000
AXPZ20 KNHC 200317
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU APR 20 2006

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 
0230 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 7N77W 6N90W 8N108W 5N120W 7N130W 
4N140W. NO SIGNIFICANT CONVECTION. 

...DISCUSSION...
MIDDLE TO UPPER LEVEL RIDGE LIES OVER THE W PORTION OF 
THE AREA WITH MEAN AXIS ROUGHLY ALONG 122W. THE RIDGE IS MOVING 
EWD AS THE NEXT UPPER LEVEL TROUGH APPROACHES THE AREA CURRENTLY 
JUST W OF 140W.  ATTENDANT SURFACE COLD FRONT IS ENTERING THE NW 
PART OF THE AREA THROUGH 33N140W TO BEYOND 30N135W.  THERE IS 
LIMITED UPPER LEVEL DYNAMICS/LIFT WITH THE FRONT SO ONLY WIDELY 
SCATTERED TO LOCALLY SCATTERED SHOWERS ARE EXPECTED ALONG THE 
BOUNDARY.  THE FRONT WILL IS ACCOMPANIED BY A SLIGHT INCREASE IN 
NORTHERLY WINDS TO 20 KT AND NW SWELLS TO 12 FT.  FURTHER 
E...MID/UPPER LEVEL TROUGH IS PUSHING EWD OVER OVER SOUTHERN 
CALIFORNIA...THE BAJA PENINSULA...AND W MEXICO. THE TROUGH IS 
PRODUCING ISOLATED SHOWERS AND TSTMS OVER E PORTIONS OF MEXICO 
NEAR THE FRONT-RANGE OF THE SIERRA MADRE ORIENTAL MOUNTAINS. 
CONFLUENT FLOW INTO THE BASE OF THE UPPER TROUGH IS PRODUCING 
STRONG SUBSIDENCE AND DRY/STABLE CONDITIONS ALOFT ELSEWHERE OVER 
MEXICO W OF THE SIERRA MADRE ORIENTAL MOUNTAINS TO 120W IN THE 
PACIFIC.  FINALLY...AN UPPER LEVEL RIDGE EXTENDS FROM COLOMBIA 
NW ALONG CENTRAL AMERICA THEN N OVER THE GULF OF MEXICO. AT THE 
SURFACE...THE SUBTROPICAL RIDGE EXTENDS FROM A 1020 MB HIGH NEAR 
33N132W SE TO 17N105W. THE RIDGE IS EXPECTED TO WEAKEN AND SHIFT 
EWD OVER THE NEXT 24 HOURS AS THE AFOREMENTIONED COLD FRONT 
MOVES INTO THE AREA.   

$$
RHOME