000 AXPZ20 KNHC 041604 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC THU OCT 04 2007 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 1530 UTC. ...TROPICAL WAVE... TROPICAL WAVE ALONG 108W FROM 5N-16N IS MOVING W ABOUT 10 KT. THE WAVE IS ON THE WESTERN MOST EDGE OF AN AREA OF UPPER LEVEL DIFFLUENCE WHICH IS ENHANCING SCATTERED STRONG CONVECTION WITHIN 120 NM W OF THE WAVE FROM 10N TO 14N. THIS CONVECTION IS EXPECTED TO WEAKEN DURING THE DAY AS THE WAVE MOVES INTO A SOMEWHAT DRIER ENVIRONMENT. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE...AXIS IS CENTERED ALONG 10N80W 11N110W 8N130W 8N140W. SCATTERED STRONG WITHIN 30 NM EITHER SIDE OF THE AXIS BETWEEN 102W-104W. SCATTERED MODERATE ISOLATED STRONG FROM 4N-7N BETWEEN 78W-80W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 96W-99W. ...DISCUSSION... W OF 110W... AN UPPER TROUGH DOMINATES THE DISCUSSION AREA W OF A LINE FROM 32N117W 19N140W. AN EMBEDDED ELONGATED CYCLONE IS NOTED NEAR 17N135W. THE ATMOSPHERE IS RATHER DRY WITHIN THE VICINITY OF THE TROUGH WITH ONLY A NARROW 130 NM WIDE MOISTURE PLUME STREAMING NEWD IN A JET STREAM BRANCH THAT ENTERS THE REGION THROUGH 17N140W AND REACHES TO 21N133W. TO THE SOUTH OF THE TROUGH...ANTICYCLONIC FLOW ASSOCIATED WITH A MID/UPPER LEVEL ANTICYCLONE LOCATED NEAR 17N124W COVERS THE AREA SOUTH TO 11N. THIS CONTINUES TO SUPPRESS ITCZ CONVECTION W OF 120W WITH ONLY WIDELY SCATTERED SHOWERS AND TSTMS SEEN FROM 9N-13N BETWEEN 111W-120W. AN UPPER LEVEL SHEAR AXIS STRETCHES ROUGHLY FROM 11N115W THROUGH 8N125W TO A SMALL MID/UPPER LEVEL CYCLONIC CIRCULATION NEAR 8N131W TO ANOTHER ONE OVER THE FAR WESTERN EDGE OF THE AREA NEAR 8N140W. MID/UPPER LEVEL ANTICYCLONIC FLOW IS FOUND SOUTH OF THIS SHEAR AXIS WEST OF 125W. THE UPPER FLOW BECOMES CONFLUENT BETWEEN THE ANTICYCLONIC FLOW AND CYCLONIC FLOW NOTED BETWEEN 110W-122W LEADING TO SUBSTANTIAL MOSTLY STRONG SUBSIDENCE AND DRY SINKING AIR HERE. E OF 110W... A LARGE UPPER ANTICYCLONE IS CENTERED OVER OLD MEXICO NEAR 28N103W WITH AN ASSOCIATED RIDGE EXTENDING SOUTHWESTWARD THROUGH 24N107W TO W OF 110W AT 19N. BROAD MID/UPPER LEVEL ANTICYCLONIC FLOW COVERS THE AREA NW OF LINE 17N110W TO THE NW PART OF THE GULF OF MEXICO NW TO FAR NW MEXICO. A MID/UPPER LEVEL CYCLONIC CIRCULATION...ABOUT 4 DEG IN DIAMETER...MOVING NNW IS LOCATED JUST INLAND THE MEXICAN COAST NEAR 20N97W. MODERATE SUBSIDENCE IS SEEN WITHIN AND NE OF THIS CIRCULATION. RATHER PRONOUNCED CONFLUENT FLOW EXISTS BETWEEN BOTH THE ANTICYCLONE AND CYCLONIC CIRCULATION COVERING THE CENTRAL PORTION OF MEXICO. THIS FLOW THEN TRANSITIONS TO UPPER DIFFLUENCE W OF THE MEXICAN COAST TO 110W AND FROM 12N-18N. SCATTERED MODERATE TO STRONG CONVECTION...DECREASING SOME IN BOTH COVERAGE AND INTENSITY...EXTENDS FROM 13N-24N E OF 108W TO JUST OFFSHORE THE MEXICAN COAST. MID/UPPER LEVEL RIDGING EXTENDS SW INTO THE AREA FROM AN UPPER LEVEL ANTICYCLONE OVER CENTRAL CUBA SW TO 10N95W. UPPER LEVEL DEBRIS MOISTURE IS BEING ADVECTED EASTWARD INTO THE FAR EASTERN PORTION OF THE AREA S OF 12N AND E OF 90W. AT THE SURFACE...A RIDGE AXIS EXTENDS SEWD THROUGH 32N135W 26N26.5W TO 22N120W. HIGH PRES COVERS THE AREA N OF 20N AND W OF 122W. $$ AGUIRRE