000
AXPZ20 KNHC 010357
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON APR 01 2013

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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
THE MONSOON TROUGH EXTENDS NW FROM THE COAST OF COLOMBIA AT 
08N78W TO OVER PANAMA AT 09N82W...THEN SW TO 05N90W WHERE 
SCATTEROMETER WINDS INDICATE A TRANSITION TO AN ITCZ. THE ITCZ 
THEN CONTINUES WSW TO 04N109W WHERE IT LOSES IDENTITY. SCATTERED 
MODERATE CONVECTION IS OBSERVED WITHIN 60 NM EITHER SIDE OF LINE
FROM 04.5N100W TO 07N120W.    

...DISCUSSION... 
GULF OF TEHUANTEPEC...LIGHT SOUTHERLY WINDS ARE EXPECTED ACROSS
THE GULF OF TEHUANTEPEC THROUGH THU EVENING...EXCEPT FOR LATE
NIGHT THROUGH SUNRISE NORTHERLY DRAINAGE FLOW AT 10 KT. THE 
NORTHERLY FLOW IS EXPECTED TO INCREASE TO 20 TO 25 KT LATE THU 
NIGHT CONTINUING THROUGH FRI...THEN FURTHER INCREASE TO 20 TO 30 
KT LATE FRI NIGHT THROUGH SUNRISE SAT.   
  
GULF OF PAPAGAYO...ENE WINDS ARE AT 15 TO 20 KT THROUGH THE GULF 
OF PAPAGAYO AND EXTEND AS FAR SW AS 10N90W...WITH MAX SEAS OF 7 
FT. THE GRADIENT WILL GRADUALLY RELAX TONIGHT WITH PULSES TO 15 
TO 20 KT EXPECTED LATE EACH NIGHT TILL JUST AFTER SUNRISE EACH 
MORNING THROUGH WED MORNING. THEREAFTER...EXPECTING LIGHT AND 
VARIABLE WINDS...WITH THE LATE NIGHT EASTERLY DRAINAGE FLOW ONLY 
AT 10 TO 15 KT. 

GULF OF PANAMA...NORTHERLY WINDS AT 10 TO 15 KT WILL CONTINUE 
THROUGH MIDDAY ON MON. THE GRADIENT WILL RELAX LATE MON WITH 
LIGHT AND VARIABLE WINDS THEN EXPECTED THROUGH FRI.

GULF OF CALIFORNIA...NW WINDS AT 10 TO 15 KT EXPECTED THROUGH 
MID WEEK.

THE LARGE SWELLS...ORIGINALLY GENERATED IN AND DOWNSTREAM OF THE 
GULFS OF TEHUANTEPEC AND PAPAGAYO...HAVE PROPAGATED W AND ARE 
NOW MIXING WITH LONG PERIOD NW SWELL ACROSS THE TROPICAL WATERS 
FROM 03N TO 12N BETWEEN 115W AND 130W...WITH COMBINED SEAS OF 7 
TO 9 FT. NE TRADES ARE EXPECTED TO INCREASE ON MON ACROSS THE 
TROPICS FROM 05N TO 18N BETWEEN 122W TO 140W WITH SEAS 7 TO 10 
FT IN THE MIXED E AND NW SWELL. BY TUE THE AREA WILL EXPAND E 
FROM 04N TO 18N BETWEEN 116W AND 140W.
    
A SURFACE HIGH PRESSURE IS ANALYZED AT 26N128W AND IS EXPECTED 
TO SHIFT E ALLOWING A COLD FRONT TO MOVE INTO THE NW PORTION ON 
TUE. SOUTHERLY FLOW WILL INCREASE TO 20 TO 25 KT ACROSS THE 
WATERS N OF 26N W OF 137W ON MON...AND N OF 18N W OF 134W ON TUE. 
NW FLOW WILL INCREASE ON MON NIGHT TO 20 TO 25 KT N OF 27N E OF 
116W TO BAJA CALIFORNIA PENINSULA. 

AN UPPER ANTICYCLONE AT 09N126W HAS AN UPPER RIDGE EXTENDING NE 
TO A CREST OVER NEW MEXICO. UPPER LEVEL WESTERLY FLOW IS 
ADVECTING DENSE UPPER MOISTURE INTO THE AREA WITHIN 360 NM OF 
LINE FROM 15N140W TO 17N120W...THEN TURNS NE TO OVER THE 
SOUTHERN GULF OF CALIFORNIA...THEN CONTINUES W ACROSS NORTHERN 
OLD MEXICO AND THE NW GULF OF MEXICO.

$$
NELSON