000
AXPZ20 KNHC 211003
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED MAY 21 2008

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 
0945 UTC.

...TROPICAL WAVES...

A TROPICAL WAVE IS ANALYZED S OF 13N ALONG 76W AND HAS BEEN 
MOVING W AT 15 KT AND THIS MOTION WILL MOVE THE WAVE OFF THE 
COAST OF COLOMBIA TODAY. SCATTERED MODERATE TO STRONG CONVECTION 
IS ALONG THE WAVE OVER THE SW CARIBBEAN AND THESE TSTMS WILL 
LIKELY MOVE W OVER PANAMA THIS MORNING.

...ITCZ...

THE ITCZ AXIS IS ALONG LINE 07N77W TO 04N90W TO 12N121W TO 
05N140. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS NOTED 
FROM 03 TO 08N BETWEEN 80W AND 97W AND ALSO WITHIN 120 NM EITHER 
SIDE OF LINE FROM 11N116W TO 09N128W. SCATTERED MODERATE TO 
STRONG CONVECTION IS OBSERVED WITHIN 30 NM OF COAST OF S AMERICA 
BETWEEN 86W AND 91W.   

...DISCUSSION...

AN UPPER LEVEL CYCLONE IS CENTERED W OF THE AREA AT 25N145W AND 
HAS FINALLY BEGUN A WESTWARD MOTION. ITS ENVELOPE OF CYCLONIC 
FLOW STILL DOMINATES THE UPPER LEVELS OF THE DISCUSSION AREA N 
OF 14N W OF 135W. A BAND OF DRY UPPER AIR IS WITHIN 120 NM OF 
LINE 15N140W 23N135W 30N134W. AN UPPER CYCLONE OVER CENTRAL OLD 
MEXICO NEAR 24N103W APPEARS TO BE FILLING BUT STILL TRAILS AN 
UPPER TROUGH S TO 12N110W WHERE IT MERGES WITH A WEAK UPPER 
TROUGH EXTENDING N ACROSS THE EQUATOR ALONG 00N110W TO 12N110W.

ANOTHER DEEP LAYERED TROUGH IS MOVING INTO THE AREA ALONG 
32N113W TO 27N120W. A LARGE AREA OF DRY UPPER AIR IS INDICATED 
OVER THE AREA N OF 17N BETWEEN 105W AND 130W.

AN RIDGE OVER THE CARIBBEAN EXTENDS SW INTO THE PAC TO NEAR 
11N104W. UPPER DIFFLUENCE HAS ENHANCED CONVECTION ALONG THE ITCZ 
BETWEEN 105W AND 131W 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 THE GULF OF MEXICO AND ACROSS FLORIDA S OF 28N.

AT THE SURFACE...HIGH PRESSURE HAS SHIFTED N OF THE AREA WITH A 
RIDGE EXTENDING SE ALONG 32N132W TO NEAR 15N110W. TO THE NE OF 
THE RIDGE A SERIES OF COLD FRONTS WILL MOVE INTO NORTHERN BAJA 
THE NEXT FEW DAYS WITH LOW WINDS MAXING AT 30 KT NEAR 30N120W.
THIS WILL DRIVE LARGE NW SWELLS TO 20 FT WITH THEIR PERIOD 
INCREASING TO ABOUT 11 SECONDS INTO THE AREA BY FRI.  

$$
NELSON