000 AXPZ20 KNHC 231602 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN MAR 23 2014 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 1545 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... A LOW LEVEL TROUGH EXTENDS ACROSS THE DEEP TROPICS FROM 03N123W TO 10N122W...BUT CURRENTLY LACKS SIGNIFICANT CONVECTION. THE ITCZ EXTENDS FROM 04N94W TO 00N116W...THEN PASSES S OF THE TROUGH TO 04N130W TO BEYOND 03N140W. ISOLATED MODERATE TO STRONG CONVECTION IS NOTED N OF THE ITCZ AXIS WITHIN 30 NM EITHER SIDE OF A LINES FROM 08N90W TO 04N104W AND FROM 03N125W TO 07N127W TO 04N134W. A SMALL CLUSTER SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED OVER...AND JUST OFFSHORE THE COAST OF COLOMBIA AT 05.5N77.5W. ...DISCUSSION... A LONG WAVE TROUGH DOMINATES THE UPPER LEVELS OF THE EASTERN N PACIFIC WITH AN EMBEDDED UPPER SHORT WAVE TROUGH MOVING THROUGH THE LONG WAVE PATTERN WITHIN THE DISCUSSION AREA FROM 32N129W TO 26N132W. AN UPPER ANTICYCLONE IS CENTERED OVER THE COAST OF GUATEMALA AT 14N91W...WITH AN UPPER RIDGE EXTENDING NW ACROSS MEXICO TO A CREST AT 30N105W. A BAND OF DENSE CIRRIFORM CLOUDS IS STREAMING NE ACROSS THE RIDGE WITHIN 120 NM OF A LINE FROM FROM OVER THE PACIFIC AT 18N120W TO OVER TEXAS AT 30N100W... WHERE IT MERGES WITH ADDITIONAL MOISTURE THAT COVERS THE SE CONUS. ANOTHER AREA OF DEBRIS MOISTURE IS E OF THE UPPER SHORTWAVE TROUGH...AND MOVING ENE ACROSS THE NORTHERN BAJA CALIFORNIA PENINSULA. THIS MOISTURE WILL SOON REPLACE THE DRY UPPER AIR OVER SOUTHERN CALIFORNIA. AN UPPER ANTICYCLONE IS QUASI-STATIONARY OVER THE DEEP TROPICS NEAR 10N137W WITH AN UPPER RIDGE EXTENDING E TO A CREST AT 12N123W. UPPER DIFFLUENCE ALONG THE SOUTHERN PORTION OF THIS RIDGE IS SUPPORTING THE ISOLATED MODERATE-STRONG CONVECTION PREVIOUSLY DESCRIBED TO THE N OF THE ITCZ. THE RESULTANT... SUPRIZINGLY DENSE...DEBRIS MOISTURE IS ADVECTED S ACROSS THE EQUATOR BETWEEN 130-140W. UPPER CYCLONES ARE NOTED OVER THE DEEP TROPICS AT 06N120W AND 07N108W AND SEPARATES THE NARROW ANTICYCLONIC UPPER FLOW OVER THE WESTERN PORTION OF THE TROPICS FROM THE BROADER ANTICYCLONIC FLOW DOMINATING THE DISCUSSION AREA S OF 20N E OF 105W. A WEAK UPPER TROUGH EXTENDS E FROM THE UPPER CYCLONE AT 07N108W INTO THE UPPER RIDGE TO NEAR 08N90W...AND IS RESPONSIBLE FOR THE NARROW BAND OF CONVECTION PREVIOUSLY DESCRIBED TO THE N OF THE ITCZ BETWEEN 9--102W. THE DEBRIS MOISTURE FROM THIS NARROW BAND OF CONVECTION QUICKLY EVAPORATES IN THE OTHERWISE VERY DRY AIR ACCOMPANYING THE UPPER RIDGE AND SUPPRESSING CONVECTION OVER CENTRAL AMERICA TO THE E OF THE ISTHMUS OF TEHUANTEPEC. SOME DEBRIS MOISTURE IS MOVING W OFF THE COASTS OF COLOMBIA AND EQUADOR. ELSEWHERE AT THE