000
AXPZ20 KNHC 011540
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE MAY 01 2007

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...ITCZ...

INTERTROPICAL CONVERGENCE ZONE IS ALONG LINE...4N77W 10N113W 
7N123W 6N140W. SCATTERED MODERATE TO STRONG FROM 1N TO 6N E OF 
81W. SCATTERED MODERATE WITHIN 120 NM S OF AXIS BETWEEN 95W AND 
98W. SCATTERED MODERATE TO STRONG WITHIN 120 NM OF AXIS BETWEEN 
109W AND 116W.

...DISCUSSION...

A WEAK CLOSED UPPER LOW NEAR 32N118W IS MOVING E INTO SOUTHERN 
CALIFORNIA...FOLLOWED BY A BROAD UPPER TROUGH TO THE W. THE WEAK 
UPPER LOW WILL OPEN UP AND BE ABSORBED BY THE LARGER TROUGH OVER 
THE SOUTHWEST U.S. AND NW MEXICO THROUGH WED. AT THE 
SURFACE...1024 MB HIGH PRES TO THE NW OF THE DISCUSSION AREA IS 
WEAKENING IN ADVANCE OF A COLD FRONT ASSOCIATED WITH THE UPPER 
TROUGH. THE RIDGE WILL BUILD AS THE UPPER TROUGH SHIFTS 
EWD...ALLOWING SLIGHT INCREASE IN INTENSITY AND COVERAGE OF 
TRADE WIND FLOW S OF THE HIGH...GENERALLY BETWEEN 6N AND 20N W 
OF 120W. ADDITIONALLY...FRESH NW FLOW ALONG THE BAJA COAST WILL 
DIMINISH OVERNIGHT AS THE HIGH WEAKENS...THEN STRENGTHEN AGAIN 
STARTING LATE WED AS THE HIGH PRES BUILDS.

FURTHER S...UPPER LEVEL ANTICYCLONE CENTERED NEAR 12N113W IS 
ENHANCING CONVECTION ALONG THE ITCZ AS NOTED ABOVE. 
SIMILARLY...UPPER ANTICYCLONIC FLOW OVER NWRN S AMERICA IS 
AIDING CONVECTION OFF THE COLOMBIAN COAST. 

$$
CHRISTENSEN