000
AXPZ20 KNHC 260919
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI JUN 26 2009

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 
0800 UTC.

...ITCZ...

THE ITCZ AXIS IS ALONG AXIS 09N85W TO 05N95W TO 13N113W TO 
06N135W TO 05N140W. SCATTERED MODERATE CONVECTION CAN BE FOUND 
WITHIN 30 NM N AND 120 NM S OF THE ITCZ AXIS FROM 121W TO 126W. 

...DISCUSSION...

OVER N WATERS...AN UPPER-LEVEL TROUGH EXTENDS FROM CALIFORNIA 
SOUTHWARD ALONG 120W TO 20N AND AN UPPER LEVEL ANTICYCLONE CAN 
BE FOUND NEAR 20N130W. MODERATE TO STRONG SUBSIDENCE IS 
MAINTAINING STABLE ENVIRONMENTAL CONDITIONS N OF 20N AND NW OF A 
LINE FROM NORTHERN BAJA CALIFORNIA SW TO 20N120W. ANOTHER 
UPPER-LEVEL HIGH CENTERED OVER THE U.S. SOUTHERN PLAINS HAS A 
RIDGE EXTENDING SOUTH-SOUTHWEST THROUGH NORTHERN MEXICO TO NEAR 
MANZANILLO. ABUNDANT DEEP-LAYERED MOISTURE LIES IN THE SOUTHERLY 
FLOW BETWEEN THE WESTERN PERIPHERY OF THIS RIDGE AND THE TROUGH 
ALONG 120W. THIS MOISTURE HELPED FUEL AFTERNOON CONVECTION OVER 
THE SIERRA MADRE OCCIDENTAL MOUNTAINS AS WELL AS SHOWERS OVER 
BAJA CALIFORNIA AND THE MOUTH OF THE GULF OF CALIFORNIA 
ASSOCIATED WITH A MID LEVEL LOW NEAR 22N112W. ISOLATED MODERATE 
CONVECTION CAN STILL BE FOUND WITHIN 90 NM OF THE COAST FROM 88W 
TO 102W. LOOK FOR THE TROUGH MOVING THROUGH THE WESTERN U.S. TO 
PASS N OF THE UPPER HIGH OVER THE SOUTHERN PLAINS...SHIFTING THE 
HIGH WESTWARD BUT LEAVING BEHIND ENERGY TO JOIN WITH THE 
INVERTED MID LEVEL TROUGH CURRENTLY ALONG 20N122W TO 10N132W.

THE QUIKSCAT PASS FROM 0232 UTC SHOWED A CLOSED CIRCULATION 
ABOUT THE 1010 MB SURFACE LOW CURRENTLY NEAR 13N121W WITH WINDS 
TO 25 KT. THIS LOW LIES WITHIN THE AFOREMENTIONED INVERTED MID 
LEVEL TROUGH AND IS UNDER A REGION OF BROAD UPPER LEVEL 
DIFFLUENCE WHICH IS HELPING TO SUSTAIN DEEP CONVECTION.  
CURRENTLY...SCATTERED MODERATE CONVECTION LIES WITHIN 300 NM SE 
QUADRANT. THIS TROUGH IS INFLUENCING THE ITCZ NORTHWARD...WITH 
THE ITCZ LYING FROM THIS LOW TO A WEAKER 1011 MB SURFACE LOW AT 
05N137W. THE INVERTED TROUGH IS EXPECTED TO BEGIN SHIFTING 
WESTWARD OVER THE WEEKEND AS THE UPPER RIDGE OVER THE SOUTHERN 
PLAINS MOVES INTO THE SOUTHWEST AND THE UPPER LOW CURRENTLY N OF 
HAWAII IS STEERED EASTWARD BY AN APPROACHING MID LATITUDE 
TROUGH...MAKING FOR BROAD TROUGHING E OF 125W BY MON. 

THE UPPER LOW CURRENTLY CENTERED OVER THE YUCATAN AND THE 
TROPICAL WAVE TO ITS E WILL PASS WESTWARD INTO THE PACIFIC OVER 
THE NEXT FEW DAYS. EXPECT AN INCREASED CHANCE OF CONVECTION OVER 
CENTRAL AMERICA THROUGH THE WEEKEND AS A RESULT. 

LONG PERIOD SWELL FROM THE SOUTH PACIFIC IS CROSSING THE 
EQUATOR RAISING SEAS TO 8 FT S OF 04N BETWEEN 82W AND 
104W...ASIDE FROM THE REGION IN THE LEE OF THE GALAPAGOS ISLANDS 
FROM 88W TO 94W. EXPECT THE LARGEST SIGNIFICANT WAVE HEIGHTS 
ASSOCIATED WITH THIS S SWELL TO SHIFT W OVER THE WEEKEND.
 
$$
SCHAUER CLARK