000
AXPZ20 KNHC 251621 CCA
TWDEP 

TROPICAL WEATHER DISCUSSION...CORRECTED   
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU JUN 25 2009

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 
1600 UTC.

...ITCZ...

THE ITCZ AXIS IS ALONG 7N78W 7N90W 11N105W 11N120W 7N130W 
6N140W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS WITHIN
180 NM S OF THE AXIS BETWEEN 97W-99W. SCATTERED MODERATE 
CONVECTION IS WITHIN 120 NM S OF THE AXIS BETWEEN 
119W-125W...AND WITHIN 60 NM S OF THE AXIS BETWEEN 129W-138W.

...DISCUSSION...

A CUT-OFF LOW HAS FORMED JUST N OF THE AREA NEAR 34N123W WITH A 
TROUGH EXTENDING S TO 17N123W TO 21N123W. THIS FEATURE HAS
FORMED OFF A DEEP LAYER TROUGH THAT EXTENDS FROM THE PACIFIC
NW SSW TO THE LOW. THE LOW IS FORECAST TO MOVE NE REACHING SRN
CALIFORNIA TONIGHT WHILE A RIDGE BUILDS WWD ACROSS THE FORECAST 
AREA ANCHORED BY AN UPPER LEVEL ANTICYCLONE NEAR 18N135W. 
MODERATE SUBSIDENCE MAINTAINING VASTLY STABLE ENVIRONMENTAL 
CONDITIONS IS PRESENT NW OF A LINE FROM CENTRAL BAJA CALIFORNIA 
SW TO 17N120W TO 10N132W. AT THE SURFACE...A RIDGE ENTERS THE 
AREA THROUGH 32N139W...AND EXTENDS SE TO 27N132W TO NEAR 
23N122W. HIGH PRES COVERS THE AREA N OF 20N W OF 115W. THE PRES 
GRADIENT BETWEEN THE RIDGE AND LOW PRES ASSOCIATED WITH THE ITCZ 
IS RESULTING IN NE TRADE WINDS OF 20 KT FROM 15N-26N W OF 132W. 
THESE TRADES ARE FORECAST TO SHIFT TO N OF 24N W OF 128W IN 
ABOUT 48 HOURS AS THE SUPPORTING HIGH CENTER NW OF THE AREA 
MOVES N...BUT A STRONG GRADIENT N OF THE AREA NEAR THE U.S. W 
COAST WILL FUNNEL NW-N WINDS OF 20 KT IN THE NRN PORTION OF THE 
AREA N OF 27N BETWEEN 121-131W OVER THE NEXT 48 HOURS. THE 
REMNANTS OF FORMER TROPICAL CYCLONE ANDRES...IS ANALYZED AS A 
TROUGH OVER FAR SRN BAJA CALIFORNIA S TO NEAR 18N108W...BUT 
SHOULD DISSIPATE OVER THE NEXT 12-18 HOURS.

OVER THE SRN PORTION OF THE AREA...A 1010 MB LOW PRES REMAINS 
EMBEDDED IN THE ITCZ NEAR 11N121W MOVING NE NEAR 7 KT. ONLY 
ISOLATED WEAK CONVECTION IS WITHIN 60 NM SE OF THE LOW. A 
QUIKSCAT PASS FROM 1400 UTC THIS MORNING SHOWED THE ITCZ 
EXTENDING FROM THE LOW ENE TO 14N110W. GLOBAL MODELS SUGGEST 
THAT THE LOW WILL WEAKEN IN ABOUT 30-48 HOURS. 

SCATTEROMETER DATA FROM THIS MORNING PICKED UP ON A WEAK LOW 
CENTER ALONG THE ITCZ NEAR 7N91W. S-SW WINDS OF 15-20 KT ARE
INDICATED S OF THE ITCZ BETWEEN 94W-100W WHERE SEAS TO 8 FT
IN S SWELL ARE ALSO OCCURRING. SMALL CLUSTERS OF WIDELY SCATTERED
MODERATE CONVECTION ARE NOTED OVER MUCH OF THE FAR ERN PART 
OF THE AREA N OF THE ITCZ E OF 103W. AN ABUNDANCE OF UPPER LEVEL
MOSITURE ORIGINATING FROM ITCZ CONVECTION AS WELL AS FROM 
CONVECTION EARLIER OVER THE INTERIOR OF MEXICO AND CENTRAL 
AMERICA IS SLOWLY SPREADING WSW UNDER STRONG UPPER LEVEL NE 
WINDS GENERATED BY STRONG MID/UPPER LEVEL RIDGING OVER MEXICO. 
THE MOISTURE EXTENDS WWD TO THE AFOREMENTIONED LINE THAT EXTENDS 
FROM SRN BAJA CALIFORNIA TO 17N120W 10N132W.
 
$$
AGUIRRE