000
AXPZ20 KNHC 231522
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC SUN NOV 23 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 
1315 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 09N83W TO 
05N90W TO 06N105W TO 10N125W TO 07N140W. SCATTERED MODERATE 
CONVECTION WITHIN 90 NM OF AXIS W OF 130W.

...DISCUSSION...

THE DEEP LAYER TROUGH APPROACHING NW WATERS WILL REINFORCE THE 
BROAD TROUGH OFF THE W COAST OF NORTH AMERICA OVERNIGHT TONIGHT 
AND PINCH OFF A LOW FROM THE WESTERLIES N OF THE AREA MON.  
EXPECT THE AN UPPER LEVEL JET MAX TO SWING INTO THE LEADING EDGE 
OF THIS TROUGH BY MON MORNING...BRINGING ITS REAR RIGHT QUADRANT 
TO NEAR 20N130W MON MORNING...WITH THE STRONGEST UPPER LEVEL 
DIFFLUENCE EXPECTED TO THE SOUTHEAST OF THIS POINT.  THE GFS 
MODEL SHOWS CONSIDERABLE AMPLIFICATION OF A MID LEVEL VORTICITY 
MAX...CURRENTLY ASSOCIATED WITH THE SURFACE TROUGH EMBEDDED IN 
THE ITCZ FROM 13N126W TO 07N130W...AS IT REACHES THE VICINITY OF 
THE UPPER JET AND GENERATES NEARLY 6 INCHES OF PRECIPITATION IN 
THE REGION OF UPPER LEVEL DIFFLUENCE AS A RESULT.  THE GFS IS 
THE STRONGEST SOLUTION WITH THE ASSOCIATED SURFACE REFLECTION 
AND IS THE MORE NE SOLUTION WITH ITS TRACK BY MON NIGHT.  
BELIEVE THE GFS IS OVERDONE HERE DUE TO GRID SCALE FEEDBACK.  
HOWEVER...THE OTHER MODELS DO SUPPORT THE GENERAL SCENARIO OF 
AMPLIFICATION OF THE VORTICITY IN THIS REGION AND THE RESULTING 
RAINFALL...BUT NOT TO THE EXTENT OF THE GFS.  THE ECMWF WAS USED 
FOR THE TROUGH LOCATION AND WIND FIELD FORECAST.

GAP WINDS...QUIKSCAT PASS AT 1138 UTC SHOWS A SIGNIFICANT REGION 
OF WINDS IN THE 25 TO 30 KT RANGE DOWNWIND OF THE GULF OF 
PAPAGAYO AND AN INCREASE IN WINDS TO THE 20 TO 25 KT RANGE 
WITHIN 300 NM DOWNWIND OF THE GULF OF FONSECA.  ADJUSTMENTS WERE 
MADE ACCORDINGLY IN THE HSFEP2.  UNFORTUNATELY...THE QUIKSCAT 
PASS MISSED THE CORE WINDS DOWNWIND OF THE GULF OF TEHUANTEPEC 
AND THERE ARE NO OBSERVATIONS IN THE REGION.  THE MODELS AGREE 
TO DISSIPATE THE GALE WARNING CURRENTLY IN EFFECT HERE IN ABOUT 
12 HOURS.  THIS IS IN TUNE WITH THE PREVIOUS FORECAST.

CONVECTION IN THE SW CARIBBEAN MAY OCCASIONALLY BLEED WESTWARD 
THROUGH PANAMA AND COSTA RICA INTO FORECAST WATERS THE NEXT FEW 
DAYS.

$$
SCHAUER CLARK