000 AXPZ20 KNHC 232204 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT JUN 23 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...THE MONSOON TROUGH EXTENDS FROM 13N88W TO 12N97W WHERE IT ENDS. IT THEN RESUMES AT 15N104W AND CONTINUES TO 10N120W TO 05N128W WHERE LOW LEVEL WINDS SUGGEST IT TRANSITIONS TO THE ITCZ TO 03N134W TO 04N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM S OF THE MONSOON TROUGH BETWEEN 88W-93W AND ALSO WITHIN 60 NM S OF THE TROUGH BETWEEN 110W-124W. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM S OF THE ITCZ W OF 136W. ...DISCUSSION... A LARGE UPPER ANTICYCLONE IS LOCATED NEAR 22N132W MOVING SLOWLY SE WITH A RIDGE NW THROUGH 24N140W...AND ANOTHER RIDGE SE TO 20N125W. BROAD UPPER TROUGHING ASSOCIATED WITH A LARGE CYCLONIC VORTEX OFF THE NW PACIFIC U.S. COAST IS PRESENT TO THE N OF THE ANTICYCLONE. A SHORTWAVE TROUGH EMBEDDED WITHIN THE BROAD TROUGH IS OVER THE FAR NE PART OF THE AREA FROM 32N122W TO 27N118W. SATELLITE WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE SUBSIDENCE OVER JUST ABOUT THE ENTIRE REGION N OF TROPICAL MOISTURE THAT IS PRESENT TO THE W OF 110W ASSOCIATED WITH THE MONSOON TROUGH AND ITCZ. A NEARLY STATIONARY UPPER ANTICYCLONE IS OVER INLAND MEXICO AT 21N102W WITH A RIDGE SW TO 15N120W. STRONG NE TO E FLOW PERSISTS ON SRN PERIPHERY OF ANTICYCLONE. THE FLOW BECOMES DIFFLUENT FROM 07N TO 14N BETWEEN 93W AND 107W...AND HELPING TO SUSTAIN SCATTERED MODERATE TO STRONG CONVECTION FROM 09N-15N BETWEEN 93W-104W. EXTENSIVE UPPER LEVEL MOISTURE ASSOCIATED WITH THIS CONVECTION CONTINUES TO BE ADVECTED WESTWARD BY THE SAME NE TO E FLOW S OF THE ANTICYCLONE. THE UPPER ANTICYCLONE AT 22N132W WILL REBUILD TO THE SW WITHIN NEXT THE 48 HRS...WHILE THE TROUGH ALSO BECOMES REPOSITIONED FROM NE TO SW ACROSS FAR NW AND N PORTIONS OF AREA. A WEAK COLD FRONT ASSOCIATED WITH THE TROUGH IS FORECAST TO DROP SWD TOWARDS THE FAR NW CORNER OF THE DISCUSSION AREA ON SUN... AND REACH A LINE FROM NEAR 32N130W TO 25N140W BY LATE MON. A BRIEF INSTANCE OF 20 KT N WINDS MAY JUST TOUCH THE FAR NW PORTION SUN INTO EARLY MON WHERE SEAS 7-8 FT IN A N SWELL ARE POSSIBLE. LONG-TERM ANIMATED SATELLITE IMAGERY REVEALS VERY SHORT AMPLITUDE TROPICAL WAVES MOVING ACROSS WRN S AMERICA. SOME OF THIS WAVE ENERGY MAY EMERGE INTO THE LOW LATITUDES OF THE FAR ERN PORTION OF THE PACIFIC OVER THE NEXT FEW DAYS...LEADING TO THE DEVELOPMENT OF MORE CONVECTIVE ACTIVITY THERE. ELSEWHERE AT THE SURFACE...A RIDGE AXIS EXTENDS INTO THE DISCUSSION AREA THROUGH 31N140W AND REACHES SE TO NEAR 24N123W. THE RIDGE IS BRIDGING ACROSS A COLD FRONT THAT STRETCHES FROM SRN CALIFORNIA SW TO 30N122W...THEN BECOMES RATHER FRACTURED TO 26N136W. AN ASCAT PASS FROM 1834 UTC THIS AFTERNOON REVEALED LIGHT NW-N WINDS ACROSS THE FRONT. A TROUGH OF LOW PRES IS ANALYZED ALONG THE WRN EDGE OF THE GULF OF CALIFORNIA. THE PRES DIFFERENCE BETWEEN THIS TROUGH AND THE RIDGE IS RESULTING IN NW WINDS OF 20 KT WITH SEAS TO 8 FT N OF 24N E OF 122W. WITH THE APPROACH OF THE WEAK COLD FRONT INTO THE FAR NW PORTION ON SUN...THIS WILL ACT TO BREAK DOWN THE RIDGE ALLOWING FOR THE PRES DIFFERENCE BETWEEN THE RIDGE AND BAJA CALIFORNIA TROUGH TO WEAKEN. THIS EFFECT WILL LOWER THE NW 20 KT WINDS TO LESS THAN 20 KT ON SUN. THE SAME 1834 UTC ASCAT PASS ALSO DEPICTED N-NE 15 KT WINDS WERE IN THE FAR NW CORNER OF THE AREA. ELSEWHERE GENERALLY LIGHT NE-E TRADES WERE NOTED NW OF THE MONSOON TROUGH AND ITCZ...AND LIGHT SLY WINDS WERE NOTED S OF THESE SAME FEATURES. $$ AGUIRRE