000
AXPZ20 KNHC 251005
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT SEP 25 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 
0900 UTC.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 11N108W TO 09N115W TO 12N125W TO 
08N140W. NO SIGNIFICANT CONVECTION IS NOTED ALONG THE ITCZ.

...DISCUSSION...

A 04Z ASCAT PASS CAPTURED THE WINDFLOW AROUND A WEAK LOW PRES 
AREA CENTERED NEAR 17N106W. THIS FEATURE HAS BEEN UNDERGOING 
SIGNIFICANT EAST SHEAR FOR THE PAST COUPLE OF DAYS...SOUTH OF A 
BROAD MID TO UPPER LEVEL RIDGE. MODERATE TO STRONG CONVECTION IS 
PULSING WITH THIS SYSTEM...BUT IS DISPLACED TO THE WEST OF THE 
LOW LEVEL CENTER. GFS AND ECMWF GUIDANCE SHOWS THE LOW PRES 
REMAINING FAIRLY WEAK OVER THE NEXT COUPLE OF DAYS AS IT 
MEANDERS ABOUT 200 NM S OF THE BAJA PENINSULA. 

A LAND BASED WEATHER OBSERVATION AT SALINA CRUZ MEXICO ON THE 
SOUTH END OF THE ISTHMUS OF TEHUANTEPEC HAS BEEN SHOWING 
NORTHERLY WINDS OF 20 TO 25 KT AHEAD OF TROPICAL STORM 
MATTHEW...CURRENTLY MOVING THROUGH NORTHERN CENTRAL AMERICA 
TOWARD SOUTHERN MEXICO. THE INCREASED NORTHERLY FLOW MAY INDUCE 
THE ONSET OF A LOW PRES IN THE GULF OF TEHUANTEPEC OVER THE NEXT 
SEVERAL HOURS. STRONG CONVECTION IS NOTED IN THIS AREA 
CURRENTLY. IN ADDITION...ASCAT DATA SHOW MODERATE SW FLOW TO THE 
SOUTH. THIS FLOW WILL INCREASE TO 20 TO 25 KT AS MATTHEW MOVES 
FURTHER WEST.  

FURTHER WEST...WEAK LOW PRES 1010 MB IS CENTERED NEAR 11N131W. A 
0540Z ASCAT PASS SHOWED PERSISTENT 20 KT WINDS AROUND THIS LOW. 
A JASON ALTIMETER PASS RIGHT OVER THE LOW YESTERDAY AFTERNOON 
SHOWED SEAS TO ABOUT 8 FT ON THE S SIDE OF THE LOW. THIS LOW 
WILL MEANDER A LITTLE FURTHER TO THE NORTHEAST ALONG THE ITCZ 
OVER THE NEXT COUPLE OF DAYS WITH LITTLE DEVELOPMENT. 

THE WAVEWATCH III MODEL INDICATES LONG PERIOD NW SWELLS DRIVING 
COMBINED SEA HEIGHTS TO 13 FT MOVING INTO THE FAR NW WATERS LATE 
SUN...REACHING THE NORTHERN BAJA PENINSULA MON NIGHT AND TUE.

$$
CHRISTENSEN