000 AXPZ20 KNHC 222117 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC SUN APR 22 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 1945 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE ITCZ AXIS WAS ANALYZED FROM 06N90W TO 03N98W TO 04N106W TO 03N116W TO 05N125W TO 04N140W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION WAS WITHIN 90 NM EITHER SIDE OF THE AXIS BETWEEN 103W AND 108W. SCATTERED MODERATE CONVECTION WAS WITHIN 90 NM S OF THE AXIS BETWEEN 90W AND 96W. ...DISCUSSION... AN UPPER LEVEL LOW LIES OFF THE W COAST OF BAJA CALIFORNIA NEAR 28N120W. 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. MOSTLY ZONAL UPPER LEVEL FLOW IS FROM 10N-22N...WITH MODERATE UPPER DIFFLUENCE FOUND E OF 130W WHERE THIS ZONAL FLOW SEPARATES FROM THE SOUTH-SOUTHWESTERLY FLOW TO THE NORTH ON THE LEADING EDGE OF THE DEEP LAYER TROUGH. ISOLATED MODERATE CONVECTION FOUND FROM 06N TO 18N BETWEEN 110W AND 130W IS BEING ENHANCED BY THIS DIFFLUENCE ALOFT. THIS AREA IS 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. IN THE DEEP TROPICS...AN UPPER LEVEL CYCLONIC CIRCULATION IS CENTERED NEAR 01N108W AND A RIDGE AXIS LIES TO ITS N ALONG 07N EAST OF 115W. DIFFLUENT FLOW ABOUT THIS RIDGE AXIS IS ACTING TO ENHANCE THE CONVECTION ALONG THE ITCZ DESCRIBED IN THE SECTION ABOVE. A 1017 MB HIGH PRES SYSTEM IS CENTERED NEAR 23N119W. 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 AFOREMENTIONED 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. THESE CONDITIONS WILL CONTINUE OVER NW WATERS BEHIND THE SLOW MOVING COLD FRONT OVER THE NEXT FEW DAYS...WITH SEAS BUILDING TO 11 FT IN NW SWELL. 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. 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. $$ SCHAUER