000
AXPZ20 KNHC 162202
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT JAN 16 2010

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.

...ITCZ...

THE ITCZ AXIS EXTENDS FROM 03N77W TO 10N104W TO 04N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 
90 NM OF 07N107W AND ALSO WITHIN 120 NM EITHER SIDE OF A LINE 
FROM 08N118W TO 05N132W.
 
...DISCUSSION...

AN UPPER TROUGH EXTENDS FROM 32N118W TO 14N140W WITH UPPER 
MOISTURE NOTED N OF 20N WITHIN ABOUT 600 NM E OF THE TROUGH 
AXIS...EXTENDING OVER NW OLD MEXICO AND WESTERN NEW MEXICO. A 
SHORTWAVE RIDGE IS BUILDING EASTWARD ALONG 22N W OF THE UPPER 
TROUGH AND IS ACCOMPANIED BY DRY UPPER AIR OVER THE AREA S OF 
24N W OF THE TROUGH AXIS.

AN UPPER CYCLONE IS LIFTING NE OVER THE NW GULF OF MEXICO  
TRAILING AN UPPER TROUGH S TO OVER THE BAY OF CAMPECHE. FURTHER 
S...A TROPICAL ANTICYCLONE IS NEAR 05N128W WITH SHORTWAVE RIDGE 
EXTENDING NE ACROSS SW OLD MEXICO TO A CREST NEAR 26N105W AND IS 
BASICALLY SEPARATING THE PREVIOUSLY MENTIONED UPPER TROUGHS.
A SECOND SHORTWAVE RIDGE COVERS THE DEEP TROPICS S OF 18N E OF 
100W. UPPER DIFFLUENCE IS ENHANCING CONVECTION ALONG THE ITCZ 
BETWEEN 118W AND 132W WITH THE DEBRIS MOISTURE QUICKLY 
EVAPORATING. OTHERWISE A BAND OF VERY DRY UPPER AIR IS ADVECTED 
ALONG THE NW PERIPHERY OF THIS RIDGE COVERING THE UPPER LEVELS 
OF THE TROPICS S OF 20N E OF 120W.

AT THE LOW LEVELS A FRONTAL TROUGH IS LOSING IDENTITY FROM 
32N125W TO 24N140W. LARGE NW SWELLS ARE PROPAGATING SE OVER THE 
AREA W OF 90W....MIXING WITH NE TRADE SWELLS AND WITH SOME SE 
SWELL MOVING ACROSS THE EQUATOR OVER THE AREA S OF 10N W OF 90W.
 
GAP WINDS...N AND NE WINDS AT 20 TO 30 KT ARE EXPECTED THROUGH 
THE GULF OF TEHUANTEPEC...PAPAGAYO AND PANAMA.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
NELSON