000
AXPZ20 KNHC 072216
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 W OF 112W.

...DISCUSSION...
DEEP AMPLITUDE TROUGH EXTENDS FROM UPPER LEVEL CYCLONIC VORTEX 
OFF SRN CALIFORNIA COAST TO 32N120W 19N124W.  STRONG SUBSIDENCE 
UNDER 120 KT JET CORE KEEPS DRY AIR MASS WITHIN 5-7 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.  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 25N E 
OF 108W VERY DRY.  

AT THE SURFACE...
DEEP LAYER LOW PRES 1010 MB OVER SRN CALIFORNIA HAS TROUGH 
EXTEND FROM 32N118W TO 30N118W TO 24N119W  SYSTEM FINDS PLENTY 
OF MOISTURE AVAILABLE TO DEVELOP STRONG DEEP CONVECTION ONCE 
OVER LAND.  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 1035 MB SITTING ALONG 30N OVER FLORIDA 
EXPECTED WEAKEN SIGNIFICANTLY AS IT MOVES E RELAXING STEEP PRES 
GRADIENT IT HAS OVER NRN CARIBBEAN AND CENTRAL AMERICA.  TRADE 
WINDS...FORCED ACROSS MOUNTAIN GAPS IN CENTRAL AMERICA...SHOULD 
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