000 AXPZ20 KNHC 081622 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON OCT 08 2012 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 OLIVIA CENTERED NEAR 16.6N 121.2W 999 MB AT 1500 UTC OCT 08 MOVING NNW OR 340 DEG AT 3 KT. MAXIMUM SUSTAINED WINDS 50 KT GUSTS 60 KT. CLUSTERS OF STRONG CONVECTION ASSOCIATED WITH OLIVIA CONTINUE TO SHIFT NE THIS MORNING. HOWEVER...MORNING MICROWAVE IMAGERY INDICATES THAT THE LOW LEVEL CENTER OF OLIVIA IS LOCATED IN THE SW PORTION OF THE CONVECTION...AND CONTINUES TO BE SHEARED BY SWLY MIDDLE TO UPPER LEVEL WINDS. THIS IS REFLECTED BY MORNING SATELLITE IMAGERY SHOWING SCATTERED MODERATE TO STRONG CONVECTION WITHIN 240 NM ACROSS THE NE QUADRANT. OLIVIA REMAINS EMBEDDED WITHIN AN ELONGATED NE TO SW LOW LEVEL CYCLONIC CIRCULATION...AND HAS LIKELY NEVER COMPLETELY DISCONNECTED FROM THE MONSOON TROUGH PREVAILING TO ITS SW. OLIVIA HAS BEGUN TO TURN LEFT...OR NW...AND SHOULD DRIFT NW IN THE SHORT TERM. SWLY VERTICAL WIND SHEAR IS FORECAST TO PERSIST ACROSS THE SYSTEM AND GRADUALLY INCREASE IN 24 TO 48 HOURS. THIS IS EXPECTED TO DECOUPLE THE MIDDLE LEVEL CIRCULATION AND STRONG CONVECTION FROM THE LOW LEVEL CENTER...AND LEAD TO THE QUICK WEAKENING OF OLIVIA. THIS DECOUPLED LOW LEVEL CENTER IS THEN EXPECTED TO MOVE SW IN THE PREVAILING LOW LEVEL FLOW LATE TUE AND WED. FOR FURTHER DETAILS ON OLIVIA SEE AWIPS/WMO HEADERS MIATCMEP5 AND WTPZ25 KNHC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS COLOMBIA NEAR 09.5N74.5W TO 11N78W TO 10N86W TO 11.5N93W TO 09N108W TO 11N116W WHERE IT REMAINS FRACTURED...THEN RESUMES S OF OLIVIA AT 14N121W TO 09N133W WHERE IT TRANSITIONS TO THE ITCZ AXIS...CONTINUING ON TO BEYOND 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 90 NM N AND 240 NM S OF TROUGH E OF 99W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 150 NM N AND 90 NM S OF TROUGH BETWEEN 121W AND 131W. ...DISCUSSION... UPPER LEVEL RIDGING REMAINS OVER MOST OF CENTRAL PORTIONS OF THE AREA...AND OVER OLIVIA...FROM N OF 10N EXTENDING E TO 108W AND W TO 130W. THE STRONG BLOCKING UPPER LEVEL PATTERN ACROSS THE REGION IS SLOWLY BEGINNING TO BREAK DOWN...WITH S/W ENERGY CONTINUING TO LIFT NE AND OVER THE LOCAL UPPER RIDGE...AND IS SLOWLY ERODING THE N PORTION OF THE RIDGE. A SIGNIFICANT S/W COULD BE SEEN IN WATER VAPOR IMAGERY THIS MORNING MOVING ACROSS NW PORTIONS OF THE DISCUSSION AREA...AND FURTHER FORCING THE ALIGNMENT OF THE RIDGE NE TO SW. TUTT LOWS EXTENDING INTO THE MIDDLE LEVELS WERE LOCATED ON BOTH THE E AND W OF THE RIDGE NEAR 17N102W AND 13N133W RESPECTIVELY. LOOK FOR THE RIDGE TO FLATTEN DURING THE NEXT 48 HOURS AS IT BECOMES FURTHER STRETCHED NE TO SW...AND SEPARATES INTO TWO SEPARATE ANTICYCLONES. ELSEWHERE AT THE LOW LEVELS...A WEAK 1019 MB SURFACE HIGH PRESSURE IS NEAR 29N128W WITH BROAD RIDGING COVERING THE DISCUSSION AREA N OF 22N W OF THE BAJA PENINSULA. THE PRES GRADIENT BETWEEN THE HIGH AND THE THERMAL TROUGH ACROSS NW MEXICO CONTINUES TO PRODUCE MODERATE TO LOCALLY FRESH WINDS ALONG THE W COAST OF BAJA CALIFORNIA. OVERNIGHT SCATTEROMETER PASSES SUGGESTED NNW WINDS TO AROUND 20 KT EXTENDED FROM THE W COAST OF BAJA OUT TO ABOUT 90 NM...SEAS SEAS RUNNING 6-8 FT THERE. MODEL GUIDANCE SUGGEST THAT THE HIGH WILL MOVE ONLY LITTLE DURING THE NEXT 24 HRS BEFORE SHIFTING SW TUE NIGHT AND WED. LITTLE CHANGE IN WINDS AND SEAS ARE EXPECTED ALONG THE W COAST OF BAJA N OF 28N THROUGH 24 HOURS BEFORE ABATING MILDLY WED. GAP WINDS...THE HIGH RESOLUTION ASCAT PASS FROM JUST PAST 0400 UTC LAST NIGHT REVEALED N WINDS OF 20-25 KT FUNNELING INTO THE GULF OF TEHUANTEPEC. THE CURRENT SYNOPTIC PATTERN OVER SW GULF OF MEXICO TO OVER SE MEXICO IS FAVORABLE FOR THIS WINDS TO LAST THROUGH TONIGHT THEN DIMINISH TUE AFTERNOON AS THE PRES GRADIENT SLACKENS OVER SE MEXICO. MODEL GUIDANCE IS CONSISTENT IN FORECASTING A SURFACE LOW DEVELOPING ALONG THE MONSOON TROUGH NEAR 10N88W LATE TUE WITH THE LOW MOVING W-NW THEREAFTER. THE GFS GUIDANCE CONTINUES TO BE THE MOST AGGRESSIVE WITH WINDS TIED INTO THE LOW...SHOWING SIGNIFICANT DEVELOPMENT OF THIS LOW AS IT MOVES WNW THROUGH THE END OF THE WEEK. PRESENTLY...THIS DEVELOPMENT APPEARS TO BE OCCURRING TO QUICKLY BY THE GFS MODEL...AND A SLOWER DEVELOPMENT MORE SIMILAR TO THE ECMWF IS PREFERRED. REGARDLESS. ACTIVE CONVECTION WILL ACCOMPANY A WAVE ALONG THE MONSOON TROUGH ACROSS THIS AREA THIS WEEK...WITH SWLY WINDS 20-25 KT AND SEAS TO AROUND 8 FT OCCURRING S OF THE TROUGH. $$ STRIPLING