000
AXPZ20 KNHC 032246
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT JAN 03 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 
2130 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE WAS ALONG THE LINE...05N79W 
TO 04N82W TO 05N86W TO 04N98W TO 10N118W TO 10N124W TO 08N129W 
TO 08N140W. SCATTERED MODERATE TO STRONG CONVECTION WAS 
OCCURRING OFF OF THE COLUMBIAN COASTLINE...WITHIN 90 NM OF 
04.5N79W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION WAS 
OCCURRING WITHIN 120 NM OF THE AXIS BETWEEN 116W AND 
140W....WHILE NUMEROUS MODERATE WITH ISOLATED STRONG CONVECTION 
WAS OCCURRING WITHIN 120 NM EITHER SIDE OF A LOW LEVEL TROUGH 
FROM 11N122W TO 16.5N113W. 

...DISCUSSION...

A STRONG SHORT WAVE TROUGH CAN BE SEEN IN WATER VAPOR IMAGERY 
MOVING ESE INTO CALIFORNIA...WITH THE BASE OF THIS TROUGH 
DIGGING SSE TO NEAR 28N125W. TO THE SOUTH OF THIS PROGRESSIVE 
SHORT WAVE...A TUTT AXIS STRETCHED FROM CENTRAL TEXAS...WSW 
ACROSS CENTRAL BAJA CALIFORNIA...THEN SW TO 20N135W...CONTINUING 
NW TO 26N150W AND BEYOND. THIS TUTT HAS BEEN MEANDERING ACROSS 
THIS GENERAL ZONE FOR THE PAST FEW DAYS...WITH SUBSIDENCE 
OCCURRING WITHIN AND N OF THE AXIS FOR A FEW DEGREES. AS THE 
SHORTWAVE DIGS FURTHER SE AND SLOWS DURING THE NEXT 48 
HOURS...IT IS EXPECTED TO REINFORCE THE TUTT AND ASSOCIATED DEEP 
LAYERED WEAKNESS THAT CURRENTLY EXTENDS FROM CENTRAL BAJA 
CALIFORNIA TO THE TROPICS ALONG 125W. ABUNDANT TROPICAL MOISTURE 
TO THE EAST OF A LOW LEVEL TROUGH FROM 11N122W TO 16.5N113W WILL 
CONTINUE TO INTERACT FAVORABLY WITH BROAD UPPER DIFFLUENCE 
OCCURRING E OF 128W TO MAINTAIN ACTIVE AND DEEP CONVECTION 
THERE. 
  
THE SHORTWAVE TROUGH IS ALSO SUPPORTING A COLD FRONT SINKING 
SOUTHWARD INTO THE DISCUSSION AREA FROM 31N116W TO 25.5N126W TO 
28N140W. NORTHERLY WINDS AROUND 20 KNOTS WILL BUILD ACROSS THE 
AREA BEHIND THE FRONT DURING THE NEXT 12 TO 18 HOURS... 
ACCOMPANIED BY A PULSE OF MODERATE PERIOD NW WIND SWELL. THE 
FRONT... HOWEVER...IS EXPECTED TO WEAKEN OVER THE NEXT 12 HOURS 
AND DISSIPATE WITHIN 24 HOURS.

ELSEWHERE BROAD ANTICYCLONIC FLOW PREVAILS. PERSISTENT UPPER 
DIFFLUENCE REMAINS NORTH OF THE ITCZ FROM 110W TO 125W AND 
CONTINUES TO ENHANCE ITCZ CONVECTION. ASSOCIATED MULTI LEVEL 
CLOUDS EXTEND NORTH OF THE ITCZ TO 20N THEN TURN NORTHEAST AND 
ARE FLOWING ACROSS CENTRAL MEXICO. ELSEWHERE AT THE SURFACE... A 
MODERATE SURFACE RIDGE IS NORTH OF 14N WEST OF 112W. A WEAK AND 
ELONGATED 1010 MB SURFACE LOW WAS CENTERED NEAR 11N123.5W...AND 
ANCHORS THE LOW LEVEL TROUGH MENTIONED ABOVE. THIS LOW LEVEL 
TROUGH IS FORECAST TO MOVE LITTLE DURING THE NEXT 48 HOURS. THE 
SURFACE RIDGE TO THE NW OF THIS LOW LEVEL TROUGH WILL MAINTAIN A 
BROAD ZONE OF FRESH TO STRONG NE WINDS...W OF 125W DURING THE 
NEXT 48 HOURS...WITH SEAS 9 TO 12 FT...AND POSSIBLY HIGHER...IN 
STEEP NE WIND SWELL.

GAP WINDS OF 20 TO 25 KT CONTINUE IN THE GULF OF PAPAGAYO 
REGION...AND WILL PULSE UP AND DOWN THROUGH 48 HOURS. WINDS 
THERE ARE FORECAST TO BE STRONGEST FROM MIDNIGHT TONIGHT THROUGH 
NOON SUNDAY. BECAUSE OF THE INTERMITTENT NATURE OF THE WINDS AND 
THE SHORT FETCH SEAS DOWNWIND ARE EXPECTED TO ONLY REACH 8 FT.

NORTHERLY GAP WINDS ALSO CONTINUE IN THE GULF OF PANAMA REGION 
WITH WINDS APPROACHING 20 KT AND SEAS LESS THAN 8 FT. THESE 
WINDS ARE FORECAST TO DIMINISH TO LESS THAN 20 KT ON SUNDAY.

$$
STRIPLING