000
AXPZ20 KNHC 090325
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC TUE SEP 09 2008

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 FEATURES...

TROPICAL STORM LOWELL IS CENTERED NEAR 20.2N 112.5W...OR ABOUT 
120 MILES NW OF SOCORRO ISLAND AND ABOUT 230 MILES SW OF THE 
SOUTHERN TIP OF BAJA CALIFORNIA AT 03 Z. LOWELL IS MOVING NW 
OR 315 DEG AT 5 KT. ESTIMATED MINIMUM CENTRAL PRESSURE IS 997 
MB. MAXIMUM SUSTAINED WINDS ARE 50 KT WITH GUSTS TO 60 KT. DEEP 
CONVECTION HAS INCREASED SLIGHTLY BUT REMAINS DOWNSHEAR W OF THE 
CENTER...DUE TO STRONG UPPER ELY WINDS...FROM 17N TO 21N BETWEEN 
112W AND 117W. WEAKENING IS FORECAST AS LOWELL MOVES TOWARDS 
COOLER WATERS. PLEASE REFER TO THE LATEST NHC PUBLIC ADVISORY 
UNDER AWIPS HEADER MIATCPEP3 OR WMO HEADER WTPZ33 KNHC AND THE 
FULL FORECAST ADVISORY UNDER AWIPS HEADER MIATCMEP3 OR WMO 
HEADER WTPZ23 KNHC FOR MORE DETAILS. 

...ITCZ...

ITCZ AXIS IS CENTERED ALONG 09N79W 07N95W 09N104W 13N115W 
10N130W 09N140W. SCATTERED MODERATE CONVECTION IS WITHIN 150 NM 
S OF THE AXIS BETWEEN 83W AND 88W. SCATTERED MODERATE CONVECTION 
IS ALSO WITHIN 180 NM S OF THE AXIS BETWEEN 120W AND 130W. 

...DISCUSSION...

SUBTROPICS...
AN UPPER TROUGH IS AMPLIFYING OVER THE SOUTHWESTERN CONUS 
PRODUCING A CONSIDERABLE WEAKNESS IN THE SUBTROPICAL RIDGE WHICH 
EXTENDS E-W ALONG 21N/22N. ABUNDANT DRY AIR IS ASSOCIATED WITH 
THESE FEATURES...ESPECIALLY N OF 27N WHERE THE UPPER FLOW IS 
MOST CONFLUENT. GLOBAL MODELS ARE IN GENERAL AGREEMENT IN 
SHOWING THE TROUGH DIGGING FARTHER S CAUSING LOWELL TO MAKE A 
TURN N AND NE...HOWEVER THERE IS QUITE A SPREAD IN MODEL TIMING. 
AT THE SFC...TRADES REMAIN RATHER LIGHT AS THE TIGHTER PRES 
GRADIENT LIES N OF THE AREA OFF THE CALIFORNIA COAST. ASSOCIATED 
NE SWELL IS SPREADING S INTO THE ZONE ELEVATING SEAS TO 9 FT N 
OF 24N W OF 132W.      

TROPICS...
FAIRLY STRONG NE TO E MID TO UPPER FLOW...ON THE S PERIPHERY OF 
SUBTROPICAL RIDGING...COVERS MUCH OF THE TROPICS. WHILE WATER 
VAPOR IMAGERY SHOWS A FAIR AMOUNT OF MOISTURE E OF ABOUT 
120W...DEEP CONVECTION IS MAINLY CONFINED TO TROPICAL STORM 
LOWELL AND A COUPLE PATCHES WITHIN THE ITCZ. CROSS-EQUATORIAL SW 
SWELL IS PRODUCING A LARGE AREA OF 8-11 FT SEAS BETWEEN 92W AND 
130W. THIS SWELL EVENT IS EXPECTED TO SLOWLY SUBSIDE OVER THE 
NEXT FEW DAYS. 

$$
CANGIALOSI