000 AXPZ20 KNHC 190338 TWDEP TROPICAL WEATHER DISCUSSION NWS NATIONAL HURRICANE CENTER MIAMI FL 0405 UTC TUE FEB 19 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0230 UTC. ...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... MONSOON TROUGH NOT DISCERNIBLE FOR 0000 UTC ANALYSIS. ITCZ EXTENDS FROM 06N85W TO 02N103W TO 07N133W TO 07.5N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION NOTED WITHIN 300 NM N OF AXIS W OF 134W. ...DISCUSSION... UPPER LEVEL TROUGHING CONTINUES TO DOMINATE N AND NW PORTIONS OF THE AREA TONIGHT...AS A STRONG SHORTWAVE WAS MOVING SE INTO THE REGION...THROUGH 34N127W TO 28N130W...AND IS BEGINNING TO COME INTO PHASE WITH NE PORTIONS OF AN ELONGATED MIDDLE TO UPPER TROPOSPHERIC TROUGH EXTENDING FROM SOUTHERN CALIFORNIA TO 27N129W TO 26N145W THEN DIVING SW AND S ACROSS THE HAWAIIAN ISLANDS. A BROAD AND WEAKENED UPPER JET OF 80-100 KT RESIDES S OF THE ELONGATED UPPER TROUGH AND CONTINUES TO TRANSPORT HIGH CLOUDS AND UPPER LEVEL MOISTURE FROM THE TROPICAL E CENTRAL PACIFIC NE ACROSS BAJA CALIFORNIA AND N MEXICO. UPPER LEVEL RIDGING S AND SE OF THE JET HAS FLATTENED THE PAST 24 HOURS...YIELDING ZONAL UPPER LEVEL FLOW GENERALLY N OF 17N AND E OF 110W... ACROSS MEXICO AND THE GULF OF MEXICO. THIS BROAD FLAT RIDGE IS CURRENTLY ANCHORED ON TWO ANTICYCLONES...ONE OVER THE S CENTRAL CARIBBEAN...AND A SECOND NEAR 09N121W...WITH A BROAD TROPICAL UPPER TROUGH IN BETWEEN...CENTERED ALONG 101W S OF 16N...EXTENDING ACROSS THE EQUATOR. AT THE SURFACE...THE CENTRAL PACIFIC RIDGE DOMINATES NW PORTIONS...CENTERED ON A 1035 MB HIGH NEAR 39N152W AND EXTENDING SE TO 25N114W. A BROAD ZONE OF FRESH TO STRONG NE TRADES RESIDE N OF THE ITCZ FROM 08N TO 22N W OF 135W AND FROM 10N TO 20N BETWEEN 129W AND 135W...WHERE SEAS ARE RUNNING 8 TO 12 FT IN MIXED NE AND NW SWELL. A COLD FRONT WILL ENTER NE PORTIONS TUESDAY EVENING...RIDING OVER THE RIDGE...AND DROP SE ACROSS THE FAR NE PACIFIC...AND INTO BAJA CALIFORNIA THROUGH WED. STRONG NWLY WINDS BEHIND THE FRONT WILL RAISE SEAS 10-16 FT IN NW SWELL N OF 26N BY WED EVENING. THE CENTRAL PACIFIC HIGH WILL SHIFT SLIGHTLY SE BEHIND THE FRONT...AND STRENGTHEN THE PRES GRADIENT TO ITS S...AND ACT TO EXPAND THE AREA OF STRONG NE TRADES ON WED. NLY WINDS THROUGH THE GULF OF TEHUANTEPEC HAVE DECREASED TO BELOW 20 KT AS SOUTHERLY RETURN WIND FLOW HAS DEVELOPED ACROSS MUCH OF THE GULF OF MEXICO. HOWEVER...STRONG NE WINDS CONTINUE THROUGH AND WELL DOWNWIND OF THE GULF OF PAPAGAYO THIS EVENING...TO NEAR 102W...WHERE SEAS 9-11 FT PREVAIL. A 1550 UTC ASCAT PASS ACROSS THIS AREA DEPICTED THE PLUME OF FRESH TO STRONG NE WINDS THERE...WITH A SMALL AREA AROUND 30 KT CONTINUING CENTERED NEAR 09N88W. WINDS THROUGH THIS ZONE HAVE SINCE DIMINISHED TO 20-25 KT AND WILL GRADUALLY WEAKEN THROUGH WED...BUT SHOULD PULSE AGAIN TO 25-30 KT NEAR 10N87.5W TONIGHT DURING THE TYPICAL NOCTURNAL MAXIMUM. FRESH TO LOCALLY STRONG NORTHERLY FLOW IS ALSO SPILLING ACROSS PANAMA AND INTO THE ADJACENT FAR EASTERN PACIFIC...EXTENDING S-SW TO NEAR 05N82W...WHERE SEAS HAVE BUILT 6-8 FT. THIS NORTHERLY FLOW IS EXPECTED TO DIMINISH BELOW 20 KT BY TUE AFTERNOON AS THE WIND FLOW ACROSS THE W AND NW CARIBBEAN RETURNS TO A MORE TYPICAL EASTERLY DIRECTION. $$ STRIPLING