000
AXPZ20 KNHC 110950
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN JAN 11 2009

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

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0830 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG A LINE FROM 04N77W 
TO 04N81W TO 09N89W TO 04N119W TO 06N140W. ISOLATED MODERATE 
CONVECTION CAN BE FOUND WITHIN 90 NM OF AXIS FROM 95W TO 102W.  
A TROUGH IS EMBEDDED IN THE ITCZ FROM 03N94W TO 10N93W AND 
SCATTERED MODERATE CONVECTION CAN BE FOUND N OF THE TROUGH 
WITHIN 60 NM OF 92W BETWEEN 10N AND 13N.

...DISCUSSION...

E OF 120W...
THE STRONG NORTHERLY FLOW AT THE SURFACE ASSOCIATED WITH THE 
COLD FRONT CURRENTLY BANKED AGAINST THE SIERRA MADRE OCCIDENTAL 
MOUNTAINS IN WESTERN MEXICO HAS BROUGHT GALE FORCE WINDS TO THE 
GULF OF CALIFORNIA.  THE QUIKSCAT PASSES FROM 0238 AND 0100 UTC 
ONLY SHOW THE WINDS N OF 30N AND S OF 24.5N IN THE GULF...WITH 
WINDS IN THE 25 TO 30 KT RANGE REPORTED IN THE FAR N GULF AND IN 
THE 25 TO 30 KT RANGE IN THE FAR S GULF OF CALIFORNIA AT THAT 
TIME.  WITHOUT OTHER SURFACE OBSERVATIONS...BELIEVE THE GALE 
EVENT IS CONTINUING IN LINE WITH THE FORECAST AND IS EXPECTED TO 
DIMINISH BELOW GALE FORCE MON MORNING AS THE COLD FRONT 
WEAKENS AND THE PRESSURE GRADIENT SLACKENS HERE.

THE COLD FRONT WILL CONTINUE SOUTH INTO SOUTHERN MEXICO 
TODAY...WITH WINDS EXPECTED TO QUICKLY RISE ABOVE GALE FORCE 
OVER THE GULF OF TEHUANTEPEC THIS AFTERNOON/EVENING.  THE FRONT 
SHOULD BE LOSING SOME OF ITS PUNCH AS IT REACHES THE GULF OF 
TEHAUNTEPEC. WINDS HERE ARE EXPECTED TO PEAK NEAR 40 TO 45 KT 
MON AND DROP TO A MARGINAL GALE BY EARLY TUE MORNING...BUT A 
REINFORCING COLD FRONT SHOULD PASS THROUGH THE WESTERN GULF OF 
MEXICO TUE AFTERNOON...BRINING WINDS BACK SOLIDLY IN THE GALE 
RANGE.

THE GULFS OF PAPAGAYO AND PANAMA CONTINUE TO SEE WINDS IN THE 20 
TO 25 KT RANGE ACCORDING TO THE 0330 UTC ASCAT AND 2322 UTC 
QUIKSCAT PASSES.  WITH STRONG TRADE WINDS FROM THE CARIBBEAN 
EXPECTED TO CONTINUE TO BLEED THROUGH THE PASSES IN SOUTHERN 
CENTRAL AMERICA FOR THE NEXT TWO DAYS...DO NOT EXPECT CONDITIONS 
TO CHANGE MUCH IN THE GULF OF PAPAGAYO AND PANAMA THROUGH TUE.

A SURFACE TROUGH FROM 03N94W TO 10N93W IS GENERATING ENOUGH LOW 
LEVEL MOISTURE CONVERGENCE AND IS WITHIN A REGION OF WEAK...YET 
SUFFICIENT UPPER LEVEL DIFFLUENCE TO SUPPORT SCATTERED MODERATE 
CONVECTION N OF THE TROUGH AXIS WITHIN 60 NM OF 92W BETWEEN 10N 
AND 13N.  THIS TROUGH IS EXPECTED TO WEAKEN AS IT PASSES W TODAY.

W OF 120W...
A STRONG RIDGE OF HIGH PRESSURE ANCHORED BY THE 1040 MB HIGH 
NEAR 41N131W WILL GRADUALLY WEAKEN OVER THE NEXT FEW DAYS AS THE 
HIGH MIGRATES NORTHWARD AND SHORTWAVE ENERGY IN THE TAIL OF THE 
MID LEVEL TROUGH SUPPORTING THE COLD FRONT OVER MEXICO AT THE 
MOMENT SHEDS WESTWARD...BREAKING UP THE DEEP LAYER RIDGING OVER 
N WATERS.  THE UPPER LOW CURRENTLY NEAR 26N140W WILL WEAKEN AS 
IT IS SLOWLY LIFTED NORTHWARD ON THE LEADING EDGE OF THE TROUGH 
CURRENTLY APPROACHING THE HAWAIIAN ISLANDS.  SCATTERED MODERATE 
CONVECTION CAN CURRENTLY BE FOUND WITHIN 120 NM OF 11N131W WHERE 
UPPER LEVEL DIFFLUENCE IS IN PLACE BETWEEN THE LEFT FRONT 
QUADRANT OF A 70 TO 90 KT WESTERLY JET S OF 06N AND MEAN 
SOUTHERLY FLOW ON THE SE SIDE OF THIS LOW.  THIS CONVECTION WILL 
WANE AS THE LOW WEAKENS AND THE JET MAX PASSES EASTWARD AND ALSO 
WEAKENS.

$$
SCHAUER CLARK