SURFACE...A SURFACE RIDGE EXTENDS SE FROM 32N130W TO NEAR 13N100W. A SURFACE RIDGE ALSO EXTENDS SW ACROSS THE FAR NW PORTION OF THE DISCUSSION AREA FROM 32N130W TO 30N140W. THE SOUTHERLY FLOW N OF THIS RIDGE IS ONLY AT 15-20 KT...BUT COMBINED SEAS OF 7-8 FT IN MIXED NW AND NE SWELL ARE OBSERVED N OF 30N W OF 137W. THESE SEA CONDITIONS WILL SHIFT N OF 32N TONIGHT JUST AS A COLD FRONT MOVES INTO THE AREA. THE FRONT WILL REACH FROM 32N138W TO 29N140W LATE TONIGHT ACCOMPANIED BY A 15-20 KT SW-W-NW WINDS SHIFT...AND NW SWELL THAT WILL MIX WITH LONG PERIOD CROSS EQUATORIAL SE SWELL AND SLOWLY BUILD SEAS OF 8-12 FT NW OF THE FRONT. THE COLD FRONT WILL REACH FROM 32N130W TO 26N135W ON TUE...THEN BE BARELY IDENTIFIABLE ALONG A POSITION FROM 32N120W TO 27N127W ON WED. HOWEVER...COMBINED SEAS OF 8-10 FT...IN MIXED NW AND SE SWELL...WILL PROPAGATE SE ACROSS THE WATERS W OF THE DECAYING FRONT. THE COMBINED SEAS OF 8 FT WILL ARRIVE ALONG THE PACIFIC COAST OF THE NORTHERN BAJA PENINSULA WED NIGHT...AND CONTINUE THROUGH FRI AFTERNOON...THEN SUBSIDE BELOW 8 FT FRI EVENING. S OF THE SURFACE RIDGE THE NE TRADES ARE AT 15-20 KT ACROSS THE TROPICAL WATERS N OF THE ITCZ TO ALONG 20N...WITH SEAS 7-8 FT PRIMARILY IN NE WIND WAVE MIXING WITH LONG PERIOD NW AND CROSS EQUATORIAL SE SWELL. THIS ENHANCED AREA OF SEAS IS EXPECTED TO CONTINUE THROUGH TUE...THEN BE REINFORCED BY NW SWELL PROPAGATING SE BEHIND THE COLD FRONT PREVIOUSLY DESCRIBED...AND COVERING THE WATERS FROM 07-20N W OF 130W BY LATE WED. A SURFACE RIDGE WILL BUILD E ACROSS THE AREA W OF THE FRONT INCREASING THE NE TRADES WINDS S OF THE RIDGE TO 20-25 KT/SEAS 7-10 FT ACROSS THE WATERS FROM 08-18N W OF 135W ON WED NIGHT. THE GRADIENT WILL THEN WEAKEN AS THE RIDGE BECOMES ORIENTATED NE-SW FROM 32N125W TO 25N140W BY FRI. SOUTHERLY FLOW NW OF THIS NE-SW RIDGE WILL INCREASE SUPPORTING 15-20 KT AGAIN ON FRI AHEAD OF THE NEXT COLD FRONT ARRIVING AT 32N140W LATE FRI. GULF OF PAPAGAYO GAP WINDS...NE-E WINDS OCCURRED AT 20-25 KT AT SUNRISE THIS MORNING ARE QUICKLY DIMINISHING. THE GRADIENT IS ONLY EXPECTED TO SUPPORT A MAXIMUM 15-20 KT DRAINAGE FLOW TONIGHT...MON NIGHT AND TUE NIGHT. GUIDANCE STILL SUGGESTS ANOTHER 20-25 KT EVENT ON WED AND THU NIGHTS. GULF OF TEHUANTEPEC...LIGHT 5-10 KT SW WINDS THIS AFTERNOON WILL INCREASE TO 10-15 KT BRIEFLY THIS EVENING...THEN DIMINISH AND BECOME LIGHT 5-10 KT NW-N WINDS LATE TONIGHT THROUGH LATE MORNING ON MON. THIS PATTERN WILL REPEAT ON MON AFTERNOON THROUGH TUE MORNING...AND REPEAT AGAIN THROUGH THE REMAINDER OF THIS WEEK...EXCEPT GUIDANCE SUGGESTS THE NOCTURNAL MAXIMUM NORTHERLY DRAINAGE FLOW WILL INCREASE TO 20-25 KT ON TUE NIGHT THROUGH SUNRISE ON WED. $$ NELSON