000 AXPZ20 KNHC 012157 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC FRI MAR 01 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2030 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS WAS ANALYZED FROM 05N77W TO 07N85W TO 01N110W TO 02N113W. THE ITCZ AXIS WAS ANALYZED FROM 02N113W TO 04N136W TO 03N140W. SCATTERED MODERATE CONVECTION WAS WITHIN 150 NM N OF THE AXIS E OF 90W AND WITHIN 120 NM S OF THE AXIS E OF 84W. SCATTERED MODERATE CONVECTION WAS WITHIN 210 NM N OF THE AXIS BETWEEN 100W AND 108W AS WELL AS WITHIN 240 NM N OF THE AXIS BETWEEN 120W AND 134W. ...DISCUSSION... GULF OF TEHUANTEPEC...NORTHERLY WINDS AT GALE FORCE SHOULD CONTINUE TO STRENGTHEN TO A STRONG GALE JUST BEFORE SUNRISE ON SAT...THEN FURTHER STRENGTHENING TO A MINIMAL STORM AROUND MIDDAY ON SAT BEFORE DIMINISHING TO A STRONG GALE AGAIN AROUND MIDDAY SUN. THE SOUTHERN EXTENT OF 25 KT WINDS WILL REACH ALONG AS FAR AS 08N ON SUN. MOST IMPRESSIVE IS THE LARGE AREA OF N SWELL PROPAGATING S FROM THE TEHUANTEPEC COAST WHICH WILL RESULT IN SEAS 8 FT OR GREATER EVENTUALLY COVERING THE PACIFIC WATERS FROM 03N TO 15N BETWEEN 91W AND 108W ON SUN. GULFS OF PAPAGAYO AND FONSECA...NORTHEASTERLY WINDS WILL BEGIN TO SURGE THROUGH THE GULFS OF PAPAGAYO AND FONSECA OVERNIGHT SAT NIGHT AND QUICKLY SHIFT S TO THE GULF OF PAPAGAYO SUN. LOOKING AHEAD...GUIDANCE SUGGESTS THE NE FLOW WILL INCREASE TO A MINIMAL GALE JUST DOWN STREAM OF THE GULF OF PAPAGAYO AROUND SUNRISE ON MON. GULF OF CALIFORNIA...NW TO N WINDS HAVE DIMINISHED TO 20 TO 25 KT OVER THE GULF OF CALIFORNIA FROM 24N-29N THIS AFTERNOON. THE 1658 UTC ASCAT PASS CONFIRMED THESE CONDITIONS. N SWELL IS PROPAGATING FROM THE GULF INTO THE PACIFIC WATERS NEAR ITS MOUTH...WITH SEAS TO 9 FT FOUND AS FAR S AS 16N. WINDS WILL DIMINISH TO A MODERATE TO FRESH BREEZE ON SAT. SEAS WILL GRADUALLY SUBSIDE DURING THIS TIME...FALLING BELOW 8 FT BY MIDDAY SAT. A NEGATIVELY TILTED...SHARP UPPER TROUGH OVER W WATERS IS BEING OVERTAKEN BY A NEW...AMPLIFYING UPPER TROUGH APPROACHING FROM THE NW. A 60-80 KT SOUTHERLY UPPER JET ON THE LEADING EDGE OF THIS BROAD TROUGHING IS CENTERED ALONG 135W AND IS DIRECTING MOISTURE FROM THE ITCZ OVER MUCH OF THE AREA W OF 125W. MUCH OF THIS MOISTURE IS MANIFESTED AS MULTIPLE-LAYER CLOUDS WITH SCATTERED SHOWERS IN THE REGION N OF 15N. THE REAR RIGHT QUADRANT OF THE JET IS SUPPORTING THE MOST VIGOROUS CONVECTION WITHIN 240 NM N OF THE ITCZ AXIS BETWEEN 120W AND 134W WHERE LOW LEVEL MOISTURE IS THE MOST ABUNDANT. THE NEW TROUGH WILL AMPLIFY W OF THE AREA AND TURN POSITIVE TILT...REORIENTING THE UPPER JET. PRECIPITATION IS EXPECTED TO GRADUALLY WANE OVER WESTERN WATERS THE NEXT FEW DAYS AS A RESULT. THE 1500 UTC WINDSAT PASS SHOWED THE CENTER OF THE SUBTROPICAL HIGH PRES CIRCULATION IS NEAR 38N128W. THE HIGH HAS BEEN IMPEDED ON BY A COLD FRONT APPROACHING FROM THE W...WEAKENING THE SUBTROPICAL RIDGING OVER THE FORECAST AREA. THE RIDGE AXIS EXTENDS SOUTHWARD FROM THE HIGH TO NEAR 15N128W. PRIMARILY MODERATE TO FRESH NE TRADE WINDS LIE W OF THE RIDGE AXIS. A TROUGH IS EMBEDDED IN THIS NE FLOW FROM 26N135W TO 21N140 ACCORDING TO THE 1840 UTC ASCAT PASS. THIS IS THE SURFACE REFLECTION OF THE AFOREMENTIONED UPPER BROAD TROUGH TO THE W. THE STRENGTHENED PRESSURE GRADIENT BETWEEN THE RIDGE AND THIS TROUGH IS SUPPORTING FRESH TO STRONG TRADES NEAR THE TROUGH THIS AFTERNOON. THE TROUGH AND THE WINDS WILL SLOWLY MOVE W OF THE AREA THROUGH SAT. BY SUN...THE SUBTROPICAL RIDGE WILL BE OVERTAKEN BY HIGH PRES W OF THE COLD FRONT N OF THE AREA. THE RIDGING IS EXPECTED TO REMAIN WEAK...AND TRADE WINDS WILL DIMINISH BELOW A STRONG BREEZE OVER THE ENTIRE AREA ON SUN. $$ SCHAUER