000 AXPZ20 KNHC 111607 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI MAR 11 2011 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 1430 UTC. ...ITCZ... THE INTERTROPICAL CONVERGENCE ZONE AXIS ANALYZED FROM 04N77W TO 01N90W TO 05N110W TO 05N140W. SCATTERED MODERATE FROM 03N TO 08N BETWEEN 115W AND 140W. ...DISCUSSION... A BROAD AND MAINLY FLAT UPPER RIDGE REMAINS OVER THE MAJORITY OF THE AREA FROM THE EQUATOR TO 20N BETWEEN 95W AND 120W CENTERED BY AN UPPER ANTICYCLONE NEAR 04N105W. SUBSIDENCE DOMINATES THE AREA N OF 10N E OF 110W WITH DRY AND STABLE AIR IN PLACE. UPPER RIDGING IS ALSO OCCURRING OVER THE ITCZ BETWEEN 120W AND 140W WITH PULSING DEEP CONVECTION OCCURRING ALONG THE ITCZ AS DESCRIBED ABOVE IN RESPONSE TO DIVERGENT FLOW ALOFT. OTHERWISE AN ENERGETIC AND PROGRESSIVE SW-W FLOW PREVAILS ALOFT W-NW OF THE RIDGING AND ITCZ TRANSPORTING PLENTIFUL MOISTURE FROM THE CENTRAL TROPICAL PACIFIC S OF THE HAWAIIAN ISLANDS TO THE CREST AND OVER THE TOP OF THE RIDGE TO ACROSS BAJA CALIFORNIA AND NW MEXICO. WEAK SHORTWAVE TROUGHS ARE NOTED IN THIS W-SW FLOW WITH LITTLE IMPACT GENERATED BY THEM. UPSTREAM...A STRONG AND DYNAMIC UPPER TROUGH WAS SWEEPING ACROSS THE N CENTRAL PACIFIC REACHING FROM 32N134W ACROSS THE FAR NW CORNER OF THE AREA TO THE BIG ISLAND OF HAWAII. THIS TROUGH IS SUPPORTING A WEAKENING STATIONARY FRONT AT THE SURFACE FROM 32N130W TO 27N140W. NW SWELL UP TO 14 FT EXISTS IN THE NW PORTION WHICH WILL GRADUALLY DECAY AS IT CONTINUES TO PROPAGATE SE DURING THE NEXT 24 HOURS. THE UPPER TROUGH WILL USHER IN A NEW FRONTAL SYSTEM AND A VERY DEEP SURFACE LOW PRES SYSTEM INTO THE NE PACIFIC N OF THE AREA BY 48 HOURS. A NEW SET OF EVEN LARGER NW SWELL WILL ARRIVE LATE SUN THROUGH EARLY NEXT WEEK. ELSEWHERE AT THE SURFACE...1024 MB HIGH PRES IS POSITIONED NEAR 29N129W WITH BROAD RIDGING EXTENDING FROM THE HIGH TO NEAR 14N110W. AS THE NEXT ABOVE MENTIONED FRONTAL SYSTEM APPROACHES THE AREA THE HIGH WILL BE NUDGED E-SE INCREASING THE PRES GRADIENT BETWEEN THE HIGH PRES AND LOWER PRES E OF THE U.S. ROCKY MOUNTAINS AND THE SIERRA MADRE OCCIDENTALS. THE RESULT WILL BE NW-N 20 KT WINDS OFF THE COAST OF BAJA CALIFORNIA FRI NIGHT THROUGH SAT NIGHT. THE SHIFTING SURFACE HIGH HAS WEAKENED THE PRES GRADIENT N OF THE ITCZ...WHICH IS LIMITING FRESH TRADE WINDS CURRENTLY FROM FROM 10N TO 14N W OF 120W. THIS AREA OF 20 KT TRADE WINDS IS EXPECTED TO SHRINK AND SHIFT TO FROM 07N TO 14N W OF 134W BY 24 HOURS THEN WILL EXPAND EASTWARD TO 126W BY 48 HOURS BECOMING REINVIGORATED AS THE NEXT FRONT APPROACHES FROM THE NW. GAP WINDS... GULF OF TEHUANTEPEC...STRONG NORTHERLY WINDS CONTINUE TO SURGE THROUGH THE GULF OF TEHUANTEPEC BEHIND A COLD FRONT WHICH HAS MOVED E OVER GUATEMALA. OBSERVATIONS AT LAND-BASED STATION IXTEPEC MEXICO PRESENTLY REPORTS 30 KT WINDS. LATEST WAVEWATCH MODEL GUIDANCE INDICATES SEAS UP TO 21 FT WITH THESE STRONG WINDS. WINDS WILL DIMINISH BELOW GALE FORCE BY 00Z SAT THEN DIMINISHING TO LESS THAN 20 KT BY 12Z SUN. NE SWELL GENERATED BY THESE WINDS WILL PROPAGATE SW REACHING ALL THE WAY TO THE EQUATOR BY 12Z SUN. GULF OF PAPAGAYO...AS THE ABOVE MENTIONED COLD FRONT CONTINUES TO MOVE SOUTHEASTWARD INTO THE WESTERN CARIBBEAN...WINDS WILL FUNNEL THROUGH SOUTHERN NICARAGUA AND NORTHERN COSTA RICA PRODUCING FRESH NE-E WINDS ACROSS THE GULF OF PAPAGAYO AND DOWNWIND TO 89W FRI NIGHT WITH WINDS INCREASING TO 20-25 KT AND EXPANDING TO 91W. WINDS WILL CONTINUE TO AFTER 12Z SUN. GULF OF PANAMA...LATEST MODEL GUIDANCE INDICATES 20 KT NORTHERLY WINDS IN THE GULF OF PANAMA BEGINNING 06Z SUN AS THE PRES GRADIENT OVER WESTERN COLOMBIA TIGHTENS. REFER TO BULLETINS FROM THE PACIFIC TSUNAMI CENTER USING HEADERS WEPA40 PHEB OR TSUPAC FOR LATEST INFORMATION. $$ LEWITSKY/FORMOSA