000
AXPZ20 KNHC 052147
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SUN JUN 05 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2145 UTC.
 
...SPECIAL FEATURE...
.A SURFACE LOW PRESSURE CENTER IS MEANDERING NEAR 10.5N 98.5W 
WITH AN ESTIMATED CENTER PRESSURE OF 1008 MB. WINDS ARE 
INCREASING TO 20 TO 25 KT WITHIN 180 NM OF CENTER. SCATTERED 
MODERATE TO STRONG CONVECTION SHOWS SIGNS OF ORGANIZATION  
WITHIN 210 NM OF CENTER...AND A BAND MAY BE FORMING BEYOND THE 
210 NM TO ABOUT TO 300 NM OVER SW QUADRANT. THE IS EXPECTED TO 
DRIFT NW FOR THE NEXT FEW HOURS...THEN INCREASE FORWARD MOTION 
REACHING NEAR 11.5N 99W ON MON AFTERNOON...AND NEAR 13N 100.5W 
TUE AFTERNOON WITH POSSIBLE TROPICAL CYCLONE FORMATION.  

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 12N87W THROUGH THE SURFACE LOW 
AT 10.5N 98.5W...WITH THE TROUGH CONTINUING SW TO 08N104W...THEN 
TURNS NW TO 12N112W...THEN DROPS SW TO 05N132W WHERE LOW LEVEL 
WINDS INDICATE THE ITCZ BEGINS AND CONTINUES W BEYOND 05N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED WITHIN 
180 NM EITHER SIDE OF A LINE FROM 07N81W TO 05N95W...AND AS
PREVIOUSLY DESCRIBED IN THE AREA FROM 07N TO 14N BETWEEN 95W AND 
102W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 150 NM 
EITHER SIDE OF A LINE FROM 11N116W TO 06N130W. LOCALLY OVERCAST 
LOW AND MID LEVEL CLOUDS... WITH EMBEDDED SHOWERS...ARE NOTED 
ELSEWHERE FROM 02N TO 09N TO THE E OF 140W.

...DISCUSSION...
A DEEP LAYERED CYCLONE IS OVER THE PACIFIC NEAR 35N126W WITH AN 
UPPER TROUGH EXTENDING S TO BASE AT 13N130W. AN UPPER 
ANTICYCLONE IS CENTERED NEAR 13N112W WITH A RIDGE EXTENDING NE 
TO BEYOND 32N104W...EVENTUALLY MERGING INTO A LONGWAVE RIDGE 
DOMINATING THE CENTRAL CONUS. A THIN BAND OF UPPER MOISTURE IS 
ROTATING CYCLONICALLY SE INTO THE DISCUSSION AREA FROM 32N140W 
TO 26N132W. A BAND OF UPPER MOISTURE SEEMS TO BE EVAPORATING 
OVER SE CALIFORNIA. DEBRIS MOISTURE FROM THE MONSOON TROUGH 
CONVECTION BETWEEN 110W AND AND 130W SEEMS TO EVAPORATE NEAR THE 
DISSIPATING CONVECTIVE CELLS. 

AN UPPER CYCLONE IS CENTERED NEAR 13N104W. THE TROPICAL LOW AT 
10.5N 98.5 IS SQUEEZED IN AN AREA OF UPPER DIFFLUENCE BETWEEN 
THIS UPPER CYCLONE AND THE WESTERN EDGE OF AN UPPER RIDGE ALONG 
93W. CONVECTION IS CURRENTLY FLARING AS PREVIOUSLY DESCRIBED... 
WITH DEBRIS MOISTURE FANNING OUT OVER THE TROPICS FROM 05N 14N 
BETWEEN 94W AND 104W. OTHERWISE...THE UPPER LEVELS APPEAR DRY W 
OF 95W.

AN UPPER ANTICYCLONE IS CENTERED OVER THE S CENTRAL CARIBBEAN 
WITH A RIDGE EXTENDING W TO A CREST ALONG 93W FROM 07N TO 16N.
SOME OF THE DEBRIS MOISTURE FROM THE CONVECTION PREVIOUSLY 
DESCRIBED TO THE E OF 95W IS ADVECTED S ACROSS THE EQUATOR 
BETWEEN 80W AND 90W...AND SOME MOISTURE ALSO SPREADS NE AROUND 
THE RIDGE AXIS...ACROSS CENTRAL AMERICA AND ACROSS THE W 
CARIBBEAN. 

ELSEWHERE AT THE LOW LEVELS A DISSIPATING COLD FRONT EXTENDS 
FROM 32N119W TO 22N130W TO 21N136W WITH A WEST TO EAST RIDGE 
BRIDGING THROUGH THE FRONTAL ZONE ALONG ROUGHLY 23N. NORTHERLY 
WINDS AT 15 KT ACCOMPANY THE FRONT WITH SEAS 8 TO 10 FT IN NW 
SWELL. NE TRADES ARE ALSO ENHANCED S OF THE RIDGE WITHIN THE 
AREA FROM 06N TO 14N BETWEEN 135W AND 140W...BUT THESE WINDS ARE 
EXPECTED TO DIMINISH TO BELOW 20 KT TONIGHT. 

GAP WINDS...NORTHERLY WINDS AT 20 TO 25 KT ARE EXPECTED TO 
CONTINUE IN THE GULF OF TEHUANTEPEC THROUGH MON AFTERNOON THEN 
DIMINISH MON NIGHT. 

$$
NELSON