000
AXPZ20 KNHC 200243
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON JUL 20 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.

...TROPICAL WAVES...

TROPICAL WAVE IS ALONG 110W FROM 03N TO 14N MOVING W 15-20 KT. 
SCATTERED MODERATE CONVECTION IS WITHIN 300 NM MOSTLY WEST OF 
THE WAVE AXIS S OF 09N. THE CONVECTIVE ACTIVITY IS SLIGHTLY 
ORGANIZED IN THE ITCZ REGION BUT DOES NOT APPEAR TO BE BECOMING 
BETTER ORGANIZED.
 
TROPICAL WAVE IS ALONG 134W FROM 05N TO 15N MOVING W 15-20 KT. 
ISOLATED MODERATE CONVECTION IS NEAR THE WAVE AXIS. THE 
CONVECTION IS NOT ORGANIZED.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...05N77W TO 
06N105W TO 10N140W. SCATTERED MODERATE TO STRONG CONVECTION IS 
WITHIN 75 NM OF THE POINT 05N77.5W. SCATTERED MODERATE WITH 
ISOLATED STRONG CONVECTION IS WITHIN 90 NM OF THE POINT 
10N101.5W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION IS 
WITHIN THE AREA FROM 05.5N TO 08.5N FROM 108W TO 115W.

...DISCUSSION...

CYCLONIC CIRCULATION NORTHWEST OF THE AREA CENTERED NEAR 36N142W.
ASSOCIATED SOUTHERLY FLOW IS OVER THE NORTHWEST PART OF THE 
AREA NW OF LINE FROM 32N127W TO 18N140W. THE AREA IS CLOUD FREE 
IN THE MIDDLE AND UPPER LEVELS WITH OVERCAST STRATOCUMULUS IN 
THE LOWER LEVELS. 

A WEAK CYCLONIC CIRCULATION IS CENTERED NEAR 18N123W. THE 
ASSOCIATED CIRCULATION EXTENDS OUT 400 NM FROM THE CENTER. THIS 
AREA IS CLOUD FREE AT ALL LEVELS. SOME MIDDLE LEVEL MOISTURE IS 
ADVECTING OVER WESTERN MEXICO AND SOUTHERN BAJA IN THIS 
CIRCULATION. 

EXCEPT FOR THE TROUGH OVER THE NORTHWEST PART OF THE AREA THE 
AREA WEST OF 128W NORTH OF THE ITCZ IS DRY AND CLOUD FREE IN THE 
MIDDLE AND UPPER LEVELS WITH BROKEN TO OVERCAST STRATOCUMULUS IN 
THE LOWER LEVELS.

THE STRONG TROUGH OVER THE EASTERN UNITED STATES EXTENDS 
SOUTHWARD ACROSS THE GULF OF MEXICO AND ACROSS SOUTHERN MEXICO 
AND AFFECTS THE AREA NORTH OF THE ITCZ EAST OF 110W. ENHANCED 
ITCZ CONVECTION IS NOTED SOUTH OF THIS TROUGH.

A WEAK TROUGH IS ALONG THE ITCZ AND ELSEWHERE A FLAT PRESSURE 
PATTERN IS ANALYZED.

NE TO E GAP WINDS IN THE GULF OF PAPAGAYO REGION AND DOWNSTREAM 
WILL CONTINUE THROUGH MONDAY THEN DIMINISH TUESDAY. THESE WINDS 
ARE ALSO FINDING THEIR WAY THROUGH THE GULF OF TEHUANTEPEC 
REGION WITH N TO NE WINDS OF 20 KT. THESE WINDS ARE FORECAST TO 
DIMINISH LATE MONDAY.

$$
LL