000
AXPZ20 KNHC 040345
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JAN 04 2009

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0100 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 WITHIN 90 NM OF 04.5N79W. SCATTERED MODERATE AND 
ISOLATED STRONG CONVECTION WAS OCCURRING WITHIN 120 NM OF THE 
AXIS BETWEEN 116W AND 140W. ALSO...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 INTERIOR CALIFORNIA...WITH THE BASE OF THIS 
TROUGH DIGGING SSE TO NEAR 26N125W. TO THE SOUTH OF THIS 
PROGRESSIVE SHORT WAVE...A TUTT AXIS STRETCHED FROM CENTRAL 
TEXAS...WSW ACROSS CENTRAL BAJA CALIFORNIA...THEN SW TO 
21N134W...CONTINUING NW TO 25N145W 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 NEARLY STATIONARY LOW LEVEL 
TROUGH FROM 11N122W TO 16.5N113W WILL CONTINUE TO INTERACT 
FAVORABLY WITH BROAD UPPER DIFFLUENCE OCCURRING E OF 125W TO 
MAINTAIN ACTIVE AND DEEP CONVECTION THERE. 
  
THE SHORTWAVE TROUGH IS ALSO SUPPORTING A DIFFUSE COLD FRONT 
SINKING SOUTHWARD INTO N PORTIONS OF THE DISCUSSION AREA FROM 
28N115W TO 23.5N130W TO 25.5N140W. NORTHERLY WINDS AROUND 20 
KNOTS ARE BUILDING SOUTH ACROSS THE AREA BEHIND THE FRONT...AND 
WILL SHIFT SLOWLY SOUTHWARD TO NEAR 25N DURING THE NEXT 24 
HOURS. THIS WIND FIELD WILL BE ACCOMPANIED BY MODERATE PERIOD NW 
WIND SWELL. THE FRONTAL REMNANTS ARE EXPECTED TO DISSIPATE 
WITHIN 12 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. THE LOW 
LEVEL TROUGH ALONG 11N122W TO 16.5N113W 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 N TO NE WINDS...W OF 125W DURING THE NEXT 48 HOURS...WITH 
SEAS 9 TO 13 FT...IN STEEP NE WIND SWELL AND FADING NW SWELL.

GAP WINDS OF 20 TO 25 KT IN THE GULF OF PAPAGAYO REGION...ARE 
EXPECTED TO INCREASE TO 20 TO 30 KT OVERNIGHT AS A LOW LEVEL 
WIND SURGE IN THE SOUTHWEST CARIBBEAN CROSSES CENTRAL AMERICA. 
HOWEVER...WINDS ACROSS THIS AREA AREA EXPECTED TO PULSE UP AND 
DOWN THROUGH 48 HOURS...WITH STRONGEST WINDS TONIGHT THROUGH 
NOON SUNDAY. SEA WILL LIKELY BUILD 8 TO 9 FT OVERNIGHT. 

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