000 AXPZ20 KNHC 230304 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC MON APR 23 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0100 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS WAS ANALYZED FROM 05N90W TO 02N98W TO 04N107W TO 02N117W TO 06N127W TO 05N140W. SCATTERED MODERATE CONVECTION WAS FOUND WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 92W AND 97W...WITHIN 90 NM S AND 270 NM N OF THE AXIS BETWEEN 103W AND 111W...AND FROM 60 NM TO 210 NM N OF THE AXIS BETWEEN 126W AND 131W. ...DISCUSSION... A WEAKENING UPPER LEVEL LOW LIES OFF THE W COAST OF BAJA CALIFORNIA NEAR 29N120W. THIS LOW IS LIFTING NORTHWARD ON THE LEADING EDGE OF A DEEP LAYER TROUGH CENTERED OVER THE PORTION OF THE DISCUSSION AREA N OF 23N ALONG 140W. FARTHER EAST...AN UPPER RIDGE LIES OVER NORTHERN MEXICO AND EXTENDS INTO THE SOUTHWESTERN UNITED STATES. BROADLY DIFFLUENT UPPER LEVEL FLOW IS FOUND IN MUCH OF THE REGION BETWEEN 10N AND 20N W OF 125W AND N OF 15N E OF 125W...SOUTH OF THE DEEP LAYER TROUGH AND THE UPPER RIDGE. MUCH OF THIS AREA IS ALSO MARKED BY RELATIVELY HIGH PRECIPITABLE WATER VALUES AS MOSITURE IS FEEDING NORTHWARD FROM SOUTH OF THE ITCZ TOWARD THE UPPER LOW ON THE LEADING EDGE OF THE DEEP LAYER TROUGH. MULTI-LAYERED CLOUDINESS ACCOMPANIED BY SCATTERED SHOWERS CAN BE FOUND IN THE AREA FROM 06N TO 13N BETWEEN 110W AND 126W AND FROM 13N TO 22N W OF 122W AS A RESULT OF THE INCREASED MOSITURE AND LIFT. IN THE DEEP TROPICS...AN UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 01N109W AND A RIDGE AXIS LIES TO ITS N ALONG 08N EAST OF 113W. DIFFLUENT FLOW ABOUT THIS RIDGE AXIS IS ACTING TO ENHANCE THE CONVECTION ALONG THE ITCZ DESCRIBED IN THE SECTION ABOVE. A 1016 MB HIGH PRES SYSTEM IS CENTERED NEAR 23N121W. THIS HIGH AND THE RESULTING PRES GRADIENT HAS BEEN WEAKENED BY THE TROUGHING ALOFT. THIS HAS RESULTED IN TRADE WINDS LESS THAN 20 KT OVER THE FORECAST AREA. A COLD FRONT ASSOCIATED WITH THE DEEP LAYER TROUGH EXTENDS FROM 30N134W TO 24N140W. SCATTERED LIGHT SHOWERS ARE ALONG THE FRONT. NORTHWEST WINDS TO 20 KT LIE WEST OF THE FRONT ACCORDING TO THE 2122 UTC OSCAT PASS. THESE CONDITIONS WILL CONTINUE OVER NW WATERS BEHIND THE SLOW MOVING COLD FRONT OVER THE NEXT FEW DAYS...WITH SEAS BUILDING TO 12 FT IN NW SWELL. THE DEEP LAYER TROUGH OVER NW WATERS IS EXPECTED TO CUT OFF FROM THE NORTHERN STREAM AND APPROACH N WATERS BY WED. THE UPPER JET ON THE LEADING EDGE OF THIS TROUGH WILL INTENSIFY AS THE TROUGH AMPLIFIES. THE REAR RIGHT QUADRANT OF THIS JET WILL LIE NEAR THE MOISTURE RICH REGION NEAR THE ITCZ BY LATE TUE. THIS AREA WILL BE FAVORED FOR CONVECTION. THE MODEL GUIDANCE SUGGESTS THAT A WEAK SURFACE TROUGH MAY ALSO DEVELOP NEAR THE ITCZ. THIS SHOULD ALLOW FOR THE PRES GRADIENT TO INCREASE ENOUGH TO SUPPORT FRESH NE WINDS PRIMARILY FROM 08N TO 14N BETWEEN 120W AND 130W BY EARLY TUE. GAP WINDS... GULF OF TEHUANTEPEC...HIGH PRES OVER THE WESTERN GULF OF MEXICO BEHIND A STRONG LATE SEASON COLD FRONT HAS TIGHTENED THE PRES GRADIENT ACROSS SOUTHERN MEXICO RESULTING IN WINDS TO GALE FORCE THROUGH THE GULF OF TEHUANTEPEC. WHILE THE LOW RESOLUTION OSCAT PASS FROM 1808 UTC ONLY CAPTURED WINDS TO 30 KT HERE...WINDS ARE BELIEVED TO BE GALE FORCE AT PRESENT. NORTH-NORTHEASTERLY GALE FORCE WINDS ARE FORECAST TO INCREASE TO 40 KT MON MORNING AND DIMINISH BELOW GALE FORCE BY TUE AFTERNOON. GULF OF PAPAGAYO...THE COLD FRONT THAT USHERED IN THE HIGH PRES OVER THE WESTERN GULF OF MEXICO THAT INCREASED THE PRES GRADIENT OVER THE GULF OF TEHAUNTEPEC WILL DO THE SAME OVER THE GULF OF PAPAGAYO OVERNIGHT MON NIGHT AFTER THE COLD FRONT MOVES INTO COSTA RICA. WINDS ARE EXPECTED TO REMAIN FRESH TO STRONG DOWNWIND OF PAPAGAYO THROUGH THE END OF THE FORECAST PERIOD ON TUE AFTERNOON AND WILL LIKELY CONTINUE INTO WEDNESDAY. GULF OF PANAMA...FRESH NORTHERLY WINDS FROM THE CARIBBEAN WILL FUNNEL INTO THE GULF OF PANAMA BEHIND THE AFOREMENTIONED COLD FRONT BY TUE MORNING. $$ SCHAUER