000
AXPZ20 KNHC 260958
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SUN SEP 26 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.

...SPECIAL FEATURE...

LATEST SATELLITE IMAGERY SHOWS CONVECTION ASSOCIATED WITH A LOW 
PRES AREA NEAR 15N108W HAS DIMINISHED CONSIDERABLY OVER THE PAST 
SEVERAL HOURS. EAST SHEAR DISPLACING THE REMAINING CONVECTION 
WELL TO THE WEST OF THE EXPOSED CENTER WILL SUBSIDE OVER THE 
NEXT 24 HOURS OVER THE NEARLY STATIONARY CIRCULATION...AS  UPPER 
RIDGING NORTH THE CIRCULATION BREAKS DOWN. IN ADDITION 
CONVECTION ASSOCIATED WITH THE LOW CENTER WILL CONTINUE TO 
PULSE. GIVEN THE EXPECTED REDUCTION IN SHEAR...THIS MAY ALLOW 
THE LOW TO DEEPEN...ALONG WITH INCREASED WINDS ON THE SOUTHERN 
PERIPHERY OF THE LOW. THERE IS A HIGH PROBABILITY OF TROPICAL 
CYCLONE FORMATION WITH THIS SYSTEM OVER THE NEXT 48 HOURS WHILE 
THE LOW PRES REMAINS MAINLY STATIONARY.

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 08N85W TO 09N99W TO 09N112W TO 
12N127W TO 10N140W. NO SIGNIFICANT CONVECTION IS NOTED.

...DISCUSSION...

E OF 115W....
WATER VAPOR IMAGERY SHOWS AN UPPER ANTICYCLONE CENTERED OVER 
CENTRAL MEXICO NEAR 20N99W. EAST WINDS ON THE SOUTH SIDE OF THIS 
RIDGE ARE RESPONSIBLE FOR THE EAST OVER THE CIRCULATION AT 
15N108W AS DESCRIBED ABOVE. AN UPPER TROUGH IS DIGGING THROUGH 
THE SOUTHWEST U.S. INTO NORTHERN MEXICO. GFS AND ECMWF SHOW THE 
TROUGH CUTTING OFF OVER THE GULF OF CALIFORNIA THROUGH THE NEXT 
24 HOURS...ALLOWING THE SHEAR TO DIMINISH OVER THE CIRCULATION. 
THIS ALONG WITH THE WESTWARD MOVEMENT OF THE REMNANTS OF MATTHEW 
THROUGH SOUTHERN MEXICO WILL ENHANCE SW FLOW FROM ROUGHLY 05N TO 
15N...WITH WINDS REACHING AS HIGH AS 25 KT. SEAS WILL BUILD 
ACCORDINGLY REACHING AS HIGH AS 12 FT OFF THE CENTRAL AMERICAN 
COAST BY MID WEEK. EXPECT AN INCREASE IN SHOWERS AND 
THUNDERSTORMS AS WELL OFF THE CENTRAL AMERICAN COAST ALONG THE 
EDGE OF THE SW FLOW.

W OF 115...
TWO WEAK AND QUASI-STATIONARY SURFACE LOW PRES SYSTEMS...BOTH 
ESTIMATED AT 1011 MB...ARE NOTED ALONG THE ITCZ NEAR 11N135W AND 
NEAR 12N123W. AN ASCAT PASS FROM 18Z SHOWED LIGHT TO MODERATE 
WINDS AROUND BOTH OF THESE SYSTEMS. THE WESTERNMOST CENTER IS 
EXPECTED TO DISSIPATE OVER THE NEXT 24 HOURS WHILE THE OTHER LOW 
WILL MOVE SLOWLY NNE AND DEEPEN SLIGHTLY WITH AN ATTENDANT AREA 
OF 20 KT WINDS WITHIN 120 NM ON THE SOUTHERN PERIPHERY OF THE 
LOW. FURTHER SOUTH...TOGA BUOYS AND ASCAT DATA SHOW A SMALL AREA 
OF SE CROSS-EQUATORIAL WINDS REACHING ABOUT 20 KT MAINLY S OF 
05N AND W OF 135W. ELSEWHERE CONVECTION REMAINS ANEMIC DUE A 
LACK OF DEEP LAYER MOISTURE. MEANWHILE A LARGE LONG-PERIOD SWELL 
IS PUSHING INTO THE DISCUSSION AREA FROM THE N CENTRAL ATLANTIC. 
A RECENT JASON ALTIMETER PASS SHOWED SEAS TO 14 FT. WAVEWATCH 
III DEPICTS DECAYING NW SWELL OF 10 TO 12 FT SPREADING INTO THE 
AREA AND REACHING THE BAJA COAST BY LATE TUE.

$$
CHRISTENSEN