000
AXPZ20 KNHC 171548
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE JUN 17 2008

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN
FROM THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE 07N78W TO 11N94W TO 12N110W TO 
08N130W TO 06N140W. SCATTERED MODERATE TO STRONG CONVECTION FROM 
07N TO 09N BETWEEN 108W AND 114W. SCATTERED MODERATE ISOLATED 
STRONG WITHIN 180 NM N OF AXIS BETWEEN 95W AND 106W...AND WITHIN 
210 NM S OF THE AXIS BETWEEN 129W AND 140W. SCATTERED MODERATE 
FROM 06N TO 10N BETWEEN 83W AND 88W.

...DISCUSSION...
A STRONG PRESSURE GRADIENT BETWEEN CLIMATOLOGICAL LOW PRESSURE 
OVER THE DESERT SW AND A 1029 MB SURFACE HIGH NEAR 39N140W HAS 
BEEN GENERATING GALE CONDITIONS OFFSHORE THE CALIFORNIA AND 
OREGON COASTS SINCE LATE LAST WEEK. EVEN THOUGH GALE CONDITIONS 
STILL CONTINUE OVER THESE AREAS...MOST RECENT QUIKSCAT DATA AND 
SHIP REPORTS INDICATE THAT NW TO N WINDS OF 20 KT OR GREATER ARE 
N OF 29N. 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 TONIGHT OR EARLY WED OVER THE AREA N OF 25N 
BETWEEN 125W AND 135W AND SLOWLY SUBSIDE 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 0654 UTC ASCAT PASS 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 GAP 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.

$$
COBB