000 AXPZ20 KNHC 242215 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 2205 UTC TUE NOV 24 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 2130 UTC. ...SPECIAL FEATURES... TROPICAL STORM SANDRA WAS CENTERED NEAR 11.9N 107.2W AT 2100 UTC MOVING WNW OR 290 DEGREES AT 12 KT. ESTIMATED MINIMUM CENTRAL PRESSURE WAS 997 MB. MAXIMUM SUSTAINED WIND SPEED WAS 55 KT WITH GUSTS TO 65 KT. SCATTERED TO NUMEROUS MODERATE TO STRONG CONVECTION WAS OCCURRING WITHIN 90 NM NE AND 120 NM SW SEMICIRCLES. SCATTERED MODERATE TO STRONG CONVECTION WAS OCCURRING IN DISTINCTIVE BANDS ELSEWHERE WITHIN 330 NM N SEMICIRCLE. SANDRA CONTINUES TO IMPROVE INORGANIZATION THIS AFTERNOON...AND HAS STRENGTHENED SLIGHTLY SINCE THIS MORNING. A DECREASE IN FORWARD SPEED IS EXPECTED OVER THE NEXT COUPLE OF DAYS...AS SANDRA TURNS NW AND THEN N...AND IS EXPECTED TO INTENSIFY TO HURRICANE STRENGTH TONIGHT OR EARLY WED. SEE THE LATEST NHC FORECAST/ADVISORY UNDER AWIPS/WMO HEADERS MIATCMEP2/WTPZ22 KNHC FOR MORE DETAILS. GULF OF TEHUANTEPEC GALE WARNING...A STRONG COLD FRONT THAT MOVED THROUGH THE CHIVELA PASS YESTERDAY HAS ALLOWED FOR COOL...DRY AIR TO MOVE OVER THE RELATIVELY WARM WATERS OF THE GULF OF TEHUANTEPEC. WINDS WERE REACHING STORM FORCE THROUGH EARLY THIS MORNING...BUT HAVE DIMINISHED TO GALE FORCE THIS AFTERNOON...AND WILL PERSIST THROUGH EARLY WED THEN DIMINISH SLIGHTLY THROUGH LATE WED...BEFORE INCREASING AGAIN TO GALE FORCE WED NIGHT/EARLY THU DURING THE PERIOD OF PEAK NOCTURNAL DRAINAGE. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH EXTENDS FROM COLOMBIA NEAR 08N75W TO05.5N80W TO 10N101W...WHERE IT HAS FRACTURED FROM SANDRA...THEN RESUMES FROM 09N107W TO 05N115W...WHERE IT TRANSITIONS TO ITCZ...CONTINUING ON TO 08N134W TO 07N140W. SCATTERED MODERATE TO STRONG CONVECTION NOTED FROM 03N TO 09N BETWEEN 78W AND 83W...AND WITHIN 210 NM N AND 120 NM S OF TROUGH BETWEEN 92W AND 101W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 90 NM N AND 240 NM S OF ITCZ BETWEEN 128W AND 134W. ...DISCUSSION... N OF 15N E OF 120W...A DEEP LAYER TROUGH IS DIGGING ACROSS THE FAR NE PACIFIC AND HAS MOVED INLAND ACROSS THE WEST COAST OF THE UNITED STATES. AN ASSOCIATED SURFACE TROUGH WILL SHIFT EAST ACROSS BAJA CALIFORNIA NORTE AND THE NORTHERN PORTION OF THE GULF OF CALIFORNIA LATE TONIGHT THROUGH WED. WESTERLY WINDS OF 15-25 KT WILL FUNNEL THROUGH LOWER LYING GAPS ACROSS BAJA CALIFORNIA NORTE AND INTO THE NORTHERN GULF OF CALIFORNIA TONIGHT AND EARLY WED AHEAD OF THE TROUGH. A COLD FRONT WILL FOLLOW THIS...MOVING INTO THE WATERS OFF BAJA CALIFORNIA NORTE