000
AXPZ20 KNHC 221006
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JUN 22 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 
0945 UTC.

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS W FROM COSTA RICA AT 10N85W TO 10N92W 
THEN TURNS NW PARALLEL TO CENTRAL AMERICA TO NEAR 15N94W. THE 
MONSOON TROUGH RESUMES NEAR 15N105W...SW OF REMNANTS OF TROPICAL 
CYCLONE BEATRIZ...AND EXTENDS SW THROUGH 10N120W TO 06N127W 
WHERE LOW LEVEL WINDS INDICATE THAT THE ITCZ BEGINS...AND 
EXTENDS W TO BEYOND 06N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED WITHIN 60 NM COAST OF CENTRAL AMERICA FROM 
81W TO 90W...AND N OF 11N BETWEEN 94W AND 100W...AND WITHIN 120 
NM EITHER SIDE OF A LINE FROM 13N104W TO 09N121W. LOCALLY 
OVERCAST LOW AND MID LEVEL CLOUDS...WITH EMBEDDED SHOWERS ARE 
OBSERVED ELSEWHERE WITHIN 240 NM OF THE MONSOON TROF AXIS W OF 
105W...AND ALSO WITHIN 120 NM EITHER SIDE OF THE ITCZ AXIS. 

...DISCUSSION...
AN UPPER TROUGH IS APPROACHING THE NW PORTION WITH SOUTHERLY 
UPPER FLOW OBSERVED TO THE N OF 20N W OF 130W. AN UPPER LEVEL 
ANTICYCLONE IS CENTERED AT 28N118W...WITH A RIDGE EXTENDING SW 
TO 15N140W...AND A RIDGE ALSO EXTENDS SE TO A SHARP CREST OVER 
INTERIOR OLD MEXICO AT 26N106W. AN UPPER CYCLONE IS CENTERED 
OVER THE W TEXAS BORDER AT 30N105W...WITH AN UPPER TROUGH 
EXTENDING SE OVER CENTRAL INTERIOR OLD MEXICO TO NEAR 25N105W. 
ANOTHER UPPER ANTICYCLONE IS OVER OLD MEXICO AT 21N99W...WITH A 
RIDGE SE ACROSS CENTRAL AMERICA. THE ASSOCIATED UPPER DIFFLUENCE 
ENHANCED VIGOROUS CONVECTION OVER CENTRAL MEXICO DURING PAST FEW 
HOURS...WITH THE DEBRIS MOISTURE COVERING MOST OF EASTERN OLD 
MEXICO...AND IS NOW SPREADING E OVER THE WESTERN GULF OF MEXICO. 

UPPER DIFFLUENCE IS ROUGHLY IN PHASE WITH THE LOW LEVEL MONSOON 
TROUGH OVER THE E PACIFIC...AND IS SUPPORTING THE PREVIOUSLY 
DESCRIBED CONVECTION AS WELL AS THE CONVECTION ALONG THE MONSOON 
TROUGH SEGMENT RUNNING PARALLEL TO CENTRAL AMERICA. THE 
RESULTANT DEBRIS MOISTURE FROM ALL THE PREVIOUSLY MENTIONED 
CONVECTION IS ADVECTED SW IN STRONG UPPER NE FLOW ACROSS THE 
ENTIRE DISCUSSION AREA TO THE S OF 20N BETWEEN 120W AND 90W. 
OTHERWISE THE UPPER LEVELS APPEAR VERY DRY TO THE NW OF A LINE 
FROM THE SOUTHERN BAJA CALIFORNIA PENINSULA TO 16N125W...AND 
OVER THE DEEP TROPICS TO THE S OF 16N W OF 125W AND SUPPRESSING 
CONVECTION ALONG THE ITCZ. 

ELSEWHERE AT THE LOW LEVELS...A BROAD RIDGE COVERS THE AREA N OF 
10N AND W OF 120W. A DRY NORTHERLY SURGE AT 20 KT WILL DIP S 
OVER THE MARINE AREA NE OF THE RIDGE...GENERALLY TO THE N OF 25N 
BETWEEN 127W AND 140W ON THU...ACCOMPANIED BY NORTHERLY SWELLS 
WHICH WILL DRIVE COMBINED SEAS UP TO 10 FT LATE FRI ALONG 30N 
BETWEEN 120W AND 130W. 

THE REMNANT LOW PRES OF BEATRIZ IS SPINNING DOWN NEAR 18N107.5W 
AND TOTALLY LACKS CONVECTION. THE LOW SHOULD WEAKEN TO AN OPEN 
TROUGH ON THU.  

LOW LEVEL SW WINDS CONTINUE AT 15 TO 20 KT S OF THE W SEGMENT OF 
MONSOON TROUGH TO ALONG 09N BETWEEN 108W AND 115W. MIXED 
SOUTHERLY SWELLS ARE CONTRIBUTING TO 8 FT SEAS IN THE WATERS S 
OF 18N BETWEEN 78W AND 100W...AND OVER THE DEEP TROPICS TO THE S 
OF 05N BETWEEN 110W AND 130W.

ANOTHER TROPICAL LOW PRES IS EXPECTED TO SLOWLY DEVELOP NEAR 
10N90W ALONG THE E SEGMENT OF THE MONSOON TROUGH THAT IS EXTENDS 
PARALLEL TO THE COAST OF CENTRAL AMERICA. 

$$
NELSON