000 AXPZ20 KNHC 251551 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC MON OCT 25 2010 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. ...ITCZ... AXIS IS CENTERED ALONG 8N85W 8N94W 10N104W 12N110W TO LOW NEAR 11N115W 1010 MB TO LOW NEAR 9N122W 1010 TO LOW NEAR 10N134W 1009 MB TO 9N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN 60 NM N OF THE AXIS BETWEEN 135W-138W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 90W-92W...AND 90 NM N OF THE AXIS BETWEEN 113W-117W. ...DISCUSSION... A MID/UPPER LEVEL TROUGH EXTENDS FROM THE FAR WESTERN GULF OF MEXICO SW TO 21N107W...AND W TO AN ELONGATED MID TO UPPER CYCLONE NEAR 21N123W AND SW TO 16N135W. IT CONTINUES FURTHER WNW TO A BROAD DEEP LAYERED CYCLONE CENTERED JUST SW OF THE HAWAIIAN ISLANDS. UPPER LEVEL RIDGES ARE NOTED ON EITHER SIDE OF THE UPPER TROUGH...WITH A LARGE UPPER ANTICYCLONE CENTERED AT 31N139W. AN ASSOCIATED RIDGE EXTENDS E ALONG 30N TO SW TEXAS... WITH ANOTHER ONE WSW WELL BEYOND THE AREA. S OF THE UPPER TROUGH AXIS AN UPPER ANTICYCLONE IS WELL W OF THE AREA WITH A RIDGE ENE TO NEAR 12N130W. SATELLITE WATER VAPOR IMAGERY SHOWS ABUNDANT MODERATE SUBSIDENCE RESULTING IN RATHER DRY AND STABLE ENVIRONMENTAL CONDITIONS OVER JUST ABOUT THE ENTIRE CENTRAL AND WESTERN PORTIONS OF THE REGION EXCEPT FOR THE FAR NORTHERN SECTION WHERE A LARGE PLUME OF UPPER LEVEL MOISTURE IS SPILLING SOUTHEASTWARD TO THE S OF 32N AROUND THE NE PERIPHERY OF THE LARGE UPPER ANTICYCLONE. TO THE E OF THE AREA...AN UPPER LEVEL ANTICYCLONE OVER THE WESTERN CARIBBEAN EXTENDS A RIDGE WESTWARD ACROSS CENTRAL AMERICA...SE MEXICO...AND INTO THE EPAC TO NEAR 14N123W. THE MID/UPPER LEVEL TROUGH IS FORECAST TO CONTINUE MOVING EASTWARD DURING THE NEXT 48 HOURS...WHILE THE ELONGATED UPPER CYCLONE ACROSS THE EPAC RETROGRADES WESTWARD TO ALONG 136W STRETCHING THE UPPER TROUGH INTO A NARROW TUTT ALLOWING FOR THE CARIBBEAN UPPER RIDGE TO EXPAND W TO NEAR 130W. A BROAD UPPER CYCLONE WAS CENTERED AT THE NEAR 00N126W AND MOVING SLOWLY W WITH TIME. AN UPPER TROUGH EXTENDS NE FROM THE CYCLONE TO NEAR 9N110W AND THEN CONTINUES E ALONG 09N TO 100W. THIS CYCLONE IS FORECAST TO LIFT N AND BECOME LINKED WITH THE ELONGATED MID TO UPPER CYCLONE MENTIONED ABOVE TO PRODUCE A NEGATIVE TILT UPPER TROUGH W OF 120W...THAT WILL BEGIN TO LIFT SLOWLY N AND NE LATE WED INTO THU. THIS WILL INDUCE UPPER LEVEL WESTERLIES CENTERED ON THE EQUATOR BETWEEN 130W AND 100W BY LATE WED...THAT WILL STRENGTHEN BY THE END OF THE WEEK AS THE UPPER TROUGH IS FORCED EWD. AT THE SURFACE...HIGH PRES WELL W OF THE AREA NEAR 28N149W HAS A RIDGE EXTENDING E TO 28N139W...THEN SE 26N127W TO 20N122W. HIGH PRES COVERS THE AREA N OF 17N W OF 118W. SCATTERED SMALL PATCHES OF STRATOCUMULUS CLOUDS MOVING WESTWARD ARE NOTED S OF RIDGE TO ABOUT 13N AND W OF 21W. A DRY COLD FRONT N OF THE THE AREA ALONG 33N AND E OF 130W WILL QUICKLY MOVE INLAND OVER THE WESTERN U.S. TONIGHT THROUGH WED AS THE RIDGE BUILDS EASTWARD TOWARDS THE FAR NE PORTION. THIS WILL ALLOW NWLY FLOW TO SPILL S OVER THE E END OF THE UPPER RIDGE. HOWEVER STRONG N WINDS DO NOT ARRIVE ALONG 30N TILL TONIGHT REACHING ALONG 25N BETWEEN 117W-123W BY LATE TUE NIGHT ACCOMPANIED BY SEAS POSSIBLY REACHING UP TO 15 OR 16 FT FROM 29N TO 30N BETWEEN 118W-123W PER LATEST WAVEWATCH MODEL GUIDANCE. IN THE MEANTIME...THE PRES GRADIENT S OF THE RIDGE AND N OF THE ITCZ IS PRODUCING AN AREA OF FRESH NE TRADE WINDS FROM 10N TO 20N W OF 130W...AND FROM 11N TO 19N BETWEEN 124W AND 130W AS THE RIDGE AXIS SHIFTS SOME TO THE TONIGHT AND TUE. SW MONSOONAL FLOW CONTINUES OVER THE EASTERN PORTION OF THE AREA S OF 9N E OF 100W WITH WINDS IN THE RANGE OF 15 TO 20 KT. BOUNDARY LAYER WIND GUIDANCE SUGGESTS THAT THESE WINDS SHOULD DIMINISH THROUGH MID WEEK AS PRESSURES RISE SOME OVER THE FAR EASTERN PORTION OF THE AREA. $$ AGUIRRE