000
AXPZ20 KNHC 200330
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 
0405 UTC FRI APR 20 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 0315 UTC.

...ITCZ...

AXIS IS ALONG 6N77W 6N94W 9N105W 3N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS NOTED WITHIN 150 NM OF AXIS 
BETWEEN 80W AND 100W AND WITHIN 15 NM OF 106W.


...DISCUSSION...

A BROAD UPPER LEVEL TROUGH DOMINATES DISCUSSION AREA N OF 20N W 
OF 112W WITH ITS MEAN AXIS ORIENTATED NW TO SE ALONG 32N120W 
21N112W. A THIN BAND OF UPPER LEVEL MOISTURE IS INDICATED WITHIN 
15 NM EITHER SIDE OF LINE 32N115W 26N123W 25N140W. OTHERWISE THE 
UPPER LEVELS APPEAR DRY WITHIN THE TROUGH.  

AN UPPER ANTICYCLONE IS CENTERED NEAR 5N75W WITH A DEEP LAYERED 
RIDGE EXTENDING NW ALONG 17N85W TO BEYOND 32N97W INTO A BROAD 
RIDGE DOMINATING CENTRAL N AMERICA. A RIDGE EXTENDS ACROSS THE 
EQUATOR DOMINATING THE TROPICS S OF 17N W OF 117W. AN UPPER 
CYCLONE IS NOTED NEAR 4N105W SURROUNDED BY DRY UPPER AIR WITHIN 
240 NM OF CENTER. THE UPPER LEVELS APPEAR MOIST S OF 18N W OF 
112W WITH A MOISTURE PLUME ADVECTED N ALONG THE W PERIPHERY OF 
THE UPPER RIDGE...ROUGHLY WITHIN 420 NM EITHER SIDE OF LINE 
14N108W 25N103W 32N92W. ASSOCIATED UPPER DIFFLUENCE IS ENHANCING 
ITCZ CONVECTION BETWEEN 99W AND 77W WITH THE RESULTANT DEBRIS 
MOISTURE NOW SPREADING N ACROSS CENTRAL AMERICA BUT EVAPORATING 
UNDER THE UPPER RIDGE AXIS. 

AT THE LOW LEVELS BROAD HIGH PRES DOMINATES THE DISCUSSION AREA 
N OF THE ITCZ W OF 105W.

$$
NELSON