000
AXPZ20 KNHC 171608
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JAN 17 2009

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...ITCZ...
AXIS ALONG 03N78W TO 07N87W TO 04N94W TO 08N124W TO 05N135W TO 
05N140W.  ISOLATED MODERATE WITHIN 45 NM OF AXIS FROM 122W-132W.

...DISCUSSION...
DEEP LAYER LARGE AMPLITUDE UPPER LEVEL TROUGH DIGS S FROM 
32N129W TO 16N131W THEN SE TO CYCLONIC VORTEX AT 16N124W.  UPPER 
TROUGH WEAKENS AS IT IS UNABLE TO PROCEED E DUE TO BLOCKING 
UPPER LEVEL RIDGE EXTENDING FROM 12N98W TO 32N120W.  STATIONARY 
SURFACE REFLECTION OF UPPER TROUGH ALONG 126W FROM 6N-17N.  AREA 
OF DIFFLUENT FLOW ALOFT W OF UPPER RIDGE S OF 20N ENHANCING 
CONVECTION ON E SIDE OF SURFACE TROUGH.  RIDGE ADVECTING 
ABUNDANT TROPICAL MOISTURE N AND NE TO BAJA PENINSULA AND W 
MEXICO...BUT NO FEATURES TO PROMPT CONVECTION OF SIGNIFICANCE.

GULF OF TEHUANTEPEC AND IMMEDIATE AREA SW OF IT CONTINUE UNDER 
WEAKENING GALE FORCE WINDS...EXPECTED TO BE BELOW GALE FORCE 
WITHIN 24 HRS AS HIGH PRES SYSTEM FORCING WINDS ACROSS ISTHMUS 
MOVES FURTHER E. 

GULF OF PAPAGAYO STRONG NE WINDS SEEPING FROM WESTERN CARIBBEAN 
WEAKEN AS FRONTAL BOUNDARY AND HIGH PRES FORCING WINDS ACROSS 
CENTRAL AMERICA MOUNTAIN GAPS DISSIPATE WITHIN NEXT 48 HRS.  

STRONG COLD FRONT ENTER NW CORNER OF AREA AND BECOME DIFFUSE 
WITHIN NEXT 48 HRS AS ITS SUPPORTING UPPER TROUGH STALLS JUST W 
OF BLOCKING RIDGE.  LARGE AREA OF 10-18 FT LONG PERIOD SWELLS 
SPREAD SE TO COVER AREA W OF 110W BY 48 HRS. 
 
$$
WALLY BARNES