000 AXPZ20 KNHC 081608 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC TUE OCT 08 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1500 UTC. ...SPECIAL FEATURE... TROPICAL STORM NARDA CENTERED AT 15.6N 126.4W AT 1500 UTC MOVING WNW OR 290 DEG AT 11 KT. MAXIMUM SUSTAINED WINDS HAVE DIMINISHED TO 40 KT GUSTING TO 50 KT WITH SURFACE PRESSURE OF 1002 MB. CONVECTION HAS DIMINISHED CONSIDERABLY WITH NARDA IN THE PAST 24 HOURS HOURS...AND CURRENTLY ONLY SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 30 NM N SEMICIRCLE AND SCATTERED MODERATE ISOLATED STRONG CONVECTION WITHIN 120 NM SW QUADRANT. THE ATMOSPHERIC CONDITIONS TO THE W AND NW OF NARDA ARE DRIER AND MORE STABLE...AND IT IS EXPECTED THAT THIS AIR WILL GRADUALLY BE INGESTED BY NARDA AS IT MOVES W TO WNW DURING THE NEXT COUPLE OF DAYS. THIS IS EXPECTED TO COMBINE WITH INCREASING WIND SHEAR AND LEAD TO A GRADUALLY WEAKENING SYSTEM...THAT IS FORECAST TO DIMINISH TO A TROPICAL DEPRESSION BY 24 HOURS AND A POST TROPICAL REMNANT LOW BY 72 HOURS. REFER TO NARDA FORECAST ADVISORY UNDER WMO/AWIPS HEADERS WTPZ24 KNHC/MIATCMEP4 FOR ADDITIONAL DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 10N74W TO 10N95W TO 12N107W TO 15N119W...WHERE IT HAS FRACTURED FROM NARDA...THEN RESUME FROM SW OF NARDA NEAR 11N128W TO 10N132W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO BEYOND 08N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 180 NM EITHER SIDE OF TROUGH BETWEEN 93W AND 104W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 240 NM SW OF TROUGH AXIS BETWEEN 110W AND 117W. SCATTERED MODERATE TO STRONG CONVECTION NOTED WITHIN 60 NM N AND 90 NM S OF AXIS W OF 132W. SCATTERED MODERATE TO STRONG CONVECTION WAS ALSO NOTED N OF 15N TO THE COAST OF MEXICO FROM 101W TO 105W AND WAS ACCOMPANIED BY FREQUENT LIGHTNING. ...DISCUSSION... A STRONG UPPER TROUGH ACROSS THE FAR NE PACIFIC AND INTO THE PACIFIC NW OF THE U.S. IS REINFORCING A BROAD UPPER TROUGH CURRENTLY DOMINATING THE DISCUSSION AREA N OF 24N AND TO THE W OF THE BAJA PENINSULA...WITH SUB-JETSTREAM ZONAL FLOW. NARROW UPPER LEVEL RIDGING PREVAILS S OF THIS WLY FLOW ALOFT...BETWEEN ABOUT 10N AND 22N...FROM CENTRAL AMERICA TO NEAR 140W. SEVERAL SMALL ANTICYCLONIC CENTERS ARE NOTED IN SATELLITE IMAGERY THIS MORNING...WITH ONE TO THE NE OF NARDA BEGINNING TO INDUCE NELY VERTICAL WIND SHEAR ACROSS SW PORTIONS OF THE STORM. AT LOWER LEVELS...STRONG 1035 MB HIGH PRES IS CENTERED ACROSS THE NE PACIFIC NEAR 41N145W AND EXTENDS SE TO NEAR 22N117W. FRESH TO STRONG NLY WINDS SPILLING DOWN TO OFFSHORE COASTAL WATERS OF CALIFORNIA TURN SW AND ENTER NW PORTIONS OF THE DISCUSSION AREA...NW OF LINE FROM 30N133W TO 28.5N140W...WHERE NE WINDS ARE 20 TO 25 KT WITH SEAS 8 TO 9 FT IN MIXED NE AND NW SWELL. WINDS WILL SHIFT SW AND DIMINISH DURING THE NEXT 24 HOURS WHILE MIXED NW AND NE SWELL MAINTAINS SEAS TO 9 FT ACROSS NW PORTIONS. ELSEWHERE...MODERATE NELY WINDS 15-20 KT EXTEND OUT SOME 400-500 NM TO THE NW AND W OF NARDA...WHERE SEAS ARE RUNNING 6-8 FT. LIGHT TO MODERATE MONSOONAL FLOW PREVAILS S OF THE MONSOON TROUGH AXIS THIS MORNING. SATELLITE IMAGERY SUGGESTS THAT A WAVE MAY BE DEVELOPING ALONG THE TROUGH NEAR 95W...AS INDICATED BY BROAD CYCLONIC TURNING. SOME OF THE GLOBAL MODELS DEVELOP A SURFACE LOW IN THIS REGION DURING THE NEXT 24-36 HOURS THAT MAY HAVE SOME POTENTIAL FOR INTENSIFICATION BY THE END OF THE WEEK AS THIS WAVE SHIFTS SLOWLY WWD. VERY ACTIVE CONVECTION IS LIKELY TO ACCOMPANY THIS FEATURE AS IT MOVES UNDERNEATH THE UPPER RIDGE. GULF OF TEHUANTEPEC...OVERNIGHT ASCAT PASS SUGGESTED NE 20-30 KT DRAINAGE FLOW WITH SEAS 7-10 FT AND HAS LIKELY PEAKED... EXTENDING TO NEAR 14N96.5W THIS MORNING...AND WILL BEGIN TO DIMINISH WITH WINDS BELOW 20 KT BY LATE WED MORNING. GULF OF CALIFORNIA...LIGHT SOUTHERLY WINDS ARE EXPECTED TODAY INCREASING TO SW AT 20-25 KT ACROSS THE GULF WATERS N OF 29N TONIGHT THEN DIMINISHING T O LESS THAN 20 KT BY WED NIGHT. STRIPLING