000
AXPZ20 KNHC 121551
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN JUN 12 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1545 UTC.
 
...SPECIAL FEATURE...
THE REMNANT LOW PRES OF ADRIAN IS CENTERED AT 16.5N 115.8W AND 
IS ESTIMATED AT 1004 MB AT 11/1500 UTC MOVING WNW OR 290 DEGREES 
AT 10 KT. CYCLONIC WINDS ARE 20 TO 30 KT WITHIN 90 NM OVER THE N 
AND WITHIN 60 NM OVER THE S SEMICIRCLE WITH SEAS 8 TO 12 FT. THE 
REMNANT IS A TIGHT SWIRL OF LOW LEVEL CLOUDS WITH SCATTERED 
MODERATE CONVECTION FLARING WITHIN 120 NM OVER THE NE SEMICIRCLE 
OF CENTER. THE LOW IS EXPECTED TO DISSIPATE LATE MON.

...ITCZ/MONSOON TROUGH...
A MONSOON TROUGH EXTENDS ALONG 08N FROM PANAMA TO NEAR 09N99W 
WHERE AN AREA OF DISTURBED WEATHER HAS PERSISTED FOR THE PAST 
DAY OR SO. THE REMNANT LOW PRESSURE FROM FORMER TROPICAL CYCLONE 
ADRIAN DISTORTS THE MONSOON FLOW BETWEEN 100W AND 110W. LOW 
LEVEL WINDS INDICATE THAT MONSOON FLOW RESUMES SW OF THE REMNANT 
LOW...WITH AN AXIS FROM 10N115W TO 05N125W WHERE THE 
INTERTROPICAL CONVERGENCE ZONE FORMS...THEN CONTINUES NW TO 
BEYOND 07N140W. ISOLATED MODERATE TO STRONG CONVECTION IS NOTED 
WITHIN 150 NM EITHER SIDE OF A LINE FROM 03N77W TO 09N87W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OBSERVED IN A 
SMALL CLUSTER WITHIN 60 NM OF 07N95W...AND ALSO ASSOCIATED WITH 
THE DISTURBANCE FROM 06N TO 12N BETWEEN 98W AND 102W. SIMILAR 
CONVECTION IS NOTED FROM 07N TO 11N BETWEEN 114W AND 120W.
 
...DISCUSSION...
AN UPPER LEVEL TROUGH EXTENDS SW ACROSS SOUTHERN CALIFORNIA INTO 
THE DISCUSSION AREA ALONG 32118W TO 21N126W TO BEYOND 28N140W. 
THE TROUGH IS ACCOMPANIED BY DRY UPPER AIR WITHIN 90 NM EITHER 
SIDE OF THE AXIS POINTS MENTIONED. UPPER MOISTURE IS SPREADING S 
INTO THE AREA N OF THIS DRY SLOT WITH SOME OF THE MOISTURE 
SPREADING E AND NE ACROSS SOUTHERN CALIFORNIA. 

AN UPPER ANTICYCLONE IS OVER THE DEEP TROPICS NEAR 08N132W THE 
ASSOCIATED ANTICYCLONIC ENVELOPE DOMINATING THE AREA S OF 22N W 
OF 120W. UPPER DEBRIS MOISTURE...ORIGINATING FROM ITCZ 
CONVECTION IN THE CENTRAL PACIFIC...IS SPREADING E INTO THE 
DISCUSSION AREA N OF 08N W OF 130W.

AN UPPER ANTICYCLONE IS CENTERED AT 17N103W WITH A RIDGE 
EXTENDING N TO A CREST OVER W TEXAS NEAR 32N101W. THE DEBRIS 
MOISTURE ASSOCIATED WITH THE DISSIPATING TROPICAL CYCLONE ADRIAN 
IS SPREADING NE AND EVAPORATING ALONG AT LINE FROM 17N112W TO 
22N103W. 

AN UPPER CYCLONE IS OVER THE DEEP TROPICS AT 02N112W WITH AN 
INVERTED UPPER TROUGH EXTENDING N TO ANOTHER UPPER CYCLONE NEAR 
16N115W. THIS SYSTEM EFFECTIVELY SEPARATES THE BROAD 
ANTICYCLONIC FLOW OVER THE SW PORTION FROM THE ANTICYCLONIC FLOW
OVER NORTHERN OLD MEXICO. THUNDERSTORMS ARE ENHANCED ALONG THE 
MONSOON TROUGH BETWEEN 112W AND 127W...WITH THE DEBRIS MOISTURE 
FANNING OUT OVER THE S OF 11N BETWEEN 112W AND 123W.     

FURTHER E...AN UPPER ANTICYCLONE CONTINUES TO MEANDER OVER THE N 
CENTRAL CARIBBEAN...CURRENTLY OVER N HISPANIOLA...WITH A RIDGE 
EXTENDING SW TO A BROAD CREST OVER MOST OF CENTRAL AMERICA. AN 
UPPER TROUGH DISSECTS THE GULF OF MEXICO FROM NE TO SW AND HAS 
DEEPENED TO BASE OVER THE SOUTHERN GULF OF TEHUANTEPEC. UPPER 
DIFFLUENCE BETWEEN THE CENTRAL AMERICAN RIDGE...THE GULF OF 
TEHUANTEPEC UPPER TROUGH AND THE UPPER CYCLONE AT 02N112W...
HAS ENHANCED CONVECTION NEAR 08N100W. A SURFACE TROUGH IS 
CURRENTLY ANALYZED FROM 04N100W TO 11N98W AND IS EXPECTED TO 
FURTHER DEVELOP INTO A SURFACE LOW.  

ELSEWHERE AT THE LOW LEVELS...A RIDGE EXTENDS FROM 32N140W TO 
20N120W. THE GRADIENT NE OF THE RIDGE HAS RELAXED AND IS ONLY 
SUPPORTING NORTHERLY SURFACE WINDS AT 15 KT...BUT ACCOMPANIED BY 
NORTHERLY SWELLS MIXING WITH LONG PERIOD S SWELL...RESULTING IN 
COMBINED SEAS TO 9 FT. NE TRADES ARE ALSO IN THE 15 TO 20 KT 
RANGE TO THE SW OF THE RIDGE...FROM 08N TO 25N W OF 130W...WITH 
SEAS 8 TO 10 FT IN NE SWELL. AS THE RIDGE SHIFTS NE THE AREA OF 
NE TRADES WILL N AS WELL.  

SOUTHERLY CROSS EQUATORIAL S TO SW SWELL EXTENDS NORTHWARD OVER 
MOST OF THE PACIFIC WATERS E OF 130W...MIXING WITH THE CONFUSED 
SEAS SURROUNDING THE REMNANT LOW PRESSURE OF ADRIAN. SE CROSS 
EQUATORIAL SWELL IS NOTED OVER THE DEEP TROPICS TO THE W OF 
130W...MIXING WITH NE SWELL ASSOCIATED WITH THE TRADES SW OF THE 
LOW LEVEL RIDGE.

$$
NELSON