000
AXPZ20 KNHC 080356
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT FEB 07 2009

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
AXIS ALONG 05N77W TO 02N90W TO 07N132W TO 06N140W.
SCATTERED MODERATE CONVECTION 150 NM N OF AXIS FROM 114W-124W.

...DISCUSSION...
LARGE AMPLITUDE TROUGH EXTENDS FROM UPPER LEVEL CYCLONIC VORTEX 
OFF SRN CALIFORNIA COAST TO 32N117W 24N122W.  STRONG SUBSIDENCE 
UNDER 120 KT JET CORE KEEPS DRY AIR MASS WITHIN 6-8 DEG FROM 
TROUGH AXIS BETWEEN 19N-28N WHILE TROPICAL MOISTURE IS ADVECTED 
FROM ITCZ CONVECTIVE DEBRIS NE INTO SRN HALF OF BAJA CALIFORNIA 
AND MEXICO.  MID-UPPER LEVEL RIDGE BUILD BEHIND TROUGH OVER FAR 
NW PORTION OF DISCUSSION AREA. 

WEAKENING UPPER LEVEL RIDGE ACROSS MEXICO AND TEXAS FLATTENS 
FLOW SE OF ISTHMUS OF TEHUANTEPEC...BUT STILL KEEP AREA S OF 20N 
E OF 110W VERY DRY.  

AT THE SURFACE...
DEEP LAYER LOW PRES 1010 MB OVER SRN CALIFORNIA HAS TROUGH 
EXTEND FROM 32N117W TO 30N117W TO 24N117W.  SYSTEM FINDING 
ABUNDANT MOISTURE AVAILABLE TO DEVELOP STRONG DEEP CONVECTION 
OVER BORDER WITH BAJA CALIFORNIA.  STRONG NE WINDS W OF TROUGH  
SHOULD WEAKEN BUT NW SWELLS EXPECTED TO CONTINUE TO SPREAD S TO 
THE EQUATOR W OF 110W.

HEALTHY HIGH PRES SYSTEM 1033 MB NOW DRIFTING E ALONG 30N 
EXPECTED WEAKEN SIGNIFICANTLY AND RELAX PRES GRADIENT IT 
CAUSED OVER NRN CARIBBEAN AND CENTRAL AMERICA.  TRADE WINDS... 
FORCED ACROSS MOUNTAIN GAPS IN CENTRAL AMERICA...SHOULD ALL
DIMINISH.  ALL GALE FORCE EVENTS HAVE BEEN ALLOWED TO EXPIRE AND 
LINGERING WINDS SHOULD CONTINUE TO WEAKEN.  E SWELLS SHOULD 
REMAIN THROUGH MON SPECIALLY FROM 03N-13N E OF 110W.   

$$
WALLY BARNES