000 AXPZ20 KNHC 172205 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT JAN 17 2009 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 2115 UTC. ...ITCZ... ITCZ AXIS IS CENTERED ALONG 3N78W 7N86W 5N94W 5N104W 5N112W 8N123W 6N134W 5N140W. SCATTERED STRONG CONVECTION EXISTS FROM 6N-11N BETWEEN 106W-109W. ...DISCUSSION... THE OVERALL PATTERN ACROSS THE REGION HAS SLOW DOWN IN TERMS OF EASTWARD PROGRESSION OF UPPER LEVEL FEATURES. A NEARLY STATIONARY CUT-OFF MID/UPPER LEVEL CYCLONIC CIRCULATION OVER SOUTHERN CALIFORNIA EXTENDS A TROUGH W TO 32N123W TO NEAR 32N126W. S OF THIS FEATURE...THE AREA REMAINS UNDER MID AND UPPER LEVEL RIDGING NE OF LINE 21N129W TO 19N118W TO 14N110W TO NEAR 8N105W. A MID/UPPER LEVEL ANTICYCLONE MOVING E ABOUT 10-15 KT IS EMBEDDED IN THIS AREA OF RIDGING NEAR 15N99W. CONFLUENT FLOW BETWEEN THE CYCLONIC CIRCULATION OVER SOUTHERN CALIFORNIA AND FAST SW-W E OF THE RIDGE IS BRINGING MODERATE SUBSIDENCE TO THE ALONG AND N OF 30N E OF 129W...BUT IS ALSO RESULTING IN SCATTERED TO BROKEN HIGH LEVEL MOISTURE IN THE FROM OF HIGH CLOUDS TO PORTIONS OF THE EASTERN PACIFIC FROM 18N TO 25N E OF 122W AND EAST ACROSS NORTHERN AND CENTRAL MEXICO. A MID/UPPER LEVEL TROUGH EXTENDS FROM SE MEXICO NEAR PUERTO ANGEL TO 11N94W. FURTHER W...A DEEP LAYERED TROUGH ENTERS THE REGION THROUGH 32N131W AND CONTINUES S ALONG 23N131W TO 18N131W...THEN TURNS SE TO 18N129W AND INTO A MID/UPPER LEVEL CYCLONIC CIRCULATION MOVING N 15 KT NEAR 18N125W. THE ASSOCIATED SURFACE COLD FRONT IS JUST ENTERING THE NW OF CORNER OF THE AREA WHILE MOVING SE 15 KT. SE-S WINDS OF 20-30 KT PRECEDE THE FRONT AS REPORTED BY A FEW SHIPS OVER THE FAR NW WATERS OF THE AREA. STRONGER S WINDS TO GALE FORCE ARE JUST W OF THE AREA AHEAD OF THE FRONT N OF ABOUT 22N. AN AREA OF BROKEN TO OVERCAST MULTILAYERED CLOUDS WITH EMBEDDED SCATTERED SHOWERS AND ISOLATED TSTMS IS ALONG AND WITHIN 480 NM E OF THE TROUGH FROM 14N-20N. SATELLITE-DERIVED UPPER LEVEL WINDS SHOW QUITE A LARGE AREA OF UPPER LEVEL DIVERGENCE CONTINUING TO ENHANCE MOSTLY SCATTERED STRONG CONVECTIVE CLUSTERS TO THE E OF THE BASE OF THE TROUGH ALONG AND N OF THE ITCZ AXIS GENERALLY CONFINED FROM 6N TO 11N BETWEEN 106W AND 109 AS MENTIONED IN FIRST PARAGRAPH UNDER ITCZ. EXPECT THIS ACTIVITY TO CONTINUE OVER THE NEXT FEW DAYS AS THE TROUGH MOVES EASTWARD. THE MID/UPPER LEVEL CYCLONIC CIRCULATION NEAR 18N125W IS FORECAST TO BECOME ABSORBED INTO THE TROUGH... WITH ANOTHER ONE POSSIBLY FORMING NEAR 13N121W WITHIN THE NEXT 48-72 HOURS. WEAK LOW PRES MAY STILL FOR SOME OF THE GLOBAL MODELS SUGGEST THAT AN EVENTUAL WEAK LOW MAY EVOLVE FROM THIS AREA AND DRIFT NWD OVER THE NEXT 48 HOURS. MODERATE TO STRONG UPPER LEVEL WINDS ARE ALONG AND W OF THE TROUGH AXIS N OF 26N. THESE WINDS CONTINUE TO TRANSPORT UPPER LEVEL MOISTURE IN THE FORM OF HIGH LEVEL CLOUDS FROM NEAR THE HAWAIIAN ISLANDS NNE TO WELL N OF THE REGION. THE SURFACE COLD FRONT IS FORECAST TO SLOWLY CLIP THE FAR NW CORNER OF THE AREA OVER THE NEXT 24-48 HOURS AS ITS DRIVING UPPER SUPPORT AND RELATED ENERGY PULLS FURTHER AWAY FROM THE AREA TOWARDS THE GENERAL VICINITY OF ALASKA AS GLOBAL MODELS ARE IN PRETTY CLOSE AGREEMENT WITH RESPECT TO THIS SCENARIO. HOWEVER ...THE MAIN ISSUE WITH THIS FRONT WILL BE LONG PERIOD NW SWELLS GENERATED BY ATTENDANT DEEP LOW PRES SYSTEMS THAT WILL PASS WELL TO THE N OF 30N UP AND AROUND THE MID/UPPER LEVEL RIDGING PRESENT E OF 130W. WAVEWATCH MODEL GUIDANCE IS VERY CONSISTENT IN SHOWING SIGNIFICANT WAVE HEIGHTS OF UP TO 19 FT NOW ENTERING THE FAR NW CORNER OF THE AREA. THESE SEAS ARE EXPECTED TO SUBSIDE TO 14 FT ON SUN. ELSEWHERE W OF ABOUT 115W SEAS WILL BE RATHER CHURNED UP...IN THE 8-143FT RANGE THROUGH THE NEXT 2 DAYS. WILL MONITOR THIS UPCOMING SWELL EVENT CLOSELY WITH RESPECT TO PROJECTED FORECAST HEIGHTS AND AREAL COVERAGE AS PORTRAYED IN FUTURE MODEL GUIDANCE. AT THE SURFACE...HIGH PRES RIDGING SWD OVER THE WESTERN GULF OF MEXICO AND MEXICO MAINTAINS A TIGHT PRES GRADIENT ALONG THE MEXICAN COAST USHERING GALE FORCE WINDS IN THE RANGE OF 35-40 KT INTO THE GULF OF TEHUANTEPEC. THESE WINDS ARE FORECAST TO DECREASE TO LESS THAN GALE FORCE IN 24 HOURS...THEN BACK TO GALE FORCR IN 36 HOURS AS INDICATED BY THE LATEST 10M AND 30M MODEL WIND GUIDANCE. LONG TERM WIND GUIDANCE INDICATES THAT WINDS MAY REACH GALE FORCE ONCE AGAIN ON MON. NE WINDS OF 20-25 KT THROUGH THE GULF OF PAPAGAYO ARE EXPECTED TO CONTINUE OVER THE NEXT 24 HOURS AS STRONG HIGH PRES RIDGING PRESSES SWD OVER CENTRAL AMERICA AND STRONG SW CARIBBEAN TRADES ADVECT WESTWARD ACROSS CENTRAL AMERICA. THESE WINDS SHOULD DIMINISH TO 20 KT IN ABOUT 48 HOURS. ELSEWHERE HIGH PRES COVERS THE AREA N OF ABOUT 15N. $$ AGUIRRE