000 AXPZ20 KNHC 190318 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC SUN SEP 19 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0315 UTC. ...ITCZ... AXIS EXTENDED FROM 11N128W TO 9N140W. A MONSOON TROUGH AXIS EXTENDED FROM COSTA RICA TO 8N85W TO 9N92W...THEN BECAME LESS DEFINED BEFORE IT CONTINUED AT 13N94W TO 1FROM 13N96W TO A 1007 MB LOW AT 16N105W TO A 1008 MB LOW AT 13N111W TO 13N118W TO ANOTHER 1008 MB AT 12N128W. SCATTERED MODERATE CONVECTION WAS WITHIN 180 NM N OF THE AXIS BETWEEN 101W-107W. ...DISCUSSION... ALOFT... A DEEP TROUGH IN THE NE PACIFIC APPROACHING THE OREGON COAST EXTENDED ACROSS FAR NW PORTION OF AREA FROM A LARGE CYCLONIC VORTEX WELL N OF THE AREA NEAR 44N131W SW INTO THE AREA AT 32N137W TO SW OF THE AREA AT 27N140W. AHEAD OF THE TROUGH A POLAR JET STREAM BRANCH STRETCHED FROM 26N140W TO NE OF THE REGION AT 32N130W. WATER VAPOR IMAGERY SHOWED AN ANTICYCLONE GRADUALLY MOVING W NEAR 26N119W WITH A RIDGE EXTENDING SW OF THE AREA AT 18N140W. ANOTHER RIDGE EXTENDED ESE FROM THE ANTICYCLONE TO FAR SOUTHERN BAJA CALIFORNIA. THE IMAGERY ALSO SHOWED AN EXTENSIVE AREA OF MODERATE SUBSIDENCE WITH RESULTANT STABLE ENVIRONMENT N OF 19N E OF THE TROUGH...AND S OF THE TROUGH TO THE ITCZ REGION W OF 131W. S OF THE ANTICYCLONE...VERY STRONG UPPER LEVEL EASTERLY WINDS WERE NOTED WITH DIVERGENT ANTICYCLONIC FLOW E OF 112W ENHANCING DEEP CONVECTION ACROSS THE TROPICAL BELT REGION. SURFACE... DEEP LAYER TROUGH MENTIONED ABOVE WAS SUPPORTING A COLD FRONT THAT EXTENDED FROM 32N130W TO 26N140W MOVING E ABOUT 15 KT. THE FRONT WILL WEAKEN TO A FRONTAL TROUGH FROM 30N127W TO 26N140W IN ABOUT 24 HOURS...THEN DISSIPATE ON MON. SW WINDS TO 20 KT WERE INDICATED WITHIN 180 NM E OF THE FRONT N OF 29N...WHILE NW TO N WINDS TO 20 KT WERE W OF THE FRONT N OF 29N. SEAS TO 8 FT IN NW SWELL WERE NOTED WITHIN THESE WIND AREAS ON EITHER SIDE OF THE FRONT...BUT WILL SUBSIDE TO LESS THAN 8 FT BY 48 HOURS. WEAK RIDGING AHEAD OF THE FRONT COMBINING WITH LOWER PRES OVER NW MEXICO AND BAJA CALIFORNIA HAD INCREASED NW TO N WINDS OF 20 KT N OF 26N E OF 120W TO THE BAJA CALIFORNIA COAST. THESE CONDITIONS ARE FORECAST TO CHANGE LITTLE OVER THE NEXT 2 DAYS. SW WINDS ASSOCIATED WITH ACTIVE MONSOON TROUGH E OF 125W IS BEING FOCUSED BY A STRING OF CURRENT WEAK LOWS AS MENTIONED ABOVE UNDER ITCZ. THE LOW NEAR 16N104W APPEARED TO BE GAINING MOMENTUM OVER THE PAST SEVERAL HOURS AS GLOBAL MODELS HAVE BEEN HINTING DURING THE PAST SEVERAL DAYS. THIS WAS NOTED BY CYCLONIC CIRCULATION OF LOW CLOUD LINES TO ITS E...AND BY THE RECENT LARGE BURST OF NUMEROUS STRONG CONVECTION TO ITS N CONFINED FROM 16N TO 20N BETWEEN 104W AND 106W. THE LOW WAS NEARLY STATIONARY...BUT IS FORECAST TO TRACK NW DIRECTION AFTER ABOUT 24 HOURS. MARINE... THE FRESH TO STRONG SW WINDS S OF THE MONSOON TROUGH AXIS ARE PRODUCING SEAS MAXING OUT TO 12 FEET WITHIN 180 NM IN THE SE SEMICIRCLE OF THE LOW NEAR 16N104W. THESE WINDS ARE EXPECTED TO INCREASE TO 30 KT CLOSE TO OR AT 24 HOURS AS THE LOW INTENSIFIES AS LARGE SWELLS WILL CONTINUE TO PROPAGATE FROM THE SW OVER A BROAD AREA OF THE EASTERN PORTION OF EASTERN PACIFIC TO THE S OF THE MONSOON TROUGH. $$ AGUIRRE