000
AXPZ20 KNHC 130905
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU APR 13 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY 
THROUGH 0815 UTC.

...ITCZ AXIS 6N77W 5N100W 5N120W 8N130W 5N140W. SCATTERED 
MODERATE CONVECTION WITHIN 60 NM EITHER SIDE OF AXIS FROM 88W TO 
93W AND WITHIN 120 NM N OF AXIS FROM 132W TO 137W. 
 
...DISCUSSION...

AN UNUSUALLY HIGH-AMPLITUDE UPPER LEVEL PATTERN PREVAILS OVER 
THE PACIFIC...MEXICO...AND CENTRAL AMERICA. THE PATTERN IS 
COMPRISED OF A SHARP TROUGH EXTENDING FROM THE W CARIBBEAN SW 
OVER CENTRAL AMERICA NEAR HONDURAS/NICARAGUA INTO THE PACIFIC AS 
A CYCLONIC SHEAR AXIS TO 2N103W...A RIDGE FROM 10N130W NEWD OVER 
MEXICO INTO THE CENTRAL UNITED STATES...AND A LARGE CUTOFF LOW 
APPROXIMATELY 600-700 NM WSW OF SAN DIEGO CALIFORNIA NEAR 
31N130W.  FROM W TO E...BROAD MIDDLE TO UPPER LEVEL TROUGH 
ASSOCIATED WITH THE CUTOFF LOW NEAR 31N130W PREVAILS OVER THE NW 
PORTION OF THE DISCUSSION AREA WITH STRONG CONFLUENT FLOW AND 
ASSOCIATED SUBSIDENCE CREATING DRY/STABLE CONDITIONS ALOFT NW OF 
A LINE FROM 13N140W TO 28N105W IN N MEXICO.  E OF THE 
TROUGH...STREAKS OF HIGH CLOUDINESS LIE EQUATORWARD OF A 
SUBTROPICAL JET...ESTIMATED BETWEEN 90-130 KT...FROM 15N140W 
NEWD OVER THE N BAJA PENINSULA AND S CALIFORNIA.  
ADDITIONALLY...DIFFLUENT FLOW ALOFT NEAR THE ENTRANCE REGION OF 
THE JET IS ENHANCING ITCZ CONVECTION W OF 130W.  AT THE 
SURFACE...COLD FRONT ENTERS AREA NEAR 32N125W AND EXTENDS SWD 
ALONG 22N130W WHERE IT WEAKENS TO BEYOND 17N140W. BROKEN TO 
OVERCAST LOW CLOUDS AND SCATTERED SHOWERS ARE OBSERVED WITHIN 
150 NM E OF THE FRONT ESPECIALLY N OF 20N.  ELSEWHERE AT THE 
SURFACE...THE SIGNIFICANT SWD PROGRESS OF THE COLD FRONT HAS 
SUPPRESSED THE SUBTROPICAL PACIFIC RIDGE SE OF THE ITS NORMAL 
LOCATION WITH A 1019 MB HIGH OFF THE BAJA COAST NEAR 26N120W.  
OVER THE E PART OF THE AREA...STRONG CONFLUENT FLOW INTO THE W 
SIDE OF AN UPPER LOW OVER CUBA IS PRODUCING SUBSIDENCE AND 
DRY/STABLE CONDITIONS ALOFT OVER PORTIONS OF CENTRAL AMERICA N 
OF COSTA RICA.  SUBSIDENCE AND DRY AIR IS ALSO NOTED ON THE 
POLEWARD SIDE OF THE CYCLONIC SHEAR AXIS FROM NICARAGUA/HONDURAS 
TO 20N103W.  DIFFLUENT FLOW ALOFT E OF THE SHEAR AXIS IS 
ENHANCING ITCZ CONVECTION BETWEEN 85W AND 95W. 

$$
RHOME