000 AXPZ20 KNHC 111609 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN MAR 11 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 1500 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH NOT PRESENT ACROSS E PACIFIC. ITCZ AXIS EXTENDS FROM 04N90W TO THE EQUATOR ALONG 107W AND THEN CONTINUES W-SW IN THE SOUTHERN HEMISPHERE. SCATTERED MODERATE CONVECTION NOTED WITHIN 60 NM N AND 30 NM S OF AXIS. ...DISCUSSION... A LARGE MIDDLE TO UPPER LEVEL CUT-OFF LOW OVER THE SW U.S. YESTERDAY HAS BEGUN TO LIFT OUT TO THE NE OVERNIGHT AND THIS MORNING...WITH TRAILING MID LEVEL TROUGH EXTENDING SW ACROSS NRN MEXICO AND THE S TIP OF THE BAJA PENINSULA TO NEAR 21N113W. TO THE E OF THIS WAS A SHORTWAVE RIDGE ACROSS CENTRAL AMERICA EXTENDING N-NE INTO THE SE U.S. OTHERWISE...GENERALLY ZONAL FLOW DOMINATED ALL BUT NW PORTIONS OF THE DISCUSSION AREA. A BROAD AND ENERGETIC UPPER TROUGH DOMINATES THE NE PACIFIC N OF 29N TODAY...WITH SEVERAL SHORTWAVES MOVING THROUGH THE TROUGH. PRESENTLY...A SHORTWAVE MOVING THROUGH THE BASE OF THE TROUGH WAS NEAR THE CENTRAL CALIFORNIA COAST EXTENDING SW TO NEAR 29N136W...WITH MIDDLE TO UPPER LEVEL TROUGH EXTENDING WWD IN A TUTT LIKE FASHION TO BEYOND 20N150W. THIS FEATURE SUPPORTS A COLD FRONTAL BOUNDARY THAT WAS APPROACHING THE FAR NW CORNER OF THE DISCUSSION AREA THIS MORNING. THIS FRONT WILL DRIFT SE AND INTO FAR NW PORTIONS OF THE AREA THIS EVENING AND BECOME NEARLY STATIONARY ON MON BEFORE DISSIPATING TUE. TO WAS LIFTING NEWD. A TROUGH EXTENDED FROM THE LOW SW TO ACROSS NORTHERN MEXICO SW TO SOUTHERN BAJA CALIFORNIA. WATER VAPOR IMAGERY SHOWED MODERATE TO STRONG SUBSIDENCE NW OF THE TROUGH AXIS COVERING THE AREA N OF 19N AND SE OF A LINE FROM NORTHERN BAJA CALIFORNIA TO 19N134W. BEHIND THE TROUGH...A FLATTENING MID/UPPER RIDGE WAS CHARACTERIZED BY THE UPPER FLOW PATTERN ACQUIRING MORE OF ZONAL PATTERN. A BROAD UPPER TROUGH WAS BRUSHING THE FAR NW PORTION OF THE DISCUSSION AREA...WHILE A VIGOROUS UPPER LEVEL LOW WELL W OF THE DISCUSSION AREA WAS HELPING TO TRANSPORT VIA A JET STREAM MOSTLY UPPER LEVEL MOISTURE IN THE FORM OF BROKEN TO SCATTERED HIGH CLOUDS INTO THE FAR WESTERN PORTION OF THE AREA FROM 17N TO 25N W OF 135W. THE JET STREAM BRANCH EXTENDED INTO THE AREA THROUGH 24N140W NE TO 27N127W. JET SEGMENTS IN THE ZONAL FLOW ALOFT WERE IDENTIFIED ENTERING W PORTIONS OF THE AREA S OF THE MIDDLE TO UPPER TROUGH BETWEEN 130W AND 140W...WHILE A SOUTHERN BRANCH WAS NOTED FROM 12N TO 16N BETWEEN 120W AND 130W. THE BROAD UPPER TROUGH OVER THE NE PACIFIC IS FORECAST TO