000
AXPZ20 KNHC 252127
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC THU JUN 25 2009

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

BASED ON 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...ITCZ...

THE ITCZ AXIS IS ALONG 04N77W TO 04N90W TO 12N118W TO 06N140W. 
SCATTERED MODERATE CONVECTION IS NOTED FROM 02N TO 10N BETWEEN 
90W AND 100W. SCATTERED MODERATE TO ISOLATED STRONG CONVECTION 
IS WITHIN 100 NM JUST S OF LOW NEAR 11N120W...AND FROM 11N TO 
14N BETWEEN 114W AND 118W.

...DISCUSSION...

AN UPPER-LEVEL TROUGH ENTERS THE FORECAST AREA NEAR 30N122W THEN 
CONTINUES SW AND W TO NEAR 27N135W. JUST SOUTH OF THE TROUGH 
THERE IS A RIDGE ANCHORED ON A HIGH NEAR 18N132W. MODERATE TO 
STRONG SUBSIDENCE MAINTAINING STABLE ENVIRONMENTAL CONDITIONS IS 
PRESENT NW OF A LINE FROM CENTRAL BAJA CALIFORNIA SW TO 20N120W 
TO 10N130W. ANOTHER UPPER-LEVEL HIGH CENTERED OVER THE SW CONUS 
HAS A RIDGE COVERING MEXICO AND THE EPAC REGIONAL WATERS. THIS 
SYSTEM CONTINUES TO PRODUCE MODERATE TO STRONG ELY WINDS MAINLY 
N OF 12N AND E OF 110W.  

AT THE SURFACE...A 1030 MB HIGH LOCATED NEAR 36N145W EXTENDS A 
RIDGE SE TO 20N115W COVERING THE AREA N OF 17N 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. THIS HIGH CENTER NW OF THE AREA IS FORECAST TO MOVE NE 
WHILE SLIGHTLY STRENGTHEN. THE STRONG GRADIENT BETWEEN THIS HIGH 
AND LOWER PRES OVER THE U.S. W COAST WILL FUNNEL NW-N WINDS OF 
20 KT IN THE NRN PORTION OF THE AREA N OF 27N W OF 125W OVER THE 
NEXT 24-36 HOURS. 

OVER THE SRN PORTION OF THE AREA...A 1010 MB LOW PRES REMAINS 
EMBEDDED IN THE ITCZ NEAR 11N120W MOVING NE NEAR 10 KT. A 
CLUSTER OF MODERATE TO ISOLATED STRONG CONVECTION IS JUST SOUTH 
OF THE LOW CENTER. ONLY ISOLATED WEAK CONVECTION IS WITHIN 60 NM 
SE OF THE LOW. A QUIKSCAT PASS FROM THIS MORNING SHOWED THE 
CYCLONIC CIRCULATION ASSOCIATED WITH THIS LOW. GLOBAL MODELS 
SUGGEST THAT THIS FEATURE WILL WEAKEN IN ABOUT 24-36 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 THE FAR ERN PART OF THE AREA 
PARTICULARLY E OF 102W. 
 
$$
GR