000 AXPZ20 KNHC 091543 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC FRI MAR 09 2012 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1515 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ IS IN COLOMBIA AND ECUADOR...ALONG 02N78W 01N80W TO THE EQUATOR ALONG 81W. THE ITCZ IS FROM 00N TO 01S BETWEEN 81W AND 105W. THE ITCZ IS TO THE SOUTH OF 01S EVERYWHERE ELSE TO THE WEST OF 105W. SCATTERED MODERATE TO STRONG CONVECTIVE PRECIPITATION HAS BEEN OCCURRING FROM THE EQUATOR TO 02N BETWEEN 78W AND 81W IN COLOMBIA...ECUADOR...AND IN THE EASTERN PACIFIC OCEAN COASTAL WATERS. NO MONSOON TROUGH WAS ANALYZED. SCATTERED MODERATE TO ISOLATED STRONG CONVECTIVE PRECIPITATION IS FROM 03N TO 04N BETWEEN 96W AND 101W. ISOLATED MODERATE CONVECTIVE PRECIPITATION IS TO THE SOUTH OF 02N BETWEEN 124W AND 130W. ...DISCUSSION... AN UPPER LEVEL TROUGH EXTENDS FROM A CYCLONIC CIRCULATION CENTER THAT IS IN CENTRAL NEW MEXICO...ACROSS NORTHERN MEXICO AND THE NORTHERN BAJA CALIFORNIA PENINSULA...TO 31N119W...TO 20N127W. UPPER LEVEL ANTICYCLONIC WIND FLOW IS RIDING ON TOP OF THE TROUGH...SPANNING THE ENTIRE AREA BETWEEN 100W AND 140W. AN UPPER LEVEL RIDGE PASSES THROUGH THE NORTHWESTERN U.S.A... NORTHERN CALIFORNIA...THROUGH 30N123W TO 20N126W. COMPARATIVELY DRIER AIR IN SUBSIDENCE COVERS THE EASTERN PACIFIC OCEAN TO THE NORTH OF 20N BETWEEN 110W AND 135W. A DEEP LAYER TROUGH PASSES THROUGH 39N136W 33N138W BEYOND 28N143W. THIS TROUGH SUPPORTS THE COLD FRONT THAT PASSES THROUGH 32N138W BEYOND 30N140W. RAINSHOWERS ARE POSSIBLE WITHIN 60 NM ON EITHER SIDE OF THE LINE THAT PASSES THROUGH 32N135W TO 30N137W BEYOND 27N140W. THE DEEP LAYER TROUGH THAT SUPPORTS THE CURRENT 39N136W 28N143W COLD FRONT EVENTUALLY FLATTENS OUT WITH TIME DURING THE NEXT 48 HOURS. THE NEW MEXICO-TO-20N127W TROUGH ALSO EVENTUALLY WILL FLATTEN OUT WITH TIME...IN RESPONSE TO THE DEEP LAYER TROUGH WEAKENING. THE LARGE-SCALE UPPER LEVEL WIND FLOW EVENTUALLY WILL BECOME COMPARATIVELY MORE ZONAL AT 48 HOURS. THE COLD FRONT THAT IS IN THE WESTERN PART OF THE FORECAST AREA DOES NOT MOVE EASTWARD INTO THE AREA MUCH AT ALL DURING THE NEXT 48 HOURS. THE COLD FRONT LOSES ITS UPPER LEVEL SUPPORT AND IT WEAKENS AS THE UPPER TROUGH QUICKLY SLIDES EASTWARD LEAVING STRONGER SURFACE HIGH PRESSURE TO BUILD EASTWARD ACROSS THE NORTHERN AND CENTRAL SECTIONS OF THE AREA THROUGH SUNDAY. LARGE NORTHWESTERLY SWELLS...RESULTING IN POSSIBLE SEAS OF 11 OR 12 FT...WILL SPREAD ACROSS THE NORTHWESTERN WATERS ON SATURDAY AND SUNDAY. A 1028 MB HIGH PRESSURE CENTER IS NEAR 34N127W. SURFACE ANTICYCLONIC WIND FLOW COVERS THE AREA TO THE NORTH OF 20N105W 13N113W 12N140W. GAP WINDS... THE GULF OF CALIFORNIA...A TIGHT SURFACE PRESSURE GRADIENT EXISTS IN THE GULF OF CALIFORNIA...BETWEEN HIGH PRESSURE THAT IS IN THE NORTH CENTRAL WATERS AND LOWER PRESSURE THAT IS IN NORTHWESTERN MEXICO. THIS GRADIENT IS BRINGING NORTHWESTERLY WINDS THAT RANGE FROM 20 TO 30 KNOTS. NORTHWESTERLY 20 KNOT WINDS ARE OCCURRING TO THE NORTH OF 26N AND TO THE EAST OF 116W TO THE COAST OF BAJA CALIFORNIA. THE WIND SPEEDS WILL DIMINISH TO 20 KNOTS FROM 23N TO 28N AS THE PRESSURE GRADIENT WEAKENS DURING THE NEXT 48 HOURS. THE GULF OF TEHUANTEPEC...20 KNOT NORTHEASTERLY WINDS WILL BEGIN IN THE GULF OF TEHUANTEPEC IN 18 TO 24 HOURS...FOLLOWED BY NORTH-TO-NORTHEASTERLY GALE-FORCE WINDS ABOUT 6 HOURS LATER. EXPECT THE WIND SPEEDS FROM 24 TO 48 HOURS TO REMAIN IN THE RANGE FROM 20 TO 30 KNOTS. THE GULF OF PAPAGAYO...A COASTAL LAND STATION SURFACE OBSERVATION IN NORTHWESTERN COSTA RICA FROM 09/0145 UTC SHOWED 20 KNOT GAP WIND FLOW IN NORTHWESTERN COSTA RICA AND SOUTHWESTERN COASTAL NICARAGUA...REACHING AS FAR WEST INTO THE PACIFIC AS 92W. A LARGE AREA OF NORTHEASTERLY SWELL HAS BEEN ESTABLISHED IN THE TROPICAL NORTH PACIFIC OCEAN TO THE EAST OF 110W DUE TO THE COMBINED INFLUENCE OF THE EARLIER TEHUANTEPEC AND PAPAGAYO GAP WINDS EVENTS. HIGH PRESSURE THAT IS BUILDING TO THE NORTH OF THE CARIBBEAN SEA WILL MAINTAIN STRONG TRADE WINDS THAT WILL WILL FUNNEL ACROSS AND THROUGH THE GULF AS NORTHEASTERLY-TO-EASTERLY 20 TO 25 KNOT WINDS DURING THE NEXT 48 HOURS. THE NORTHEASTERLY-TO-EASTERLY SWELL IN THE DOWNSTREAM PLUME ALSO WILL BE MAINTAINED. THE GULF OF PANAMA...STRONG TRADE WINDS IN THE SOUTHWESTERN CARIBBEAN SEA WILL MAINTAIN SPURTS OF FRESH NORTHERLY FLOW ACROSS THE PANAMA ISTHMUS AND INTO THE BAY OF PANAMA THROUGH THE NEXT 48 HOURS. $$ MT