000 AXPZ20 KNHC 290247 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE SEP 29 2009 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 0215 UTC. ...TROPICAL WAVE... TROPICAL WAVE WAS ANALYZED ALONG 87W/88W N OF 06N MOVING W 10-15 KT. NO SIGNIFICANT CONVECTION ASSOCIATED WITH THE WAVE OVER THE EAST PACIFIC. A WIND SURGE MOVING ACROSS CENTRAL AMERICA WAS INITIATING SCATTERED MODERATE TO STRONG CONVECTION OVER NICARAGUA AND EL SALVADOR. ...ITCZ... AXIS WAS ALONG 08N78W TO 09N86W TO 14N105W TO 14N119W TO 12N125W TO 14N140W. SCATTERED MODERATE WITHIN 120 NM EITHER SIDE OF AXIS BETWEEN 92W AND 96W AND WITHIN 120-180 NM EITHER SIDE OF AXIS BETWEEN 120W AND 129W. ...DISCUSSION... A SW-NE ELONGATED UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 27N137W WITH ASSOCIATED BROAD CYCLONIC FLOW N OF 18N BETWEEN 125W AND 150W. AXIS OF 55-65 KT SUBTROPICAL JET WAS SLICING DOWN THE BACKSIDE OF THE CIRCULATION ALONG 20N140W TO 18N135W...THEN TURNED NE THROUGH 26N125W 32N115W WITH CORE SPEEDS OF 80-90 KT. THE CYCLONIC CIRCULATION IS FORECAST TO DIG SLOWLY SWD OVERNIGHT AS IT IS REINFORCED BY A LARGE UPPER TROUGH TO ITS N AND ASSUME A SSW-NNE ELONGATION OVER THE NEXT FEW DAYS. DOWNSTREAM...AN AMPLIFYING UPPER LEVEL RIDGE IS LOCATED SE OF THE CYCLONIC CIRCULATION...AND EXTENDED FROM A LARGE ANTICYCLONE OVER WRN MEXICO NEAR 22N107W EASTWARD INTO THE GULF OF MEXICO... AND SW THROUGH 20N118W TO A COL NEAR 13N130W. ANOTHER UPPER ANTICYCLONE WAS CENTERED OVER THE S CENTRAL PACIFIC NEAR 12N152W. GENERALLY DRY AND SUBSIDENT CONDITIONS COULD BE FOUND ACROSS THE BASE OF THE UPPER TROUGH...AND ACROSS THE NW AND NRN FLANKS OF THE RIDGE...JUST SE OF THE SUBTROPICAL JET. AN UPPER LEVEL CYCLONIC CIRCULATION WAS NOTED NEAR 15N97W AND WAS MOVING W AT 15 KT ACROSS ALONG THE S COAST OF MEXICO AND THE ADJACENT TROPICAL EPAC. THIS SYSTEM WAS PRODUCING SCATTERED MODERATE TO STRONG CONVECTION ACROSS THE EPAC. A LOW TO MID LEVEL TROUGH THAT TRACKED ACROSS THE FAR W CARIB...CENTRAL AMERICA...AND THEN S CENTRAL MEXICO AND THE ADJACENT PACIFIC OVER THE PAST SEVERAL DAYS HAS CONTRIBUTED TO THE FORMATION OF BROAD CYCLONIC TURNING FROM 10N TO THE COAST OF MEXICO BETWEEN 100W AND 112W. A 1625 UTC ASCAT PASS INDICATED A LOW PRES HAD FORMED NEAR 15N105W. THE LOW HAS SINCE DRIFTED TO THE NW TO NEAR 16N106W. SCATTERED MODERATE TO STRONG CONVECTION WAS NOTED WITHIN 240-300 NM OF THE LOW BUT LOOSELY ORGANIZED. THERE IS A MODERATE CHANCE FOR TROPICAL CYCLONE DEVELOPMENT WITH THIS SYSTEM OVER THE NEXT 48 HOURS AND THIS FEATURE WILL BE PLACED IN THE SPECIAL FEATURES SECTION WITH THE NEXT ISSUANCE. SEVERAL SHIPS HAVE REPORTED 20-25 KT WINDS ALONG THE COAST OF MEXICO IN THE AREA OF CONVECTIVE ACTIVITY. AT THE SURFACE...A HIGH PRES RIDGE EXTENDED FROM A 1043 MB HIGH LOW NEAR 43N153W SE TO OFFSHORE OF BAJA CALIFORNIA NEAR 21N115W. THE ITCZ CONTINUED TO BE QUITE ACTIVE ACROSS SEVERAL ZONES IN THE AREA...UNDER GOOD DIFFLUENCE ALOFT. SEVERAL WAVES...LOWS AND PERTURBATIONS WERE EVIDENT IN SHORT WAVE INFRARED SATELLITE IMAGERY THIS AFTERNOON. FIRST THE BROAD LOW AND CONVECTION OFF OF MEXICO...ANOTHER LARGE CYCLONIC CIRCULATION CENTERED NEAR 13N119W...THE REMNANTS OF NORA...A 1011 MB LOW NEAR 17N132W... AND ANOTHER LOW ALONG A WAVE AT 14N139W. REGIONAL SEAS ARE BEING DOMINATED BY MODERATE PERIOD SRN HEMISPHERE SE SWELL...AND LONGER PERIOD NW AND SSW SWELL. THE FRESH TO STRONG E TO SE FLOW ALONG THE MEXICAN COAST WAS GENERATING SEAS OF 7 TO 10 FT IN THIS CONFUSED MIX. SEAS IN EXCESS OF 8 FT WILL GRADUALLY PROPAGATE NWD ACROSS THE EQUATOR TO 12N BY MID WEEK AS SEVERAL NEW PULSES OF LARGE SE AND SW SWELL MOVE INTO THE AREA. $$ COBB