000
AXPZ20 KNHC 202109
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2045 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 8N83W 7N95W 9N100W 5N120W 6N135W 
3N140W.  SCATTERED MODERATE CONVECTION WITHIN 90 NM EITHER SIDE 
OF AXIS FROM 125W-135W. 

...DISCUSSION...

N OF 20N...
A TROUGH-RIDGE-TROUGH CONFIGURATION PREVAILS IN THE MID/UPPER 
LEVELS WITH A TROUGH OVER THE NW PORTION OF THE AREA FROM 
32N133W TO 20N140W...A RIDGE ALONG 115W INTO SW UNITED 
STATES...AND A TROUGH OVER MEXICO. SIGNIFICANT CLOUDS/CONVECTION 
REMAIN ABSENT IN THIS PATTERN ESPECIALLY OVER THE FAR NW PART 
AND MEXICO WHERE CONFLUENT FLOW IN THE UPPER LEVELS IS CREATING 
DRY/STABLE CONDITIONS.  A FEW HIGH CLOUDS ACCOMPANIES A 70-110 
KT JET STREAM ALONG 18N140W 18N130W TO 31N125W.  AT THE 
SURFACE...WEAKENING COLD FRONT LIES OVER THE NW PORTION OF THE 
AREA FROM 32N135W TO BEYOND 29N140W.  LACKING APPRECIABLE 
DYNAMICS AND MOISTURE...THE FRONT IS NOTICEABLY ABSENT OF BOTH 
SHOWERS AND CLOUDS.  THE FRONT IS EXPECTED TO CONTINUE WEAKENING 
OVER THE NEXT 24 HRS AS IS PUSHES EWD FURTHER WEAKENING THE 
PACIFIC SUBTROPICAL RIDGE. 

S OF 20N...
BROAD MIDDLE TO UPPER LEVEL RIDGE EXTENDS FROM COLOMBIA NW ALONG 
CENTRAL AMERICA INTO S MEXICO. EXCEPT FOR SOME MOISTURE ALONG 
THE ITCZ S OF PANAMA VERY DRY AIR PREVAILS IN THE MID AND UPPER 
LEVELS E OF 110W. AS A RESULT...ITCZ ACTIVITY IS LIMITED OVER 
THE E HALF OF THE AREA.  FARTHER W...DIFFLUENT FLOW ALOFT NEAR 
THE BASE OF AN UPPER TROUGH N OF 20N W OF 120W IS AIDING ITCZ 
CONVECTION BETWEEN 125W AND 135W. 

$$
RHOME