000
AXPZ20 KNHC 221000
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT NOV 22 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.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS ALONG 08N78W TO 06N90W 
TO 09N118W TO 07N140W. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION NOTED WITHIN 90 NM EITHER SIDE OF LINE FROM 08N101W 
TO 08N118W TO 07N127 AND ALSO WITHIN 30 NM OF 06N140W.

...DISCUSSION...

AN INITIAL UPPER LEVEL TROUGH LIES ALONG 34N124W TO 29N127W INTO 
AN UPPER CYCLONE AT 26N125W WITH THE TROUGH CONTINUING S TO BASE 
DEEP IN THE TROPICS NEAR 07N128W. A LARGE OF OF DRY UPPER AIR IS 
INDICATED FROM 07N TO 25N BETWEEN 120W AND 132W. A SECONDARY 
UPPER TROUGH IS APPROACHING FROM THE NW...AND IS CURRENTLY NEAR 
36N AT 127W. A BAND OF UPPER MOISTURE PRECEDES THE SECOND 
TROUGH...WITHIN 120 NM EITHER SIDE OF A LINE FROM 35N125W TO 
35N128W...AND CONTINUES NE ACROSS SOUTHERN CALIFORNIA. 
CONVECTION WAS PREVIOUSLY ENHANCED NEAR THE UPPER CYCLONE AT 
26N125W...AND THE DEBRIS MOISTURE HAS SPREAD NE OVER THE AREA N 
OF 28N BETWEEN 107W AND 127W AND NOW MOVING E OVER ARIZONA. THE 
UPPER TROUGHS ARE EXPECTED TO MERGE ALONG ROUGHLY 120W INTO 
EARLY NEXT WEEK THEN FILL AS ZONAL FLOW ESTABLISHES OVER THE 
AREA N OF THE ITCZ AND S OF 28N. ANOTHER UPPER TROUGH MOVES OVER 
THE AREA N OF 28N N OF 125W MON. 

AN UPPER ANTICYCLONE IS OVER THE SW CARIBBEAN WITH A RIDGE 
EXTENDING NW TO A CREST ALONG 14N116W TO 22N115W TO 29N102W. A 
BAND OF UPPER DRY AIR IS NOTED WITHIN 120 NM OF LINE 28N96W TO 
28N116W. UPPER DIFFLUENCE CONTINUES TO ENHANCE ITCZ CONVECTION 
ALONG 08N BETWEEN 101W AND 122W. THE RESULTANT DEBRIS MOISTURE 
IS ADVECTED N ALONG THE PERIPHERY OF THE UPPER RIDGE BETWEEN 
100W AND 118W TO ALONG 26N WHERE MOST OF THE MOISTURE 
EVAPORATES. CONVECTION IS ALSO ENHANCED OVER THE SW CARIBBEAN
WITH THE MOISTURE SPREADING W ACROSS CENTRAL AMERICA AND THE E 
PAC TO THE N OF 09N E OF 87W. OTHERWISE THE UPPER LEVELS APPEAR 
DRY.  

AT THE LOW LEVELS A RIDGE EXTENDS ALONG 32N137W TO 17N112W. A 
LOW LEVEL TROUGH LIES ALONG 07N124W TO 13N118W WITH A FEW 
CLUSTERS OF CONVECTION NOTED WITHIN 120 NM OF ITS AXIS.  

GAP WINDS...NORTHERLY WINDS IN AND DOWNSTREAM OF THE GULF OF  
TEHUANTEPEC ARE CURRENTLY AT 30-40 KT PER A HI RESOLUTION Q-SCAT 
PASS...WITH SEAS TO AROUND 14 FT. A SECOND COLD SURGE IS MOVING 
INTO THE NW BAY OF CAMPECHE AT THE MOMENT AND SHOULD CONTINUE 
THE GALE EVENT THROUGH LATE SUN...THEN CONDITIONS WILL DIMINISH. 
NE WINDS ARE AT 20 KT IN THE GULF OF PAPAGAYO AND EXPECTED TO 
INCREASE TO 20 TO 30 KT TONIGHT AND SUN AND CONTINUE THROUGH 
EARLY TUE BEFORE RELAXING TO 15 TO 20 KT. BROAD LOW PRESSURE 
OVER THE SW CARIBBEAN IS PREVENTING N WINDS FROM BRIDGING ACROSS 
PANAMA INTO THE PACIFIC.   

$$
NELSON