000 AXPZ20 KNHC 301600 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1605 UTC SUN NOV 30 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. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC GALE WARNING...AFTER A RECENT PROLONGED STORM AND EVENT N-NE WINDS THROUGH THE GULF HAVE DIMINISHED TO 20-25 KT. THESE WINDS WILL DIMINISH TO 15-20 KT BY EARLY THIS AFTERNOON BEFORE THE NOCTURNAL NORTHERLY DRAINAGE AGAIN KICKS IN THIS EVENING WITH N WINDS MATERIALIZE THROUGH THE GULF WITHIN 30 NM OF A LINE FROM 16N95W TO 14.5N95W. AS HIGH PRES BUILDS OVER THE EASTERN MEXICO...THE RESULTANT PRES GRADIENT OVER SOUTHEASTERN MEXICO WILL TIGHTEN ONCE AGAIN OVERNIGHT AND INTO EARLY MON ALLOWING FOR THE N-NE WINDS TO INCREASE TO 20-30 KT WITHIN 45 NM OF A LINE FROM 16N95W TO 14N96W...INCLUDING THE GULF OF TEHUANTEPEC...AND WITH SEAS OF 8-10 FT. ELSEWHERE WITHIN 75 NM OF A LINE FROM 16N95W TO 14.5N95.5W TO 13N96W N-NE WINDS OF 20-25 KT WITH SEAS TO 8 FT ARE EXPECTED BY THEN. THESE WINDS WILL INCREASE FURTHER REACHING MINIMAL GALE FORCE BY LATE MON NIGHT WITH SEAS UP TO 14 FT ABOUT 90-120 NM OFFSHORE ON TUE NIGHT AND WED. THE EXTENT OF NORTHERLY SWELLS RESULTING IN COMBINED SEAS OF 8 FT OR GREATER HAS CROSSED THE EQUATOR BETWEEN 100W-111W. THESE SEAS ARE EXPECTED TO SHIFT WESTWARD...AND GRADUALLY SUBSIDE OVER THE NEXT SEVERAL DAYS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W FROM THE CARIBBEAN COAST OF COLOMBIA AT 08N78W TO 07N94W TO 10N106W WHERE SCATTEROMETER WINDS INDICATES A TRANSITION TO AN ITCZ WHICH CONTINUES WNW TO 11N116W TO 10N121W WHERE IT ENDS BRIEFLY. IT RESUMES AT 08N132W TO BEYOND 10N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS OBSERVED FROM 03N-07N E OF 80W TO ALONG COAST OF COLOMBIA. SCATTERED MODERATE CONVECTION IS WITHIN 60 NM N OF THE ITCZ BETWEEN 110W-115W...AND WITHIN 30 NM OF ITCZ BETWEEN 126.5W -129W. ...DISCUSSION... UPPER LEVELS...WATER VAPOR IMAGERY DEPICTS BROAD RIDGING N OF 10N BETWEEN 109W-130W WITH THE ASSOCIATED ANTICYCLONE ANCHORED AT 10N128W. BROAD TROUGHING IS TO THE W OF THIS RIDGE...AND IS SHIFTING EASTWARD WITH TIME. A MID-LEVEL TROUGH OVER THE EASTERN PORTION IS ALSO SHIFTING EASTWARD EASTWARD..AND HAS ITS AXIS ALONG 106W N OF 12N. A SUBTROPICAL JET STREAM BRANCH WITH MAXIMUM WINDS OF 60-90 KT ROUNDS THE BASE OF THE BROAD TROUGH WHILE TRANSPORTING MOISTURE FROM THE CENTRAL PACIFIC TROPICS NEWD WITHIN 200 NM OF LINE FROM 24N118W TO 18N130W TO 13N140W. THIS MOISTURE IS SEEN AS BROKEN TO OVERCAST MID AND UPPER CLOUDS WITH POSSIBLE PATCHES OF LIGHT RAIN WITH THE MID LEVEL CLOUDS LOCATED FROM 18N-21N BETWEEN 124W-132W. THE IMAGERY ALSO DEPICTS MODERATE SUBSIDENCE N OF 18N E OF 117W...AND BEHIND THE BROAD TROUGH. S OF 18N...THE ATMOSPHERE REMAINS VERY MOIST AND UNSTABLE AS JET STREAM ENERGY PROVIDES ADDITIONAL LIFT TO CONVECTION ASSOCIATED WITH THE ITCZ W OF 127W...AND SLIGHT DIFFLUENCE FLOW BETWEEN THE MID-LEVEL TROUGH AND THE ANTICYCLONE AT 10N128W AIDS CONVECTION JUST SW OF THE MID-LEVEL TROUGH. SCATTERED TO BROKEN HIGH CLOUDS...MAINLY ATTRIBUTED TO CONVECTION ALONG AND NEAR THE ITCZ AS DESCRIBED ABOVE ARE STREAMING EASTWARD TO ACROSS MEXICO FROM 15N-20N. AT THE SURFACE...NEARLY STATIONARY HIGH PRES IS NEAR 23N116W. A WEAK TROUGH EXTENDS FROM 32N123W TO 25N130W...WHILE A COLD FRONT IS JUST NW OF THE AREA. N SWELL RESULTING IN COMBINED SEAS OF 7- 9 FT ARE W OF A LINE FROM 32N130W TO 23N140W. THE COLD FRONT WILL PUSH INTO THE NW WATERS EARLY THIS AFTERNOON ACCOMPANIED BY A 20-30 KT SW-W-NW WIND SHIFT AND SEAS 8-13 FT. THE FRONT WILL BEGIN TO STALL TUE NIGHT AS WINDS DIMINISH TO 20 KT OR LESS ACROSS THE DISCUSSION WATERS. HOWEVER...ANOTHER BATCH OF LONG PERIOD NW SWELL WILL PROPAGATE SEWD ACROSS THE DISCUSSION WATERS EARLY THIS WEEK WITH COMBINED SEAS TO 18 FT REACHING NEAR 32N140W LATE MON. THE 12 UTC SURFACE ANALYSIS ALSO HAS A WEAK TROUGH FROM 17N127W TO 10N130W MOVING W AT 16 KT. THIS FEATURE REMAINS RATHER WEAK WITH SATELLITE IMAGERY SHOWING ONLY ISOLATED WEAK CONVECTION WITHIN 180 NM W OF THE TROUGH FROM 11N-13N. OTHER GAP WINDS... GULF OF PAPAGAYO...A TIGHT PRES GRADIENT ATTRIBUTED TO CARIBBEAN HIGH PRES WILL MAINTAIN 20-25 KT NE WINDS IN AND DOWNSTREAM OF THE GULF OF PAPAGAYO THROUGH EARLY TONIGHT...THE DIMINISH TO 15- 20 KT AS THE GRADIENT SLACKENS. THESE WINDS THEN PICK UP AGAIN TO 20-25 KT AROUND DAYBREAK MON IN PULSING FASHION THROUGH TUE. $$ AGUIRRE