000 AXPZ20 KNHC 271632 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU AUG 27 2009 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 1345 UTC. ...SPECIAL FEATURE... TROPICAL DEPRESSION IGNACIO WAS CENTERED NEAR 25.4N 127.3W...OR ABOUT 1110 MILES...1785 KM...WEST-NORTHWEST OF THE SOUTHERN TIP OF BAJA CALIFORNIA AT 27/1500Z...AND WAS MOVING NW AT 320 DEGREES AT 12 KT. MAXIMUM SUSTAINED WINDS ARE 30 KT WITH GUSTS TO 40 KT AND THE ESTIMATED MINIMUM PRESSURE WAS 1006 MB. IGNACIO IS EXPECTED TO BECOME A REMNANT LOW LATER TODAY AND THE LAST ADVISORY HAS BEEN ISSUED. ADDITIONAL INFORMATION CAN BE FOUND UNDER AWIPS/WMO HEADERS MIATCMEP3/ WTPZ23 KNHC. A BROAD AREA OF LOW PRESSURE IS CENTERED NEAR 09N114W MOVING W NEAR 10 KT. SATELLITE IMAGES SHOW AN ASSOCIATED LARGE CLOUD FIELD WITH CONVECTION LOOSELY ORGANIZED IN BANDS WELL AWAY FROM THE CIRCULATION CENTER FROM 06N TO 13N BETWEEN 106W AND 120W. MANY OF THE NUMERICAL MODELS SHOW SOME DEVELOPMENT OF THIS SYSTEM OVER THE NEXT FEW DAYS AS IT TRACKS WEST-NORTHWESTWARD. AN AREA OF CONVECTION IS GETTING MORE ORGANIZED OFF THE COAST OF MEXICO NEAR ACAPULCO. THE CONVECTION IS NOTED MAINLY N OF 11N BETWEEN 92W AND 99W. THIS ACTIVITY IS ASSOCIATED A TROPICAL WAVE NEAR 98W THAT IS INTERACTING WITH AN UPPER LEVEL DIVERGENCE BETWEEN THE WESTERN EDGE OF AN UPPER ANTICYCLONE TO THE NE AND AN UPPER LOW TO THE NW. WHILE THE CONVECTION REMAINS FAIRLY DISORGANIZED...IT IS PRODUCING HEAVY RAINFALL ALONG THE MEXICAN COAST. ACAPULCO REPORTED 5.38 INCHES OF RAIN IN THE PREVIOUS 24 HOURS. THE PROBABILITY OF THIS SYSTEM BECOMING A TROPICAL CYCLONE IS CONSIDERED LOW...BELOW 30 PERCENT. HOWEVER...THE ASSOCIATED HEAVY RAINFALL POSES THE DANGER OF MUDSLIDES ALONG THE MEXICAN COAST ALONG THE COASTLINES OF OAXACA AND GUERRERO. ...TROPICAL WAVES... A TROPICAL WAVE IS ALONG 97W/98W N OF 06N MOVING W NEAR 15 KT OVER THE PAST 24 HOURS. SEE DETAILS IN SPECIAL FEATURES ABOVE. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE IS ALONG 07N78W TO 10N100W 09N111W 12N140W. SCATTERED MODERATE CONVECTION IS FROM 09N TO 12N W OF 132W. ...DISCUSSION... A STRONG COLD FRONT LIES A COUPLE HUNDRED NM NW OF THE DISCUSSION ZONE...SUPPORTED BY A LARGE UPPER TROUGH OVER THE N PACIFIC. THIS UPPER TROUGH IS PIVOTING NE WHICH WILL CAUSE THE FRONT TO WEAKEN AS IT CROSSES 30N140W LATE TONIGHT. WHILE WINDS SHOULD BE FAIRLY LIGHT ALONG THE FRONT AT THAT TIME...NW SWELL COMBINED WITH THE EFFECTS OF WEAKENING IGNACIO WILL PRODUCE 8-12 FT CONFUSED SEAS OVER THE NW PORTION OF THE SUBTROPICS. ELSEWHERE AT THE MID AND UPPER LEVELS...A LARGE ANTICYLONE IS LOCATED NEAR 20N120W AND A NARROW TROUGH EXTENDS FROM 30N135W THROUGH 23N140W. FURTHER TO THE EAST...AN UPPER TROUGH EXTENDS FROM AN UPPER LOW OVER CENTRAL MEXICO TO 11N115W. DIVERGENCE ALOFT ASSOCIATED WITH THIS UPPER TROUGH IS AIDING CONVECTION ALONG THE LOW PRES NEAR 09N114W. GULF OF TEHUANTEPEC...A HIGH RESOLUTION 0038 UTC QUIKSCAT PASS INDICATED THAT WINDS HAVE SHIFTED NE TO E ACROSS THE GULF OF TEHUANTEPEC DUE TO THE TROPICAL WAVE MOVING THROUGH THE AREA. WHILE THIS FLOW WILL LIMIT FUNNELING THROUGH THE GAP...A BROAD AREA OF E 20 KT WINDS IS EXPECTED TO CONTINUE FOR ANOTHER DAY OR SO DUE TO THE PRESSURE GRADIENT BETWEEN THE WAVE AND RIDGING OVER THE GULF OF MEXICO/MEXICO. $$ CANGIALOSI/CHRISTENSEN