000
AXPZ20 KNHC 160958
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT JAN 16 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0930 UTC.

...ITCZ...
AXIS IS ALONG 04N78W TO 03N85W TO 09N105W TO 06N120W TO 04N140W. 
SCATTERED MODERATE WITHIN 90 NM N OF AXIS BETWEEN 120W AND 130W. 

...DISCUSSION...

LARGE SPRAWLING UPPER LEVEL ANTICYCLONE OVER THE HAWAIIAN 
ISLANDS EXTENDS EASTWARD INTO THE DISCUSSION AREA N OF 20N W OF 
135W. A SHARP MID TO UPPER LEVEL TROUGH EXTENDS FROM  WELL 
DEFINED CYCLONIC CIRCULATION NEAR 34N124W THROUGH 32N124W 
21N135W THROUGH 18N140W. AXIS OF SUBTROPICAL JET WITH CORE 
SPEEDS OF 100-130 KT WAS LOCATED JUST SE OF THE TROUGH AXIS AND 
WAS ADVECTING A PLUME OF MID TO UPPER LEVEL MOISTURE NE TOWARD 
CALIFORNIA...ARIZONA AND BAJA CALIFORNIA. 

THE UPPER TROUGH WAS PROVIDING SOME SUPPORT FOR A COLD FRONT 
WHICH EXTENDED FROM 32N128 TO 23N140W. THE FRONT APPEARED TO BE 
WEAKENING OVER TIME WITH AN AREA OF 20 KT WINDS E OF THE FRONT 
GRADUALLY LIFTING N OF THE AREA. 

ELSEWHERE AT THE SURFACE...A WEAK AREA OF HIGH PRESSURE OVER THE 
NE PACIFIC WAS IN THE PROCESS OF DISSIPATING IN THE FACE OF THE 
APPROACHING COLD FRONT NOTED ABOVE. A 0558 UTC ASCAT PASS 
INDICATED NORTHEASTERLY TRADES OF 20 TO 25 KT S OF THE HIGH 
PRESSURE AND ASSOCIATED RIDGE...GENERALLY FROM 8N TO 15N WEST OF 
120W. THESE WINDS SHOULD GRADUALLY WEAKEN SOMEWHAT DURING THE 
NEXT FEW DAYS AS MAIN FOCUS SHIFTS FURTHER NORTH WITH A SERIES 
OF GALE CENTERS PASSING N OF THE AREA. LONG PERIOD...20-22 
SECOND...NW SWELL IS FORECAST TO MOVE INTO THE FAR NW PORTION OF 
THE AREA SUN NIGHT INTO MON AND SPREAD SE.

ELSEWHERE OVER THE AREA...A 0422 UTC ASCAT PASS INDICATED 
NORTHWESTERLY WINDS OF 20 KT IN THE GULF OF CALIFORNIA N OF 25N. 
THESE WINDS ARE FORECAST TO DROP BELOW 20 KT LATER TODAY. 

GAP WINDS...
A PAPAGAYO WIND EVENT IS ONGOING WEST OF NICARAGUA. SEVERAL
NWP MODELS SUGGEST THAT THE WINDS WILL REACH 20 KT FOR THE HIGH 
SEAS FORECAST LATE NIGHT AND EARLY MORNING DURING THE NEXT FEW 
DAYS. 

THE MAIN SIGNIFICANT FEATURE IN THE FORECAST IS THE DEVELOPMENT 
OF A TEHUANTEPEC GAP WIND EVENT. THE GFS IS MORE AGGRESSIVE WITH 
ONSET LATE THIS AFTERNOON AND TONIGHT PEAKING AROUND 25 TO 30  
KT EARLY SUN...THEN WEAKENING BY LATE MON.

FOR ADDITIONAL INFORMATION PLEASE VISIT 
HTTP://WWW.HURRICANES.GOV/MARINE

$$
COBB