000
AXPZ20 KNHC 120925
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED SEP 12 2012

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...
BROAD AREA OF LOW PRESSURE CENTERED NEAR 16N105W MOVING W-NW AT 
ABOUT 10 KT IS EMBEDDED ALONG THE MONSOON TROUGH. WINDS TO 25 KT 
ARE IN THE NE SEMICIRCLE OF THE LOW. NUMEROUS STRONG CONVECTION 
IS WITHIN 300 NM NW OF THE LOW. SCATTERED MODERATE TO STRONG 
CONVECTION WITH 180 NM NE OF THE LOW. ENVIRONMENTAL CONDITIONS 
ARE CONDUCIVE FOR TROPICAL FORMATION TODAY OR THU. THE 
DISTURBANCE IS EXPECTED TO INTENSIFY AS IT MOVES NORTHWEST 
OFFSHORE OF THE MEXICAN COAST.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH FROM 10N85W TO 8N90W 10N100W THEN FROM 16N110W TO 
8N135W. ITCZ FROM 8N135W TO 08N140. SCATTERED MODERATE ISOLATED 
STRONG CONVECTION WITHIN 150 NM N AND 70 NM S OF AXIS FROM 
113W-117W AND WITHIN 30 NM EITHER SIDE OF AXIS FROM 123W-126W.

...DISCUSSION...
UPPER LEVEL TROUGH OVER THE W PORTION OF THE DISCUSSION AREA 
FROM 27N131W TO 15N115W. UPPER LEVEL RIDGE EXTENDS FROM 25N120W 
TO 32N123W. STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE 
AND UPPER LEVELS IS ACROSS THE AREA N OF 20N W OF 110W. A LARGE 
UPPER LEVEL ANTICYCLONIC CIRCULATION CENTERED OFF THE W COAST OF 
MEXICO NEAR 17N103W. THE ANTICYCLONE IS OVER THE DEVELOPING LOW 
DESCRIBED ABOVE AND IS PROVIDING GOOD OUTFLOW FOR THE STRONG 
CONVECTION ASSOCIATED WITH THE LOW.

SURFACE HIGH PRES RIDGE IS N OF 18N W OF 120W. THE TRADES ARE 
LESS THEN 20 KT...HOWEVER THE PRES GRADIENT IS EXPECTED TO 
TIGHTEN SOME THU AND THE ELY WINDS ARE FORECAST TO ONCE AGAIN 
INCREASE TO 20 KT.

$$
DGS