000
AXPZ20 KNHC 110930
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JUN 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.
 
...SPECIAL FEATURE...
HURRICANE ADRIAN IS CENTERED NEAR 15.8N 110.5W AT 11/0900 UTC 
MOVING W OR 280 DEGREES AT 10 KT. MAXIMUM SUSTAINED WIND SPEED 
IS 75 KT WITH GUSTS TO 90 KT. ADRIAN IS A CATEGORY ONE HURRICANE 
ON THE SAFFIR-SIMPSON HURRICANE WIND SCALE. IT IS EXPECTED 
TO WEAKEN TO A TROPICAL STORM LATER TODAY AND TO A TROPICAL 
DEPRESSION SUNDAY NIGHT OR MONDAY MORNING. ESTIMATED MINIMUM 
CENTRAL PRESSURE IS 979 MB. SEE THE LATEST NHC ADVISORY UNDER 
AWIPS/WMO HEADERS MIATCPEP1/WTPZ21 KNHC FOR MORE DETAILS. LARGE 
SWELLS GENERATED BY ADRIAN WILL CONTINUE TO AFFECT A PORTION OF 
THE SOUTHWESTERN COAST OF MEXICO THROUGH AT LEAST EARLY THIS 
WEEKEND. THESE SWELLS COULD CAUSE LIFE-THREATENING SURF AND RIP 
CURRENTS. NUMEROUS MODERATE TO SCATTERED STRONG CONVECTION IS 
WITHIN 90 NM NE SEMICIRCLE OF ADRIAN.

...ITCZ/MONSOON TROUGH...
A MONSOON TROUGH EXTENDS FROM 08N78W TO 09N88W TO 07N96W. THE 
INTERTROPICAL CONVERGENCE EXTENDS FROM 10N113W TO 09N130W TO 
07N140W. A CLUSTER OF MODERATE TO STRONG CONVECTION IS JUST OFF 
THE COLOMBIAN COAST COVERING THE AREA FROM 05N TO 08N E OF 79W. 
SCATTERED MODERATE TO ISOLATED STRONG CONVECTION IS OVER THE 
GULF OF PANAMA. ANOTHER CLUSTER OF MODERATE TO STRONG CONVECTION 
IS WITHIN 60 NM OF 10N94W. SCATTERED MODERATE CONVECTION IS 
NOTED BETWEEN THE ITCZ AND 10N W OF 132W. A DIFFLUENT PATTERN 
ALOFT IS HELPING TO INDUCE THIS CONVECTIVE ACTIVITY.
 
...DISCUSSION...
AN UPPER LEVEL TROUGH ENTERS THE FORECAST AREA NEAR 30N125W THEN 
CONTINUES SW TO BEYOND 27N140W. DRY AIR ALOFT IS NOTED ALONG THE 
TROUGH AXIS AND OVER NW MEXICO. WLY WINDS AHEAD OF THE TROUGH 
ARE ADVECTING MID/TO UPPER LEVEL MOISTURE INTO THE FORECAST AREA 
FROM THE W. AN ANTICYCLONIC CIRCULATION IS CENTERED AT 20N105W 
WITH A RIDGE EXTENDING OVER NE MEXICO AND TEXAS. ANOTHER UPPER 
LEVEL HIGH IS LOCATED NEAR 12N122W. AN UPPER LEVEL TROUGH OVER 
THE GULF OF MEXICO ENTERS THE AREA THROUGH THE ISTHMUS OF 
TEHUANTEPEC. E OF 90W...A RIDGE DOMINATES THE FORECAST REGION. 
UPPER DIFFLUENCE ASSOCIATED WITH THIS SYSTEM IS ENHANCING 
CONVECTION NEAR THE COAST COLOMBIA AND OVER THE GULF OF PANAMA. 
 
ELSEWHERE AT THE LOW LEVELS...A RIDGE REMAINS IN CONTROL OF THE 
WEATHER PATTERN N OF 15N AND W OF 115W. PRES GRADIENT NE OF THE 
RIDGE WILL MAINTAIN NORTHERLY WINDS AT 15 TO 20 KT N OF 25N 
ALONG THE W COAST OF THE BAJA CALIFORNIA PENINSULA THROUGH 
TONIGHT...WITH THE GRADIENT RELAXING THEREAFTER. FRESH TO STRONG 
NE TRADE WINDS ARE ALSO NOTED TO THE SW OF THE RIDGE...FROM 08N 
TO 22N W OF 130W. THE 0308 UTC WINDSAT PASS CAPTURED AN AREA OF 
20 TO 25 KT NE WINDS W OF 130W. THE O622 UTC ASCAT PASS ALSO 
CORROBORATED THE PRESENCE OF NE WINDS OF 20 KT BETWEEN 125W AND 
130W. THIS AREA OF ENHANCED NE TRADES SHOULD SHRINK TO THE 
WATERS ROUGHLY FROM 10N TO 20N W OF 130W IN ABOUT 24 HOURS.   

SOUTHERLY CROSS EQUATORIAL SWELL EXTENDS NORTHWARD OVER THE 
PACIFIC WATERS W OF 95W MIXING WITH THE CONFUSED SEAS OVER THE 
SOUTHERN SEMICIRCLE OF HURRICANE ADRIAN. 

$$
GR