000
AXPZ20 KNHC 271540
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC TUE OCT 27 2009

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

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 07N80W TO 
10N91W TO 10N118W TO 12N117W TO 07N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION WITHIN 120 NM EITHER SIDE OF THE AXIS 
BETWEEN 90W AND 100W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION WITHIN 150 NM N OF AXIS BETWEEN 105W AND 110W. 

...DISCUSSION...

A LONGWAVE TROUGH EXTENDS FROM THE WEST CENTRAL U.S. S SE TO 
SOUTH OF BAJA CALIFORNIA. AN UPPER LEVEL RIDGE IS WEST OF THIS 
TROUGH CENTERED NEAR 40N142W. A SHORT WAVE TROUGH IS DIGGING 
SOUTHWARD WEST OF THE TROUGH AXIS. THIS SHORT WAVE TROUGH WILL 
AMPLIFY THE LONGWAVE TROUGH...AND PUSH A SURFACE COLD FRONT 
TOWARD 30N OVER THE EASTERN PACIFIC...INCLUDING THE GULF OF 
CALIFORNIA. A 1036 SURFACE HIGH...CURRENTLY CENTERED NEAR 
44N140W WILL SHIFT SOUTHEAST OVER THE NEXT 24 HOURS. THE 
COMBINATION OF LOW SURFACE PRESSURE OVER THE SOUTHERN GREAT 
PLAINS WITH THE SURFACE HIGH MOVING EASTWARD OVER THE EASTERN 
PACIFIC WILL TIGHTEN THE PRESSURE GRADIENT TO PRODUCE WINDS OF 
25 TO 30 KT W OF 122W AND N OF 22N. THE GFS HINTS AT 35 KT WINDS 
OVER THE FAR NORTHERN WATERS N OF 30N TONIGHT...HOWEVER...THE 
UKMET AND ECMWF INDICATE LOWER WINDS. THUS...WILL NOT INCLUDE 
MENTION OF GALE FORCE WINDS FOR THIS FORECAST PERIOD. 
HOWEVER...GALE FORCE GUSTS WILL BE POSSIBLE. NORTHERLY SURFACE 
WINDS OF 25 TO 30 KT HAVE BEEN REPORTED ALONG THE COASTAL 
STATIONS OF CALIFORNIA. THESE WINDS WILL CONTINUE TO SPREAD 
SOUTHWARD INTO THE GULF OF CALIFORNIA OVER THE NEXT 24 HOURS. 
THIS WILL PRODUCE NEAR GALE FORCE GUSTS OVER THE GULF OF 
CALIFORNIA. A COLD FRONT HAS STALLED OVER THE GULF OF 
MEXICO...HOWEVER...THERE IS THE POTENTIAL FOR SOME NORTHERLY 
WINDS NEAR 20 KT TO SPREAD OVER THE GULF OF TEHUANTEPEC. A 
CYCLONIC GYRE HAS BEEN ANALYZED NEAR 09N102W. CONVECTION 
ASSOCIATED WITH THIS FEATURE REMAINS WELL REMOVED FROM THE 
CENTER. THOUGH THE SYSTEM IS UNORGANIZED AT THIS POINT...MODELS 
INDICATE THE POTENTIAL FOR DEVELOPMENT AS THE LOW DRIFTS NE OVER 
THE NEXT FEW DAYS. SOUTH OF THE LOW CENTER...A QUIKSCAT PASS HAS 
INDICATED SW 20 KT WINDS...AND A JASON ALTIMETER PASS FROM 02Z 
INDICATED SEAS NEAR 8 FEET.  

$$
AL/EC