000
AXPZ20 KNHC 191545
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT FEB 19 2011

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 
1500 UTC.

...ITCZ...
AXIS ANALYZED FROM 03N77W TO 00N87W TO 02N120W TO 05N140W. 
SCATTERED MODERATE CONVECTION IS FROM 06N TO 09N BETWEEN 129W 
AND 132W.

...DISCUSSION...
A SHARP MIDDLE TO UPPER LEVEL TROUGH AXIS EXTENDS FROM AN UPPER 
LEVEL LOW CENTERED OVER NORTHERN CALIFORNIA NEAR 41N123W THROUGH 
32N122W TO A MID-LEVEL CYCLONE NEAR 07N132W. THE TROUGH SUPPORTS 
A FRONTAL BOUNDARY EXTENDING FROM 32N117W TO 24N124W TO 22N130W. 
ANOTHER REINFORCING PUNCH OF MID-LEVEL SHORTWAVE ENERGY IS 
FORECAST TO ENTER THE NORTH-CENTRAL WATERS BY LATE SATURDAY INTO 
EARLY SUNDAY WITH A NEW COLD FRONT INTRODUCING INCREASING NW 
WINDS IN THE RANGE OF 20 TO 25 KT N OF 26N W OF THE FRONT TO 
124W BY EARLY SUNDAY. LARGE NW SWELL IS EXPECTED TO BUILD SEAS 
TO 14 FT BEHIND THE NEW FRONT...THEN GRADUALLY SUBSIDE BELOW 12 
FT BY EARLY MONDAY. THE NW SWELL TRAIN WILL CONTINUE TO SPREAD 
SE OVER MUCH OF THE FORECAST WATERS W OF 105W THROUGH THE PERIOD.

THE FRONTAL TROUGH IS ALSO GENERATING STRONG SW WINDS TO 25 KT 
IN THE NORTHERN PORTION OF THE GULF OF CALIFORNIA. LITTLE CHANGE 
IS EXPECTED OVER THE NEXT 24 HOURS UNTIL FRONTAL PASSAGE WHEN 
WINDS WILL THEN SHIFT NORTH-NORTHWESTERLY AND REMAIN BELOW 20 
KT. 

AS THE UPPER LEVEL TROUGHING AND ASSOCIATED SURFACE FRONTS SHIFT 
E-NE THROUGH LATE SUNDAY...SURFACE HIGH PRESSURE IS FORECAST TO 
SETTLE BACK OVER THE WESTERN WATERS W OF 120W. THIS WILL ONCE 
AGAIN INCREASE THE PRESSURE GRADIENT BETWEEN THE RIDGE AND LOWER 
PRESSURE LOCATED WITHIN THE ITCZ REGION AND INTRODUCE AN AREA OF 
NE TO E TRADE WINDS OF 20 TO 25 KT FROM 05N TO 20N W OF 125W BY 
THE END OF THE FORECAST PERIOD. MERGING NE AND NW SWELL OVER 
THIS AREA IS EXPECTED TO RESULT IN SEAS RANGING 8 TO 10 FT. 

GAP WINDS...
A SMALL PLUME OF NORTHEASTERLY WINDS CONTINUES TO EXIT CENTRAL 
AMERICA THROUGH THE GULF OF PAPAGAYO AND WILL MAINTAINING FRESH 
WINDS SPILLING INTO THE E PACIFIC FROM THE WESTERN CARIBBEAN 
THROUGH THE PERIOD. 

A 1010 MB LOW PRESSURE CENTER OVER NW COLOMBIA WILL TIGHTEN THE 
GRADIENT OVER THE GULF OF PANAMA SUFFICIENTLY TO PRODUCE 
NORTHERLY WINDS OF 20 KT TODAY THAT WILL LIKELY PERSIST THROUGH 
MONDAY. 

NORTHEASTERLY WINDS IN THE SW GULF OF MEXICO ARE EXPECTED TO 
SPILL THROUGH THE CHIVELA PASS AND BLOW THROUGH THE GULF OF 
TEHUANTEPEC...RESULTING IN 20 TO 25 KT NORTHERLY WINDS THROUGH 
EARLY SUNDAY...WHICH ARE THEN EXPECTED TO DIMINISH TO LESS THAN 
20 KT LATE SUNDAY NIGHT.
 
$$
HUFFMAN