000 AXPZ20 KNHC 170935 TWDEP TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 1005 UTC TUE JUN 17 2008 TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM THE EQUATOR TO 32N...EAST OF 140W. BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0915 UTC. ...ITCZ... INTERTROPICAL CONVERGENCE ZONE ALONG 07N78W TO 10N93W TO 09N110W TO 07N130W TO 05N140W. SCATTERED MODERATE CONVECTION IS WITHIN 180 NM N OF AXIS BETWEEN 97W AND 100W. SCATTERED MODERATE CONVECTION IS ALSO WITHIN 150 NM S AND 210 NM N OF AXIS BETWEEN 108W AND 112W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 120 NM EITHER SIDE OF AXIS BETWEEN 132W AND 140W. ...DISCUSSION... A STRONG PRESSURE GRADIENT BETWEEN CLIMATOLOGICAL LOW PRESSURE OVER THE DESERT SW AND A 1029 MB SURFACE RIDGE NEAR 38N137W HAS BEEN GENERATING GALE CONDITIONS OFFSHORE THE CALIFORNIA AND OREGON COASTS SINCE LATE LAST WEEK. EVEN THOUGH GALE CONDITIONS STILL CONTINUE OVER THESE AREAS...LATEST QUIKSCAT DATA AND NEARBY SHIP REPORTS INDICATE THAT NW TO N WINDS OF 20 KT OR GREATER REMAIN N OF 31N. HOWEVER...THE SUSTAINED GALE FORCE WINDS HAVE CAUSED SEAS TO BUILD TO AS HIGH AS 15 TO 17 FT THE LAST FEW DAYS N OF THE AREA...AND THE ASSOCIATED N SWELL HAS BEEN CREEPING INTO THE FAR NORTHERN WATERS GENERALLY N OF 27N BETWEEN 120W AND 134W DURING THE LAST 24 HOURS. MODEL GUIDANCE INDICATES THAT NLY SWELL SHOULD PEAK TODAY OVER THE AREA N OF 25N BETWEEN 125W AND 135W AND SLOWLY SUBSIDE WED AND THU. THE SAME GUIDANCE ALSO SHOWS THAT THE TOTAL SEA STATE OVER THE WATERS W OF THE BAJA PENINSULA SHOULD NOT ONLY BE COMPRISED OF THE NLY SWELL PROPAGATING SOUTHWARD BUT ALSO LONGER PERIOD SW SWELL ORIGINATING FROM THE SOUTHERN HEMISPHERE. FARTHER SOUTH...TWO SWELL TRAINS...ONE FROM THE SE AND ONE FROM SW...HAVE BEEN PROPAGATING OUT OF THE SOUTHERN HEMISPHERE AND CROSSING THE EQUATOR THE PAST FEW DAYS. AS THEY ARRIVE...A LARGE AREA OF 8 TO 10 FT SEAS HAS DEVELOPED...GENERALLY S OF 15N W OF 94W. IN ADDITION TO THE SWELL...AN 0242 UTC QUIKSCAT IMAGE SHOWED A BROAD AREA OF NE 20 KT WINDS FROM 10N TO 17N W OF 130W ...SUGGESTING THAT NE WIND WAVES HAVE COMBINED WITH SE AND SW SWELL OVER THIS AREA. ALREADY THE SE SWELL HAS BECOME MUCH LESS SIGNIFICANT AND NOAA WAVEWATCH III GUIDANCE SUGGESTS THAT THE SW SWELL OVER THE ENTIRE AREA SHOULD SHRINK IN AREAL EXTENT AND ALSO GRADUALLY SUBSIDE OVER THE NEXT FEW DAYS. HOWEVER...A LARGE AREA OF AROUND 8 TO 9 FT SEAS SHOULD STILL COVER THE SOUTHERN WATERS GENERALLY S OF 10N BETWEEN 95W AND 130W BY THU AFTERNOON. ELSEWHERE...STRONG TRADES IN THE CENTRAL AND EASTERN CARIBBEAN SHOULD EVENTUALLY SPREAD FARTHER WEST INTO THE WESTERN CARIBBEAN THIS WEEK AND COULD SPARK A GAP WIND EVENT IN THE GULF OF PAPAGAYO. ALTHOUGH MODEL GUIDANCE SHOWS NO THREAT OF GAY WINDS DEVELOPING BEFORE ABOUT THU...THERE IS STILL SOME CHANCE OF INTERMITTENT NE TO E 20 KT WINDS DOWNSTREAM OF THE GULF REGION. BY FRI...INDICATIONS ARE THAT A STEADY STREAM OF 20 KT WINDS SHOULD LIE FROM 10N TO 12N AND AS FAR W AS 90W. ONCE WINDS BECOME ESTABLISHED...EXPECT SEAS TO FOLLOW SUIT BY BUILDING TO 8 OR 9 FT BY LATE FRI. FINALLY...REAL-TIME NCEP RE-ANALYSIS DATA INDICATE ANOMALOUS CYCLONIC CIRCULATIONS AT UPPER-LEVELS ON THE DATELINE NEAR 25N AND 20S170W. A STREAM OF ANOMALOUS WESTERLY FLOW ASSOCIATED WITH THESE FEATURES...WITH ANOMALIES OF OF 20 TO 60 KT ABOVE CLIMATOLOGY...EXTENDS THE TROPICAL WESTERN PACIFIC TO 115W. THE STRONG WESTERLY FLOW PRECEDES A MODERATELY STRONG MADDEN-JULIAN OSCILLATION /MJO/...WHICH IS CURRENTLY ORGANIZING OVER THE INDIAN OCEAN AND SLOWLY HEADING EAST. ALTHOUGH THE EXACT DETAILS ARE ELUSIVE AT THIS TIME...THE CURRENT MJO SHOULD SPREAD ACROSS THE REMAINDER OF THE INDIAN OCEAN AND WESTERN PACIFIC IN THE NEXT WEEK OR TWO...LIKELY RESULTING IN AN INCREASE IN THE CHANCE OF TROPICAL CYCLONE ACTIVITY IN THESE AREAS. THE MJO SIGNAL SHOULD THEN PROPAGATE INTO THE WESTERN HEMISPHERE...LIKELY RESULTING IN A SIMILAR INCREASE IN THE CHANCE OF TROPICAL CYCLONE ACTIVITY SHOULD EVENTUALLY REACH THE TROPICAL EASTERN PACIFIC TOWARD THE VERY END OF JUNE OR THE FIRST WEEK OF JULY. $$ KIMBERLAIN