000
AXPZ20 KNHC 250237
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JUL 25 2010

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 
0130 UTC.

...ITCZ...
AXIS EXTENDS ALONG 09N83W TO 09N86W TO 07N92W THEN BECOMES ILL 
DEFINED. AXIS BEGINS ANEW FROM 15N104W TO 13N129W TO 09N140W. 
SCATTERED MODERATE ISOLATED STRONG CONVECTION WAS NOTED WITHIN 
60 NM N AND 150 NM S OF AXIS FROM 101W TO 122W. SCATTERED 
MODERATE CONVECTION WAS NOTED WITHIN 60 NM OF AXIS W OF 129W.

...DISCUSSION...
MID TO UPPER LEVEL TROUGH PERSISTS ACROSS NW PORTION OF AREA 
FROM NEARLY STATIONARY MID LEVEL VORTEX NEAR 34N130W TO 
26N130W...WITH SOUTHERN PORTION DRIFTING SE UNDER THE INFLUENCE 
OF UPSTREAM RIDGE EDGING SLOWLY EWD. A TUTT AXIS THEN CONTINUED 
FROM THE S END OF THE TROUGH...EXTENDING SW TO A WWD MOVING MID 
TO UPPER LEVEL VORTEX NEAR 18N149W. A BLOCKING RIDGE REMAINED TO 
THE E OF THIS TROUGH...ANCHORED ON AN UPPER LEVEL ANTICYCLONE 
NEAR 26N117W AND EXTENDING W-NW INTO NW MEXICO...AND SW TO 
17N138W. DRY AND STABLE CONDITIONS PERSIST UNDER THE RIDGE AND E 
OF THE TROUGH UNDER MODERATE TO STRONG SUBSIDENCE EVIDENT N OF 
20N W OF 120W. THE VORTEX ASSOCIATED WITH THE UPPER TROUGH WILL 
LIFT OUT SLOWLY TO THE NE OVER THE NEXT 48 HOURS CAUSING THE 
RIDGE TO ELONGATE NE TO SW.

S AND SE OF THE RIDGE...UPPER LEVEL EASTERLIES PREVAILED S OF 
20N EXTENDING FROM CENTRAL AMERICA W TO 128W WHERE WINDS TURNED 
SE TO S. AMPLE CONVECTION OVER THE S HALF OF MEXICO AND ABUNDANT 
MOISTURE ASSOCIATED WITH A PERSISTENT LOW LEVEL CYCLONIC GYRE 
WERE PROVIDING MID TO UPPER LEVEL MOISTURE THAT WAS BEING 
TRANSPORTED WWD ACROSS THE TROPICS BY THESE UPPER LEVEL 
EASTERLIES. ALTHOUGH THIS SHEARED ENVIRONMENT WOULD APPEAR 
CONDUCIVE FOR ACTIVE CONVECTION...LOW LEVEL MOISTURE AND 
CONVERGENCE ACROSS THE EPAC TROPICS WAS CONFINED PRIMARILY TO 
THE ITCZ...WHERE ACTIVE CONVECTION WAS BEING FORCED BY SW WINDS 
OF 20KT ON S SIDE OF ITCZ TROUGH...BETWEEN 101W AND 122W.

ELSEWHERE AT THE SURFACE...LARGE HIGH PRES CENTER 1026 MB WELL N 
OF AREA EXTENDS TO A SECOND HIGH PRES CENTER 1019 MB AT 25N134W. 
A VERY WEAK TROUGH TRAPPED BETWEEN RIDGES WILL MAINTAIN FRESH NW 
BREEZE PERSIST WITHIN 90 NM OF W COAST OF BAJA CALIFORNIA FROM 
24N-28N AS HIGH PRES DRIFTS E-SE. TIGHTENING PRES GRADIENT MAY 
PRODUCE FRESH SOUTHERLY WINDS INSIDE GULF OF CALIFORNIA BY 24  
HOURS AND BEYOND. 

CROSS EQUATORIAL SOUTHWESTERLY SWELL REACHING TO 8 FT WITH 
PERIODS OF 13-15 SECONDS WILL FADE THIS EVENING AS SRN HEMI WIND 
SWELL BEGINS TO DOMINATE THE REGIONAL WATERS THROUGH 48 
HOURS...MAINTAINING SEAS NEAR 8 FT AND GREATER S OF 10N. 

$$
STRIPLING