000 AXPZ20 KNHC 091001 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC SAT NOV 09 2013 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 0945 UTC. ...SPECIAL FEATURE... GULF OF TEHUANTEPEC...CURRENT MINIMAL GALE FORCE WINDS ARE EXPECTED TO CONTINUE THROUGH MAXIMUM DRAINAGE AROUND SUNRISE THIS MORNING...THEN DIMINISH TO A MAXIMUM OF 30 KT BY NOON TODAY. THE NORTHERLY FLOW WILL CONTINUE TO SURGE TO 30 KT THROUGH SUN EVENING. THE NORTHERLY WINDS WILL INCREASE AGAIN TO MINIMAL GALE FORCE LATE SUN NIGHT CONTINUING THROUGH SUNRISE ON MON. THE GRADIENT THEN RELAXES SLIGHTLY WITH SURGES TO 30 KT THROUGH TUE EVENING WHEN THE NORTHERLY FLOW IS EXPECTED TO RAPIDLY INCREASE TO MINIMAL GALE FORCE AT THE MAXIMUM DRAINAGE AROUND SUNRISE ON WED. GUIDANCE FLUCTUATES ON THE STRENGTH OF THE MID TO LATE WEEK GAP EVENT BUT HINTS AT MINIMAL STORM FORCE WED NIGHT INTO THU MORNING. A SAFE BET FOR NOW WOULD BE TO EXPECT STRONG GALE FORCE WINDS WITH FREQUENT GUSTS TO STORM FORCE...AND SEAS BUILDING TO NEAR 20 FT ON THU. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS NW FROM THE PACIFIC COAST OF COLOMBIA AT 08N78W TO ACROSS WESTERN PANAMA...THEN OFFSHORE ORIENTATED PARALLEL TO THE CENTRAL AMERICA COAST TO 13N91W... THEN TURNS ABRUPTLY SW TO 10N97W...THEN W TO 09N105W...THEN NW TO 12N120W...THEN WSW TO 11N133W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ WHICH IN TURN CONTINUES W TO BEYOND 11N140W. SCATTERED MODERATE TO STRONG CONVECTION...WITH FREQUENT LIGHTNING...IS OBSERVED EXTENDING OVER AND PARALLEL TO THE COAST OF CENTRAL AMERICA WITHIN 75 NM EITHER SIDE OF A LINE FROM 07N84W TO 14N91W. ISOLATED MODERATE TO OCCASIONALLY STRONG CONVECTION IS NOTED ALONG THE EASTERN SEGMENT MONSOON TROUGH... WITHIN 240 NM EITHER SIDE OF A LINE FROM 07N85W TO 07N88W TO 12N106W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED ALONG THE WESTERN PORTION OF THE MONSOON TROUGH WITHIN 120 NM EITHER SIDE OF A LINE FROM 10N113W TO 11N125W TO 09N130W WHERE IT NARROWS TO WITHIN 30 NM EITHER SIDE OF A LINE FROM 09N132W TO 14N138W. ...DISCUSSION... AN UPPER LEVEL CYCLONE IS CENTERED AT 32N133W TRAILING A NEGATIVE TILT UPPER TROUGH SE TO 25N127W. THIS CYCLONE WILL LIFT QUICKLY NE LATER TODAY BUT RAPIDLY FILL BEFORE MOVING ACROSS SOUTHERN CALIFORNIA ON SUN AFTERNOON. THE ASSOCIATED SURFACE 1012 MB LOW...CURRENTLY NEAR 30N142W...WILL ALSO RACE OFF TO THE NE DRAGGING A NEWLY FORMING COLD FRONT INTO THE NW WATERS TONIGHT. SURFACE WINDS ARE CURRENTLY ONLY AT 15-20 KT WITHIN 270 NM OVER THE E SEMICIRCLE OF THE LOW...AND SEAS HAVE SUBSIDED TO MAX OF 7 FT. AS THE FRONT APPROACHES FROM THE NW TONIGHT...THE SOUTHERLY FLOW WILL INCREASE TO 20-25 KT/SEAS 7-10 FT ACROSS THE DISCUSSION WATERS N OF 31N WITHIN 300 NM AHEAD OF THE FRONT. ALTHOUGH THE NORTHERLY FLOW W OF THE FRONT WILL INCREASE TO 20- 30 KT THIS EVENING...THE GRADIENT IS EXPECTED TO RELAX SUPPORTING ONLY 15-20 KT TO THE S OF 32N BEHIND THE FRONT AS IT MOVES INTO THE NW WATERS TONIGHT. HOWEVER...THE NORTHERLY FLOW WILL DRIVE NW SWELLS INTO THE AREA MIXING WITH LONG PERIOD CROSS- EQUATORIAL SE SWELL...WITH COMBINED SEAS REACHING 8-11 FT OVER THE DISCUSSION WATERS NW OF A LINE FROM 32N131W TO 25N140W ON SUN...THEN SUBSIDING SOME ON SUN NIGHT. A SURFACE HIGH WILL SHIFT SE TO NEAR 30N124W TONIGHT...THEN SHIFT SLIGHTLY NE AS THE SOUTHERLY FLOW INCREASES TO 20-25 KT AHEAD OF THE FRONT BRIEFLY SUN NIGHT INTO MON