000
AXPZ20 KNHC 100329
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC SAT JAN 10 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC. 

...SPECIAL FEATURES...

GULF OF TEHUANTEPEC GALE WARNING...THE PRESSURE GRADIENT BETWEEN 
STRONG RIDGING EXTENDING S FROM THE NE COAST OF MEXICO TOWARD 
THE ISTHMUS OF TEHUANTEPEC AND TROUGHING TO THE S ALONG THE ITCZ 
IS STILL SUPPORTING 35 KT GALE FORCE WINDS IN THE GULF OF 
TEHUANTEPEC DURING THE OVERNIGHT AND EARLY MORNING HOURS. AN 
EARLIER ASCAT PASS CONFIRMED THE PRESENCE OF THESE WINDS. THE 
RIDGE IS FORECAST TO WEAKEN...BUT MINIMAL GALE FORCE WINDS WILL 
CONTINUE TO PULSE ACROSS THE GULF OF TEHUANTEPEC TONIGHT INTO 
SAT MORNING...THEN AGAIN SAT NIGHT INTO SUN MORNING. SEAS ARE 
EXPECTED TO GRADUALLY SUBSIDE TO 9-12 FT TONIGHT...AND TO 8-11 
FT SAT NIGHT. 

NE SWELL FROM BOTH THE GULFS OF PAPAGAYO AND TEHUANTEPEC 
CONTINUES TO PRODUCE A VERY LARGE AREA OF SEAS 8 FT OR GREATER 
THAT EXTENDS S AND SW TO NEAR 120W. THIS AREA OF SEAS PRIMARILY 
ATTRIBUTED TO NE SWELL WILL SHRINK EASTWARD AS THE WINDS IN THE 
GAPS GENERALLY DIMINISH. NW SWELL WILL CONTINUE TO PROPAGATE SE 
ACROSS THE WATERS W OF 120W. THESE TWO SWELL EVENTS WILL MERGE 
LATE SAT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
             
THE MONSOON TROUGH EXTENDS FROM THE COAST OF COLOMBIA NEAR 
05N77W TO 03N80W TO 05N90W. THE ITCZ AXIS CONTINUES FROM 05N90W 
TO 04N110W TO 06N130W TO 07N140W. A SMALL CLUSTER OF MODERATE 
CONVECTION IS NEAR 2.5N81W. SCATTERED MODERATE CONVECTION IS 
NOTED FROM 06N TO 08N BETWEEN 112W AND 120W...AND FROM 09N TO 
10N BETWEEN 120W AND 124W. 
 
...DISCUSSION...                                                 

A COLD FRONT EXTENDS FROM 30N122W TO 22N127W THEN CONTINUES AS A 
STATIONARY FRONT TO NEAR 19N140W. A 1024 MB HIGH PRES LOCATED NW 
OF THE AREA NEAR 33N139W FOLLOWS THE FRONT. THE PRES GRADIENT 
BETWEEN THIS HIGH AND LOWER PRES IN THE VICINITY OF THE ITCZ IS 
RESULTING IN AN AREA OF FRESH TO LOCALLY STRONG TRADE WINDS 
ROUGHLY FROM 09N TO 13N W OF 128W. THESE WINDS WERE SAMPLED BY 
RECENT SCATTEROMETER DATA. THE AERIAL EXTENT OF THE TRADES WILL 
DECREASE LATE SAT AS HIGH PRES SLIGHTLY WEAKENS. ANOTHER WEAK 
HIGH PRES OF 1018 MB SITUATED NEAR 24N118W DOMINATES THE NE PART 
OF THE FORECAST REGION AND IS FORECAST TO DISSIPATE IN ABOUT 24 
HOURS. THE COLD FRONT WILL GRADUALLY WEAKEN AS IT CONTINUES TO 
MOVES EASTWARD. THE MAIN IMPACT OF THE FRONT IS NW SWELL...WITH 
PERIODS IN THE 19-20 SECOND RANGE...CURRENTLY REACHING THE 
REVILLAGIGEDO ISLANDS. THIS SWELL EVENT IS BUILDING SEAS UP TO 
11 FT W OF 120W THIS EVENING...WITH THE HIGHEST SEAS IN THE AREA 
OF THE TRADES.  

FRESH TO LOCALLY STRONG N WINDS ARE FUNNELING INTO THE GULF OF 
PANAMA FROM THE CARIBBEAN. WINDS WILL PULSE TO 25 KT DURING THE 
LATE NIGHT AND EARLY MORNING HOURS THROUGH SUN MORNING AND 
DIMINISH TO 20 KT OR LESS DURING THE AFTERNOON AND EVENING 
HOURS. 

MINIMAL GALE CONDITIONS WERE IN PLACE ACROSS THE GULF OF 
PAPAGAYO FRI MORNING. GAP WINDS WILL PERSIST ACROSS THIS GULF AS 
STRONG TRADE WIND FLOW IN THE SW CARIBBEAN FUNNELS THROUGH THE 
GAP. THE WINDS ARE GREATEST DURING THE OVERNIGHT AND EARLY 
MORNING HOURS WITH THE AID OF THE DRAINAGE FLOW. WINDS WILL 
PULSE TO 30 KT SAT MORNING AND TO 25 KT SUN MORNING AS THE 
PRESSURE GRADIENT BEGINS TO WEAKEN ACROSS THE REGION.

$$ 
GR