000 AXPZ20 KNHC 022155 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT OCT 02 2010 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2145 UTC. ...ITCZ... AXIS IS CENTERED ALONG 10N97W 11N105W 10N120W 11N132W TO A 1010 MB LOW NEAR 10N137W. SCATTERED MODERATE CONVECTION IS WITHIN 120 NM E AND 90W NM W QUADRANTS OF LOW...AND WITHIN 30 NM S OF THE ITCZ BETWEEN 102W-104W. ...DISCUSSION... AN UPPER LEVEL CYCLONIC CIRCULATION LIFTING N IS LOCATED JUST N OF THE FAR NE CORNER OF THE DISCUSSION AREA OFF THE SOUTHERN CALIFORNIA COAST WITH A TROUGH EXTENDING SSW TO 24N121W... HOWEVER THE ASSOCIATED MOISTURE AND PRECIPITATION REMAINS OVER SOUTHERN CALIFORNIA WITH A SMALL BATCH OVER THE NORTHERN BAJA CALIFORNIA PENINSULA. THIS MOISTURE AREA AND PRECIPITATION WILL LIFT N WITH THE CYCLONIC CIRCULATION THROUGH SUN AS A LARGE UPPER TROUGH CURRENTLY CROSSING THE FAR NW PORTION OF THE AREA PRESSES EASTWARD INITIATING MOVEMENT WITH THE LOW. THE CORRESPONDING SURFACE FEATURE OF THE UPPER CYCLONIC CIRCULATION IS ANALYZED AS A TROUGH FROM 26N121W TO 21N123W...WHILE THAT ASSOCIATED WITH THE UPPER TROUGH IS ANALYZED AS A DISSIPATING STATIONARY FRONT ABOUT 60 NM NW OF THE AREA. TO THE SE OF THE UPPER CYCLONIC CIRCULATION...AN UPPER RIDGE OVER THE SW U.S. EXTENDS SW ACROSS NW MEXICO AND SOUTHERN BAJA CALIFORNIA TO AN UPPER ANTICYCLONE NEAR 17N116W. ANOTHER RIDGE EXTENDS FROM THE ANTICYCLONE WNW TO 17N131W. A NARROW RIDGE IS IN BETWEEN THE UPPER LEVEL CYCLONIC CIRCULATION AND THE UPPER TROUGH OVER THE FAR NW PORTION. A JET STREAM BRANCH EARLIER NOTED AHEAD OF THE UPPER TROUGH HAS RECENTLY LIFTED NE OF THE AREA. SATELLITE WATER VAPOR IMAGERY SHOWS MODERATE SUBSIDENCE ALLOWING FOR LIMITED DEEP ATMOSPHERIC MOISTURE OVER JUST ABOUT THE ENTIRE AREA WITH STABLE ENVIRONMENTAL CONDITIONS AS NOTED BY THE MOSTLY OVERCAST STRATOCUMULUS CLOUD FIELD N OF 16N W OF 111W. ITCZ CONVECTION RELATED TO THE ITCZ WAS NEAR THE ITCZ IS MOSTLY RELATED TO THE 1010 MB LOW NEAR 10N137W. OVER THE FAR EASTERN PORTION OF THE AREA...AN UPPER TROUGH EXTENDS FROM EASTERN U.S. SW TO THE WESTERN GULF OF MEXICO TO ACROSS CENTRAL MEXICO AND SW TO NEAR 14N108W. N TO NE UPPER WINDS BEHIND THE TROUGH WITH MODERATE SUBSIDENCE PRESSING SOUTHWARD ARE HAMPERING ANY DEEP CONVECTION THAT ATTEMPTS TO FORM NEAR OR ALONG THE ITCZ THROUGH THE NEXT 48 HOURS. WITH MODERATE SUBSIDENCE LEADING TO DRIER AIR ALOFT BECOMING MORE EVIDENT OVER THE FAR EASTERN PORTION OF THE REGION IN THE WAKE OF THE UPPER TROUGH...THE NOW WEAKENED MONSOON GYRE THAT HAS PERSISTED ACROSS THE FAR EASTERN PACIFIC...SRN MEXICO...AND CENTRAL