000
AXPZ20 KNHC 120343
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE MAY 12 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 
0300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS ALONG THE LINE...06N77W TO 
06N110W TO 06N140W. SCATTERED MODERATE WITH ISOLATED STRONG 
CONVECTION IS WITHIN 75 NM OF THE POINT 07N87W. SCATTERED 
MODERATE WITH ISOLATED STRONG CONVECTION IS WITHIN 100 NM OF THE 
POINT 10N95W. SCATTERED MODERATE WITH ISOLATED STRONG CONVECTION 
IS WITHIN 60 NM OF THE POINT 08N112.5W. SCATTERED MODERATE 
CONVECTION IS WITHIN 60 NM OF THE FOLLOWING TWO POINTS 05.5N125W 
AND 03N134W.

...DISCUSSION...

A DEEP LAYER TROUGH IS OVER THE EASTERN PART OF THE AREA EAST OF 
95W. AN EXTENSIVE AREA OF DEEP LAYER MOISTURE WITH MULTI LEVEL 
OVERCAST CLOUDS EXTENDS FROM THE ITCZ NORTHWARD OVER CENTRAL 
AMERICA EAST OF 85W. THIS MOISTURE EMANATES FROM ENHANCED ITCZ 
CONVECTION WHICH HAS DIMINISHED IN THE LAST SEVERAL HOURS.

A MUCH LARGER CYCLONIC CIRCULATION IS CENTERED NEAR 17N123W. 
ASSOCIATED WITH THIS CIRCULATION IS ANOTHER EXTENSIVE AREA OF 
DEEP LAYER MOISTURE WITH MULTI LEVEL OVERCAST CLOUDS THAT 
EXTENDS EAST OF A LINE FROM THE CENTRAL GULF OF CALIFORNIA NEAR 
27N112W TO 15N117W TO THE ITCZ NEAR 115W...THE AREA EXTENDS EAST 
TO ABOUT 95W. ENHANCED CONVECTION IS WITHIN THIS AREA SOUTH OF 
15N AND THE MOISTURE EMANATES FROM THIS CONVECTION INCLUDING 
CONVECTION WITHIN THE ITCZ. FROM THE ITCZ TO 25N WEST OF THIS 
AREA OF MOISTURE THE ATMOSPHERE IS DRY AND CLOUD FREE IN THE 
MIDDLE AND UPPER LEVELS. NORTH OF 25N THE MIDDLE AND UPPER 
LEVELS ARE SOMEWHAT MOIST BUT ARE STILL CLOUD FREE. 

REMAINDER OF THE MIDDLE AND UPPER LEVELS ARE A FLAT HIGHT 
PATTERN.

WEAK SURFACE RIDGE IS NORTH OF 15N WEST OF 105W. A SURFACE 
TROUGH IS NEAR 122W/123W FROM 11N TO 06N. THIS TROUGH HAS BEEN 
ASSOCIATED WITH ENHANCED CONVECTION IN THE ITCZ BUT IT NOW 
APPEARS THAT THE TROUGH IS MOVING WEST OF THE MAIN AREA OF 
CLOUDINESS AND CONVECTION...HOWEVER SOME CONVECTION IS WITHIN 60 
NM OF THE TROUGH BUT SHOWS NO SIGN OF ORGANIZATION. REMAINDER OF 
THE AREA IS ANALYZED AS A BROAD TROUGH.

GAP NORTHEAST TO EAST WINDS IN THE GULF OF PAPAGAYO REGION WILL 
OCCASIONALLY REACH 20 KT MAINLY IN THE NIGHTTIME HOURS.
 
$$
LL