000 AXPZ20 KNHC 130926 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON OCT 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0900 UTC. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC...THE MOST RECENT ASCAT PASS SHOWED NLY WINDS OF 15-20 KT ACROSS THE GULF OF TEHUANTEPEC OVERNIGHT TONIGHT. A STRONG COLD FRONT IS EXPECTED TO MOVE THROUGH THE SW GULF OF MEXICO ON TUE. NLY WINDS AT 20-30 KT WILL BEGIN TO SURGE INTO THE AREA TUE AFTERNOON WITH BUILDING SEAS TO 8 FT. THEN... WINDS WILL QUICKLY INCREASE TO GALE FORCE TUE EVENING. THIS GAP WIND EVENT IS EXPECTED TO PEAK TUE NIGHT WITH POSSIBLE MAXIMUM WINDS REACHING 40 KT. THESE WINDS WILL CONTINUE TO BE ENHANCED BY THE NOCTURNAL DRAINAGE FLOW. A GALE WARNING IS ALREADY IN EFFECT BEGINNING AT 15/0000Z. SEAS ARE FORECAST TO BUILD TO AROUND 16 FT WITH THE STRONGEST WINDS. THE FORECAST CALLS FOR WINDS BELOW GALE FORCE BY WED AFTERNOON. THE NORTHERLY FLOW WILL PULSE TO 30 KT AGAIN LATE WED NIGHT AND TO 25 KT LATE THU NIGHT...WITH THE N WINDS DIMINISHING BELOW 20 KT AND SEAS SUBSIDING BELOW 8 FT BY FRI AFTERNOON. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH EXTENDS FROM 11N86W TO LOW PRES NEAR 11N91W TO 14N110W TO LOW PRES NEAR 15N120.5W TO 14N125W. ITCZ CONTINUES FROM 14N125W TO 13N130W TO 14N140W. SCATTERED MODERATE CONVECTION IS NOTED N OF 09N TO THE COAST OF CENTRAL AMERICA BETWEEN 86W AND 90W...INCLUDING THE GULF OF FONSECA. SIMILAR CONVECTION IS ALSO OBSERVED FROM 10N TO 13N BETWEEN 118W AND 132W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS FROM 08N TO 12N W OF 134W. ...DISCUSSION... A WEAK 1010 MB LOW PRESSURE CENTER REMAINS EMBEDDED WITHIN THE MONSOON TROUGH NEAR 11N91W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM SE QUADRANT OF LOW CENTER. SCATTEROMETER DATA SHOW VERY WELL THE CYCLONIC CIRCULATION ASSOCIATED WITH THIS LOW WITH WINDS OF ONLY 5-10 KT WITH SEAS OF 3-5 FT. THIS LOW PRESSURE IS FORECAST TO MEANDER IN ROUGHLY THIS SAME POSITION THROUGH TONIGHT...THEN MOVE SLOWLY EASTWARD TUE NIGHT AS STRONG WINDS BEGIN TO FUNNEL THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. THE SOUTHWESTERLY MONSOONAL FLOW IS FORECAST TO INCREASE TO 20 KT S OF THE LOW CENTER BY WED. ANOTHER WEAK LOW PRES OF 1010 MB IS LOCATED BY AN ASCAT PASS NEAR 15N120.5W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS WITHIN 120 NM NE QUADRANT OF LOW CENTER. THE LOW IS EXPECTED TO MOVE W-NW ALONG THE MONSOON TROUGH THEN OPEN UP INTO A TROUGH ALONG 125W IN ABOUT 48 HOURS. A THIRD LOW PRES IS JUST W OF THE FORECAST AREA NEAR 12N141W WITH AN ESTIMATED MINIMUM CENTRAL PRES OF 1008 MB. A CLUSTER OF MODERATE TO STRONG CONVECTION IS TO THE N OF THE LOW CENTER AND COVERS THE FORECAST WATERS FROM 13N TO 15N W OF 138W. PRES GRADIENT BETWEEN THE LOW AND A RIDGE TO THE N MAINTAINS AN AREA OF FRESH TO STRONG WINDS FROM 12N TO 16N W OF 138W WITH SEAS OF 8-10 FT. THIS TROPICAL LOW HAS A HIGH PROBABILITY OF BECOMING A TROPICAL CYCLONE JUST W OF THE AREA...AND A TROPICAL DEPRESSION MAY FORM TODAY OR TUE. LONG PERIOD NW SWELL CONTINUES TO SPREAD SE ACROSS MUCH OF THE FORECAST WATERS W OF 120W WITH COMBINED SEAS OF 8-12 FT. SEAS ARE EXPECTED TO QUICKLY SUBSIDE FROM WEST TO EAST MON NIGHT INTO TUE WITH SEAS ACROSS THE ENTIRE WATERS W OF 110W BELOW 8 FT BY TUE NIGHT. A COLD FRONT IS FORECAST TO MOVE INTO THE NW CORNER OF THE AREA TUE MORNING REACHING A POSITION FROM 30N127W TO 26N40W BY WED MORNING. NLY WINDS OF 15-20 KT WILL FOLLOW THE FRONT WITH BUILDING SEAS TO AROUND 11 FT IN NW SWELL. $$ GR