AMERICA DURING THE PAST SEVERAL DAYS WILL ONLY CONTINUE TO BECOME MORE OBSOLETE. TO THE SE OF TROUGH...A MID LEVEL RIDGE AXIS EXTENDS FROM THE N CENTRAL CARIBBEAN SW TO 16N82W AND W TO ACROSS CENTRAL AMERICA...TO FAR SOUTHEASTERN MEXICO. FAST UPPER LEVEL ELY FLOW ON THE SOUTHERN PERIPHERY OF THE RIDGE IS ADVECTING UPPER LEVEL DEBRIS MOSITURE FROM CLUSTERS OF DEEP CONVECTION OVER THE SW CARIBBEAN SEA...AND EASTERN PACIFIC WESTWARD TO NEAR 108W BUT THINS OUT AS IT SPREADS TOWARDS THE UPPER TROUGH. CROSS-EQUATORIAL S TO SW WINDS INTO THE WEAKER MONSOON TROUGH HAVE DIMINISHED TO LESS THAN 20 KT...HOWEVER SEAS TO 9 FT IN A NW SWELL ARE EVIDENT S OF 10N BETWEEN 120W AND 135W. THESE SEAS ARE EXPECTED TO BUILD INTO THE 8 TO 10 FT RANGE IN MIXED SW AND NW SWELL S OF 17N BETWEEN 102W AND 130W...AND IN SW SWELL BETWEEN 92W AND 103W IN ABOUT 24 HOURS....THEN S OF 15N BETWEEN 92W AND 120W IN 48 HOURS. N WINDS OF 20 TO 25 KT ARE OCCURRING WITHIN 90 NM EITHER SIDE OF A LINE FROM 16N94.5W TO 13N95.5W...INCLUDING THE ISTHMUS OF TEHUANTEPEC...WITH SEAS TO 9 FT. RIDGING BUILDING SOUTHEASTWARD ACROSS MEXICO WILL TIGHTEN THE PRESSURE GRADIENT OVER SOUTHEASTERN MEXICO AND IN THE ISTHMUS OF TEHUANTEPEC OVER THE NEXT 18 ALLOWING FOR N TO NE WINDS TO INCREASE TO 30 TO 35 KT WITHIN 30 NM OF LINE 16N94.5W TO 14N95W WITH SEAS BUILDING 9 TO 12 FT. THE GALE WINDS ARE FORECAST TO INCREASE TO 30 TO 40 KT IN 36 HOURS AT WHICH TIME SEAS ARE FORECAST TO BUILD INTO THE RANGE OF 12 TO 16 FT. BY 48 HOURS...WINDS ARE FORECAST TO DIMINISH BACK TO 30 TO 35 KT WITH SEAS 12 TO 15 FT. ELSEWHERE THROUGH THE ISTHMUS OF TEHUANTEPEC AND VICINITY...WINDS WILL BE N TO NE 20 TO 30 KT THROUGH THE NEXT 48 HOURS WITH SEAS TO 9 FT...BUILDING TO 8 TO 13 FT IN 36 HOURS. OVER THE WESTERN PORTION OF THE AREA HIGH PRES WILL STRENGTHEN AS IT BUILDS SE ACROSS FORECAST WATERS. THIS WILL INCREASE THE PRES GRADIENT BETWEEN IT AND THE 1010 MB LOW NEAR 101N37W ALLOWING FOR NE TO E TRADES OF 20 KT TO MATERIALIZE FROM 13N TO 20N W OF 134W IN ABOUT 24 HOURS...AND FROM 12N TO 22N W OF 132W IN 48 HOURS WITH SEAS BUILDING TO 9 TO 11 FT IN A NW SWELL. THIS SAME NW SWELL WILL BE DUE TO A LARGE NW SWELL TRAIN WILL SPREAD ACROSS THE NW WATERS IN 24 HOURS AT WHICH TIME W OF A LINE FROM 30N118W TO 15N140W WINDS WILL BE LESS THAN 20 KT WITH SEAS 8 TO 11 FT IN NW SWELL...HIGHEST NW PART ACCORDING TO LATEST WAVEWATCH MODEL GUIDANCE. THE GUIDANCE THEN LOWERS THE SEAS TO 10 FT IN 48 HOURS. THESE SWELLS ARE FORECAST TO HAVE PERIODS OF 11-13 SEC TONIGHT AND SUN...DIMINISHING TO 9-11 SEC LATE SUN NIGHT INTO MON. $$ AGUIRRE