AND THE NORTHERN GULF OF CALIFORNIA BY LATE WED. THIS WILL BE ACCOMPANIED BY FRESH NW WINDS AND LONG PERIOD NW SWELL TO 9 FT. THE LEADING EDGE OF THE SWELL WILL REACH GUADALUPE ISLAND BY LATE WED...AND THE NORTHERN COAST OF BAJA CALIFORNIA SUR BY EARLY THU. MEANWHILE THE OUTER EDGE OF MIXED SWELL IN EXCESS OF 8 FT ASSOCIATED WITH THE APPROACHING SANDRA WILL MOVE NORTH OF THE REVILLAGIGEDO ISLANDS WED NIGHT...FOLLOWED BY THE OUTER PERIPHERY OF STRONG WINDS AHEAD OF SANDRA BY LATE THU. LOOKING AHEAD...SANDRA AND ITS ACCOMPANYING STRONG WINDS AND HIGH SEAS WILL SHIFT N TO NE AHEAD OF THE STALLING FRONT...GRAZING THE LOS CABOS AREA FRI INTO SAT BEFORE SHIFTING ACROSS THE MOUTH OF THE GULF OF CALIFORNIA AND MOVING INLAND NORTH OF MAZATLAN BY LATE SAT. S OF 15N E OF 110W...A TIGHT PRES GRADIENT BETWEEN HIGH PRES OVER THE SOUTHEAST UNITED STATES AND THE MONSOON TROUGH TO THE S HAS SET UP ACROSS CENTRAL AMERICA. A FRESH TO STRONG E-NE BREEZE HAS BEEN OCCURRING DOWNWIND OF THE GULF OF PAPAGAYO LAST NIGHT AND TODAY. THESE WINDS WILL DIMINISH THIS EVENING BEFORE FRESHENING AGAIN LATE TONIGHT THROUGH EARLY WED AFTERNOON. WEAKER GAP WIND FLOW IS EXPECTED EARLY THU. N TO NE WINDS OF 15-20 KT ARE SPILLING ACROSS PANAMA AND ACROSS THE GULF OF PANAMA THIS AFTERNOON...RAISING SEAS TO 4-6 FT...AND ARE EXPECTED TO CONTINUE THROUGH TONIGHT BEFORE DIMINISHING BY AROUND NOON ON WED. ELSEWHERE SW SWELL WILL MOVE ACROSS THE EQUATOR AND MIX WITH SHORTER PERIOD NE SWELL EMERGING OUT OF TEHUANTEPEC. TO THE NW...THE 1009 MB POST-TROPICAL REMNANT LOW RICK WAS LOCATED NEAR 21.5N123.5W AND DRIFTING NW. THERE IS NO SIGNIFICANT DEEP CONVECTION ASSOCIATED WITH THE LOW. STRONG UPPER LEVEL SOUTHWEST WINDS ARE EXPECTED TO REMAIN OVER THE SYSTEM FOR THE NEXT TWO DAYS. FRESH NE WINDS WILL PERSIST ACROSS THE NW SEMICIRCLE OF THE LOW THROUGH THIS EVENING...BUT WILL DIMINISH AS THE LOW OPENS UP TO A TROUGH TONIGHT AS THE SYSTEM MOVES SLOWLY TO THE NW. MEANWHILE STRONG HIGH PRES OVER THE NE PACIFIC IS BUILDING SOUTHWARD TOWARDSNPORTIONS OF THE DISCUSSION AREA...BEHIND A COLD FRONT CURRENTLY ALONG 32N. THIS COLD FRONT IS FORECAST TO REACH FAR N WATERS OVERNIGHT TONIGHT...WITH N-NW WINDS EXPECTED TO REACH 20-25 KT BEHIND THE FRONT OVER FAR NE WATERS BY EARLY WED MORNING. NW SWELL ASSOCIATED WITH THIS SYSTEM WILL PROPAGATE INTO THE AREA AHEAD OF THE FRONT...WITH SEAS IN THE 7-9 FT RANGE EXPECTED OVER WATERS N OF 28N BETWEEN 118W AND 133W BY EARLY WED MORNING. SEAS WILL REACH AS HIGH AS 11 FT THROUGH EARLY THU MORNING AND THE SWELL PROPAGATES AS FAR S AS 21N124W. $$ STRIPLING