000
AXPZ20 KNHC 142145
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC MON DEC 14 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...
THE ITCZ AXIS IS ALONG 06N77W TO 05N100W TO 06N120W TO 05N140W. 
SCATTERED MODERATE CONVECTION IS NEAR 07N102W AND FROM 06N TO 
09N BETWEEN 120W AND 135W. 

...DISCUSSION...
A MID TO UPPER LEVEL TROUGH EXTENDS FROM THE NORTHERN BAJA 
PENINSULA SW TO NEAR 15N125W. A JET STREAM BRANCH WITH CORE 
WINDS OF 70-90 KT ROUNDS THE BASE OF THE TROUGH TURNING NE 
ACROSS THE SOUTHERN BAJA CALIFORNIA PENINSULA AND NW MEXICO INTO 
TEXAS. TO THE W OF THE TROUGH...A RIDGE DOMINATES THE W PORTION 
OF THE AREA...PARTICULARLY N OF THE ITCZ AND W OF 130W.  

AT THE SURFACE...A 1023 MB HIGH PRES AREA IS CENTERED N OF AREA 
NEAR 32N123W. ASCAT...WINDSAT AND SHIP OBSERVATIONS INDICATE A 
BROAD AREA OF FRESH TO STRONG TRADE WINDS ON THE SOUTHERN 
PERIPHERY OF THE SURFACE HIGH PRES...MAINLY FROM 08N TO 18N W OF 
115W. SHIP OBSERVATIONS ALSO INDICATE 20 KT WINDS BETWEEN THE 
HIGH PRES AND THE BAJA PENINSULA COAST. THE MID TO UPPER LEVEL 
TROUGH WILL DIG INTO NORTH CENTRAL MEXICO AS THE RIDGE SHIFTS 
EAST AND BUILDS OVER NORTHERN BAJA...AHEAD OF A BROAD UPPER 
TROUGH DIGGING OVER THE N CENTRAL PACIFIC. THE SURFACE HIGH PRES 
WILL STRENGTHEN AS THE UPPER RIDGE BUILDS ACROSS THE 
REGION...MAINTAINING THE FRESH TO STRONG TRADES THROUGH MIDWEEK. 
A COLD FRONT WILL ENTER THE FAR NW PORTION OF THE DISCUSSION 
AREA TONIGHT...EXTENDING FROM 30N137W TO 27N140W TUE EVENING 
THEN WILL DISSIPATE.

MEANWHILE 8 TO 10 FT NW SWELL WITH PERIODS TO 11 SECOND IS 
MOVING INTO THE WATERS N OF 20N. ANOTHER SET OF NW SWELL WILL 
MOVE INTO THE DISCUSSION AREA TONIGHT...COVERING AN AREA NW OF A 
LINE FROM 30N130W TO 25N140W BY MIDDAY TUE.

SURFACE HIGH PRES WILL ALSO BUILD OVER THE GREAT BASIN AS THE 
UPPER RIDGE MOVES INTO THE ROCKIES...CAUSING WINDS TO INCREASE 
THROUGH THE GULF OF CALIFORNIA STARTING TONIGHT. WINDS TO NEAR 
GALE FORCE ARE POSSIBLE OVER THE NORTHERN PORTIONS OF THE GULF 
OF CALIFORNIA BY TUESDAY. 

AN EARLIER ASCAT PASS INDICATED FRESH TO STRONG GAP WIND FLOW 
PERSISTING THROUGH THE GULF OF TEHUANTEPEC. THESE WINDS ARE 
LIKELY THE RESULT OF DRAINAGE FLOW DUE TO COOL AND DRY 
CONDITIONS OVER THE LAND. THIS IS ALSO THE CONTRIBUTING TO FRESH 
TO STRONG THROUGH THE GULF OF PAPAGAYO FURTHER SOUTH...WHERE 
MORNING DRAINAGE FLOW OVER THE MOUNTAINS OF COSTA RICA IS 
PUSHING FRESH TRADE WINDS OFF THE CARIBBEAN INTO THE GULF OF 
PAPAGAYO. THESE WINDS WILL PERSIST THROUGH MIDWEEK...WHILE WINDS 
THROUGH TEHUANTEPEC ARE EXPECTED TO DIMINISH TONIGHT. HOWEVER... 
AS A COLD FRONT PUSHES INTO THE SW GULF WED...A NEW ROUND OF 
STRONG GAP WINDS IS EXPECTED ACROSS THE GULF OF TEHUANTEPEC   
WED INTO THU.

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