000 AXPZ20 KNHC 121005 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON MAR 12 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0945 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH NOT PRESENT ACROSS E PACIFIC. ITCZ AXIS EXTENDS FROM 04N93W TO S OF THE EQUATOR AT 107W AND THEN CONTINUES W-SW IN THE SOUTHERN HEMISPHERE. SCATTERED STRONG CONVECTION WAS WITHIN 60 NM N OF THE AXIS BETWEEN 95W-101W. ...DISCUSSION... THE MAIN NOTICEABLE FEATURE AFFECTING PART OF THE REGION IS A BROAD TROUGH COVERING THE EASTERN PACIFIC WATERS N OF THE DISCUSSION WITH ITS SRN PERIPHERY EXTENDING S TO OVER THE FAR NRN BOUNDARY OF THE DISCUSSION AREA. WITHIN THIS BROAD TROUGH A COUPLE OF SHORTWAVE TROUGHS ARE PRESENTLY NOTED. THE FIRST EXTENDS FROM NRN BAJA CALIFORNIA SW TO 22N125W...AND IS QUICKLY MOVING EASTWARD. THE SECOND.... APPEARING STRONGER ON SATELLITE WATER VAPOR IMAGERY... WAS RAPIDLY SWEEPING ESE JUST CROSSING THE FAR NW CORNER OF THE AREA. THE WATER VAPOR IMAGERY ALSO REVEALED MOSTLY MODERATE SUBSIDENCE IN W TO NW FLOW W OF THE FIRST TROUGH. A CENTRAL PACIFIC JET STREAM BRANCH EXTENDS INTO THE AREA THROUGH 22N140W AND NEWD ROUNDING THE BASE OF THE TROUGH. A JET MAXIMA CROSSING INTO THE FAR WRN PART OF THE AREA FROM 15N-19N W OF 137W AND BEYOND 140W IS PRECEDED BY AND ALSO FOLLOWED BY UPPER LEVEL MOSITURE IN THE FORM OF BROKEN TO SCATTERED HIGH CLOUDS STREAMING AS FAR E AS 128W FROM 16N-23N. SCATTERED HIGH CLOUDS ARE NOTED WITHIN 150 NM SE OF THE JET STREAM E OF 128W. THESE CLOUDS ARE PASSING ACROSS CENTRAL BAJA CALIFORNIA...AND TO OVER FAR NW MEXICO AND NE FROM THERE TO OVER CENTRAL TEXAS AND NWD TO THE PLAINS STATES. ELSEWHERE GENERALLY ZONAL FLOW DOMINATES THE MAJORITY OF THE REMAINDER OF THE AREA...WITH THE EXCEPTION OF THE FAR SE SECTION OF THE AREA WHERE A RATHER WEAK UPPER TROUGH IS NOTED BETWEEN 84W AND 96W WITH MEAN AXIS ALONG 91W. SLIGHTLY DIFFLUENT FLOW OVER THE FAR SRN PART OF THE BASE OF THE TROUGH IS FIRING UP CONVECTION JUST N OF THE ITCZ AS DESCRIBED ABOVE. OTHERWISE...SATELLITE WATER VAPOR IMAGERY SHOWS QUITE AND EXTENSIVE AREA OF MODERATE TO STRONG SUBSIDENCE COVERING THE JUST ABOUT ALL OF THE ERN PART OF THE AREA S AND SE OF THE JET STREAM BRANCH. DEEP ATMOSPHERIC MOISTURE IS ONLY CONFINED OVER THE FAR SRN WATERS IN RELATION TO THE CONVECTION OCCURRING JUST N OF THE ITCZ. THE DEBRIS CLOUDINESS FROM THIS CONVECTION IS BEING DRIVEN EASTWARD BY THE UPPER W TO NW FLOW TO THE W OF THE WEAK TROUGH. A WEAK FRONT OVER THE FAR NW WATERS JUST RECENTLY DISSIPATED ...HOWEVER A MORE SIGNIFICANT FRONT IS FORECAST TO MOVE INTO THE NW PORTION OF THE AREA LATE TONIGHT INTO TUE WITH SW