000
AXPZ20 KNHC 020955
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC THU SEP 02 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 
0945 UTC.

...SPECIAL FEATURES...

BROAD LOW PRES CONTINUES ABOUT 300 NM S OF THE SOUTHERN TIP OF 
THE BAJA PENINSULA WITH A LOW LEVEL CENTER CURRENTLY ANALYZED AT 
17.5N 107.5W...AND ESTIMATED AT 1005 MB. CONVECTION CONTINUES TO 
FLARE WITHIN ROUGHLY 150 NM OF THE CENTER...AND IS CURRENTLY 
BANDING OVER THE W SEMICIRCLE. CYCLONIC LOW LEVEL WINDS HAVE 
FLUCTUATING BETWEEN 15 AND 25 KT WITHIN ABOUT 240 NM OF THE 
CENTER. MONSOONAL FLOW S OF THIS LOW CONTINUES TO ADVECT 
SOUTHWESTERLY SWELL THROUGH THE LOW DRIVING SEAS TO 11 FT. THE 
UPPER LEVEL ENVIRONMENT IS EXPECTED TO BECOME MORE FAVORABLE AND 
THERE IS A HIGH PROBABILITY OF THIS SYSTEM BECOMING A TROPICAL 
CYCLONE DURING THE NEXT 48 HOURS. 

...ITCZ...

SOUTHWESTERLY MONSOONAL FLOW AT 15 TO 20 KT CONTINUES OVER THE 
TROPICAL E PAC TO THE E OF 110W. SCATTERED MODERATE AND ISOLATED 
STRONG CONVECTION IS NOTED E OF 110W WITHIN ABOUT 180 NM W OF 
THE COAST OF CENTRAL AMERICA. THE ITCZ FORMS NEAR 13N110W...AND 
CONTINUES W ALONG 10N TO BEYOND 11N140W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS OBSERVED WITHIN 30 NM OF THE ITCZ 
AXIS BETWEEN 110W AND 131W. 

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONE IS OVER THE OLD MEXICO AND TEXAS 
BORDER 29N104W WITH A RIDGE EXTENDING W THROUGH ANOTHER SMALL 
UPPER ANTICYCLONE AT 27N122W...WITH A RIDGE CONTINUING SW TO A 
SHARP CREST AT 20N135W. AN UPPER TROUGH IS APPROACHING THE NW 
CORNER OF THE DISCUSSION AREA NEAR 32N142W...BUT APPEARS TO BE  
SOMEWHAT BLOCKED BY THE QUASI STATIONARY UPPER RIDGE. VERY DRY 
UPPER AIR IS INDICATED W OF A LINE FROM 32N105W TO 14N130W. A 
GENTLE RIDGE EXTENDS SE ALONG 30N140W TO 20N120W AT THE LOW 
LEVELS.    

CONVECTION WAS ENHANCED EARLIER OVER OLD MEXICO UNDER THE UPPER 
RIDGE WITH THE REMAINING CONVECTION NOW DISSIPATING OVER THE 
SOUTHERN GULF OF CALIFORNIA. THE RESULTANT DEBRIS MOISTURE IS 
NOW SPREADING SW ACROSS THE SOUTHERN GULF OF CALIFORNIA AND BAJA 
PENINSULA...MERGING WITH DENSE DEBRIS MOISTURE FROM THE 
INTERMITTENT CONVECTION ASSOCIATED WITH THE LOW LEVEL CYCLONE 
THAT MEANDERS ABOUT 300 NM S OF THE BAJA PENINSULA. UPPER LEVEL 
NE FLOW DOMINATES THE TROPICS E OF 120W. UPPER LEVEL DEBRIS 
MOISTURE...FROM THE PREVIOUSLY DESCRIBED CONVECTION ALONG THE 
COAST OF CENTRAL AMERICA...IS ADVECTED SW ACROSS THE REMAINDER 
OF THE DISCUSSION AREA...BUT SEEMS TO EVAPORATE IN THE VICINITY 
OF THE EQUATOR BETWEEN S AMERICA AND 140W.   

$$
NELSON