000
AXPZ20 KNHC 250332
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE DEC 25 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...THE MONSOON 
TROUGH 06N78W TO 08N85W TO 06N94W. ITCZ 06N94W TO 08N120W TO 
06N140W. SCATTERED MODERATE CONVECTION FROM 08N TO 11N BETWEEN 
120W AND 125W. SCATTERED MODERATE CONVECTION WITHIN 60 NM N OF 
ITCZ W OF 135W.

...DISCUSSION...

A WEAKENING COLD FRONT EXTENDS THROUGH THE COAST OF SOUTHERN 
CALIFORNIA...POISED TO MOVE SOUTHWARD INTO THE WATERS OFF 
NORTHERN BAJA. THE SUPPORTING UPPER TROUGH IS ALREADY EXITING 
THROUGH THE SOUTHERN ROCKIES...AND THE SURFACE FRONT WILL START 
TO DISSIPATE THIS EVENING. THE MAIN SENSIBLE WEATHER IMPACT WILL 
BE A BRIEF PERIOD OF NW WINDS FROM 20 TO 25 KT N OF 24N OFF THE 
COAST OF BAJA...ON THE EASTERN EDGE OF A 1026 MB SURFACE HIGH 
CENTERED NEAR 28N135W...CURRENTLY SHIFTING WEST TO 28N140W 
THROUGH 24 HOURS. ASCAT DATA FROM 1645 UTC AND 1830 UTC ARE 
SHOWING FRESH TO STRONG TRADES S OF THE SURFACE HIGH PRES...FROM 
ROUGHLY 07N TO 20N W OF 120W. JASON ALTIMETRY DATA FROM THE PAST 
12 HOURS CONFIRM GLOBAL WAVE MODEL INITIALIZATIONS SHOWING A 
BROAD AREA OF SEAS FROM 8 TO 12 FT...MAINLY IN NW SWELL...W OF 
110W. AN UPPER TROUGH FROM 27N125W TO 11N135W IS ENHANCING 
MODEST CONVECTION FROM 09N TO 12N BETWEEN 120W AND 125W.

THROUGH MIDWEEK...ANOTHER UPPER TROUGH WILL MIGRATE EASTWARD 
TOWARD THE CALIFORNIA COAST N OF 30N TUE AND WED...WITH A THIRD 
IMPULSE DIGGING OVER THE WATERS N OF 20N W OF 120W THROUGH LATE 
WED...SUPPORTING ANOTHER COLD FRONT INTRUSION S OF 30N TUE 
THROUGH WED N OF 25N. THE RIDGE ALONG 28N BREAKS DOWN...TO BE 
REPLACED WITH A STRONGER RIDGE BUILDING N OF AREA BEHIND THE 
SECOND FRONT. THIS WILL REINVIGORATE TRADE WIND FLOW S OF 20N 
AFTER WED. GLOBAL WAVE MODELS ALSO INDICATE A NEW GROUP OF NW 
SWELL PUSHING INTO THE AREA FOLLOWING THE FRONT.

FOR THE GULF OF PAPAGAYO...GAP WIND FLOW WILL PERSIST THROUGH 
THE NEXT 21 HOURS...THEN DIMINISH AS WINDS OVER THE SW CARIBBEAN 
WEAKEN AND AFTER THE EARLY MORNING DIURNAL MAXIMUM OF DRAINAGE 
WINDS. 

GULF OF TEHUANTEPEC...A COLD FRONT WILL PUSH THROUGH THE GULF OF 
MEXICO...DELIVERING A SURGE OF COLDER AND DRIER AIR DOWN THE 
COAST OF MEXICO TOWARD THE ISTHMUS OF TEHUANTEPEC LATE WED...AND 
INTO THE GULF OF TEHUANTEPEC STARTING LATE WED INTO EARLY THU. 
WITH THE EXCEPTION OF THE NOGAPS...GLOBAL MODELS INDICATE A 
BRIEF 30 TO 35 KT EVENT THAT IS OVER BY EARLY THU. A GALE 
WARNING HAS BEEN ISSUED ACCORDINGLY FOR THE GULF OF TEHUANTEPEC 
STARTING 27/00 UTC. 

$$
CHRISTENSEN