000
AXPZ20 KNHC 090951
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JUL 09 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 
0915 UTC.

...ITCZ...
AXIS EXTENDS FROM 08N78W TO 06N85W TO 11N100W TO 07N114W TO 
10N124W TO 07N140W.  ISOLATED MODERATE CONVECTION WITHIN 60 NM 
OF AXIS FROM 86W TO 102W AND WITHIN 75 NM OF 09N125W.
 
...DISCUSSION...
UPPER LEVEL ANTICYCLONE AT 30N113W WITH RIDGE EXTENDING SW TO  
BEYOND 26N140W MAINTAIN A VERY DRY AIR MASS ALOFT W OF 110W.  
WEAK UPPER LEVEL TROUGH EXTENDS FROM 20112W TO A NOT WELL 
DEFINED CYCLONE AT 09N103W.  DYNAMIC MODELS SOLUTIONS OFFER 
LITTLE CHANGE IN CONDITIONS FOR NEXT 48 HRS.  ONLY INCREASING 
PARAMETER IS MOISTURE SPREADING WESTWARD FROM MEXICO AND YUCATAN 
WITH SCATTERED CONVECTION OVER MAINLAND MEXICO IS ENHANCED BY 
THERMAL SURFACE TROUGH ALONG MOUNTAIN RANGE.  ELSEWHERE...THE 
LACK OF SURFACE UPLIFT MAKES IT HARD FOR ANY SERIOUS DEEP 
CONVECTION TO GET INITIATED UNDER SUCH ADVERSE CONDITIONS.

AT THE SURFACE...
BROAD SURFACE RIDGE WELL NW OF E PAC HAS RIDGE EXTEND TO 
15N115W.  TIGHT PRES GRADIENT KEEP FRESH NW BREEZE ALONG BAJA 
CALIFORNIA W COAST...BUT WEAKENING OF RIDGE DIMINISHES WINDS 
BELOW 20 KT WITHIN NEXT 6-12 HRS.

FRESH SOUTHERLY BREEZE S OF 10N WEAKEN DURING NEXT TWO DAYS WITH 
LINGERING CROSS EQUATORIAL S SWELL TO 9 FT THROUGH SUN.

$$
WALLY BARNES