000
AXPZ20 KNHC 160923
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU JUN 16 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURES...
A 1008 MB LOW PRES IS ANALYZED NEAR 11N93W...ALONG THE MONSOON 
TROUGH ON THE 0600 UTC SURFACE MAP. WHILE THE ASSOCIATED SHOWER 
AND THUNDERSTORM ACTIVITY IS SOMEWHAT LIMITED AND DISORGANIZED 
AT THIS TIME...GRADUAL DEVELOPMENT IS POSSIBLE AS A TROPICAL 
WAVE CURRENTLY NEAR THE NICARAGUA/HONDURAS BORDER INTERACTS WITH 
THIS SYSTEM OVER THE NEXT COUPLE OF DAYS. THERE IS A MEDIUM 
CHANCE OF TROPICAL CYCLONE FORMATION DURING THE NEXT 48 HOURS. 
MOST OF THE RELIABLE GLOBAL MODELS SUGGEST THE DEVELOPMENT OF A 
TROPICAL CYCLONE IN THIS AREA DURING THE NEXT SEVERAL DAYS. THE 
LOW PRES IS FORECAST TO REMAIN NEARLY STATIONARY DURING THE NEXT 
24 HOURS THEN WILL MOVE W-NW TO REACH A POSITION AROUND 300 NM S 
OF THE GULF OF TEHUANTEPEC BY SAT. 

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 10N85W TO 11N110W TO 10N110W TO 
09N120W. AT THIS POINT...THE INTERTROPICAL CONVERGENCE ZONE 
CONTINUES TO 07N130W TO 09N138W. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION IS FROM 03N TO 08N E OF 85W...FROM 05N TO 08N 
BETWEEN 90W AND 100W...AND NEAR 11N100W. NUMEROUS MODERATE TO 
SCATTERED STRONG CONVECTION IS NOTED N OF 06N E OF 80W... 
INCLUDING THE GULF OF PANAMA.

...DISCUSSION...
LOW LEVEL CONVERGENCE OF MODERATE SW FLOW INTO THE ABOVE 
MENTIONED LOW PRES S OF THE MONSOON TROUGH...ALONG WITH UPPER 
LEVEL DIVERGENCE NEAR THE BASE OF AN UPPER-LEVEL TROUGH OVER SE 
MEXICO ARE TOGETHER ENHANCING CLUSTERS OF CONVECTION AROUND THE 
LOW PRES. WINDS ARE GENERALLY 10 TO 15 KT OVER THE WHOLE AREA  
AS NOTED BY THE MOST RECENT SCATTEROMETER DATA. COMPUTER MODELS 
SUGGEST A GRADUAL INCREASE IN WINDS AN SEAS IN ASSOCIATION WITH 
THIS LOW DURING THE NEXT 48-72 HOURS. FOR NOW...THE FORECAST 
SHOWS WINDS OF 20 TO 25 KT AND BUILDING SEAS OF UP TO 11 FT BY 
FRI NIGHT.  

AN UPPER CYCLONE REMAINS PARKED OVER 25N127W...WITH AN UPPER 
TROUGH EXTENDING S THEN SW TO NEAR 15N135W. MODERATE TO STRONG 
SUBSIDENCE IS NOTED UNDER THE INFLUENCE OF THIS TROUGH OVER MOST 
OF THE AREA N OF 10N W OF 121W. E OF THE TROUGH...THERE IS AN 
ANTICYCLONIC CIRCULATION CENTERED OVER MEXICO NEAR 24N104W. S 
AND SW FLOW BETWEEN THIS TWO UPPER LEVEL FEATURES ARE ADVECTING 
MID/UPPER LEVEL MOISTURE FROM THE DEEP TROPICS ALL THE WAY N TO 
BAJA CALIFORNIA AND NW MEXICO. UPPER DIFFLUENCE SE OF THIS 
ANTICYCLONE IS ALSO SUPPORTING A CLUSTER OF MODERATE TO ISOLATED 
STRONG CONVECTION NEAR THE NORTHERN END OF A SURFACE TROUGH THAT 
EXTENDS FROM 15N113W TO 10N115W. 

ELSEWHERE AT LOW LEVELS...A 1032 MB SURFACE HIGH LOCATED NW OF 
THE AREA EXTENDS A RIDGE SE OVER THE FORECAST WATERS TO NEAR 
20N120W. PRES GRADIENT TIGHTS OVER THE NW CORNER WHERE NE WINDS 
OF 20 KT ARE OBSERVED BY THE 0624 UTC ASCAT PASS. WINDS ARE 
EXPECTED TO DIMINISH BELOW 20 KT DURING THE NEXT 24 HOURS. 
HOWEVER...EXPECT BUILDING SEAS UP TO 11 FT AS N SWELL CONTINUES 
TO PUSH S OF 30N...REACHING AS FAR S AS 20N BY LATE FRI AS IT 
DECAYS.

$$
GR