000
AXPZ20 KNHC 050936
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI DEC 05 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 
0815 UTC.

...ITCZ...
THE INTERTROPICAL CONVERGENCE ZONE LIES ALONG A LINE FROM 08N78W 
TO 07N100W TO 08N119W TO 07N135W TO 06N140W. SCATTERED MODERATE 
WITH ISOLATED STRONG CONVECTION CAN BE FOUND WITHIN 180 NM N AND 
150 NM S OF THE AXIS FROM 93W TO 102W. SCATTERED MODERATE 
CONVECTION CAN BE FOUND WITHIN 90 NM S OF AXIS BETWEEN 123W TO 
127W.

...DISCUSSION...
THE QSCAT PASS FROM 0022 UTC REVEALS THAT GALE FORCE WINDS HAVE 
BEGUN IN THE GULF OF TEHAUNTEPEC WITHIN 45 NM EITHER SIDE OF A 
LINE FROM 16N94.5W TO 15N95W.  THE SAME PASS SHOWS THAT WINDS 
HAVE ALSO PICKED UP TO THE 25 TO 30 KT RANGE DOWNWIND OF THE 
GULF OF PAPAGAYO.  THIS ROUND OF GAP WINDS IS EXPECTED TO BE 
RELATIVELY SHORT LIVED AS THE COLD FRONT DIVING SOUTHWARD 
THROUGH THE WESTERN GULF OF MEXICO BRINING THE STRONG NORTHERLY 
FLOW THROUGH THE ISTHMUS OF TEHAUNTEPEC IS EXPECTED TO LOSE MUCH 
OF ITS PUNCH OVER THE NEXT DAY OR TWO AS ITS IMPETUS TROUGHING 
ALOFT IS FORCED NORTHEASTWARD OVER A PERSISTENT RIDGE OVER THE 
NE CARIBBEAN.  THE GALE WARNING IS SET TO EXPIRE FOR THE GULF OF 
TEHUANTEPEC SAT MORNING...WITH WINDS DIMINISHING BELOW 25 KTS IN 
THE GULF OF PAPAGAYO AROUND THE SAME TIME.

ELSEWHERE...THE REAR RIGHT QUADRANT OF THE UPPER JET DIRECTED 
SOUTHWESTWARD FROM FL THROUGH SOUTHERN MEXICO IS ASSOCIATED WITH 
SPEED DIFFLUENCE ALOFT AND ALLOWING FOR AND AREA OF DEEP 
CONVECTION WITHIN 180 NM N AND 150 NM S OF THE ITCZ AXIS FROM 
93W TO 102W.  ATMOSPHERIC MOISTURE IS RELATIVELY PLENTIFUL 
HERE...WITH PRECIPITABLE WATER VALUES IN THE 2.00 TO 2.25 INCH 
RANGE.  THE LARGE SCALE PATTERN IS EXPECTED TO CHANGE LITTLE 
OVER THE NEXT FEW DAYS...WITH A WEAK UPPER TROUGH AXIS SETTLED 
BETWEEN 90W AND 105W WHILE DEEP LAYER TROUGHING TO THE N OVER 
THE GULF OF MEXICO AND EASTERN CONUS RELOADS BEGINNING LATER 
TODAY.

FARTHER W...A STRONG MID TO UPPER LEVEL TROUGH STRETCHED FROM 
CA/NORTHERN BAJA CALIFORNIA OVER THE NW FORECAST WATERS WILL 
PERSIST FOR THE NEXT FEW DAYS WITH THE MODELS AGREEING ON 
PINCHING OFF TWO UPPER LOWS...ONE OVER NW WATERS AND ONE OFF THE 
SOUTHERN CA COAST BY SAT EVE.  THE STRONGER OF THESE LOWS WILL 
LIE OVER NW WATERS AND IS EXPECTED TO TRANSLATE TROUGHING TO THE 
SURFACE TOMORROW.  LOOK FOR WINDS TO INCREASE TO 20 KT NEAR THE 
SURFACE TROUGH OVER THE WEEKEND.  WINDS ALOFT DOWNSTREAM OF THE 
LEADING EDGE OF THE TROUGH SHOULD CONTINUE TO BE DIFFLUENT 
THROUGH THE PERIOD AS THEY TURN MORE WESTERLY AROUND THE 
NORTHERN EDGE OF THE UPPER RIDGING BETWEEN 115W AND 125W.  
EXPECT CONVECTION TO BE MOST LIKELY TO OCCUR UNDER THE REGION OF 
UPPER LEVEL DIFFLUENCE WHERE IT CAN ACT UPON A POOL OF 
ELEVATED MID TO LOW LEVEL MOISTURE CENTERED NEAR 125W S OF 15N.

$$
SCHAUER CLARK