000
AXPZ20 KNHC 140238
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU APR 14 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 ANALYZED 04N77W TO 
1008 MB LOW PRES NEAR 06N90W TO 04N100W TO 06N110W TO 02N130W TO 
04N140W. SCATTERED MODERATE CONVECTION IS S OF 06N BETWEEN 82W 
AND 92W. SIMILAR CONVECTION IS WITHIN 120 NM S OF AXIS FROM 103W 
TO 107W. ISOLATED MODERATE CONVECTION IS WITHIN 130 NM N OF AXIS 
BETWEEN 120W AND 128W. 

...DISCUSSION...
A RIDGE/TROUGH/RIDGE PATTERN DOMINATES MOST OF THE FORECAST 
AREA. AN UPPER LEVEL RIDGE COVERS THE NW CORNER. THE UPPER LEVEL 
TROUGH ENTERS THE REGION THROUGH NORTHERN BAJA CALIFORNIA AND 
EXTENDS SW TO NEAR 20N128W. A 70-110 KT JETSTREAM BRANCH IS SE 
OF THE TROUGH AXIS FROM 25N116W ACROSS CENTRAL BAJA CALIFORNIA 
AND NW MEXICO INTO THE SW UNITED STATES. MODERATE TO STRONG 
UPPER LEVEL SUBSIDENCE AND IMPLIED DRY AIR MASS IS NOTED N OF 
18N W OF 120W. A LARGE UPPER-LEVEL ANTICYCLONIC CIRCULATION IS 
CENTERED NEAR THE ISTHMUS OF TEHUANTEPEC. S TO SW FLOW BETWEEN 
THIS ANTICYCLONE AND THE ABOVE MENTIONED TROUGH IS ADVECTING MID 
TO UPPER LEVEL MOISTURE FROM ITCZ CONVECTION TOWARD SOUTHERN 
BAJA CALIFORNIA INTO NORTHERN MEXICO.

A 1030 MB SURFACE HIGH PRES LOCATED NEAR 32N134W EXTENDS A RIDGE 
SE OVER THE FORECAST WATERS TO NEAR CABO CORRIENTES. THE MOST 
RECENT ASCAT PASSES SHOW A BROAD AREA OF FRESH TO STRONG TRADE 
WINDS OF 20 TO 25 KT ON THE SOUTHERN PERIPHERY OF THE RIDGE 
COVERING ROUGHLY THE REGION FROM 05N TO 25N W OF 120W. THESE 
WINDS ARE ALLOWING SEAS TO BUILD TO 11-12 FT. THE HIGH PRES IS 
FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT 24 HOURS THEN 
WILL DRIFT EWD. LITTLE CHANGE IS EXPECTED IN THE STRENGTH AND 
AREAL EXTENT OF THESE TRADE WINDS THROUGH FRI MORNING. PRESSURE 
GRADIENT BETWEEN THIS HIGH AND LOWER PRES OVER MEXICO IS 
RESULTING IN NW TO N WINDS OF 20 TO 25 KT W OF THE BAJA 
CALIFORNIA PENINSULA TO AROUND 125W. SOME SHIP OBSERVATIONS 
CORROBORATED THESE WIND SPEEDS. IN ADDITION...EXPECT INCREASING 
WINDS UP TO 25 KT ACROSS THE GULF OF CALIFORNIA THIS THU AS HIGH 
PRES SETTLES OVER THE GREAT BASIN. NOAA WW3 INDICATES SEAS 
BUILDING TO 7 FT IN THE GULF OF CALIFORNIA EARLY FRI MORNING. 

A WEAK 1010 MB LOW PRES IS ANALYZED NEAR 11N110W. THE CONVECTIVE 
ACTIVITY ASSOCIATED WITH THIS SYSTEM HAS DIMINISHED DUE TO 
STRONG SE WINDS ALOFT. AS PREVIOUSLY MENTIONED...ANOTHER 1008 MB 
LOW PRES IS EMBEDDED WITHIN THE ITCZ NEAR 06N90W. 

GAP WINDS...
WINDS WILL CONTINUE TO PULSE TO 20 KT ACROSS THE GULF OF 
PAPAGAYO THROUGH THU MORNING WITH SEAS REMAINING JUST BELOW 8 
FT. 

$$
GR