000
AXPZ20 KNHC 211531
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED MAY 21 2008

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 
1530 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ANALYZED S OF 13N ALONG 77W AND HAS BEEN 
MOVING W AT 10-12 KT AND THIS MOTION WILL MOVE THE WAVE OFF THE 
COAST OF COLOMBIA THIS AFTERNOON. SCATTERED MODERATE TO STRONG 
CONVECTION IS ALONG THE WAVE OVER THE SW CARIBBEAN AND THESE 
TSTMS WILL LIKELY MOVE W OVER PANAMA THIS AFTERNOON.

...ITCZ...

THE ITCZ AXIS IS ALONG LINE 07N77W TO 05N91W TO 12N121W TO 
07N140W. SCATTERED MODERATE TO STRONG FROM 03N TO 07N BETWEEN 
83W AND 90W. SCATTERED MODERATE ISOLATED STRONG WITHIN 120 NM OF 
COAST OF CENTRAL AMERICA BETWEEN 84W AND 90W. SCATTERED MODERATE 
WITHIN 180 NM OF THE AXIS BETWEEN 122W AND 130W...AND WITHIN 120 
NM OF THE AXIS BETWEEN 90W AND 98W.

...DISCUSSION...

A LARGE UPPER LEVEL CYCLONE CENTERED W OF THE AREA NEAR 25N146W 
IS MOVING WWD AT 10-15 KT. ITS ENVELOPE OF CYCLONIC FLOW STILL 
DOMINATES THE UPPER LEVELS OF THE DISCUSSION AREA N OF 14N W OF 
135W. A BAND OF STRONG UPPER LEVEL SUBSIDENCE IS WITHIN 120 NM 
OF LINE 15N140W 23N135W 30N134W. AN UPPER CYCLONE OVER CENTRAL 
OLD MEXICO NEAR 23N105W IS SHEARING OUT WITHIN THE BASE OF AN 
UPPER TROUGH WHICH EXTENDS SWD TO 12N110W WHERE IT MERGES WITH A 
WEAK UPPER TROUGH/SHEAR AXIS EXTENDING N ACROSS THE EQUATOR 
ALONG 00N110W TO 12N110W.

ANOTHER DEEP LAYERED TROUGH IS DIGGING SWD ALONG THE CALIFORNIA 
COAST INTO THE FAR NW CORNER OF THE AREA. A LARGE AREA OF STRONG 
UPPER LEVEL SUBSIDENCE IS INDICATED OVER THE AREA N OF 14N 
BETWEEN 100W AND 125W.

A DEEP LAYERED RIDGE OVER THE CARIBBEAN EXTENDS SW INTO THE PAC 
TO NEAR 11N102W. UPPER DIFFLUENCE HAS ENHANCED CONVECTION ALONG 
THE ITCZ BETWEEN 105W AND 130W WITH THE RESULTANT DEBRIS 
MOISTURE REMAINING WITHIN THE SAME AREA FROM 03N TO 13N BETWEEN 
105W AND 130W. CONVECTION IS ALSO ENHANCED OVER THE TROPICS E OF 
100W WITH THE DEBRIS MOISTURE SPREADING N AND NE IN A TROPICAL 
PLUME ACROSS CENTRAL AMERICA AND THE GULF OF MEXICO AND ACROSS 
FLORIDA S OF 30N.

AT THE SURFACE...HIGH PRESSURE HAS SHIFTED WELL N OF THE AREA 
WITH A RIDGE EXTENDING SE ALONG 32N130W TO NEAR 15N110W. TO THE 
NE OF THE RIDGE A SERIES OF COLD FRONTS WILL MOVE INTO NORTHERN 
BAJA THE NEXT FEW DAYS WITH SFC WINDS MAXING AT 30 KT ALONG 
30N. THIS WILL DRIVE LARGE NW SWELLS TO 20 FT WITH THEIR 
PERIOD INCREASING TO ABOUT 11 SECONDS INTO THE AREA BY FRI.  

$$
COBB