000 AXPZ20 KNHC 080958 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC THU OCT 08 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. ...SPECIAL FEATURES... LOW PRES WITH AN ESTIMATED PRESSURE OF 1009 MB IS CENTERED ALONG THE ITCZ NEAR 08N124W. SCATTERED MODERATE CONVECTION ASSOCIATED TO THIS AREA OF LOW PRESSURE WAS NOTED FROM 10N TO 14N BETWEEN 119W AND 126W. THERE IS CURRENTLY A MEDIUM CHANCE THAT THIS LOW WILL DEVELOP INTO A TROPICAL CYCLONE IN THE NEXT 48 HOURS AS IT MOVES WEST AT 10 TO 15 KT. SEE LATEST NHC TROPICAL WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOEP/ABPZ20 KNHC FOR MORE DETAILS. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM 08N84W TO 08N92W TO 12N107W TO 11N115W. THE ITCZ CONTINUES FROM 11N115W TO THE LOW PRES 1009 MB NEAR 08N124W TO LOW PRES 1009 MB NEAR 09N139W TO 09N140W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS NOTED WITHIN 90 NM N OF TROUGH BETWEEN 85W AND 95W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 90 NM EITHER SIDE OF TROUGH BETWEEN 110W AND 113W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 90 NM EITHER SIDE OF THE ITCZ W OF 130W. ...DISCUSSION... N OF 15N E OF 120W...HIGH PRES IS CENTERED OFF THE COAST OF CENTRAL CALIFORNIA WITH A RIDGE EXTENDING SOUTHEAST ALONG THE COAST OF THE BAJA CALIFORNIA PENINSULA. A WEAK GRADIENT IS IN PLACE BETWEEN THIS RIDGE AND TROUGH OVER N CENTRAL MEXICO...ALLOWING MODERATE NW ALONG THE PACIFIC COAST OF BAJA AND THE GULF OF CALIFORNIA. A RECENT ALTIMETER PASS INDICATED 4 TO 5 FT SEAS OFF BAJA...WITH LONG PERIOD SW SWELL A MAJOR COMPONENT. THE HIGH PRES WILL SHIFT SOUTHWARD THROUGH FRI AS HURRICANE OHO FARTHER TO THE WEST SHIFTS NE OF THE AREA AND DISSIPATES. THIS WILL ALLOW NW WINDS TO INCREASE SLIGHTLY ALONG THE COAST OF BAJA FRI BUT DIMINISH SAT. MEANWHILE WESTERLY SWELL GENERATED FROM OHO WILL MIX WITH THE DECAYING SW SWELL AND NW WIND WAVES TO PRODUCE COMBINED SEAS OF 6 TO 8 FT OFF BAJA THROUGH LATE FRI. A TROUGH WILL FORM N OF 15N BETWEEN 115W AND 120W SAT AND SUN...ALLOWING WINDS OFF BAJA TO REVERSE TO SE AND INCREASE TO POSSIBLY 20 KT BY SUN. GFS...UKMET AND ECMWF INDICATE THIS WITH SEAS TO 8 OR 9 FT OFF BAJA CALIFORNIA SUR...AND 4 TO 6 FT INTO THE SOUTHERN GULF OF CALIFORNIA. THE MODELS DIFFER A BIT ON TIMING AND EXACT LOCATION HOWEVER...BUT THE FORECAST MAY HAVE TO BE ADJUSTED OVER THE NEXT COUPLE OF DAYS IF THESE TRENDS PERSIST. FOR THE GULF OF TEHUANTEPEC...A 04 UTC ASCAT PASS CONFIRMED FRESH GAP WINDS IN THE GULF OF TEHUANTEPEC. THE LOCAL WIND WAVES FROM THESE GAP WINDS ARE MIXING WITH SW SWELL TO PRODUCE SEAS TO 8 FT THAT WILL SUBSIDE LATER TODAY AS THE GAP WINDS DIMINISH. EXPECT A RETURN OF THESE WINDS TONIGHT WITH SEAS AGAIN OR 9 FT IN THE GULF OF TEHUANTEPEC. LOOKING AHEAD...STARTING FRI NIGHT THROUGH EARLY NEXT WEEK...COOLER AND DRIER AIR WILL PUSH THROUGH THE WESTERN GULF OF MEXICO AND INTO THE GULF OF TEHUANTEPEC CAUSING STRONG GAP WINDS WITH SEAS 8 TO 12 FT BY EARLY SAT. S OF 15N E OF 110W...MODERATE TO FRESH GAP WINDS WILL PULSE THROUGH THE GULF OF PAPAGAYO MAINLY DURING THE OVERNIGHT HOURS THROUGH EARLY SUN. LOCALLY GENERATED SEAS WILL MIX WITH LONGER PERIOD SW SWELL TO PRODUCE COMBINED SEAS TO 8 FT DOWNSTREAM OF THE GULF TO ALMOST 90W. MEANWHILE 7 TO 8 FT SW SWELL COVERING THE MUCH OF THE REMAINDER OF THE AREA WILL GRADUALLY SUBSIDE THROUGH SAT. GLOBAL MODELS INDICATE VARIOUS WEAK CIRCULATIONS FORMING AND DISSIPATING ALONG THE MONSOON TROUGH THROUGH THE PERIOD...BUT WITH NO WELL DEFINED LOW PRES AREA. SCATTERED CONVECTION WILL PERSIST OFF AND ON ALONG THE MONSOON TROUGH...PRIMARILY E OF 90W WHERE DEEP LAYER MOISTURE IS GREATER. N OF 20N W OF 120W...SCATTEROMETER DATA FROM 06 UTC INDICATED STRONG SOUTHERLY FLOW IS NOTED BETWEEN HURRICANE OHO CENTERED NW OF THE AREA AND SURFACE RIDGING N OF 20N E OF 130W. ALTIMETER DATA ALSO CONFIRMED SEAS TO 15 FT NEAR 30N140W IN THE AREA OF STRONG WINDS. WINDS AND SEAS WILL DIMINISH THROUGH TONIGHT AS OHO MOVES RAPIDLY N OF THE AREA AND DISSIPATES...ALLOWING THE RIDGE TO BUILD SOUTH OF THE AREA THROUGH SAT. A SURFACE TROUGH SOUTH OF THE RIDGE ALONG ROUGHLY 130W HAD BEEN MAINTAINING FRESH WINDS BETWEEN THE RIDGE AND THE NORTHERN PORTION OF THE TROUGH...BUT THESE WINDS APPEAR TO HAVE DIMINISHED AS PER RECENT SCATTEROMETER PASSES. $$ CHRISTENSEN