WINDS POSSIBLY INCREASING TO 20 KT N OF 29N WITHIN 300 NM AHEAD OF IT. THE FRONT IS FORECAST TO WEAKEN FROM NEAR 30N133W TO 26N140W BY LATE TUE NIGHT AS THE BROAD UPPER TROUGH TRANSLATED EASTWARD. MODELS SUGGEST THAT THIS TROUGH THEN SHEARS OUT TO THE SW ACROSS THE NRN AND CENTRAL SECTIONS OF THE AREA BEGINNING ON WED WITH SOME INDICATIONS THAT A CUT-OFF UPPER LOW FORMS OVER THE FAR WRN PART OF THE AREA BEYOND THE FORECAST PERIOD. ELSEWHERE AT THE SURFACE...THE EPAC HIGH PRES RIDGE WAS CENTERED ON A 1036 MB HIGH OVER THE NORTH-CENTRAL PACIFIC WELL NW OF THE HAWAIIAN ISLANDS. THE RIDGE BRIDGED ACROSS THE RECENTLY DISSIPATED COLD AND EXTENDS ALONG 28N/29N. THE PRES GRADIENT TO THE S OF THE RIDGE WAS INDUCING NE TRADES OF 20-25 KT GENERALLY FROM 05N TO 19N W OF 130W...AND LIGHTER NE TRADES OF 20 KT FROM 05N TO 16N BETWEEN 120W AND 130W WITH SEAS IN THE 9-11 FT RANGE ...HIGHEST LOCATED W OF 130W. THIS AREA OF TRADES IS FORECAST TO DIMINISH IN THE SRN 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 1019 TO 1020 MB HIGH CENTER IN THE NE PART OF THE AREA. 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 DECAY SOME THIS MORNING ALLOWING FOR SEAS TO BE IN THE RANGE OF 9-10 FT. ANOTHER BATCH OF LONG PERIOD NW SWELLS WILL ARRIVE WITH THE STRONGER COLD FRONT TUE MORNING AND PRODUCE SEAS OF 9-12 FT N OF 24N AND W OF 127W BY TUE EVENING. THESE SEAS ARE FORECAST BY WAVEWATCH MODEL GUIDANCES TO LINGER INTO WED. GAP WINDS... THE GULF OF TEHUANTEPEC...THE SMALL AND NARROW PLUME OF NORTHERLY WINDS HAVE DIMINISHED TO 20 KT WITHIN 45 NM OF THE COAST AS OF EARLY THIS MORNING. MODEL WIND GUIDANCE SUGGESTS THAT N-NE WINDS WILL INCREASE TO 20-25 KT IN THE NEXT 3-6 HRS ...AND CONTINUE THROUGH THE NEXT 48 HOURS AS THEY INCREASE SOME IN AREAL COVERAGE TO THE S. WINDS MAY BRIEFLY APPROACH 30 KT WITHIN THE NEXT 36-48 HRS. THE GULF OF PAPAGAYO...FRESH TRADES ACROSS THE CARIBBEAN CONTINUE TO FUEL GAP WIND FLOW ACROSS CENTRAL AMERICA THEN THROUGH THE GULFS OF PAPAGAYO AND FONSECA AND WELL SW TO NEAR 92W THIS AFTERNOON...WITH DOWNWIND SEAS PRESENTLY AT 8 TO 10 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. THE WINDS ARE EXPECTED TO SPREAD DOWNSTREAM FROM THE GULF TO 93W OR 94W AT 24 AND 48 HRS WITH NE-E WINDS OF 20 KT REACHING AS FAR W AS 115W. 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. BOTH OSCAT AND ASCAT DATA FROM LATE LAST NIGHT CAPTURED THESE WINDS. THE OSCAT PASS FROM JUST PAST 0300 UTC EVEN SHOWED A SMALL AREA OF N-NE 20 KT WINDS N OF 06N BETWEEN 81W-83W. SEAS ARE LESS THAN 8 FT THERE...BUT ARE EXPECTED TO BUILD TO 8 FT IN 24 HRS BEFORE SUBSIDING TO LESS THAN 8 FT IN 36 TO 48 HRS. $$ AGUIRRE