVES TO THE W OVER THE NEXT FEW DAYS. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM E AND 270 NM E OF THE WAVE FROM 13N TO 17N AND ELSEWHERE WITHIN 90 NM W OF WAVE FROM 11N TO 13N. THIS WAVE LIES IN A REGION OF PLENTIFUL LOW LEVEL MOISTURE AND DIFFLUENT FLOW ALOFT BETWEEN ANTICYCLONES CENTERED NEAR 17N121W AND 15N108W. THE WAVE SHOULD CONTINUE TO BE A FOCUS FOR CONVECTION OVER THE NEXT DAY OR SO. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 07N78W TO 08N88W. ITCZ AXIS WAS ANALYZED FROM 08N98W TO 11N112W THEN FROM 10N116W TO 06N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 60 NM EITHER SIDE OF THE AXIS E OF 85W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM N AND BETWEEN 120 NM AND 240 NM S OF THE AXIS BETWEEN 116W AND 123W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 150 NM EITHER SIDE OF THE AXIS W OF 126W. ...DISCUSSION... THE 1030 MB SUBTROPICAL HIGH NEAR 38N139W IS FORECAST TO MOVE NW OVER THE NEXT TWO DAYS...WEAKENING THE RIDGING OVER THE FORECAST AREA. THE BELT OF FRESH TRADE WINDS CURRENTLY FOUND N OF THE ITCZ AND W OF 125W WILL SHRINK WESTWARD BEGINNING LATE THU AS THE SUBTROPICAL HIGH MIGRATES. A STRONG SOUTH PACIFIC SUBTROPICAL RIDGE IS CURRENTLY IN PLACE AND IS FORCING A FRESH SE BREEZE PRIMARILY S OF 06N BETWEEN 110W AND 135W. THE 1652 UTC AND 1832 UTC ASCAT PASSES CONFIRMED THE FRESH BREEZE IN THIS AREA. THE SUBTROPICAL HIGH IN THE SOUTH PACIFIC SHOULD WEAKEN OVERNIGHT AND WINDS WILL DIMINISH. CROSS-EQUATORIAL SE TO S SWELL WILL OOZE INTO THE FORECAST AREA W OF THE GALAPAGOS BEGINNING LATE THU AND SPREAD THROUGH WATERS S OF 06N BY THE END OF THE PERIOD FRI AFTERNOON. A BROAD UPPER TROUGH CENTERED ALONG 130W N OF 22N AND THEN TO 15N138W WILL WEAKEN AS IT MOVES E TO 120W N TO 19N THROUGH FRI EVENING. ENERGY OVER THE GULF OF CALIFORNIA WEDGED BETWEEN THIS TROUGH AND A VAST ANTICYCLONE CENTERED OVER TEXAS WILL LIFT NORTHWARD THROUGH THE GULF TODAY AND MEET UP WITH AN UPPER LOW OVER THE SW UNITED STATES. THE SURFACE REFLECTION OF THE ENHANCED TROUGHING ALOFT SHOULD ALLOW THE PRES GRADIENT TO INCREASE ENOUGH ALONG THE PACIFIC COAST OF BAJA CALIFORNIA SUR TO SUPPORT NW WINDS BRIEFLY BECOMING A FRESH BREEZE THU EVENING INTO EARLY FRI MORNING BEFORE DIMINISHING. STRONG UPPER LEVEL DIFFLUENCE BETWEEN 30-40 KT SOUTHWESTERLIES ON THE S SIDE OF THE AFOREMENTIONED BROAD TROUGH ALONG 130W AND WEAK ANTICYCLONIC FLOW S OF THE RIDGE AXIS THAT EXTENDS FROM THE ANTICYCLONE AT 17N121W TO 11N137W IS ENHANCING CONVECTION ALONG THE ITCZ AXIS W OF 126W. THERE IS PLENTIFUL MOISTURE POOLED ALONG THE ITCZ. THESE CONDITIONS ARE EXPECTED TO CONTINUE FOR THE NEXT DAY OR SO AND BEGIN TO WANE LATE FRI AS THE UPPER TROUGH PASSES EASTWARD AND THE AIR MASS BEGINS TO BECOME DRIER. $$ SCHAUER