000
AXPZ20 KNHC 090354
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC WED JAN 09 2008

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0345 UTC.
 
...ITCZ...
INTERTROPICAL CONVERGENCE ZONE...AXIS 6N77W 10N85W 3N100W 6N119W 
6N140W. ISOLATED MODERATE CONVECTION HAS FLARED NEAR 4.5N80.5W 
AND NEAR 6.5N89.5W AND CONTINUES TO FLARE WITHIN 15 NM EITHER 
SIDE OF THE AXIS BETWEEN 119W AND 127W AND BETWEEN 135W AND 138W.

...DISCUSSION...
AN UPPER LEVEL LONGWAVE TROUGH LIES N TO S ACROSS CENTRAL N 
AMERICA ALONG 107W WITH AN ASSOCIATED SHORTWAVE TROUGH EXTENDING 
INTO THE AREA ALONG 32N103W 25N110W THEN THE TROUGH CONTINUES SW 
THROUGH AN UPPER CYCLONE AT 18N129W THEN THE TROUGH CONTINUES S 
TO A BASE NEAR 7N126W. AN UPPER ANTICYCLONE CENTERED W OF AREA 
NEAR 22N148 HAS A RIDGE AXIS EXTENDING NE TO WELL BEYOND 32N145W 
WITH THE ASSOCIATED ANTICYCLONIC FLOW OVER THE UPPER LEVELS N OF 
18N W OF 134W. A NEW UPPER TROUGH IS ENTERING THE AREA ALONG 
32N125W 26N125W. UPPER MOISTURE CONTINUES TO SPILL E  ACROSS THE 
UPPER RIDGE AND TURNING CYCLONICALLY INTO THE TROUGH...ROUGHLY 
NW OF LINE 29N115W 23N135W. A BAND OF DRY UPPER AIR LIES ALONG 
THE UPPER TROUGH AXIS WITHIN 180 NM EITHER SIDE OF LINE 28N103W 
25N118W 16N130W 16N140W.

A TROPICAL UPPER ANTICYCLONE IS QUASI STATIONARY NEAR 6N112W 
WITH A RIDGE AXIS EXTENDING N TO NEAR 19N112W. THIS RIDGE LIES 
JUST N OF THE ITCZ AND IS ENHANCED CONVECTION ALONG ITS AXIS 
BETWEEN 118W AND 131W. THE RESULTANT DEBRIS MOISTURE IS STILL
SPREADING N BETWEEN 111W AND 123W TO ALONG 20N WHERE THE PLUME 
TURNS NE AND NARROWS TO NEAR 24N92W.

AN UPPER ANTICYCLONE IS NEAR 5N65W WITH A RIDGE EXTENDING W 
ACROSS TROPICAL E PAC TO A CREST ALONG 2N86W 14N94W 22N80W. THE 
ASSOCIATED UPPER DIFFLUENCE IS ENHANCING ISOLATED CLUSTERS OF 
CONVECTION ALONG THE ITCZ BETWEEN 79W AND 94W WITH THE DEBRIS 
MOISTURE SPREADING N A CROSS CENTRAL AMERICA E OF 96W. OTHERWISE 
THE UPPER LEVELS ARE DRY S OF 20N E OF 108W AND SUPPRESSING 
CONVECTION ALONG THE ITCZ.

AT THE LOW LEVELS...HIGH PRES IS CENTERED NEAR 27N132W 1026 MB 
WITH A RIDGE SE TO NEAR 15N103W. TO THE S OF THIS RIDGE NE 
WINDS ARE 20 TO 25 KT WITH SEAS 9 TO 14 FT IN MIXED WIND WAVE 
AND NW SWELL. N OF THE RIDGE...NW 20 KT WINDS ARE OBSERVED NEAR 
THE SOUTHERN TIP OF THE BAJA PENINSULA. THE HIGH PRES IS 
EXPECTED TO SHIFT NE AND CONTINUE TO BLOCK THE SE ADVANCE OF THE 
NEXT SERIES OF COLD FRONTS...BUT FRESH NW SWELL IN THE 12 TO 18 
FT RANGE SHOULD ARRIVE NEAR 32N140W AROUND SUNRISE FRI.

BRISK NE TRADES IN THE W CARIBBEAN SEA ARE DIMINISHING AND THE 
NE SURGES THROUGH THE GULF OF PAPAGAYO GAP SHOULD ALSO DIMINISH 
TO LESS THAN 20 KT WED AFTERNOON.  

$$
NELSON