000
AXPZ20 KNHC 230954
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI NOV 23 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0945 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH EXTENDS NW FROM THE COAST OF COLOMBIA AT 
06N77W TO 10N85W TO 07N94W...THEN TURNS SW TO 07N87W WHERE LOW 
LEVEL WINDS INDICATE A TRANSITION TO AN ITCZ WHICH THEN WIGGLES 
W-NW TO BEYOND 08N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS OBSERVED WITHIN 30 NM OF 07N105W...AND WITHIN 75 
NM EITHER SIDE OF A LINE FROM 12N120W TO 09N122W TO 10N125W TO 
06N130W.
ISOLATED MODERATE CONVECTION IS NOTED OVER THE SOUTHERN GULF OF 
PANAMA AND WITHIN 15 NM OF 08N90W AND 07N113W. 

...DISCUSSION...

GULF OF TEHUANTEPEC...THE PRESSURE GRADIENT IS MAINTAINING 
NORTHERLY 20-30 KT WINDS IN/DOWNSTREAM OF THE GULF OF 
TEHUANTEPEC. A REINFORCING NORTHERLY SURGE WILL PUSH THROUGH THE 
CHIVELA PASS AND INTO THE GULF OF TEHUANTEPEC THIS EVENING WITH 
A CONSERVATIVE 30-40 KT GALE WARNING POSTED...NOTING THAT SOME  
GUIDANCE IS SUGGESTING THE NORTHERLY WINDS MAY BE AS STRONG AS 
45 KT. EXPECT THE WINDS TO DIMINISH BELOW GALE AROUND MID 
MORNING ON SUN...THEN INCREASE TO A GALE AGAIN TUE NIGHT. 

GULF OF PAPAGAYO...NE-E 20-25 KT WINDS CONTINUE TO SURGE THROUGH 
A GAP IN THE CORDILLERA INTO AND DOWNSTREAM OF THE GULF OF 
PAPAGAYO TO NEAR 08N93W. THE AFFECTED AREA IS FORECAST TO SHRINK 
EASTWARD TO NEAR 09N88W ON SAT NIGHT WITH LITTLE CHANGE THEN 
EXPECTED THROUGH LATE TUE.

GLOBAL MODEL CONSENSUS CONTINUES TO SUGGEST A SURFACE LOW 
PRESSURE WILL DEVELOP WITHIN THE MONSOON TROUGH NEAR 06N96W ON 
SAT...AND MOVE W AT 15 KT FOR A FEW DAYS ACCOMPANIED BY 15 KT 
WINDS WITHIN 240 NM OVER THE N SEMICIRCLE.
 
A SURFACE RIDGE EXTENDS FROM 32N132W TO 16N104W. ALTHOUGH THE 
NORTHERLY WINDS ARE AT 10 KT NE OF THE RIDGE...COMBINED SEAS OF 
8-10 FT IN MIXED NW AND N SWELL ARE OBSERVED N OF 25N E OF 135W 
TO THE WESTERN SHORE OF THE BAJA CALIFORNIA PENINSULA. THESE 
SEAS ARE EXPECTED TO SUBSIDE 5-7 FT ON SAT...AND FURTHER SUBSIDE 
TO 3-4 FT ON SUN. SW OF THE RIDGE THE NE-E TRADES ARE AT 15-20 
KT WITH SEAS 7-11 FT IN MIXED NW AND NE SWELL. THE GRADIENT IS 
FORECAST TO RELAX SUPPORTING NE 15-20 KT AND SEAS 7-9 FT ON SAT 
AND MOSTLY 10-15 KT ON SUN.
 
A COLD FRONT WILL APPROACH THE FAR NE PORTION MON NIGHT 
INCREASING THE SOUTHERLY FLOW TO 20 KT ACROSS THE WATERS N OF 
24N W OF 135W. THE FRONT IS EXPECTED TO STALL AT 32N140W ON TUE 
WITH THE SOUTHERLY WINDS AT 20-25 KT SPREADING E ACROSS THE 
WATERS W OF A LINE FROM 32N132W TO 25N140W...WITH SEAS 
INCREASING TO 8-12 FT IN MIXED SW AND NW LONG PERIOD SWELL.

$$
NELSON