MORNING. THE SURFACE HIGH THEN RETURNS S TO NEAR 27N125W ON MON NIGHT...AND EFFECTIVELY BLOCKS THE FORWARD ADVANCE OF THE FRONT WHICH WILL WASH OUT FROM 32N127W TO 22N135W ON TUE. LIGHT NW 5-10 KT WINDS/SEAS 2-4 FT IN MIXED NW AND LONG PERIOD S SWELL WILL CONTINUE ALONG THE PACIFIC COAST OF THE BAJA CALIFORNIA PENINSULA THROUGH SUN AFTERNOON. THE GRADIENT WILL TIGHTEN ON SUN EVENING SUPPORTING NW 10-15 KT THROUGH MON EVENING...THEN INCREASE TO 15-20 KT ALONG THESE WESTERN SHORE WATERS N OF 26N ON MON NIGHT THROUGH TUE NIGHT...WITH SEAS BUILDING 4-6 FT IN MIXED NW AND S SWELL. NE TRADES...ALONG THE SOUTHERN PERIPHERY OF THE LOW LEVEL RIDGE...WILL INCREASE ACROSS THE TROPICS FROM 10-20N BETWEEN 115-140W ON TUE AND WED. A SHORTWAVE UPPER TROUGH EXTENDS SW FROM 32N106W TO ACROSS THE SOUTHERN GULF OF CALIFORNIA TO A BASE OVER THE DEEP TROPICS AT 12N116W. DRY UPPER AIR IS INDICATED WITHIN 420 NM W OF THE TROUGH AXIS TO THE N OF 22N...THEN WIDENS TO ABOUT 600 NM W OF THE TROUGH AXIS ACROSS THE TROPICS S OF 22N. AN UPPER ANTICYCLONE IS QUASI-STATIONARY OVER THE DEEP TROPICS AT 09N143W WITH A SHORTWAVE RIDGE EXTENDING NE ACROSS THE TROPICS TO A CREST AT 18N132W. AN UPPER MOISTURE PLUME...ORIGINATING IN THE CENTRAL PACIFIC...IS STREAMING E IN UPPER ZONAL FLOW BETWEEN THE MENTIONED TROPICAL ANTICYCLONE AND SUBTROPICAL CYCLONE...ACROSS THE AREA WITHIN 240 NM OF LINE FROM 20N140W TO 22N126W...THEN NARROWS AND THINS SOMEWHAT AS IT CONTINUES NE ACROSS THE BAJA CALIFORNIA PENINSULA AND GULF OF CALIFORNIA...EVENTUALLY EVAPORATING OVER SOUTHERN ARIZONA. UPPER MOISTURE IS INDICATED OVER THE EASTERN SEMICIRCLE OF THE UPPER CYCLONE AT 32N133W... AND IS ADVECTED NE...AND WILL CROSS OVER CALIFORNIA LATER TODAY. AN UPPER LEVEL ANTICYCLONE IS ANCHORED OVER THE NW CARIBBEAN AT 20N86W WITH AN UPPER RIDGE EXTENDING SW TO A SHARP CREST OVER THE DEEP TROPICS AT 12N114W. AN AREA OF UPPER DIFFLUENCE IS INDUCED...AND IS ENHANCING THE CONVECTION PREVIOUSLY DESCRIBED ALONG THE LOWER LEVEL MONSOON TROUGH. SOME OF THE RESULTANT DEBRIS MOISTURE IS ADVECTED NE ALONG THE W PERIPHERY OF THE UPPER RIDGE...CONCENTRATED INTO A 360 NM WIDE TROPICAL PLUME MOVING NNE ACROSS THE TROPICAL PACIFIC AND NORTHERN OLD MEXICO FROM 14N107W TO 28N100W...WHERE THE MOISTURE PLUME THEN BECOMES VERY DENSE AS IT TURNS E ACROSS THE SE CONUS. AN UPPER CYCLONE IS SHIFTING W ACROSS THE SW CARIBBEAN NEAR 14N79W...AND ERODING THE UPPER RIDGE OVER CENTRAL AMERICA. UPPER DIFFLUENCE...WELL W OF THE UPPER CYCLONE AND UNDER THE UPPER RIDGE...ENHANCED CONSIDERABLE CONVECTION OVER NICARAGUA AND HONDURAS ON FRI. THIS CONVECTION HAS MOVED W OVER THE PACIFIC WATERS ALONG CENTRAL AMERICA AS PREVIOUSLY DESCRIBED. THE INTENSE CONVECTION HAS MOISTENED THE UPPER LEVELS OVER CENTRAL AMERICA TO INCLUDE SOUTHEASTERN MEXICO...AND WILL LIKELY SUPPORT INTERIOR CONVECTION OVER THE WESTERN PORTIONS OF CENTRAL AMERICA AT PEAK HEATING AGAIN THIS AFTERNOON. GULF OF CALIFORNIA...LIGHT...MOSTLY NW...WINDS AT 5-10 KT WILL CONTINUE ACROSS THE GULF WATERS THROUGH THIS EVENING...THEN INCREASE TO 10-15 KT TONIGHT...FURTHER INCREASING TO 15-20 KT ON SUN EVENING ACROSS THE GULF WATERS TO THE S OF 28N. LITTLE CHANGE THEN EXPECTED THROUGH TUE AFTERNOON WITH GUIDANCE THEN INDICATING THE NW FLOW WILL INCREASE TO 20-25 KT...WITH SEAS 3-5 FT IN LONG FETCH CENTRAL WATERS...BRIEFLY ON TUE NIGHT...THEN DIMINISH TO 10-15 KT LATE WED. $$ NELSON