000
AXPZ20 KNHC 271604
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT JUN 27 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 
1545 UTC.

...TROPICAL WAVE...

A TROPICAL WAVE MOVING W AT 10-15 KT HAS ENTERED THE FAR ERN 
PORTION OF THE PACIFIC ALONG 87W N OF 5N. IT IS ENHANCING ITCZ 
CONVECTION BETWEEN 84W-89W.

...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 6N78W 9N88W 7N101W 12N115W
9N130W 6N140W. SCATTERED STRONG CONVECTION EXISTS FROM 4N-7N
BETWEEN 84W-89W...AND WITHIN 120 NM N OF THE AXIS BETWEEN 
123W-129W. SCATTERED MODERATE/ISOLATED STRONG CONVECTION IS 
WITHIN 180 NM S OF THE AXIS BETWEEN 77W-79W.

...DISCUSSION...

THE TAIL END OF A MID/UPPER LEVEL TROUGH EXTENDS FROM SOUTHERN 
CALIFORNIA SW TO NEAR 31N124W. ANOTHER MID/UPPER LEVEL TROUGH
ENTERS THE AREA THROUGH 32N137W...AND REACHES TO 28N126W TO
A COL REGION NEAR 21N119W. IN BETWEEN BOTH OF THESE TROUGHS
A SMALL UPPER LEVEL ANTICYCLONE MOVING SE IS N OF THE AREA
NEAR 35N125W WITH A RIDGE NE ACROSS NRN CALIFORNIA. SATELLITE 
WATER VAPOR IMAGERY IS EXHIBITING MODERATE SUBSIDENCE RESULTING
IN STABLE ENVIRONMENTAL CONDITIONS OVER THE MAJORITY THE 
DISCUSSION AREA NW OF A LINE FROM CENTRAL BAJA CALIFORNIA SW TO 
17N121W TO 10N135W. AT THE SURFACE...THE ASSOCIATED RIDGE ENTERS 
THE AREA THROUGH 32N137W TO 27N130W TO NEAR 22N122W WITH THE 
PARENT HIGH CENTER NW OF THE AREA NEAR 36N142. THE PRES 
GRADIENT BETWEEN THE RIDGE AND LOW PRES ASSOCIATED WITH THE ITCZ 
IS RESULTING IN NE TRADE WINDS OF 20 KT FROM 13N-20N W OF 130W
...WITH ANOTHER AREA OF TRADES N OF 24N W OF 130W. THESE WINDS
ARE FORECAST TO BE CONFINED TO THE FAR NW PORTION OF THE AREA IN 
ABOUT 24 HOURS AS THE HIGH CENTER MOVES NW...THEN DIMINISH TO 
LESS THAN 20 KT IN 48 HOURS. A VERY STRONG PRES GRADIENT N OF 
THE AREA BETWEEN THE HIGH CENTER AND THE U.S. W COAST IS 
RESULTING IN NW-N WINDS OF 20 KT ACROSS NRN BOUNDARY OF THE AREA 
N OF 27N BETWEEN 121W-130W WITH SEAS 8 TO 01 FT IN N SWELL.
THESE CONDITIONS WILL SLOWLY SUBSIDE OVER THE NEXT 48 HOURS.

OVER THE TROPICAL ZONE...A PERSISTENT WEAK 1011 MB LOW PRES 
CENTER REMAINS EMBEDDED IN THE ITCZ NEAR 11N122W MOVING LITTLE.
CONVECTION HAD DIMINISHED 24 HOURS AGO...BUT JUST WITHIN THE PAST
FEW HOURS HAS RETURNED. A QUIKSCAT PASS FROM LATE LAST NIGHT
REVEALED 20 KT WINDS WITHIN 150 NM OF THE LOW IN THE NW QUADRANT
...AND WINDS TO 20 KT WITHIN 120 NM OF THE LOW IN THE SE
QUADRANT. THE LOW SHOULD BE GONE BY 24 HOURS WITH JUST THE
ITCZ AXIS REMAINING IN THAT AREA.

SURFACE ANALYSIS FROM THIS MORNING SHOWS BROAD LOW PRES COVERING
THE ERN PORTION OF THE AREA E OF 120W. SE-S WINDS OF 15-20 KT 
ARE INDICATED S OF THE ITCZ BETWEEN 80W-100W WHERE SEAS TO 8 FT 
IN S SWELL ARE NOTED. SMALL CLUSTERS OF WIDELY SCATTERED 
MODERATE CONVECTION ARE NOTED OVER MUCH OF THE FAR ERN PART OF 
THE AREA DUE TO THE ELONGATED AREA OF LOW PRES. 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
...AND ITS ADJACENT PACIFIC WATERS. THE MOISTURE AREA IS NEARING 
115W.
 
$$
AGUIRRE