000 AXPZ20 KNHC 071604 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN SEP 07 2014 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 1545 UTC. ...SPECIAL FEATURE... AT 1500 UTC SEP 7 TROPICAL STORM NORBERT WAS CENTERED NEAR 26.0N 117.0W WITH ESTIMATED MINIMUM SEA LEVEL PRESSURE OF 994 MB. NORBERT WAS MOVING WNW OR 295 DEG AT 7 KT WITH MAXIMUM SUSTAINED WINDS OF 50 KT WITH GUSTS TO 60 KT. LATEST SATELLITE IMAGERY SHOWS JUST ABOUT NO DEEP CONVECTION ASSOCIATED WITH NORBERT. ONLY A SMALL CLUSTER SCATTERED MODERATE CONVECTION IS NOTED WITHIN 30 NM SW OF THE CENTER. NORBERT WILL CONTINUE TO ENCOUNTER COOLER SEA SURFACE TEMPERATURES ALONG WITH A STABLE ENVIRONMENT OVER THE NEXT 24-30 HRS AS IT MOVES PARALLEL TO THE BAJA CALIFORNIA PENINSULA. THESE FACTORS WILL ACT TO WEAKEN THE CYCLONE FURTHER TO A POST TROPICAL REMNANT LOW BY EARLY MON. AFTER MON EVENING THE POST TROPICAL REMNANT LOW IS FORECAST TO TURN NE...AND TRACK TOWARDS THE GENERAL DIRECTION OF THE BAJA CALIFORNIA AS THE SYSTEM MOVES NW PARALLEL TO THE BAJA CALIFORNIA PENINSULA WITH A FORECAST POSITION OF NEAR 29N118W BY EARLY TUE. PLEASE SEE LATEST NHC INTERMEDIATE PUBLIC ADVISORY UNDER AWIPS/ WMO HEADERS MIATCPEP4/WTPZ34 KNHC AND THE FULL FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP4/WTPZ245 KNHC FOR MORE DETAILS. ...TROPICAL WAVES... A TROPICAL WAVE AXIS IS ANALYZED FROM 12N99W TO 16N97W MOVING W AT 15 KT. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 240 NM E OF WAVE N OF 12N. GLOBAL MODELS SUGGEST THE INTERACTION OF THIS WAVE WITH THE MONSOON TROUGH DURING THE NEXT FEW DAYS MAY HELP FOR THE DEVELOPMENT OF A TROPICAL CYCLONE. PLEASE REFER TO THE LATEST EAST PACIFIC TROPICAL WEATHER OUTLOOK FOR FURTHER INFORMATION. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 10N85W TO 12N98W TO 12N110W TO 13N121W TO 11N136W WHERE LOW LEVEL WINDS SUGGEST A TRANSITION TO ITCZ WHICH EXTENDS BEYOND 10N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION EXISTS WITHIN 180 NM N AND 240 NM S OF TROUGH BETWEEN 85W-97W. SIMILAR CONVECTION IS N OF TROUGH BETWEEN 89W-94W...AND WITHIN 180 NM S OF TROUGH BETWEEN 99W-112W. SCATTERED MODERATE WITHIN 60 NM OF TROUGH BETWEEN 119W-125W. ...DISCUSSION... THE ANTICYCLONIC FLOW ALOFT ABOVE AND IN THE VICINITY OF NORBERT CONTINUES TO ADVECT A PLUME OF UPPER LEVEL MOISTURE FROM THE CYCLONE N AND NE TOWARDS NORTHERN BAJA CALIFORNIA...AND TO FAR NW MEXICO. THIS IS HELPING TO TRIGGER OFF POCKETS OF SCATTERED SHOWERS AND ISOLATED TSTMS OVER THESE GEOGRAPHICAL AREAS. UPPER LEVEL MODERATE TO STRONG NE-E WINDS AROUND THE SE PERIPHERY OF THE SAME ANTICYCLONE ARE ADVECTING UPPER LEVEL DEBRIS MOISTURE FROM MONSOON CONVECTION WESTWARD TOWARDS 132W WHERE IT ERODES IN VERY DRY AND STABLE AIR WHICH COVERS THE JUST ABOUT THE ENTIRE CENTRAL AND WESTERN PORTIONS OF THE AREA TO THE NW OF A LINE FROM NW BAJA CALIFORNIA TO 21N127W TO 09N132W. AT THE SURFACE...THE 12 UTC ANALYSIS HAS A WEAK RIDGE STRETCHING FROM 31N140W SE TO NEAR 21N125W. IT CONTINUES TO SUPPORT GENTLE TO MODERATE WINDS ACROSS MUCH OF THE FORECAST AREA. SEAS ARE GENERALLY 5-7 FT OVER MUCH OF THE FORECAST AREA. AS MENTIONED ABOVE...THE INTERACTION OF A TROPICAL WAVE WITH THE MONSOON TROUGH WILL HELP DEVELOP A PERTURBATION WITHIN THE MONSOON TROUGH. THIS PERTURBATION WILL HELP INCREASE SW MONSOON FLOW INTO THE MONSOON TROUGH...AND THIS ENHANCED MONSOON FLOW WILL BUILD SEAS TO THE 8-9 FT RANGE S OF THE MONSOON TROUGH DURING MON. MIXED SE AND SW SWELLS YIELDING SEAS TO 8 FT CONTINUE TO OCCUR S OF 01N W OF 132W. THIS AREA OF MIXED SWELLS IS FORECAST TO THE S OF THE EQUATOR BETWEEN 110W-120W BY EARLY ON MON...AND TO S OF 02N BETWEEN 97W-120W BY EARLY ON TUE. $$ AGUIRRE