SHIFT EASTWARD THROUGH MON AS A MORE PRONOUNCED UPPER TROUGH MOVES INTO THE NW PORTION OF THE DISCUSSION AREA LATE MON INTO TUE. ELSEWHERE AT THE SURFACE...THE EPAC HIGH PRES RIDGE WAS CENTERED ON A 1037 MB HIGH OVER THE CENTRAL PACIFIC NW OF THE HAWAIIAN ISLANDS...BRIDGING ACROSS THE COLD FRONT AND SE TO NEAR 19N107W. THE PRES GRADIENT TO THE S OF THE RIDGE WAS INDUCING NE TRADES OF 20-25 KT GENERALLY N OF 05N TO A LINE FROM 21N140W TO 12N123W WITH SEAS IN THE 8-12 FT RANGE. THIS AREA OF TRADES IS FORECAST TO DIMINISH IN THE SOUTHERN LATITUDES BY THE NEXT 24 HRS...THEN DIMINISH CONSIDERABLY BOTH IN AREAL COVERAGE AND IN WIND SPEEDS BY 48 HRS AS THE RIDGE BREAKS DOWN TO A 1018 TO 1020 MB HIGH CENTER IN THE NE PART OF THE AREA. THIS WILL THEN ALLOW FOR A STRONGER COLD FRONT SUPPORTED BY THE MORE PRONOUNCED TROUGH TO MOVE INTO THE FAR NW WATERS LATE MON NIGHT INTO TUE PRECEDED BY SW WINDS OF 20 KT. THE MAIN IMPACT OF THESE FRONTS MOVING INTO THE NORTHERN WATERS THROUGH THE NEXT 48 HRS WILL BE THE ASSOCIATED PULSES OF LONG PERIOD NW SWELLS SWEEPING SE ACROSS THE AREA. NWLY SWELL CURRENTLY ACROSS NW PORTIONS OF THE AREA WILL SLOWLY DECAY THROUGH TONIGHT ALLOWING FOR SEAS TO LOWER TO 9 FT FOR THE MOST PART. ANOTHER PULSE OF LONG PERIOD SWELLS WILL ARRIVE WITH THE STRONGER COLD FRONT TUE MORNING AND PRODUCE SEAS OF 9 TO 10 FT N OF 27N AND W OF 125W BY TUE EVENING. GAP WINDS... THE GULF OF TEHUANTEPEC...A SMALL AND NARROW PLUME OF N WINDS 20-25 KT CONTINUES THROUGH THE GULF THIS MORNING BUT IS EXPECTED TO WEAKEN TO LESS THAN 20 KT BY THIS EVENING...THEN INCREASE AGAIN TO 20-25 KT LATE TONIGHT THROUGH TUE. THE GULF OF PAPAGAYO...FRESH TRADES ACROSS THE CARIBBEAN CONTINUE TO FUEL GAP WIND FLOW ACROSS CENTRAL AMERICA THEN THROUGH THE GULF OF PAPAGAYO AND WELL SW TO NEAR 92W THIS MORNING...WITH DOWNWIND SEAS PRESENTLY AT 8 TO 9 FT. HIGH PRES IS EXPECTED TO BUILD S AND SW ACROSS THE BAHAMAS AND W CARIBBEAN IN THE NEXT 24 HOURS AND WILL REINFORCE THIS FLOW THROUGH THROUGH THE GULF...WITH AREAS TO 30 KT EXPECTED LATE TONIGHT. THIS AREA OF 20 KT WINDS AND HIGHER IS EXPECTED TO SPREAD WILL DOWNWIND TO 110W BY TUE MORNING DUE TO THE INCREASED PRES GRADIENT ACROSS THE W CARIBBEAN. THE GULF OF PANAMA...TRADES IN THE SOUTHWESTERN CARIBBEAN SEA WILL CONTINUE TO SUPPORT PULSES OF FRESH NORTHERLY FLOW ACROSS THE ISTHMUS OF PANAMA AND ACROSS THE GULF OF PANAMA. SEAS OF 6 TO 8 FT ARE EXPECTED TO CONTINUE S AND SW OF THE GULF. LITTLE CHANGE IN THIS WIND PATTERN IS EXPECTED THROUGH THE NEXT 24-48 HOURS. $$ STRIPLING