000 AXPZ20 KNHC 171604 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SAT APR 17 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1545 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 7N78W 7N90W 8N101W 5N111W 5N120W 6N129W 5N140W. SCATTERED MODERATE CONVECTION IS S OF THE AXIS BETWEEN 120W-126W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM N OF THE AXIS BETWEEN 130W-135W...AND WITHIN 180 NM S OF THE AXIS BETWEEN 111W-115W AND 60 NM OF THE AXIS BETWEEN 95W-98W. ...DISCUSSION... A WELL DEFINED CYCLONIC VORTEX EMBEDDED IN A DEEP LAYER TROUGH IS OBSERVED ON SATELLITE WATER VAPOR IMAGERY TO BE JUST W OF THE AREA NEAR 29N141W. THE LOW IS COLLOCATED WITH THE SURFACE LOW OF 1006 MB AT THE SAME POSITION WITH A COLD FRONT EXTENDING TO 30N136W TO 25N137W TO SW OF THE AREA NEAR 22N140W. THE LOW IS MOVING ENE ABOUT 17 KT. DRY AIR INTRUSION FROM W OF THE AREA IS NOTED AS A SWATH OF MODERATE SUBSIDENCE PRESENT WITHIN 150 NM SE AND S OF THE VORTEX. AN UPPER LEVEL ANTICYCLONE IS QUASI STATIONARY NEAR 10N121W WITH A HIGHLY AMPLIFIED RIDGE EXTENDING N TO WELL BEYOND THE AREA TO OVER THE WESTERN U.S. ANOTHER RIDGE EXTENDS W FROM THE ANTICYCLONE TO 10N140W. BROAD ANTICYCLONIC CIRCULATION COVERS THE AREA BETWEEN 105W-139W EXCEPT NW OF A LINE FROM 30N136W TO 22N140W WHERE THE DEEP LAYER TROUGH MENTIONED ABOVE IS LOCATED. UPPER LEVEL DIFFLUENCE SITUATED TO THE SW AND W OF THE ANTICYCLONE CONTINUES TO SUPPORT ENHANCED ITCZ CONVECTION BETWEEN 120W-135W. A VERY PRONOUNCED SUBTROPICAL JET STREAM BRANCH ROUNDS THE BASE OF THE TROUGH THROUGH 23N140W...AND TURNS NE TO N OF THE AREA AT 30N133W. SATELLITE-DERIVED WINDS SHOW WINDS IN THE RANGE OF 90-150 KT IN THE RIGHT ENTRANCE REGION OF THE JET. THESE VERY FAST WINDS IN COMBINATION WITH SW WINDS IN THE NW SEMICIRCLE OF THE ANTICYCLONE ARE ACTING TO TRANSPORT AMPLE MID AND UPPER LEVEL MOSITURE IN THE FORM OF BROKEN TO OVERCAST CLOUDS...FURTHER ENHANCED BY DEBRIS MOISTURE FROM ITCZ CONVECTION...NE TOWARDS THE NE PORTION OF THE AREA AS WELL AS TO N OF THE AREA TOWARDS SRN CALIFORNIA. SOME OF THE MOISTURE WRAPS AROUND THE AMPLIFIED RIDGE SEWD TO ACROSS BAJA CALIFORNIA AND MUCH OF WRN AND CENTRAL MEXICO. A DEEP LAYER TROUGH EXTENDS FROM THE WRN GULF OF MEXICO SWD TO ACROSS SE MEXICO...AND WELL INTO THE E PACIFIC TO 10N93W TO 4N93W...THEN CURVES SW TO ALONG THE EQUATOR REACHING TO NEAR 109W. MODERATE SUBSIDENCE AND ASSOCIATED DRY AIR IS LOCATED TO THE SE AND S OF THE TROUGH. A SURFACE TROUGH IS NOTED FROM 5N101W TO 11N96W...AND IS AIDING ITCZ CONVECTION IN THAT VICINITY. SW WINDS DUE TO THE UPPER TROUGH ARE ADVECTING DEBRIS MOISTURE NE ACROSS HONDURAS AND NICARAGUA WELL INTO THE WRN CARIBBEAN SEA. ALL OF THIS DEBRIS MOISTURE IS MAINTAINING THE UPPER LEVELS OF THE TROPICS QUITE MOIST. ELSEWHERE AT THE SURFACE...A 1020 MB HIGH IS CENTERED NEAR 27N125W WITH A WEAK RIDGE SE TO NEAR 17N112W. A 1019 MB HIGH IS JUST N OF THE AREA NEAR 33N127W. WITH THE HIGH FORECAST TO DISSIPATE DURING THE NEXT 24 HRS...THE 1006 MB AND COLD FRONT WILL THEN PROGRESS INTO THE NW WATERS OF THE AREA OVER THE NEXT 24 TO 48 HRS WHILE WEAKENING. THE PRES GRADIENT BETWEEN THE RIDGE AND THE COLD FRONT MENTIONED IN FIRST PARAGRAPH WILL INCREASE S-SW WINDS AHEAD OF THE FRONT TO THE RANGE OF 20-30 KT...BUT THEN WEAKEN TO 20-25 KT IN 24 HRS AND TO LESS THAN 20 KT IN 48 HRS. EXPECT SEAS TO MAX OUT TO ABOUT 15 FT IN A NW SWELL BEHIND THE FRONT IN 24 HRS AS THE FRONT REACHES A PSN FROM THE LOW NEAR 30N133W TO 27N130W TO 21N132W...WEAKENING TO 16N136W. FURTHER S...NE TRADES OF 20 KT ARE OCCURRING FROM 8N TO 13N BETWEEN 115W AND 130W WITH THIS AREA OF TRADES EXPECTED TO SHRINK TO W OF 132W IN 48 HRS AS THE GRADIENT RELAXES. RESIDUAL N SWELLS WILL ALLOW FOR SEAS IN THE RANGE OF 8-11 FT IN 48 HRS WITHIN THIS AREA. THE PRES GRADIENT BETWEEN THE AFOREMENTIONED SURFACE HIGH PRESSURE...AND A TROUGH OVER THE SIERRA MADRE OCCIDENTAL...IS PRODUCING NW WIND SURGES TO 20 KT WITHIN 120 NM W OF NRN BAJA CALIFORNIA. THESE WINDS ARE EXPECTED TO DIMINISH IN 24 HRS. ALSO A SMALL AREA OF 20 KT WITHIN 60 NM OF THE GULF OF TEHUANTEPEC IS FORECAST TO DIMINISH IN ABOUT 12 HRS. $$ AGUIRRE