000
AXPZ20 KNHC 040344
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SAT JUN 04 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.
 
...ITCZ/MONSOON TROUGH...
THE MONSOON TROUGH EXTENDS FROM 09N83W TO 10N117W WHERE THE ITCZ 
AXIS BEGINS AND CONTINUES SW TO 05N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED TO THE N OF 04N E OF 88W AND 
IN 3 CLUSTERS DISSIPATING WITHIN 60 NM OF 07N107W AND 08N114W 
AND 08N123W. 

...DISCUSSION...
AN UPPER CYCLONE HAS NEARLY CUT OFF OVER THE PACIFIC JUST W OF 
THE OREGON AND CALIFORNIA BORDER WITH A SERIES OF SHORT WAVE 
TROUGHS ROTATING SE AROUND THE CYCLONE INTO THE DISCUSSION AREA. 
CURRENTLY AN UPPER TROUGH EXTENDS FROM 32N123W TO 20N127W TO 
10N130W. AN UPPER ANTICYCLONE IS CENTERED AT 17N112W WITH A 
RIDGE EXTENDING NE TO A SHARP CREST OVER N CENTRAL OLD MEXICO AT 
27N108W. AN EVAPORATING BAND OF UPPER MOISTURE IS FEEDING INTO A 
CONVECTIVE LINE ACROSS NORTHERN OLD MEXICO...W TEXAS AND EASTERN 
NEW MEXICO. ADDITIONAL UPPER MOISTURE ACCOMPANIES THE UPPER 
TROUGH...AND IS SPREADING NE ACROSS CALIFORNIA AND ARIZONA. A 
THIRD AREA OF UPPER MOISTURE CONTINUES TO SPREAD E OVER THE 
DISCUSSION AREA FROM 15N TO 26N W OF 134W.

AN UPPER ANTICYCLONE IS JUST W OF THE AREA AT 06N147W WITH AN 
UPPER RIDGE EXTENDING E OVER THE DEEP TROPICS S OF 10N TO THE W 
OF 134W. ASSOCIATED UPPER DIFFLUENCE IS ENHANCING CONVECTION 
ALONG THE ITCZ FROM 134W TO 147W...WITH THE DEBRIS MOISTURE 
ADVECTED S ACROSS THE EQUATOR BETWEEN 133W AND 139W. 

AN UPPER TROUGH CONTINUES W ACROSS THE GULF OF MEXICO THROUGH AN 
UPPER CYCLONE AT 24N96W THEN TURNING SW ACROSS CENTRAL OLD 
MEXICO ALONG 19N99W AND INTO AN UPPER CYCLONE OVER THE E PACIFIC 
AT 13N106W...WITH THE UPPER TROUGH CONTINUING SW THROUGH ANOTHER 
WEAK UPPER CYCLONE AT 08N112W...THEN ACROSS THE EQUATOR AT 122W. 
CONVECTION WAS ENHANCED NEAR THE UPPER CYCLONE AT 08N112W. THE 
RESULTANT DEBRIS MOISTURE FROM THIS CONVECTION...AND PREVIOUSLY 
DESCRIBED CONVECTION ALONG THE ITCZ...SEEMS TO REMAIN IN THE 
AREA BOUNDED BY 05N TO 11N BETWEEN 105W AND 126W. OTHERWISE THE 
UPPER LEVELS APPEAR VERY DRY W OF 104W.

AN UPPER ANTICYCLONE IS CENTERED OVER THE CENTRAL CARIBBEAN WITH 
A RIDGE EXTENDING W TO A CREST ALONG 101W BETWEEN 16N AND 18N. 
AT THE LOW LEVELS A TROUGH IS ANALYZED FROM 09N99W TO 14N96W. 
UPPER DIFFLUENCE IS ENHANCING SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 30 NM OF 11N98W AND 13N96W. SOME OF THE 
DEBRIS MOISTURE IS SPREADING NE ACROSS THE SW MEXICAN COAST 
BETWEEN 92W AND 101W. UPPER DIFFLUENCE S OF THE RIDGE IS 
SUPPORTING CONVECTION OVER THE DEEP TROPICS TO THE S OF THE 
MONSOON TROUGH...CURRENTLY WEAKENING. SOME OF THE RESULTANT 
DEBRIS MOISTURE IS ADVECTED S ACROSS THE EQUATOR BETWEEN 80W AND 
90W...AND SOME MOISTURE ALSO SPREADS NE AROUND THE RIDGE AXIS 
ACROSS CENTRAL AMERICA THEN TURNING E INTO A DISTURBANCE S OF 
JAMAICA. 

ELSEWHERE AT THE LOW LEVELS A RIDGE EXTENDS FROM 31N142W TO 
16N109W. A COLD FRONT IS APPROACHING THE NORTHERN PORTION ALONG 
32N BETWEEN 125W AND 140W. THE GRADIENT IS STILL SUPPORTING 
NORTHERLY WINDS TO 20 KT OVER THE PACIFIC WATERS N OF 27N E OF 
120W TO THE BAJA CALIFORNIA PENINSULA. NE TRADES ARE ALSO 
ENHANCED S OF THE RIDGE WITHIN THE AREA FROM 12N TO 22N BETWEEN 
125W AND 140W. THE GRADIENT IS EXPECTED RELAX TONIGHT INTO EARLY 
SAT WITH ONLY A SMALL AREA OF NE TRADES AT 15 TO 20 KT 
PERSISTING NEAR 13N137W BY LATE SAT. SOUTHERLY SWELLS ARE STILL 
PREDOMINATE OVER THE ENTIRE AREA E OF 120W AND MIXED N SWELL IS 
DOMINATE OVER THE AREA W OF 120W. A NEW BATCH OF CROSS 
EQUATORIAL SWELL...RESULTING IN COMBINED SEAS TO 8 FT...WILL 
MOVE INTO THE WATERS S OF 10N BETWEEN 123W AND 92W ON SUN.
 
GAP WINDS...NORTHERLY WINDS AT 20 KT WILL CONTINUE TO SURGE 
THROUGH THE CHIVELA PASS AND INTO AND DOWNSTREAM OF THE GULF OF 
TEHUANTEPEC THROUGH SUNRISE SAT...THEN DIMINISH TO LESS THAN 20 
KT BY LATE SAT. HOWEVER...NORTHERLY WINDS AREA EXPECTED TO SURGE 
S INTO THE GULF OF TEHUANTEPEC JUST BEFORE SUNRISE SUN AND 
INCREASE TO 20 TO 25 KT SUN AFTERNOON...INCREASING TO 25 TO 30 
KT SUN NIGHT. 

$$
NELSON