000 AXPZ20 KNHC 130930 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE OCT 13 2015 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. ...TROPICAL WAVES... A TROPICAL WAVE WAS ANALYZED FROM 13N107W TO LOW PRES NEAR 10N107W 1008 MB. THE WAVE HAS BEEN MOVING W AT 10-15 KT OVER THE LAST 24 HOURS. MODERATE EASTERLY SHEAR CONTINUES ACROSS THE THIS REGION...TO THE SOUTH OF AN UPPER ANTICYCLONE CENTERED N OF AREA NEAR 19N108W. AS A RESULT...SCATTERED MODERATE CONVECTION IS DISPLACED TO THE WEST OF THE TROPICAL WAVE AND LOW PRES...FROM 06N TO 13N BETWEEN 107W AND 114W. AN ASCAT SATELLITE PASS FROM 04 UTC INDICATED ONLY MODERATE WINDS ON THE NORTH QUADRANT OF THE LOW...AND LIGHTER WINDS ELSEWHERE. SIMILARLY A PAIR OF ALTIMETER SATELLITE PASSES AT 01 AND 03 UTC INDICATED SEAS 7 FT OR LESS TO THE EAST OF THE LOW PRES. THE UPPER ANTICYCLONE WILL SHIFT WEST KEEPING PACE WITH THE TROPICAL WAVE/LOW PRES...INHIBITING SIGNIFICANT DEVELOPMENT THROUGH THE NEXT 48 HOURS. AFTERWARD THE LOW PRES WILL ENTER A MORE FAVORABLE AREA OF WEAKER SHEAR THAT IS MORE CONDUCIVE FOR DEVELOPMENT. PLEASE SEE THE LATEST NHC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOEP/ABPZ20 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS FROM 08N83W TO 09N95W TO LOW PRES NEAR 10N107W 1008 MB TO 09N115W...THEN CONTINUES FROM 14N122W TO 10N130W TO 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS NOTED WITHIN 150 NM S OF AXIS BETWEEN 128W AND 139W. ...DISCUSSION... N OF 15N E OF 120W...WEAK HIGH PRES IS BUILDING OVER BAJA CALIFORNIA SUR...ESTABLISHING A LIGHT WIND REGIME OVER THE REGION AS NOTED IN SEVERAL SHIP OBSERVATIONS AND AN ASCAT SATELLITE PASS FROM 04 UTC. THIS IN THE WAKE OF A TROUGH THAT MOVED ACROSS THE REGION OVER THE PAST COUPLE OF DAYS BRINGING A ROUND OF FRESH TO STRONG SE WINDS AND SEAS TO 11 FT. SEAS MAY STILL BE AS HIGH AS 8 FT W OF GUADELUPE ISLAND IN NW SWELL. THIS IS EXPECTED TO SUBSIDE BELOW 8 FT THROUGH LATE TODAY. THE SURFACE HIGH WILL SHIFT WEST OF THE BAJA PENINSULA LATE TODAY...ALLOWING A RETURN TO NW WINDS ACROSS THE REGION. EXPECT MODERATE TO FRESH NW FLOW ALONG CENTRAL AND SOUTHERN PORTIONS OF THE GULF OF CALIFORNIA BY MID WEEK AS HIGH PRES BUILDS OVER THE GREAT BASIN N OF THE AREA. GULF OF TEHUANTEPEC...WINDS AND SEAS HAVE TEMPORARILY DIMINISHED IN THE GULF OF TEHUANTEPEC. A TROPICAL WAVE...CURRENTLY STRETCHED FROM NORTHERN COSTA RICA THROUGH EASTERN HONDURAS...WILL PASS THROUGH THE GULF OF TEHUANTEPEC LATER IN THE WEEK. THE INCREASED PRESSURE GRADIENT BETWEEN THIS WAVE AND HIGHER PRESSURE OVER NE MEXICO WILL DRIVE STRONG TO NEAR GALE FORCE N-NE WINDS THROUGH CHIVELA PASS WED MORNING THROUGH THE END OF THE FORECAST PERIOD WED NIGHT. SEAS WILL GRADUALLY BUILD TO AS HIGH AS 11 FT DURING THIS TIME...MIXING WITH PERSISTENT LONG PERIOD SW SWELL. LOOKING AHEAD...GAP WINDS MAY REACH GALE FORCE THROUGH TEHUANTEPEC LATER IN THE WEEK BETWEEN HIGH PRES N OF THE AREA AND DEVELOPING LOW PRES TO THE SOUTH. S OF 15N E OF 110W...OTHER THAN THE AFOREMENTIONED TROPICAL WAVE AND LOW PRES NEAR 107W...ANOTHER TROPICAL WAVE WILL MOVE OFF COASTS OF EL SALVADOR AND NICARAGUA LATE TODAY AND PASS 95W LATE WED. SW WINDS SOUTH OF THE MONSOON TROUGH REMAIN GENTLE TO MODERATE. SEAS ARE STILL REACHING AS HIGH AS 7 FT IN SW SWELL. A REINFORCING ROUND OF SW SWELL WILL KEEP OVERALL WAVE HEIGHTS AROUND 5 TO 7 FT THROUGH MID WEEK. LOOKING AHEAD...GLOBAL MODELS CONTINUE TO SHOW LOW PRES FORMING ALONG THE MONSOON TROUGH OFF COSTA RICA LATE IN THE WEEK...ALTHOUGH THE STRENGTH AND EXACT LOCATION OF THE LOW PRES VARIES. N OF 15N W OF 120W...THE PERSISTENT UPPER LOW THAT HAS BEEN IMPACTING THE AREA OVER THE PAST COUPLE OF DAYS IS NOW CENTERED NEAR 27N122W. THIS FEATURE CONTINUES TO DRIFT NORTH AS IT DRIFTS NORTHWARD...AHEAD OF A DEEP LAYER TROUGH APPROACHING THE DISCUSSION AREA FROM THE N CENTRAL PACIFIC. AN ASSOCIATED SURFACE TROUGH IS DIRECTLY BENEATH THE UPPER LOW...EXTENDING FROM 30N120W TO 23N123W. RECENT ALTIMETER PASSES INDICATE SEAS ARE 7 TO 9 FT ACROSS MUCH OF THE REGION...LIKELY IN RESIDUAL NW SWELL. THIS WILL SUBSIDE BELOW 8 FT THROUGH LATE TODAY. FOR WED AND BEYOND...A WEAK PRES PATTERN WILL SET UP ALLOWING LIGHT TO GENTLE WINDS AND SEAS 5 TO 7 FT PRIMARILY IN NW SWELL. S OF 15N W OF 110W...THE CONVERGENCE OF A SURGE OF SOUTHERLY FLOW IS SUPPORTING SCATTERED MODERATE TO STRONG CONVECTION WITHIN 150 NM SOUTH OF THE MONSOON TROUGH AXIS WEST OF 125W. THE MAIN ISSUE LATER IN THE WEEK WILL BE THE DEVELOPMENT AND WESTWARD MOVEMENT OF THE LOW PRES AREA CURRENTLY NEAR 10N107W...WHICH HAS A HIGH CHANCE THROUGH LATE IN THE WEEK OF DEVELOPING INTO A TROPICAL CYCLONE. $$ CHRISTENSEN