000
AXPZ20 KNHC 021553
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI JUL 02 2010

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. 

BASED ON 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1515 UTC.

...ITCZ...

AXIS ALONG 08N81W TO 07N90W TO 10N96W TO 09N115W TO 07N125W TO 
08N140W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS WITHIN 
240 NM OF THE AXIS BETWEEN 87W AND 98W. SCATTERED MODERATE 
ISOLATED STRONG CONVECTION IS WITHIN 120 NM OF THE AXIS BETWEEN 
98W AND 114W. 

...DISCUSSION...

AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 20N133W 
AND DOMINATES THE NW PORTION OF THE DISCUSSION AREA WITH DRY AND 
AND RELATIVELY STRONG SUBSIDENCE NOTED ON WATER VAPOR IMAGERY 
THIS MORNING. THE DRY AIR ALOFT IS LOCATED W OF A LINE FROM 
FROM THE SOUTHERN BAJA PENINSULA NEAR 24N110W TO 15N120W THEN 
SOUTHWARD TO THE EQUATOR. AN UPPER LEVEL RIDGE AXIS EXTENDS E-NE 
FROM THE CIRCULATION TO 21N120W THEN INTO ANOTHER UPPER LEVEL 
ANTICYCLONIC CIRCULATION IMPACTING MEXICO AND MUCH OF THE 
SOUTHERN U.S. PLAINS. WITH A NEARLY CONTINUOUS UPPER LEVEL RIDGE 
AXIS ROUGHLY ALONG 20N...MOIST EASTERLY UPPER LEVEL FLOW IS S OF 
20N W OF 90W. THIS UPPER LEVEL RIDGE IS FORECAST TO SHIFT NORTH- 
NORTHEASTWARD OVER THE NEXT COUPLE OF DAYS AND LOCATE NEAR 
26N130W BY LATE SUNDAY.

AT THE SURFACE...A STRONG 1036 MB HIGH IS CENTERED WELL NW OF 
THE AREA NEAR 40N153W THAT EXTENDS A RIDGE AXIS SE OVER THE 
FORECAST WATERS ALONG 30N134W TO 18N113W. A WEAK TROUGH IS ALL 
THAT REMAINS AT THE SURFACE OF FORMER CYCLONE CELIA AND IS 
ANALYZED FROM 12N TO 16N ALONG 125W. AN EARLIER MORNING ASCAT 
PASS AROUND 02/0502 DEPICTED THE TROUGH WAS NO LONGER ABLE TO 
SUSTAIN WINDS GREATER THAN 20 KT AND WAVEWATCH III MODEL 
GUIDANCE WAS INDICATING SEAS BELOW 8 FT. A SECOND TROUGH 
ANALYZED FROM 07N TO 14N ALONG 96W CONTINUES TO PERTURB THE ITCZ 
NORTHWARD WITHIN SW SURFACE MONSOONAL FLOW AND AN UPPER LEVEL 
ENVIRONMENT PROVIDING EASTERLY WINDS...MARGINALLY UNFAVORABLE 
FOR STRENGTHENING OVER THE NEXT FEW DAYS. HOWEVER...SCATTERED 
MODERATE AND ISOLATED STRONG CONVECTION IS ASSOCIATED WITH THE 
LOW-LEVEL SURFACE CONVERGENCE AND TROUGH THAT REMAINS IN THE 
VICINITY OF THE ITCZ.   

AN AREA OF NW WINDS REMAIN N OF 26N BETWEEN 115W AND 128W AND 
CONTINUES TO RETREAT NORTHWARD. THE PRESSURE GRADIENT IS ONCE 
AGAIN FORECAST TO INCREASE ALONG THE CALIFORNIA COAST N OF 30N 
OVER THE NEXT 48 HOURS AS THE SURFACE HIGH NORTH OF THE AREA 
DRIFTS EASTWARD. HOWEVER...SEAS REMAIN TO 11 FT OVER THE 
NORTHEAST CORNER OF THE DISCUSSION AREA AND SPREAD SOUTHWARD... 
SUBSIDING OVER THE NEXT 24 TO 36 HOURS AND THEN ARE EXPECTED TO 
MERGE WITH THE NEXT LONG-PERIOD SWELL TRAIN CURRENTLY S OF 10N 
BETWEEN 94W AND 132W WITH SEAS 8 TO 11 FT. THIS SOUTHERN AREA OF 
SWELL IS FORECAST TO SPREAD NORTHWARD THROUGH THE FORECAST 
PERIOD REACHING 23N BY EARLY SUNDAY.

$$
HUFFMAN