000
AXPZ20 KNHC 100326
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU JAN 10 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 IS ALONG 05N77W TO 08N82W TO 07N90W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 07N90W TO 
08N110W TO 09N124W TO 07N140W. SCATTERED MODERATE CONVECTION IS 
WITHIN 120 NM S OF THE ITCZ BETWEEN 120W AND 127W...AND ALSO 
WITHIN 120 NM N OF THE ITCZ BETWEEN 123W AND 128W.

...DISCUSSION...

A DEEP UPPER LOW REMAINS QUASI-STATIONARY NEAR THE BIG BEND OF 
TEXAS WITH AN ATTENDANT UPPER TROUGH STRETCHING FROM THE LOW 
OUTWARD ACROSS THE FAR WESTERN GULF OF MEXICO TO ACROSS CENTRAL 
MEXICO INTO THE NE PACIFIC WATERS NEAR 12N111W. MOISTURE 
CONTINUES TO BE ADVECTED FROM THE TROPICS ALONG THE ITCZ TO THE 
NE AHEAD OF THIS TROUGH ACROSS SOUTHERN MEXICO AND THE CENTRAL 
AND EASTERN GULF OF MEXICO. AN UPPER LEVEL DIRTY RIDGE IS W OF 
THIS TROUGH EXTENDING FROM 32N121W THROUGH 16N122W TO 07N123W. 

MOISTURE IS STREAMING INTO THIS RIDGE AHEAD OF ANOTHER UPPER 
TROUGH WHICH ARCS INTO THE AREA FROM 24N140W TO 16N130W. 
ELSEWHERE ACROSS THE DISCUSSION WATERS MAINLY DRY AND STABLE AIR 
IS PRESENT.

AT THE SURFACE...BROAD RIDGING IS PRESENT OVER THE NW PORTION. 
FRESH TO NEAR GALE FORCE TRADES ARE IN PLACE ACROSS THE W 
CENTRAL WATERS SW OF THE RIDGE AND N OF THE ITCZ...ALONG WITH 
SEAS UP TO 12 FT IN MIXED NE AND NW SWELL. A SURROUNDING AREA OF 
MIXED NE AND NW SWELL OF 8 FT OR GREATER ENCOMPASSES A LARGE 
PORTION OF THE DISCUSSION WATERS W OF 106W.

A VIGOROUS COLD FRONT HAS BREACHED THE NORTHERN DISCUSSION 
WATERS REACHING FROM 30N130W TO 24N140W. FRESH TO NEAR GALE 
FORCE NORTHERLY WINDS WILL CONTINUE TO FOLLOW IN BEHIND THE 
FRONT ALONG WITH LONG PERIOD SEAS UP TO 15-16 FT IN MIXED NE AND 
NW SWELL. NONE OF THE GLOBAL MODELS ARE EXPLICITLY CALLING FOR 
GALE CONDITIONS TO OCCUR BEHIND THE FRONT NOR DO ANY OF THE GFS 
ENSEMBLES. THE FRONT WILL EXTEND FROM 30N114W THROUGH 26N120W TO 
22N130W WHILE WEAKENING BY THU EVENING...DISSIPATING BY FRI 
EVENING AS IT ATTEMPTS TO MOVE ACROSS THE BAJA CALIFORNIA 
PENINSULA. THE FRESH TO STRONG WINDS WILL MERGE WITH THE AREA OF 
TRADES IN THE W CENTRAL WATERS DESCRIBED ABOVE AS THE FRONTAL 
BOUNDARY BECOMES DIFFUSE. WHILE THE NE TRADES SHOULD DIMINISH 
SOMEWHAT ON SAT...THEY ARE LIKELY TO BE AT FRESH TO STRONG 
LEVELS THROUGH THE MIDDLE OF NEXT WEEK.

ALSO...A TIGHT PRES GRADIENT WILL EXIST AHEAD OF THE FRONT IN 
THE FAR NORTHERN GULF OF CALIFORNIA WHERE SOUTHERLY WINDS ARE 
FORECAST TO BE 20-25 KT N OF 29N THU AFTERNOON...VEERING TO THE 
W-NW BEHIND THE FRONT AND INCREASING TO 30 KT LATE THU NIGHT. 
THE NORTHERLY WINDS BEHIND THE FRONT WILL THEN DIMINISH TO 20 KT 
OR LESS BY LATE FRI NIGHT AS THE PRES GRADIENT RELAXES OVER NW 
MEXICO.

GAP WINDS...A GULF OF PAPAGAYO GAP WIND EVENT WILL RE-INITIALIZE 
LATER TONIGHT PERSISTING THROUGH THE END OF THE WEEK. AS IS 
TYPICAL...WINDS AND SEAS WILL BE LOWER DURING THE AFTERNOON AND 
EARLY EVENING HOURS. THE PAPAGAYO GAP WINDS SHOULD CONTINUE 
THROUGH SAT BEFORE DIMINISHING ON SUN.

NO SIGNIFICANT GULF OF TEHAUNTEPEC GAP WIND EVENTS ARE 
ANTICIPATED FOR THE NEXT SEVERAL DAYS.

$$
LEWITSKY