000
AXPZ20 KNHC 011602
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
1605 UTC THU JAN 01 2015

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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC. 
 
...SPECIAL FEATURES...                                        
HIGH PRES BUILDING ACROSS SOUTHERN MEXICO HAS TIGHTENED THE 
PRESSURE GRADIENT AND INCREASED THE WINDS THROUGH THE CHIVELA 
PASS INTO THE GULF OF TEHUANTEPEC TO GALE FORCE...WITH WINDS 30-
35 KT AND SEAS 8-12 FT THIS MORNING. THE GALE WILL BE SHORT 
LIVED AND WINDS WILL DECREASE BELOW GALE FORCE THIS 
AFTERNOON...THEN FURTHER DECREASE TO 20 KT LESS BY EARLY FRI. 
LOOKING AHEAD...A STRONG COLD FRONT IN THE GULF OF MEXICO WILL 
USHER ANOTHER ROUND OF GAP WINDS INTO THE GULF OF TEHUANTEPEC BY 
SUNDAY...REACHING GALE FORCE BY LATE SUNDAY.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
THE MONSOON TROUGH EXTENDS FROM 07N78W TO 05N80W TO 06N85W TO 
05N90W WHERE IT TRANSITIONS TO THE ITCZ. THE ITCZ CONTINUES FROM 
05N90W TO 07N110W TO WEST OF 06N140W. SCATTERED MODERATE 
CONVECTION IS NOTED WITHIN 60 NM S OF THE MONSOON AXIS E OF 
80W...AND WITHIN 60 NM N OF THE ITCZ AXIS BETWEEN 100W AND 105W.

...DISCUSSION...                                                 
AN UPPER TROUGH IS MOVING ACROSS THE BAJA CALIFORNIA 
PENINSULA...SUPPORTING A COLD FRONT AT THE SURFACE REACHING FROM 
27N110W ACROSS BAJA CALIFORNIA SUR TO 24N120W THEN AS A 
DISSIPATING COLD FRONT TO 25N125W. RECENT SHIP OBSERVATIONS AND 
AN ASCAT PASS FROM 05 UTC INDICATED MODERATE NORTHERLY FLOW 
BEHIND THE FRONT. A PAIR OF CONCURRENT ALTIMETER SATELLITE 
PASSES INDICATED 8 FT WAVE HEIGHTS LIMITED TO THE WATERS N OF 
27N E OF 130W. AN ELONGATED SURFACE RIDGE EXTENDS FROM FROM HIGH 
PRES CENTERED NEAR 46N133W TO 20N125W. 

FOR THE GULF OF CALIFORNIA...THE COLD FRONT WILL WEAKEN OVER THE 
NEXT 24 TO 36 HOURS ACROSS THE MIDDLE AND SOUTHERN GULF REGIONS. 
HIGH PRES BUILDING EASTWARD BEHIND THE FRONT WILL ALLOW AN AREA 
OF 20 TO 25 KT NW WINDS OVER THE MIDDLE GULF WATERS FROM TONIGHT 
THROUGH EARLY FRI...THEN DIMINISHING THROUGH LATE FRI. SEAS WILL 
REMAIN LESS THAN 8 FT.

FARTHER WEST...ASCAT AND RAPIDSCAT PASSES ALONG WITH SHIP 
OBSERVATIONS SHOWED BROAD AREA OF MODERATE TO FRESH SE FLOW 
BETWEEN THE RIDGE AND DEEPENING LOW PRES N OF HAWAII NEAR 
29155W. WINDS WILL REMAIN 20 KT OR LESS THROUGH THE NEXT 24 TO 
36 HOURS...WITH SEAS OF 8 TO 10 FT PRIMARILY IN SE SWELL 
GRADUALLY SUBSIDING. LOOKING AHEAD...THIS TREND WILL REVERSE 
STARTING LATE FRI AND SAT AS A NEGATIVELY TILTED DEEP LAYER 
TROUGH N OF HAWAII SHIFTS EASTWARD INTO THE RIDGE...SUPPORTING 
FRESH TO STRONG SE FLOW AND BUILDING SEAS OVER THE NW DISCUSSION 
AREA...GENERALLY N OF 20N W OF 135W BY SUNDAY.

THE PERSISTENT TROUGHING N AND NE OF HAWAII HAS WEAKENED THE 
SUBTROPICAL RIDGE AND DISPLACED IT NORTHWARD...RESULTING IN 
GENERALLY MODERATE TO FRESH TRADE WIND FLOW ALONG THE ITCZ.   

GULF OF PAPAGAYO...HIGH PRES N OF THE SW CARIBBEAN ALONG WITH 
LOCAL OVERNIGHT DRAINAGE EFFECTS WILL SUPPORT PULSES OF FRESH TO 
STRONG GAP WINDS THROUGH LATE FRI. LOOKING AHEAD...REINFORCED 
RIDGING TO THE NORTH WILL ALLOW STRONG PULSES TO PERSIST INTO 
EARLY NEXT WEEK.

$$
CHRISTENSEN