000
AXPZ20 KNHC 260344
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN SEP 26 2010

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

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURE...

VISIBLE SATELLITE IMAGERY INDICATES THE LOW PRESSURE AREA NEAR 
15N108W HAS A POORLY ORGANIZED DIFFUSE LOW LEVEL CIRCULATION. 
DEEP CONVECTION CONTINUES TO CYCLE W OF THE LOW LEVEL CENTER THEN
DISSIPATE UNDER MODERATE ELY SHEAR. ASCAT PASS DIRECTLY OVER THE 
LOW 24 HOURS AGO SHOWED WINDS LESS THAN 20 KT...BUT A 1632 UTC 
PASS INDICATED WINDS WERE 20 TO 25 KT WITHIN 120-150 NM OF THE 
LOW. THERE IS A HIGH PROBABILITY OF TROPICAL CYCLONE FORMATION 
WITH THIS SYSTEM OVER THE NEXT 48 HOURS AS IT REMAINS NEARLY 
STATIONARY.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 08N85W TO 09N99W TO 09N117W TO 
12N128W TO 12N135W. SCATTERED MODERATE CONVECTION WITHIN 120 NM 
OF AXIS BETWEEN 87W AND 104W.

...DISCUSSION...

AN EXPANSIVE RIDGE DOMINATING MOST OF THE DISCUSSION AREA IS 
ANCHORED BY AN ANTICYCLONE CENTERED NEAR 28N119W. ANOTHER 
ANTICYCLONE LOCATED OVER SOUTHERN MEXICO IS PROVIDING EXCELLENT 
OUTFLOW IN ALL DIRECTIONS FROM TROPICAL DEPRESSION MATTHEW OVER 
LAND IN CENTRAL AMERICA. A BROAD SWATH OF MODERATE TO STRONG ELY 
WINDS WERE NOTED S OF THE RIDGE AXIS. THESE WINDS WERE ADVECTING 
TROPICAL MOISTURE WESTWARD TO ALONG 125W. VIGOROUS MID-LATITUDE 
TROUGHS ARE SWEEPING THROUGH THE CENTRAL PACIFIC AS THE FALL 
TRANSITION SEASON ARRIVES WITH A VENGEANCE. 

SURFACE OBS FROM SALINA CRUZ MEXICO LOCATED ON THE SOUTH END OF 
THE ISTHMUS OF TEHUANTEPEC CONTINUE TO SHOW N WINDS AROUND 20 KT 
AS TROPICAL DEPRESSION MATTHEW MOVES FURTHER W. 1454 AND 1634 
UTC ASCAT PASSES SHOWED SW WINDS OF 15 TO 20 KT WELL SOUTH OF 
TEHUANTEPEC. SW WINDS WILL INCREASE TO OVER 20 KT LATER TODAY AS 
THE REMNANT LOW OF MATTHEW MOVES FURTHER INTO CENTRAL AMERICA. 
SEAS TO 10 FEET ARE LIKELY S OF COSTA RICA.

FURTHER WEST...WEAK LOW PRES 1011 MB IS CENTERED NEAR 12N135W. 
THIS LOW WILL MOVE SLOWLY NORTHEAST ALONG THE ITCZ AND STEADILY 
WEAKEN OVER THE NEXT COUPLE OF DAYS. 

THE WAVEWATCH III MODEL INDICATES LONG PERIOD NW SWELLS ARRIVING 
LATER TODAY IN FAR NW WATERS. COMBINED SEAS EXPECTED TO BUILD 
QUICKLY TO 13 FT BEHIND LEADING EDGE OF SWELL TRAIN. SWELLS WILL 
DAMPEN WITH TIME BUT ARE EXPECTED TO REACH THE NORTHERN BAJA 
PENINSULA TUE...JUST AS A NEW SWELL TRAIN ARRIVES IN THE NW 
CORNER OF THE AREA. 

$$
MUNDELL