000
AXPZ20 KNHC 010243
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN MAY 01 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 05N77W TO 
06N96W TO 07N110W TO 06N130W TO 05N140W. SCATTERED MODERATE IS 
WITHIN 90 NM S OF AXIS BETWEEN 84W AND 89W. SIMILAR CONVECTION 
IS NEAR 04N94W...AND NEAR 03N109W.  

...DISCUSSION...

A WELL AMPLIFIED MID TO UPPER LEVEL RIDGE IS PRESENT N OF 25N 
ALONG 135W. THE RIDGE IS MAINTAINING STRONG SURFACE HIGH PRES 
ACROSS THIS AREA. NW WINDS OF 20 TO 25 KT PERSIST ALONG THE BAJA 
COAST BETWEEN THE HIGH PRES AND A SURFACE TROUGH ALONG THE GULF 
OF CALIFORNIA. PERSISTENT 20 KT NE TRADE WINDS ARE ALSO EVIDENT 
S OF THE SURFACE RIDGE...MAINLY N OF 18N W OF 120W. THE SURFACE 
HIGH PRES WILL WEAKEN AND SHIFT SOUTH TODAY. THIS WILL ALLOW THE 
FRESH TO STRONG WINDS OFF BAJA CALIFORNIA TO DIMINISH THROUGH 
LATE TODAY...LEAVING MODERATE TO FRESH TRADES OVER MOST OF THE 
AREA W OF 125W. A REINFORCING HIGH PRES N OF THE FORECAST REGION 
WILL BRING AGAIN AN INCREASE IN WINDS MAINLY ACROSS THE N WATERS 
BY MON.
 
A DIFFLUENT PATTERN ALOFT BETWEEN AN UPPER ANTICYCLONE NEAR 
11N101W AND AN UPPER SHORT WAVE TROUGH ALONG 120W IS SUPPORTING 
A SURFACE TROUGH THAT EXTENDS FROM 11N110W TO 3N112W. SCATTERED 
MODERATE CONVECTION IS NOTED NEAR THE NORTHERN END OF THE TROUGH 
AXIS. E OF THE UPPER ANTICYCLONE...THE TAIL END OF DEEP LAYER 
TROUGH EXTENDS SW FROM WESTERN CARIBBEAN TO ACROSS NICARAGUA AND 
COSTA RICA INTO THE EPAC TO A COL NEAR 7N94W. A DIFFLUENT 
PATTERN ALOFT BETWEEN THIS TROUGH AND A RIDGE OVER ECUADOR AND 
COLOMBIA IS SUPPORTING SOME SHOWER AND TSTM ACTIVITY NEAR THE 
ITCZ. 

GAP WINDS...
NE FLOW THROUGH THE GULF OF PAPAGAYO WILL PULSE UP AND DOWN AT 
OR BELOW 20 KT THROUGHOUT THE NEXT COUPLE OF DAYS...WITH MAIN 
OCCURRENCES DURING THE OVERNIGHT AND EARLY MORNING HOUR WITH THE 
AID OF DRAINAGE FLOW. 

GULF OF CALIFORNIA...TIGHT PRES GRADIENT BETWEEN HIGH PRES OVER 
THE NE PACIFIC AND TROUGH OVER NW MEXICO WILL RESULT IN FRESH TO 
STRONG NW FLOW TO BLOW ACROSS THE GULF OF CALIFORNIA DURING THE 
NEXT COUPLE OF DAYS. SEAS WILL REMAIN NEAR OR BELOW 8 FT DUE TO 
FETCH LIMITATIONS.

$$
GR