000 AXPZ20 KNHC 191531 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC TUE JUN 19 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1430 UTC. ...SPECIAL FEATURES... BOTH FIRST VISIBLE SATELLITE IMAGERY FROM THIS MORNING AND A SSMIS MICROWAVE PASS SHOWED THAT THE LOW LEVEL CIRCULATION ASSOCIATED WITH THE LOW PRES NEAR 18N107W REMAINS TOTALLY EXPOSED DUE TO A MODERATE NE WIND VERTICAL SHEAR WITH THE DEEP CONVECTION WITHIN 180 NM TO THE SW OF LOW CENTER. A BAND OF NUMEROUS MODERATE TO ISOLATED STRONG CONVECTION IS NOTED TO THE E OF THE CENTER FROM 16N TO 19N E OF 104W TO THE MEXICAN COASTLINE. THE LOW REMAINS EMBEDDED IN THE NE PORTION OF THE MONSOON TROUGH...WITH STRONG SW TO S WINDS CONTINUING ACROSS A BROAD AREA SE OF THE LOW AND THE TROUGH. UPPER-LEVEL WINDS REMAIN MARGINALLY CONDUCIVE FOR DEVELOPMENT...AND ONLY A SMALL INCREASE IN ORGANIZATION WOULD RESULT IN THE FORMATION OF A TROPICAL DEPRESSION DURING THE NEXT DAY OR SO. THIS SYSTEM HAS A HIGH CHANCE OF BECOMING A TROPICAL CYCLONE DURING THE NEXT 48 HOURS AS IT DRIFTS EASTWARD. INTERESTS ALONG THE SOUTHWESTERN COAST OF MEXICO SHOULD MONITOR THE PROGRESS OF THIS SYSTEM. REGARDLESS OF DEVELOPMENT...LOCALLY HEAVY RAINFALL AND THE THREAT FOR FLASH FLOODS AND MUD SLIDES WILL CONTINUE OVER PORTIONS OF SOUTHWESTERN MEXICO FOR THE NEXT COUPLE OF DAYS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH FROM 07N78W ALONG THE PACIFIC COAST OF CENTRAL AMERICA TO 14N94W THEN FROM LOW PRES NEAR 18N107W TO 10N125W. ITCZ FROM 110N125W TO BEYOND 10N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION FROM 01N TO 08N E OF 81W...N OF 13N BETWEEN 90W AND 98W...AND FROM 10N TO 13N BETWEEN 112W AND 121W. ...DISCUSSION... ALOFT...A MIDDLE TO UPPER LEVEL CUT OFF LOW IS NEAR 26N134W AND SHIFTING W. AN INVERTED TROUGH...REFLECTION OF THIS LOW IS NOTED AT THE SURFACE EXTENDING FROM 30N130W TO 20N137W. UPPER RIDGING GENERALLY PREVAILS BETWEEN THIS LOW AND NW MEXICO...INCLUDING THE BAJA CALIFORNIA PENINSULA. THE RIDGE IS ANCHORED ON AN ANTICYCLONIC CIRCULATION LOCATED NEAR 24N117W. UPPER DIFFLUENCE ON THE SE AND S PARTS OF THIS SYSTEM IS HELPING TO INDUCE CONVECTION NEAR THE LOW PRES AT 18N107W AND ALONG THE MONSOON TROUGH. THE RIDGE ALSO EXTENDS SE ALONG THE MEXICAN COAST. UPPER LEVEL NE WINDS PREVAIL E OF 100W. AT THE SURFACE...A 1030 HIGH PRES CENTERED NEAR 40N143W EXTENDS A RIDGE OVER THE NW CORNER OF THE FORECAST AREA. A VERY TIGHT PRES GRADIENT CONTINUES BETWEEN THE SURFACE TROUGH MENTIONED ABOVE...AND THIS HIGH...YIELDING FRESH TO STRONG NELY WINDS ACROSS NW PORTIONS OF THE DISCUSSION AREA...PARTICULARLY N OF 24N AND W OF THE TROUGH AXIS WITH SEAS OF 8 TO 11 FT. GLOBAL MODELS INDICATE THAT THE TROUGH WILL DRIFT WWD WHILE THE HIGH PRES WILL WEAKEN AND SHIFT SW...RESULTING IN A GRADUAL DECREASE IN WINDS AND SEAS ACROSS THE NW WATERS OVER THE NEXT 48 HOURS. A WEAK 1016 MB HIGH IS CENTERED NEAR 25N125W AND WILL MOVE W-NW OVER THE NEXT 24 HOURS TO A POSITION NEAR 25.5N129W. AS MENTIONED ABOVE...SW WINDS OF 20-25 KT ARE NOTED IN A LARGE AREA SE OF LOW PRES CENTER NEAR 18N107W...AND ALONG AND SE OF THE MONSOON TROUGH THERE...COVERING ROUGHLY FROM 14N TO 17N BETWEEN 102W AND 108W...AND WITHIN 90 NM SE OF THE MONSOON TROUGH FROM 15N109 TO 12N114W. THE SW FLOW EXTENDS FARTHER E AND BECOMES WLY ALONG THE PACIFIC COAST OF MEXICO TO OFFSHORE OF THE GULF OF TEHUANTEPEC. THIS FLOW IS BRINGING ABUNDANT TROPICAL MOISTURE ACROSS THESE AREAS...PROVIDING THE POTENTIAL FOR PERIODS OF LOCALLY HEAVY RAIN AND THE THREAT FOR FLASH FLOODS AND MUDSLIDES...PARTICULARLY OVER MOUNTAINOUS AND STEEP TERRAIN. THIS PATTERN IS EXPECTED TO REMAIN IN PLACE FOR THE NEXT FEW DAYS AND WILL MAINTAIN A WET WEATHER PATTERN ACROSS CENTRAL AMERICA AND SOUTHERN MEXICO. $$ GR