000
AXPZ20 KNHC 090958
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI MAY 09 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 
0900 UTC.

...ITCZ...
INTERTROPICAL CONVERGENCE ZONE ALONG THE LINE...08N82W TO 05N95W 
TO 07N109W TO 09N126W TO 03N140W.  SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION WITHIN 90 NM OF THE ITCZ AXIS BETWEEN 
82W AND 90W.  SCATTERED MODERATE TO STRONG CONVECTION WITHIN 90 
NM OF 12N111W.

...DISCUSSION...
UPPER LEVELS...
AN UPPER LOW NEAR 30N123W IS OPENING UP AND LIFTING OUT.  
ANOTHER SMALLER VORT MAX HAS DROPPED INTO THE AREA NEAR 26N134W. 
A LARGE ANTICYCLONE IS CENTERED OVER S MEXICO NEAR 19N98W.  THE 
RESULTING SW JET BETWEEN THE LOWS AND THE RIDGE IS ADVECTING 
UPPER LEVEL MOISTURE AND CLOUDINESS FROM THE ITCZ AND THE 
TROPICAL DISTURBANCE NEAR 110W INTO MEXICO AND THE SW UNITED 
STATES.  SOUTH OF MEXICO IS DOMINATED BY SUBSIDENT FLOW ON THE 
EQUATORWARD SIDE OF THE RIDGE.

SURFACE...
THE MODERATE STRENGTH PRESSURE GRADIENT SOUTH OF A 1030 MB 
RIDGE NORTH OF THE REGION IS KICKING UP NE TRADES OF 20 KT AND 8 
TO 9 FT WIND WAVES IN THE WESTERN PORTION OF OUR REGION.  THESE 
WINDS SHOULD CONTINUE DURING THE NEXT TWO DAYS...THOUGH 
RESTRICTED MORE TOWARD THE SW CORNER OF THE REGION.  THE 
AFOREMENTIONED HIGH IN COMBINATION WITH THE LOW PRESSURE IN THE 
SW UNITED STATES CONTINUES TO CAUSE GALE FORCE WINDS JUST OFF OF 
THE CALIFORNIA COAST.  THESE GALES ARE ADVECTING HIGH SEAS INTO 
OUR REGION BETWEEN 118W AND 130W.  SOME ADDITIONAL HIGH SEAS ARE 
OBSERVED ALONG THE SOUTHERN BORDER FROM S SWELL.

THE TROPICAL DISTURBANCE NEAR 110W HAS DEVELOPED A WEAK 1010 MB 
LOW PRESSURE CENTER AS SEEN FROM TAO BUOYS...SCATTEROMETER 
DATA...AND LOW-LEVEL CLOUD MOTIONS.  CONVECTION ASSOCIATED WITH 
THE SYSTEM HAS SHOWN DIURNAL PULSES THAT ADVECT NORTHWARD AWAY 
FROM THE SURFACE CENTER.  CONTINUED MODERATE SOUTHERLY VERTICAL 
SHEAR SHOULD PRECLUDE FURTHER DEVELOPMENT.

THE EARLIER ANALYZED GAP WINDS IN THE GULF OF PAPAGAYO REGION 
HAVE DIMINISHED TO JUST BELOW 20 KT...ACCORDING TO OBSERVATIONS 
FROM BOTH QUIKSCAT AND ASCAT.

$$
LANDSEA