000 AXPZ20 KNHC 032135 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SAT DEC 03 2011 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND METEOROLOGICAL ANALYSIS. BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2130 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH IS ALONG 09N84W TO 06N92W. THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N92W TO LOW PRES NEAR 08N103W TO 06N111W TO 10N120W TO 10N127W TO 08N140W. SCATTERED MODERATE WITHIN 60 NM OF ITCZ W OF 138W. ...DISCUSSION... A SHARP UPPER LEVEL TROUGH EXTENDS FROM A WELL DEFINED MID TO UPPER LEVEL CYCLONE OVER WRN ARIZONA NEAR 35N114W SW OVER THE NORTHERN BAJA INTO THE PACIFIC WATERS TO A BASE NEAR 20N118W. REINFORCING SHORTWAVE ENERGY IS ROUNDING THE BASE OF THE UPPER LEVEL TROUGH AND HAS BECOME ABSORBED INTO THE DEEP LAYERED CYCLONE NOTED ABOVE AND WAS INSTRUMENTAL IN CARVING OUT A BROAD TROUGH BASE REMAINING N OF 20N E OF 133W. WATER VAPOR IMAGERY INDICATES VERY DRY AIR AND RELATIVELY STABLE CONDITIONS ALOFT WITH THIS UPPER LEVEL FEATURE. ELSEWHERE BROAD UPPER LEVEL RIDGES ARE FOUND BOTH TO THE W AND SE OF THE UPPER LEVEL TROUGHING...ONE WITH AN AXIS ALONG 135W AND THE OTHER CENTERED IN THE DEEP TROPICS NEAR 04N93W EXTENDING N-NE ACROSS MUCH OF CENTRAL AMERICA...SOUTHERN MEXICO AND OVER THE GULF OF MEXICO. HIGH PRESSURE IS FORECAST TO BUILD INTO THE SOUTHWEST CONUS ACROSS THE GULF OF CALIFORNIA REGION FROM THE N TONIGHT INTO SUNDAY AND PRODUCE FRESH TO LOCALLY STRONG NORTHERLY WINDS...PERSISTING THROUGH MONDAY AFTERNOON AND NIGHT. WINDS MAY LOCALLY GUST TO 30 KT. HIGH PRESSURE WELL N OF THE AREA ACROSS THE FAR EASTERN NORTH PACIFIC EXTENDS S TO 18N BETWEEN 125W-150W ACROSS WESTERN PORTIONS OF THE DISCUSSION AREA...AND IS MAINTAINING FRESH NELY WINDS GENERALLY W OF 125W SOUTHWARD TO THE ITCZ ALONG ABOUT 08N. THIS WAS CONFIRMED BY AN 1836 UTC ASCAT PASS AND A FEW SHIP OBSERVATIONS. SEAS OF 8 TO 12 FT PREVAIL ACROSS THIS AREA IN A MIX OF N AND NEW NW SWELL...AND BUILDING NE WIND WAVES. THIS WIND FLOW WILL DIMINISH AND VEER MORE NE TO E THROUGH 48 HOURS AS HIGH PRES N OF THE AREA WEAKENS SLIGHTLY AND DRIFTS SE. TO THE SE...A 1011 MB LOW PRES CENTER REMAINS EMBEDDED WITHIN THE ITCZ NEAR 08N103W WAS MOVING W AT 10-12 KT. AN ASCAT PASS FROM 1656 UTC STILL INDICATED 20 TO 25 KT WINDS WITHIN 150 NM ACROSS THE NRN SEMICIRCLE OF THE LOW PRES. GLOBAL MODELS SUGGEST SOME INCREASE IN SOUTHERLY FLOW INTO THE LOW OVER THE NEXT 48 HOURS... WITH THE LOW PERSISTING AT LEAST THROUGH 72 HOURS AS IT SHIFTS WNW AT AROUND 10 KT. THIS IS PLAUSIBLE THROUGH 48 HOURS GIVEN THAT THE LOW WILL MOVE INTO INTO THE FAVORABLE SE PORTION OF A BROAD UPPER LEVEL TROUGH TO THE N. THE UPPER LEVEL TROUGH AMPLIFIES BEYOND THAT...WITH THE LOW LIKELY WEAKENING. A LACK OF DEEP LAYER MOISTURE IS PREVENTING ANY MAJOR CONVECTIVE ACTIVITY NEAR THIS LOW PRES AREA PRESENTLY. GULF OF TEHUANTEPEC...ALTHOUGH THERE WERE NO SCATTEROMETER PASSES SAMPLING THE REGION DURING THE DAY NEARBY SURFACE OBSERVATIONS SUGGESTED WINDS HAVE DROPPED TO AROUND 20 KT AT BEST IN THE AREA. OVERNIGHT DRAINAGE FLOW THROUGH THE CHIVELA PASS SHOULD KEEP WINDS AT 20 KT THROUGH THE MORNING HOURS SUN THEN SYNOPTIC SCALE FORCING SHOULD ALLOW WINDS TO DROP TO LIGHT AND VARIABLE THEREAFTER. GULF OF PAPAGAYO...OVERNIGHT DRAINAGE FLOW WILL ENHANCE THE N-NE FLOW CURRENTLY PREVAILING ACROSS THE WESTERN CARIBBEAN. FRESH NORTHEASTERLY GAP WINDS ARE EXPECTED DURING THE NEXT COUPLE OF DAYS...WITH WINDS LIKELY STRONGEST DURING THE LATE NIGHT AND EARLY MORNING HOURS. $$ COBB