000
AXPZ20 KNHC 170941
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC MON MAR 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...

ITCZ AXIS AXIS 1N79W 4N85W 2N102W 6N115W EQUATOR AT 140W. 
SCATTERED MODERATE ISOLATED STRONG WITHIN 60 NM EITHER SIDE OF 
3.5N BETWEEN 92W AND 100W. SCATTERED MODERATE 60 NM EITHER SIDE 
OF A LINE FROM 7.5N119W 11N111W. SCATTERED TO NUMEROUS STRONG 
WITHIN 90NM EITHER SIDE OF 7.5N BETWEEN 136W AND 140W.

...DISCUSSION...

E OF 110W...
SCATTEROMETER DATA AND SHIP OBSERVATIONS CONTINUE TO INDICATE A 
LIGHT WIND REGIME OVER EASTERN PACIFIC WATERS S OF MEXICO AND W 
OF CENTRAL AMERICA. THE PRESENT PATTERN OF LIGHT WINDS CAN BE 
ATTRIBUTED TO THE INFLUENCE OF BROAD...MID- TO UPPER-LEVEL 
ANTICYCLONE EXTENDING FROM THE CARIBBEAN BASIN INTO THE TROPICAL 
EASTERN NORTH PACIFIC TO ABOUT 110W. EARLIER JASON ALTIMETER 
DATA AND SHIP OBSERVATIONS CONFIRMED A TRANQUIL SEA STATE AND 
LIGHT WINDS...WITH REPORTS OF WAVE HEIGHTS GENERALLY IN THE 3 TO 
5 FT RANGE FROM THE EQUATOR TO THE COAST OF MEXICO AND E OF 
105W.  OTHERWISE...DIVERGENCE ALOFT ASSOCIATED WITH THE WESTERN 
EDGE OF THE SPRAWLING CARIBBEAN ANTICYCLONE CONTINUES TO ENHANCE 
CONVECTION NEAR AND NORTH OF THE ITCZ BETWEEN 92W AND ALMOST 
100W. HOWEVER ...MOST OF THE REGION FARTHER NORTH AND EAST 
REMAINS CONVECTION FREE THANKS TO MODERATE TO STRONG SUBSIDENCE 
UNDERNEATH THE IMPRESSIVE UPPER-LEVEL RIDGE. 

LOOKING AHEAD...A STRONG SURFACE RIDGE EXTENDING FROM THE GREAT 
LAKES TO FLORIDA SHOULD BUILD SOUTHWARD INTO THE CARIBBEAN TODAY 
WHILE SLOWLY SLIDING EWD.  AS THIS OCCURS...WINDS OVER THE 
CARIBBEAN SHOULD INCREASE EARLY THIS WEEK...PROMPTING A FRESH TO 
STRONG ELY FLOW THROUGH THE GULF OF PAPAGAYO BEGINNING AS SOON 
AS THIS MORNING AND LIKELY CONTINUING PAST MID-WEEK. SEAS COULD 
BUILD AS HIGH AS 9 FT DOWNSTREAM OF THE GULF OF PAPAGAYO AROUND 
THE TIME OF PEAK CONDITIONS. ELSEWHERE...THE PASSAGE OF A COLD 
FRONT THROUGH MUCH OF NORTHERN MEXICO MON AND TUE SHOULD USHER 
IN STRONG LOW-LEVEL RIDGING AND A SURGE OF NLY WINDS FROM THE 
GULF OF CALIFORNIA TO ABOUT 16N E OF 110W LATE MON THROUGH TUE 
BEFORE DYING DOWN ON WED. IN TURN...LONG PERIOD NW SWELL SHOULD 
BEGIN ARRIVING GENERALLY THROUGH MID-WEEK...WITH SEAS BUILDING 
TO 6 TO 10 FT W OF 100W. FINALLY...THE SAME FRONT SHOULD SWEEP 
THROUGH THE GULF OF MEXICO WED AND BRING A STRENGTHENING NLY FLOW
NEAR AND DOWNSTREAM OF THE GULF OF TEHUANTEPEC WED AFTERNOON AND 
EVENING...WITH POSSIBLE GALE CONDITIONS BY THU MORNING.


W OF 110...
A SHARP UPPER-LEVEL TROUGH AND EMBEDDED CLOSED CYCLONE EXTENDING 
FROM THE ARIZONA-NEW MEXICO BORDER TO NEAR 7N117W IS SHIFTING 
EWD AHEAD OF A BROAD UPPER-LEVEL RIDGE CENTERED NEAR 29N138W. IN 
THE WAKE OF THE AMPLIFYING TROUGH...THE GRADIENT BETWEEN A LARGE 
1035 MB HIGH N OF THE AREA NEAR 34N138W AND THE COAST OF BAJA 
HAS RESULTED IN A LARGE SWATH OF 20- TO 30-KNOT NW TO N WINDS N 
OF 25N E OF 128W...WITH GALE FORCE NLY WINDS CONTINUING JUST N 
OF 30N. THE BROAD FETCH AND LONG DURATION OF THIS WIND EVENT HAS 
CAUSED SEAS TO BUILD TO 10 TO 17 FT IN NW SWELL OVER THIS 
AREA...AS REVEALED BY RECENT JASON ALTIMETER DATA AND SHIP 
OBSERVATIONS. AT THE SAME TIME...THE GRADIENT SOUTH OF THE 
SURFACE HIGH HAS LED TO FRESH TO STRONG NE TO E WINDS FROM ABOUT 
8 TO 22N W OF 125W...WITH SEAS ALREADY BETWEEN 10 TO 15 FT IN NE 
SWELL. WINDS OFF THE BAJA COAST SHOULD DIMINISH OVER THE NEXT 48 
HOURS...AS THE SURFACE HIGH SHIFTS SE AND WEAKENS...BUT NW SWELL 
WILL ENVELOPE MOST OF THE REGION FROM 110 TO 120W THROUGH 
MID-WEEK. FARTHER W...THE LARGE EXPANSE OF STRONG TRADES SHOULD 
GRADUALLY SHRINK BY MID-WEEK...THOUGH N TO NE SWELL SHOULD 
CONTINUE PROPAGATING AWAY FROM ITS SOURCE REGION AND REACH THE 
EQUATOR W OF 130W BY WED. 

FARTHER S...A DIFFLUENT UPPER-LEVEL FLOW AHEAD OF THE BASE OF 
THE AMPLIFYING TROUGH OVER THE SW CONUS IS IGNITING SCATTERED 
MODERATE CONVECTION NORTH OF THE ITCZ...WITHIN ABOUT 60 NM 
EITHER SIDE OF A LINE FROM 7.5N119W 11N111W.  FINALLY...A WEAK 
SHORTWAVE TROUGH NEAR 10N 140W IS ALSO EXCITING SCATTERED TO 
NUMEROUS...MODERATE TO STRONG CONVECTION WITHIN 90NM EITHER SIDE 
OF 7.5N BETWEEN 136W AND 140W.


$$
KIMBERLAIN/COBB