000
AXPZ20 KNHC 030321
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE NOV 03 2009

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 
0230 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...06N77W TO 
09N105W TO 12N125W TO 08N135W TO 08N140W. SCATTERED MODERATE 
WITH ISOLATED STRONG CONVECTION IS WITHIN 60 NM EITHER SIDE OF 
THE ITCZ AXIS WEST OF 136W.

OTHER CONVECTION NORTH OF THE ITCZ...
SCATTERED MODERATE CONVECTION IS WITHIN 60 NM OF 14N97W.

...DISCUSSION...

THE DOMINATE FEATURES OVER THE AREA ARE TWO TROUGHS. ONE HAS 
BECOME A BROAD CYCLONIC CIRCULATION CUT-OFF FROM THE WESTERLIES. 
THE CIRCULATION IS CENTERED NEAR 22N133W AND COVERS A LARGE 
PORTION OF THE PACIFIC OCEAN REGION TO THE NORTHWEST OF A LINE 
FROM NORTHERN BAJA CALIFORNIA TO THE ITCZ AT 140W. THE AREA IS 
DRY AND CLOUD FREE IN THE MIDDLE AND UPPER LEVELS AND IN THE 
LOWER LEVELS BROKEN TO OVERCAST STRATOCUMULUS IS NORTH OF 22N 
AND SCATTERED STRATOCUMULUS IS SOUTH OF 22N. THIS CIRCULATION IS 
BRINGING SOME DEEP LAYER MOISTURE WITH AREAS OF OVERCAST MIDDLE 
TO HIGH CLOUDS FROM ITCZ CONVECTION NORTHWARD WITHIN 200 NM 
EITHER SIDE OF A LINE FROM 25N113W TO THE ITCZ NEAR 135W. THE 
PATTERN IS FORECAST TO BE STATIONARY AND WEAKEN SLIGHTLY IN THE 
NEXT 24 HOURS THEN THE WEAKEN FURTHER AND BE ABSORBED BY 
WESTERLIES AS A STRONG TROUGH APPROACHES THE NORTHWEST PART OF 
THE AREA WEDNESDAY.

THE OTHER TROUGH IS OVER MEXICO AND EXTENDS SOUTH TO NEAR THE 
ITCZ FROM 100W TO 110W. THE SOUTHERLY FLOW TO THE EAST OF THE 
TROUGH AXIS IS ALSO BRINGING DEEP LAYER MOISTURE FROM THE ITCZ 
NORTHWARD TO OVER EASTERN MEXICO AND CENTRAL AMERICA EAST OF 
100W. MULTI LEVEL CLOUDS AND EMBEDDED AREAS OF CONVECTION ARE 
OBSERVED IN THIS AREA.

WEAK SURFACE RIDGE IS NORTH OF 17N WEST OF 110W. THE SURFACE 
HIGH IS FORECAST TO WEAKEN FURTHER AND CONTRACT IN SIZE AS A 
COLD FRONT ASSOCIATED WITH THE STRONG TROUGH MENTIONED ABOVE 
APPROACHES FROM THE NORTHWEST. ELSEWHERE AT THE SURFACE A BROAD 
TROUGH IS ANALYZED WITH SEVERAL LOWS EMBEDDED ALONG THE ITCZ. 
THE MOST SIGNIFICANT LOW IS NEAR 11N91W 1007 MB AND IS NEAR 
STATIONARY. THIS LOW IS FORECAST TO STRENGTHEN DURING THE NEXT 
COUPLE OF DAYS WITH INCREASING SURFACE WINDS AROUND THE LOW 
MAINLY TO THE EAST OF THE CENTER.

GAP WINDS...
HIGH PRES OVER MEXICO IS ASSOCIATED WITH N TO NE WINDS OF 25-35 
KT THROUGH THE GULF OF TEHUANTEPEC. THESE WINDS ARE EXPECTED TO 
CONTINUE FOR AT LEAST THE NEXT SEVERAL DAYS AS THE HIGH NORTH OF 
THE AREA CONTINUES TO BE REINFORCED.

$$
LL