000 AXPZ20 KNHC 080242 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON APR 08 2013 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 0045 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 06N77W TO 10N85W TO 05N100W. THE ITCZ AXIS WAS ANALYZED FROM 05N100W TO 07N115W TO 02N140W. ISOLATED MODERATE CONVECTION WAS WITHIN 150 NM S OF THE AXIS BETWEEN 84W AND 95W. SCATTERED MODERATE CONVECTION WAS WITHIN 120 NM N AND 180 NM S OF THE AXIS BETWEEN 108W AND 131W. ...DISCUSSION... GULF OF CALIFORNIA...A COLD FRONT WILL PASS THROUGH THE GULF OF CALIFORNIA N OF 29N MON EVENING. SOUTHERLY WINDS WILL INCREASE TO A FRESH TO STRONG BREEZE AHEAD OF THE FRONT MON AFTERNOON AND SHIFT WESTERLY BEHIND THE FRONT MON EVENING. FUNNELING THROUGH MOUNTAIN PASSES WILL MAKE WINDS LOCALLY STRONGER...POSSIBLY TO GALE FORCE. WINDS WILL DIMINISH BY TUE MORNING AS THE FRONT RACES EASTWARD. RELATIVELY ZONAL WESTERLY FLOW ASSOCIATED WITH A WIDE 60 KT UPPER JET CENTERED FROM 05N140W TO 17N130W AND ALONG 17N INTO SOUTHERN MEXICO DOMINATES MUCH OF THE PACIFIC FORECAST AREA WITH A FEW EXCEPTIONS. TO THE W OF THE AREA...A COMPLEX UPPER LOW IS CAUSING THE JET AXIS TO DIP SOUTHWARD OVER W WATERS AND TAP INTO TROPICAL MOISTURE ALOFT. THIS MOISTURE IS MANIFESTED AS CIRRUS FROM 07N TO 22N W OF 130W. TO THE S OF THE JET...UPPER DIFFLUENCE ALONG A RIDGE AXIS THAT EXTENDS FROM A WEAK ANTICYCLONE OVER THE GULF OF PANAMA TO 11N94W IS ENHANCING ISOLATED MODERATE CONVECTION ALONG THE MONSOON TROUGH. A LARGER AREA OF SCATTERED MODERATE CONVECTION LIES ALONG THE ITCZ BETWEEN 110W-130W. BOTH AREAS OF CONVECTION ARE DESCRIBED IN THE SECTION ABOVE. THE WESTERN AREA IS CONINCIDENT WITH PRECIPITABLE WATER VALUES AROUND 60 MILLIMETERS AND A REGION OF STRONG UPPER DIFFLUENCE. TO THE N OF THE JET...WINDS ARE SHIFTING NW ON THE SW EDGE OF A DEEPENING UPPER TROUGH OVER THE WESTERN U.S. THAT WILL MAKE THE PATTERN MORE AMPLIFIED OVER MUCH OF THE FORECAST AREA TONIGHT THROUGH TUE. THE 1030 MB SUBTROPICAL SURFACE HIGH LIES NEAR 33N141W AND EXTENDS A RIDGE SOUTHEASTWARD TO 12N100W. THE PRESSURE GRADIENT BETWEEN THE SUBTROPICAL RIDGE AND THE ITCZ IS FORCING FRESH TO STRONG NE TRADE WINDS FROM 10N-20N W OF 130W AS SEEN BY THE 1918 UTC ASCAT AND 2124 UTC OSCAT PASSES. THE HIGH IS EXPECTED TO REMAIN RELATIVELY STATIONARY AND SHOW LITTLE CHANGE IN PRESSURE THROUGH EARLY TUE. THIS SHOULD KEEP THE FRESH TO STRONG TRADE WINDS IN PLACE OVER WESTERN WATERS. BY TUE EVENING...THE HIGH WILL SHIFT NE AHEAD OF A COLD FRONT WELL N OF THE AREA. THIS WILL WEAKEN THE SUBTROPICAL RIDGE OVER THE FORECAST AREA AND BRING TRADES DOWN TO A MODERATE TO FRESH BREEZE. THE PRESSURE GRADIENT ON THE E SIDE OF THE SUBTROPICAL RIDGE IS FORCING FRESH TO STRONG WINDS N OF 27N ALONG THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA TO 123W AS SEEN BY THE 1732 UTC ASCAT PASS AND 1942 UTC OSCAT PASS. FRESH TO STRONG NW WINDS WILL EXPAND AS FAR W AS 128W OVER THE NEXT TWO DAYS AS THE NORTHERN STREAM TROUGH MOVES INTO THE WESTERN U.S...SENDING A COLD FRONT THROUGH FAR NE WATERS LATE MON. A GALE WARNING IS IN EFFECT FOR WATERS N OF 30N ON MON AND TUE. 16-18 SECOND PERIOD NW SWELL CURRENTLY LIES OFF THE BAJA CALIFORNIA PACIFIC COAST. THIS DAMPENING NW SWELL IS COMBINING WITH NW WIND WAVES IN PACIFIC WATERS OFF THE BAJA CALIFORNIA PENINSULA...WITH SEAS EXPECTED TO REACH 15 FT S OF 30N BY MON EVENING. THE LEADING EDGE OF THE NW SWELL TRAIN...WITH PERIODS EXCEEDING 20 SECONDS...WILL CLIP THE CENTRAL MEXICAN COAST NEAR CABO CORRIENTES TONIGHT AND REACH THE GALAPAGOS ISLAND BY TUE AFTERNOON. $$ SCHAUER