000 AXPZ20 KNHC 082157 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC THU NOV 08 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 W ACROSS THE GULF OF PANAMA FROM COLOMBIA AT 08N77W TO 09N84W...THEN TURNS WSW TO 07N97W WHERE LOW LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ...WHICH TURNS NW TO 10N114W...THEN SW THROUGH 05N134W TO BEYOND 05N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 60 NM EITHER SIDE OF A LINE FROM 08N85W TO 08N100W AND A SECOND LINE FROM 05N116W TO 08N123W TO 06N136W. SCATTERED MODERATE TO STRONG CONVECTION...WITH FREQUENT LIGHTNING STRIKES...IS OBSERVED FROM 07N-16N BETWEEN 105W-118W. ...DISCUSSION... BROAD UPPER TROUGHING EXISTS ACROSS THE SUBTROPICAL PORTION OF THE DISCUSSION AREA WITH THE MEAN AXIS FROM 32N120W TO 06N115W. A REINFORCING SHORTWAVE TROUGH IS NOW MOVING INTO THE LONGWAVE PATTERN FROM 32N120W TO 29N130W TO 27N140W...THEN INTO AN UPPER CYCLONE JUST W OF THE AREA AT 24N145W. THE RESULT IS UPPER WESTERLY FLOW ACROSS THE ENTIRE AREA TO THE N OF 20N. UPPER DEBRIS MOISTURE IS OBSERVED NE OF THE LONGWAVE TROUGH AXIS... AND IS FANNING OUT ACROSS THE SOUTHWESTERN CONUS IN BROAD UPPER RIDGING. W-NW DIFFLUENT UPPER FLOW IS NOTED S OF 20N W OF 115W...AND IS SUPPORTING THE CONVECTION DESCRIBED BETWEEN 116W-136W...WITH THE DEBRIS MOISTURE ADVECTED SE AND ACROSS THE EQUATOR BETWEEN 115W-124W. AN UPPER LEVEL ANTICYCLONE IS STATIONARY AT 12N95W WITH AN UPPER RIDGE EXTENDING N ACROSS CENTRAL OLD MEXICO...AND CONTINUING N ACROSS MOST OF N AMERICA. UPPER DIFFLUENCE ALONG THE W PERIPHERY OF THE ANTICYCLONE IS ENHANCING THE AREA OF MODERATE TO STRONG CONVECTION FROM 07N-16N AS PREVIOUSLY DESCRIBED. THE DEBRIS MOISTURE IS ADVECTED N AND NE ACROSS W OLD MEXICO FROM 15N-21N. THE REINFORCED UPPER TROUGH WILL PROGRESS E ACROSS THE WESTERN CONUS THROUGH THE UPCOMING WEEKEND MAINTAINING THE UPPER WESTERLY FLOW ACROSS THE DISCUSSION AREA TO THE N OF 12N. AN UPPER CYCLONE WILL DEVELOP OVER THE DEEP TROPICS AT 03N110W SPLITTING THE UPPER FLOW OVER THE DISCUSSION AREA TO THE S OF 12N. AT THE LOW LEVELS A WEAK COLD FRONT IS STILL SET TO SWEEP THROUGH THE NE WATERS ON FRI-SAT...WITH STRONG HIGH PRESSURE BUILDING S ACROSS THE N-CENTRAL WATERS IN THE WAKE OF THE FRONT ON FRI...WITH NLY WINDS OF 20 KT AND SEAS TO 10 FT IN N SWELL. THIS INCREASING PRESSURE GRADIENT WILL ARRIVE THE W COAST OF THE NORTHERN BAJA PENINSULA IN THE FORM OF NW 15-20 KT WINDS LATE FRI...WITH SEAS OF 6-8 FT IN NW SWELL ARRIVING ON SAT. THESE CONDITIONS WILL SPREAD S ALONG THE ENTIRE W COAST OF BAJA BY MIDDAY SUN. BY THEN A SURFACE RIDGE WILL EXTEND FROM 32N130W TO 20N110W. NE TRADES WILL INCREASE TO 20-25 KT S OF THE RIDGE ACROSS THE TROPICS FROM 11N-22N W OF 115W ON SUN. GAP WINDS...THE 30-40 KT GALE WINDS IN/DOWNSTREAM OF THE GULF OF TEHUANTEPEC ARE EXPECTED CONTINUE THROUGH SUNRISE SAT THEN DIMINISH TO LESS THAN GALE FORCE...AND QUICKLY WEAKEN TO NEAR CALM BY LATE SUN. NLY WINDS WILL AGAIN SURGE INTO THE GULF OF TEHUANTEPEC LATE MON AND RAPIDLY INCREASE TO GALE FORCE MON NIGHT. EXPECT THE NE 20-25 KT WINDS IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO TO PULSE THROUGH SUN AFTERNOON. THE RESULTANT NE SWELL WILL PROPAGATE W TO ALONG 94W...MERGING WITH THE SWELL ORIGINATING FROM THE NORTHERLY WINDS SURGING THROUGH THE GULF OF TEHUANTEPEC. CROSS EQUATORIAL SOUTHERLY SWELL...RESULTING IN SEAS TO 8 FT... ARE NOTED ACROSS THE DEEP TROPICS S OF 07N BETWEEN 97W-120W. THESE SOUTHERLY SWELLS ARE EXPECTED TO DIMINISH BELOW 8 FT BY LATE FRI NIGHT. $$ NELSON