000
AXPZ20 KNHC 080325
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC MON SEP 08 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 
0315 UTC.

...SPECIAL FEATURES...

TROPICAL STORM LOWELL IS CENTERED NEAR 17.9N 108.8W W...OR ABOUT 
300 NM S OF THE SOUTHERN TIP OF THE BAJA PENINSULA...MOVING WNW 
OR 295 DEG AT 10 KT. ESTIMATED CENTRAL PRESSURE IS 996 MB. 
MAXIMUM SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT. LOWELL IS A 
HIGHLY ASYMMETRIC STORM...DUE TO STRONG NE/E UPPER LEVEL 
WINDS...WITH NUMEROUS MODERATE TO STRONG CONVECTION NOTED WITHIN 
300 NM OVER THE SW QUADRANT. SCATTERED MODERATE CONVECTION IS 
OBSERVED ELSEWHERE OVER THE WRN SEMICIRCLE FROM 14N TO 19N 
BETWEEN 109W AND 115W. SLOW STRENGTHENING IS FORECAST AS SHEAR 
IS EXPECTED TO LESSEN. 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 ALONG 06N77W 05N86W 10N100W 11N120W 08N140W. 
SCATTERED MODERATE CONVECTION IS WITHIN 180 NM N OF THE AXIS E 
OF 83W. SCATTERED MODERATE CONVECTION IS WITHIN 90 NM OF THE 
AXIS BETWEEN 127W AND 131W.

...DISCUSSION...

SUBTROPICS...
A WELL DEFINED MID TO UPPER RIDGE IS ORIENTED E-W ALONG 21N/22N 
WHILE AN UPPER TROUGH LIES OVER THE SW UNITED STATES TO NEAR 
33N134W. MODELS ARE IN GENERAL AGREEMENT IN SHOWING THE TROUGH 
DEEPENING. THIS WILL WEAKEN THE RIDGE AND CAUSE LOWELL TO 
EVENTUALLY TURN N AND NE OVER THE NEXT FEW TO SEVERAL DAYS. AT 
THE MOMENT...THE COMBINATION OF THESE FEATURES IS PRODUCING  
ABUNDANT DRY STABLE AIR...ESPECIALLY N OF 25N W OF 128W WHERE 
THE UPPER FLOW IS CONFLUENT. AT THE SFC...TRADES ARE GENERALLY 
LIGHT TO MODERATE DUE TO A WEAK TROUGH ALONG 135W. THE ONLY AREA 
OF 15-20 KT WINDS ARE NEAR THE COAST OF BAJA N OF 28N E OF 117W 
...WHERE THE PRESSURE GRADIENT TIGHTENS DUE TO LOW PRES OVER THE 
DESERT SOUTHWEST...BUT EVEN THESE WINDS ARE EXPECTED TO DIMINISH 
SHORTLY. NE SWELL IS PRODUCING SEAS TO 9 FT N OF 20N W OF 129W. 
THIS SWELL TRAIN IS EXPECTED TO SUBSIDE OVER THE NEXT DAY OR TWO 
BEFORE ANOTHER SIMILAR SWELL EVENT ARRIVES.

TROPICS...
MAINLY NE TO E MID TO UPPER FLOW ON THE SOUTHERN PERIPHERY OF A 
SUBTROPICAL RIDGE DOMINATES THE TROPICS. A CONSIDERABLE AMOUNT 
OF MOISTURE IS LOCATED E OF ABOUT 115W BUT DEEP CONVECTION 
REMAINS CONFINED TO TROPICAL STORM LOWELL AND PORTIONS OF THE 
ITCZ. A WEAK SFC TROUGH IS PERTURBING THE ITCZ FROM 12N126W TO 
06N129W...ENHANCING A SMALL AREA OF CONVECTION (OUTLINED IN ITCZ 
SECTION). CROSS-EQUATORIAL S TO SW SWELL IS THE PRIMARY WAVE 
DIRECTION ACROSS THE BULK OF THE AREA E OF ABOUT 
135W...ELEVATING SEAS TO 8-11 FT BETWEEN 92W AND 132W.

$$
CANGIALOSI