000
AXPZ20 KNHC 110254
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU AUG 11 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0245 UTC.

...ITCZ/MONSOON TROUGH...

A MONSOON TROUGH PARALLELS THE CENTRAL AMERICAN COAST FROM COSTA 
RICA AT 09N79W TO 14N100W THEN TURNS W TO 15N113W...THEN SW TO 
13N125W WHERE LOW LEVEL WINDS INDICATE THE ITCZ AXIS BEGINS AND 
CONTINUES SW TO BEYOND 08N140W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS NOTED ALONG THE COASTS OF WESTERN PANAMA 
AND COSTA RICA EXTENDING SW OVER THE PACIFIC WITHIN 150 NM 
EITHER SIDE OF A LINE FROM 08N81W TO 06N87W TO 06N98W TO 
09N108W. SIMILAR CONVECTION IS OBSERVED ALONG THE MONSOON 
TROUGH AND ITCZ WITHIN 120 NM EITHER SIDE OF LINE FROM 13N110W 
TO 13N121W TO BEYOND 08N140W.

...DISCUSSION...

AN UPPER ANTICYCLONE IS OVER EXTREME SW NEW MEXICO AT 31N108W 
WITH AN UPPER RIDGE EXTENDING W TO A CREST AT 30N122W. AN UPPER
LEVEL CYCLONE IS OVER THE BORDER OF SE TEXAS AND E OLD MEXICO
WITH A TROUGH EXTENDING W ACROSS THE SOUTHERN TIP OF THE BAJA 
CALIFORNIA PENINSULA ALONG 22N INTO AN UPPER CYCLONE AT 22N126W 
WITH TROUGH CONTINUING SW TO 12N140W. CONVECTION WAS ENHANCED 
OVER NW OLD MEXICO AND OVER THE EASTERN GULF OF CALIFORNIA WED
AFTERNOON...WITH THE DEBRIS MOISTURE NOW ADVECTED W OVER THE 
PACIFIC FROM 22N TO 31N TO THE E OF 127W. LITTLE CHANGE IS 
ANTICIPATED WITH THE UPPER ANTICYCLONE OVER THE SW CONUS AND THE 
UPPER TROUGH DISSECTING THE AREA...BUT AN UPPER TROUGH WILL 
MOVE INTO THE NW PORTION ON THU.

AN UPPER ANTICYCLONE IS JUST S OF THE UPPER TROUGH OVER CENTRAL 
OLD MEXICO AT 22N102 WITH A RIDGE EXTENDING SW TO A CREST OVER 
THE PACIFIC AT 16N112W. ANOTHER UPPER ANTICYCLONE IS ESTIMATED 
NEAR 15N121W WITH A RIDGE EXTENDING W OVER THE MONSOON TROUGH 
AND ITCZ AXIS ENHANCING CONVECTION...AS PREVIOUSLY DESCRIBED... 
WITH THE DEBRIS MOISTURE FANNING OUT OVER THE DISCUSSION AREA 
FROM 07N TO 14N BETWEEN 100W AND 140W. OTHERWISE...THE UPPER 
LEVELS APPEAR DRY N OF 14N W OF 110W.
  
AN INVERTED UPPER TROUGH EXTENDS FROM 19N98W TO 08N102W AND IS 
EXPECTED TO CONTINUE MOVING W REACHING ALONG 110W FRI MORNING. 
UPPER DEBRIS MOISTURE IS NOTED OVER THE DEEP TROPICAL PACIFIC 
FROM 03N TO 12N BETWEEN 79W AND 94W.  

AT THE SURFACE...A RIDGE EXTENDS FROM 32N140W TO 17N107W. AN 
AREA OF MIXED SE AND SW SWELL...COMBINED SEAS TO 8 FT...IS 
LOCATED S OF 14N BETWEEN 115W AND 130W NA D ELSEWHERE S OF 05N W 
O 100W. THESE CROSS EQUATORIAL SWELLS SHOULD CONTINUE TO 
PROPAGATE NE TO ALONG 16N TO THE E OF 108W BY LATE FRI. 
SOUTHEASTERLY WINDS WILL INCREASE BRIEFLY TO 20 KT THU IN SE 
SWELL OVER THE DEEP TROPICS TO THE S OF 05N BETWEEN 112W AND 
140W. 

$$
NELSON