000
AXPZ20 KNHC 070406
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE JUN 07 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0245 UTC.
 
...SPECIAL FEATURE...
.A SURFACE LOW PRESSURE CENTER IS CENTERED NEAR 11.5N99W AND 
DRIFTING SLOWLY NE WITH AN ESTIMATED CENTER PRESSURE OF 1007 MB. 
SURFACE WINDS AT 20 TO 25 KT AND SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION...IS INDICATED WITHIN 180 NM N AND 330 NM S 
SEMICIRCLES OF CENTER. THE OVERALL CONVECTIVE ACTIVITY CONTINUES 
TO PULSE...AND IS CURRENTLY IN A WEAKENING TREND. THE LOW IS 
EXPECTED TO MOVE NW REACHING NEAR 13N100.5W TUE EVENING...
AND NEAR 14N101W WED EVENING. CONDITIONS ARE FAVORABLE FOR 
TROPICAL CYCLONE FORMATION.  

...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH DISSECTS HONDURAS FROM NE TO SW AND CONTINUES 
SW TO NEAR 11N96W...THEN RESUMES FROM 10N102W TO AN EMBEDDED 
1012 MB SURFACE LOW AT 09N114W...WITH THE TROUGH CONTINUING SW 
TO 06N123W WHERE LOW LEVEL WINDS INDICATE THE ITCZ BEGINS AND 
CONTINUES W TO BEYOND 05.5N140W. ISOLATED MODERATE AND STRONG 
CONVECTION IS NOTED S OF MONSOON TROUGH AXIS TO 08N ALL TO THE E 
OF 93W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION 
SURROUNDS THE TROPICAL LOW...ROUGHLY FROM 06N TO 14N BETWEEN 96W 
AND 104W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
OBSERVED WITHIN 60 NM OF 09N117W AND O7N125W. BROKEN TO LOCALLY 
OVERCAST LOW AND MID LEVEL CLOUDS WITH EMBEDDED SHOWERS IS 
OBSERVED ELSEWHERE FROM 03N TO 10N BETWEEN 97W AND 140W.  

...DISCUSSION...
AN UPPER TROUGH EXTENDS ALONG 32N128W THROUGH AN UPPER CYCLONE 
AT 18N131W THEN CONTINUES S TO A BASE AT 08N131W. AN UPPER 
ANTICYCLONE IS CENTERED NEAR 16N112W WITH A RIDGE EXTENDING NE 
TO BEYOND 31N108W MERGING INTO A LONGWAVE RIDGE DOMINATING THE 
CENTRAL CONUS. UPPER MOISTURE IS ROTATING CYCLONICALLY SE INTO 
THE DISCUSSION AREA WITHIN 240 NM OF 30N135W. SOME OF DEBRIS 
MOISTURE FROM THE MONSOON TROUGH CONVECTION BETWEEN 114W AND 
126W IS ADVECTED NE UNDER THE RIDGE BUT EVAPORATES BEFORE 
REACHING ALONG 21N AS THE UPPER LEVELS ARE VERY DRY ELSEWHERE N 
OF 20N W OF 96W.

AN UPPER CYCLONE IS CENTERED NEAR 11N106W...AND NOW APPEARS TO 
BE FILLING. THE TROPICAL LOW AT 11.5N99W IS ALMOST STATIONARY IN 
AN AREA OF UPPER DIFFLUENCE BETWEEN THIS UPPER CYCLONE AND THE 
WESTERN EDGE OF AN UPPER RIDGE ALONG 94W. CONVECTION IS 
CURRENTLY FLARING AS PREVIOUSLY DESCRIBED...WITH DEBRIS MOISTURE 
FANNING OUT OVER THE TROPICS S OF 16N BETWEEN 94W AND 108W.

AN UPPER ANTICYCLONE IS CENTERED OVER THE SW CENTRAL CARIBBEAN 
WITH A RIDGE EXTENDING W TO A CREST ALONG 94W FROM 10N TO 16N.
SOME OF THE DEBRIS MOISTURE FROM THE CONVECTION PREVIOUSLY 
DESCRIBED TO THE E OF 94W IS ADVECTED S TO ALONG 04N BETWEEN 80W 
AND 94W...AND SOME MOISTURE ALSO SPREADS NE AROUND THE RIDGE 
AXIS...ACROSS CENTRAL AMERICA...ACROSS THE W CARIBBEAN...THE SE 
GULF OF MEXICO AND IS NOW MOVING ACROSS FLORIDA S OF 28N. 

ELSEWHERE AT THE LOW LEVELS...A WEST TO EAST RIDGE EXTENDS FROM 
32N140W TO 13N112W. NW WINDS AT 15 TO 20 KT...WITH SEAS 6 TO 8 
FT...AREA EXPECTED TO CONTINUE ALONG THE W COAST OF THE BAJA 
CALIFORNIA PENINSULA THROUGH LATE WED. NORTHERLY SWELLS WILL 
PROPAGATE SE ACROSS THE WATERS N OF 10N W OF 110W AND MIX WITH 
SOUTHERLY SWELLS THROUGH WED. 

GAP WINDS...NORTHERLY WINDS AT 20 TO 25 KT WERE INDICATED IN THE 
GULF OF TEHUANTEPEC THIS EVENING...BUT SHOULD DIMINISH TO LESS 
THAN 20 KT JUST AFTER SUNRISE TUE AS THE SURFACE LOW TO THE SW 
MOVES OUT TO THE NW.
 
$$
NELSON