000
AXPZ20 KNHC 132155
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC WED MAR 13 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...MONSOON 
TROUGH AXIS EXTENDS FROM 08N83W TO 00N96W TO 01N104W.  ITCZ AXIS 
EXTENDS FROM 04N120W TO 02N140W.  SCATTERED MODERATE CONVECTION  
WITHIN 180 NM OF AXIS E OF 91W.

...DISCUSSION...
BROAD MID TO UPPER LEVEL RIDGE CRESTS AT 32N128W BRINGING DRY 
AND STABLE AIR MASS ALOFT S OF 22N W OF 117W.  VIGOROUS SHORT
WAVE TROUGH OVER BAJA CALIFORNIA SWINGS AROUND BASE OF LONGWAVE
TROUGH ADVECTING ABUNDANT TROPICAL MOISTURE FROM ITCZ CONVECTIVE
DEBRIS ACROSS SOUTHERN MEXICO AND INTO SOUTHERN HALF OF GULF OF
MEXICO.  WHILE SHORT WAVE HAS NOT BECOME AN UPPER LEVEL CYCLONE
...AS PREVIOUSLY EXPECTED...THE LONGWAVE TROUGH HAS EFFECTIVELY
FORCED GULF OF MEXICO 1030 MB HIGH PRES CENTER FURTHER S AND
INCREASED WINDS FUNNELING ACROSS CHIVELAS PASS UNTO GULF OF 
TEHUANTEPEC.  THESE WINDS ARE EXPECTED TO REACH STORM FORCE 
LATER TONIGHT BEFORE QUICKLY DIMINISHING BACK TO GALE BY EARLY
MORNING. SIMILARLY...WINDS ARE EXPECTED TO INCREASE ACROSS 
MOUNTAIN GAPS IN NICARAGUA RESULTING IN FRESH TO STRONG BREEZE
OVER GULF OF PAPAGAYO AND EXTENDING TO GULF OF FONSECA LATE
IN THE PERIOD. 

ELSEWHERE AT THE UPPER LEVEL...BROAD RIDGE REMAINS ANCHORED OVER
SW CARIBBEAN EXTENDS ACROSS ENTIRE BASIN KEEPING IT DRY WHILE 
ADVECTED MOISTURE FLIES OVER ITS CREST ACROSS SW N ATLC.   

...ELSEWHERE AT THE LOWER LEVELS...
HIGH PRES CENTER 1024 MB AT 34N128W MAINTAINS MODERATE TO FRESH
NE BREEZE ACROSS E PAC N OF ITCZ W OF 120W.  WEAK COLD FRONT 
APPROACHING NW CORNER OF BASIN EXPECTED TO INCREASE SOUTH-
SOUTHEASTERLY WINDS N OF 25N W OF 135W TO A MODERATE BREEZE
TONIGHT AND THU BUT FRONT SWINGS MORE TO THE NE LATE THU PULLING
WINDS AWAY WITH IT.

NE SWELLS LINGER S OF 20N W OF 120W FROM PREVIOUS FRESH TRADES
SUBSIDE THROUGH FORECAST PERIOD WHILE NEW AREA OF MERGING SWELLS
ARISE FROM GULFS OF TEHUANTEPEC AND PAPAGAYO EVENTS DISCUSSED
ABOVE.     

  
$$
WALLY BARNES