000
AXPZ20 KNHC 221533
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SAT NOV 22 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 
1515 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS...08N82W TO 09N110W TO 
11N118W TO 07N140W. SCATTERED MODERATE TO ISOLATED STRONG WITHIN 
90 NM EITHER SIDE OF AXIS BETWEEN 110W AND 122W.

...DISCUSSION...

AN UPPER-LEVEL TROUGH EXTENDS FROM A CUT-OFF LOW NEAR 29N123W TO 
10N120W. NEAR THE BASE OF THIS TROUGH...CONVECTION IS ENHANCED 
ALONG THE ITCZ AXIS. UPPER SWLY WINDS AHEAD OF THIS FEATURE ARE 
TRANSPORTING MID/UPPER LEVEL MOISTURE ALL THE WAY NE ACROSS THE 
SOUTHERN BAJA PENINSULA AND NORTHERN MEXICO. AN UPPER-LEVEL 
RIDGE ANCHORED ON A HIGH OVER THE SW CARIBBEAN DOMINATES THE 
EPAC EAST OF 105W AND SE MEXICO. MODERATE TO STRONG UPPER-LEVEL 
SUBSIDENCE AND IMPLIED DRY AIR MASS IS NOTED WITHIN THE RIDGE 
SUPPRESSING CONVECTION ALONG THE ITCZ EAST OF 100W. ANOTHER 
UPPER-LEVEL RIDGE CENTERED JUST WEST OF THE FORECAST REGION NEAR 
11N143W EXTENDS A RIDGE OVER THE SW PORTION OF THE AREA. 

AT THE SURFACE...A 1027 MB HIGH LOCATED N OF AREA NEAR 33N140W 
EXTENDS A RIDGE OVER THE REGION COVERING THE AREA N OF 12N AND W 
OF 110W. THIS FEATURE IS PRODUCING A BELT OF TRADE WINDS IN THE 
20 T0 25 KT RANGE MAINLY BETWEEN 7N AND 22N. SURFACE DATA AND AN 
EARLIER QUIKSCAT PASS CONFIRMED THESE WIND SPEEDS. A COLD FRONT 
IS EXPECTED TO MOVE ACROSS THE NW CORNER OF THE AREA IN ABOUT 36 
HOUR. BEHIND THE FRONT...SEAS CONDITIONS ARE EXPECTED TO 
DETERIORATE AS NW SWELLS INVADE THE REGION. THE SWELL HEIGHTS 
ARE EXPECTED TO PEAK LATE MON WITH SEAS IN THE 12 TO 18 FOOT 
RANGE.     

GAP WINDS...NORTHERLY WINDS IN AND DOWNSTREAM OF THE GULF OF  
TEHUANTEPEC ARE CURRENTLY AT 30-45 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 TO 25 KT IN THE GULF OF PAPAGAYO AND EXPECTED 
TO INCREASE TO 30 KT TONIGHT AND SUN AND THEN SLIGHTLY WEAKEN ON 
MONDAY. BROAD LOW PRESSURE OVER THE SW CARIBBEAN IS PREVENTING N 
WINDS FROM BRIDGING ACROSS PANAMA INTO THE EASTERN PACIFIC.   

$$
GR