000
AXPZ20 KNHC 260317
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI JUN 26 2009

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 
0300 UTC.

...ITCZ...

THE ITCZ AXIS IS ALONG 09N85W TO 05N95W TO 13N115W TO 07N130W 
TO 05N140W. SCATTERED STRONG CONVECTION IS NOTED WITHIN 60 NM OF 
LOW PRES CENTER NEAR 12N119W...AND WITHIN 45 NM OF 10N120W. 
SCATTERED MODERATE CONVECTION IS WITHIN 70 NM S OF AXIS BETWEEN 
116W 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 NORTHERN BAJA CALIFORNIA SW TO 20N120W 
TO 10N132W. ANOTHER STRONGER 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 N OF 10N AND E OF 110W. ABUNDANT DEEP-LAYERED MOISTURE IS 
OBSERVED AROUND THE WESTERN PERIPHERY OF THIS HIGH RESULTING IN 
MODERATE TO STRONG CONVECTION OVER MUCH OF MEXICO WITH THE 
EXCEPTION OF THE NE PORTION AND THE YUCATAN PENINSULA.   

AT THE SURFACE...A 1030 MB HIGH LOCATED NEAR 37N140W EXTENDS A 
RIDGE SE TO 20N115W COVERING THE AREA N OF 14N 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 14N-22N W OF 
132W. THIS HIGH IS FORECAST BY THE COMPUTER MODELS TO MOVE NE 
WHILE SLIGHTLY STRENGTHEN. THE STRONG GRADIENT BETWEEN THIS 
FEATURE AND LOWER PRES OVER THE U.S. W COAST WILL FUNNEL NLY 
WINDS OF 20 KT IN THE NRN PORTION OF THE AREA N OF 27N W OF 120W 
OVER THE NEXT 24-48 HOURS. IN ADDITION...NORTHERLY SWELLS ARE 
ALSO EXPECTED TO AFFECT THE NORTH WATERS. SEAS WILL RANGE FROM 8 
TO 10 FT. 

FARTHER SOUTH...A 1010 MB LOW PRES REMAINS EMBEDDED IN THE ITCZ 
NEAR 12N119W MOVING NE NEAR 10 KT. CONVECTION HAS INCREASED THIS 
EVENING WITHIN 60 NM OF THE LOW CENTER. GLOBAL MODELS SUGGEST 
THAT THIS FEATURE WILL WEAKEN IN ABOUT 24-36 HOURS. 

FARTHER EAST ALONG THE ITCZ...WEAK CYCLONIC TURNING IS NOTED 
NEAR A WEAK INVERTED TROUGH EXTENDING FROM CENTRAL AMERICA INTO 
THE EPAC ALONG 89W/90W. SCATTEROMETER DATA FROM THIS MORNING 
SHOWED THE PRESENCE OF THIS FEATURE WHICH IS PRODUCING ISOLATED 
TO SCATTERED CONVECTION ALONG THE ITCZ E OF 102W. 

LARGE AND LONG PERIOD SWELLS FROM THE SOUTH PACIFIC ARE CROSSING 
THE EQUATOR RAISING SEAS TO 8 FT S OF 05N BETWEEN 94W AND 100W. 
THESE CONDITIONS ARE EXPECTED TO SPREAD WWD WITH TIME. THE SWELL 
HEIGHTS ARE FORECAST TO PEAK IN ABOUT 48 HOURS. 
 
$$
GR