000 AXPZ20 KNHC 110955 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC MON NOV 11 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 THIS EVENING. THE NORTHERLY WINDS ARE EXPECTED TO INCREASE AGAIN TO MINIMAL GALE FORCE LATE TONIGHT. GUIDANCE SUGGESTS THE NORTHERLY FLOW WILL THEN GRADUALLY INCREASE THROUGHOUT THE DAY WED REACHING STORM FORCE WITH SEAS BUILDING TO 19 FT ON WED EVENING...AND CONTINUE AT MINIMAL STORM FORCE THROUGH THE MAXIMUM DRAINAGE LATE WED NIGHT. WINDS WILL THEN DIMINISH THROUGHOUT THE DAY ON THU WITH A MAXIMUM OF 25 KT EXPECTED AT SUNSET THU. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... THE MONSOON TROUGH AXIS EXTENDS W ACROSS THE GULF OF PANAMA CROSSING PANAMA AND CONTINUING W OVER AND ALONG THE CARIBBEAN COAST OF PANAMA...CROSSING NORTHERN COSTA RICA TO THE PACIFIC COAST OF COSTA RICA AT 09N85W...THEN TURNS SW TO 07N92W...THEN WIGGLES W TO 09N120W WHERE SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ AXIS...WHICH IN TURN CONTINUES W TO BEYOND 09N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED OVER AND JUST OFFSHORE EL SALVADOR WITHIN 60 NM OF 13.5N90W. ISOLATED MODERATE TO OCCASIONALLY STRONG SMALL CLUSTERS ARE NOTED ALONG THE MONSOON TROUGH WITHIN 60 NM EITHER SIDE OF A LINE FROM 07N78W TO 12N95W TO 13N101W TO 08N110W. BROKEN TO OVERCAST LOW/MID LEVEL CLOUDS...WITH ONLY EMBEDDED WEAK SHOWERS...ARE NOTED ACROSS THE DEEP TROPICS FROM 08N TO THE EQUATOR FROM THE S AMERICA COAST TO ALONG 123W...AND WITHIN 120 NM OF THE ITCZ AXIS. ...DISCUSSION... A LONGWAVE UPPER RIDGE DOMINATES WESTERN N AMERICA EXTENDING N FROM A LARGE UPPER ANTICYCLONE QUASI-STATIONARY OVER THE NW CARIBBEAN AT 20N84W. AN UPPER LEVEL NEGATIVE-TILT SHORTWAVE TROUGH IS SWINGING NE THROUGH THE LONGWAVE RIDGE PATTERN... ROUGHLY FROM SOUTHERN ARIZONA SOUTHWARD ACROSS THE GULF OF CALIFORNIA TO A BASE OVER THE DEEP TROPICAL PACIFIC AT 11N110W. THIS TROUGH EFFECTIVELY SEPARATES THE UPPER FLOW OVER TROPICAL PORTION OF THE DISCUSSION AREA. DRY UPPER AIR IS INDICATED N OF 30N WITHIN 180 NM OF THE TROUGH AXIS AND WILL PASS ACROSS SOUTHERN CALIFORNIA AND SOUTHERN ARIZONA TODAY. TO THE S OF 30N THE UPPER TROUGH IS PRECEDED BY DEBRIS MOISTURE CURRENTLY RACING NE ACROSS NORTHERN OLD MEXICO AND SW TEXAS. AN UPPER ANTICYCLONE IS CENTERED NEAR 13N126W WITH A SHORTWAVE RIDGE AMPLIFYING N ALONG THE PACIFIC COAST OF CALIFORNIA...AND A RIDGE EXTENDS W TO A SHARP CREST AT 11N138W...AND A RIDGE EXTENDS E TO 13N115W. A DEEP LAYERED TROUGH IS APPROACHING THE NW PORTION OF THE DISCUSSION AREA FROM 32N143W TO THE HAWAIIAN ISLANDS. UPPER MOISTURE...ORIGINATING IN THE CENTRAL PACIFIC... IS STREAMING NE IN THE STRONG UPPER SOUTHWESTERLY FLOW AHEAD OF THE APPROACHING TROUGH...WITH SOME OF THE MOISTURE SPREADING E ACROSS THE DISCUSSION AREA N OF 20N...WITH ITS EASTERN EXTENT JUST NOW PASSING OVER THE BAJA CALIFORNIA PENINSULA TO THE S OF 29N. AN UPPER RIDGE EXTENDS SW FROM THE CARIBBEAN UPPER ANTICYCLONE PREVIOUSLY MENTIONED AT 20N84W TO A FAIRLY SHARP CREST OVER THE DEEP TROPICS AT 12N106W. UPPER DIFFLUENCE CONTINUES TO ENHANCE PEAK-HEATING CONVECTION OVER CENTRAL AMERICA WITH THE DECAYING CLUSTERS MOVING W OFF THE PACIFIC COAST OF CENTRAL AMERICA EACH NIGHT. THE CONVECTION TONIGHT IS SIGNIFICANTLY LESS CONCENTRATED THAN THE PAST 4 NIGHTS. HOWEVER...THE UPPER LEVELS STILL APPEAR QUITE MOIST OVER ALL OF CENTRAL AMERICA AND OVER THE TROPICAL PACIFIC AND OVER OLD MEXICO FROM 10-20N TO THE E OF 105W. GULF OF CALIFORNIA...NW WINDS AT 10-15 KT ARE EXPECTED ACROSS THE GULF WATERS THROUGH LATE TUE...THEN ARE EXPECTED TO INCREASE TO 15-20 KT TUE NIGHT WITH SEAS OF 3-5 FT IN LONG FETCH CENTRAL WATERS. GUIDANCE THEN SUGGESTS THE GRADIENT WILL RELAX SUPPORTING NW 10-15 KT THROUGH LATE THU NIGHT. EXTENDED GUIDANCE NOW SUGGEST THE WINDS WILL BECOME LIGHT AND VARIABLE ON FRI AND THEN LIGHT AND SOUTHERLY ON FRI NIGHT. GULF OF PAPAGAYO...NE WINDS AT EXPECTED TO SURGE ACROSS THE GULF OF PAPAGAYO AT 15-20 KT WITH SEAS TO 4-7 FT THROUGH LATE TUE. THEREAFTER...NE 5-10 KT WINDS EXPECTED...EXCEPT INCREASING BRIEFLY TO 10-15 KT LATE EACH NIGHT THROUGH THU. BAJA CALIFORNIA PENINSULA...NW 10-15 KT WINDS WITH SEAS 3-5 FT ARE EXPECTED THROUGH TUE AFTERNOON THEN INCREASING BRIEFLY TO 15- 20 KT ACROSS THE WATERS N OF 27N TUE NIGHT. GUIDANCE RELAXES THE GRADIENT SUPPORTING ONLY 5-10 KT WED THROUGH FRI NIGHT...THEN TURNING TO THE SW ON SAT. ELSEWHERE AT THE SURFACE...THE SOUTHERLY FLOW AHEAD OF A COLD FRONT OVER THE FAR NW WATERS WILL INCREASE FROM THE CURRENT 15-20 KT TO 20-25 KT BRIEFLY THIS MORNING. THE FRONT WILL STALL AND DISSIPATE ON TUE. A SURFACE RIDGE WILL STRENGTHEN ACROSS THE DISCUSSION AREA E OF THE DISSIPATING FRONT ON TUE WITH NE TRADES INCREASING ACROSS THE TROPICS FROM 10-20N BETWEEN 120-140W THROUGH THU. N WINDS WILL INCREASE ACROSS THE SUBTROPICS LATE IN THE WEEK. $$ NELSON