000
AXPZ20 KNHC 130923
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT DEC 13 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 
0915 UTC.

...ITCZ...
ITCZ AXIS IS CENTERED ALONG 06N77W TO 05N98W TO 09N110W TO 
11N120W TO 08N140W. SCATTERED MODERATE TO STRONG WITHIN 150 NM N 
OF AXIS BETWEEN 86W AND 90W. SCATTERED MODERATE WITHIN 300 NM N 
OF AXIS BETWEEN 118W AND 122W.

...DISCUSSION...

GAP WINDS...
A PARTIAL ASCAT PASS AROUND 0330 Z REVEALED 30 KT AT THE SWATH 
EDGE W OF THE EXPECTED CORE WINDS OVER THE GULF OF TEHUANTEPEC. 
BASED ON THIS DATA AND SUFFICIENT N FUNNELING EVIDENT IN THE 
LOW-LEVEL CLOUDS...A GALE WARNING REMAINS IN PLACE FOR THE GULF 
OF TEHUANTEPEC. HOWEVER...WINDS SHOULD SUBSIDE QUICKLY TODAY AS 
SLY RETURN FLOW SETS UP OVER THE WRN GULF OF MEXICO. NE WINDS 
ARE ALSO BLOWING OVER THE GULFS OF PAPAGAYO AND FONSECA TONIGHT. 
SHIP 9HJG9 REPORTED 32 KT NEAR THE GULF OF PAPAGAYO AND SHIP 
P3GY9 REPORTED 28 KT NEAR THE GULF OF FONSECA AT 06Z. THESE 
REPORTS ARE IN AGREEMENT WITH AN EARLIER ASCAT PASS. THESE GAP 
WINDS SHOULD DIMINISH OVER THE NEXT COUPLE OF DAYS AS THE FRONT 
IN THE W CARIBBEAN DISSIPATES. 

ELSEWHERE...
HIGHLY AMPLIFIED RIDGE-TROUGH PATTERN IS IN PLACE W OF 110W. 
EXTENSIVE MID-HIGH LEVEL MOISTURE CONTINUES TO STREAM N-NE FROM 
THE DEEP TROPICS ACROSS BAJA CALIFORNIA...MAINLAND MEXICO AND 
INTO THE SOUTH CENTRAL CONUS. WATER VAPOR IMAGES INDICATE A 
SHORTWAVE DIVING SOUTH OVER THE SW CONUS. A SERIES OF THESE 
SHORTWAVES WILL CONTINUE TO DEEPEN THE TROUGH OVER THE NEXT 
COUPLE OF DAYS ...SUPPORTING A COUPLE OF COLD FRONTS OVER THE NE 
CORNER OF THE DISCUSSION ZONE. N WINDS WILL INCREASE TO 20 KT 
BEHIND THE FIRST FRONT SAT NIGHT THEN DIMINISH SUN. NW WINDS 
INCREASE AGAIN MON BEHIND THE SECOND ONE AND DIMINISH TUE. LONG 
PERIOD N SWELL COMBINED WITH SHORT PERIOD WIND WAVES WILL CREATE 
CONFUSED AND QUITE ELEVATED SEAS LATE THIS WEEKEND AND EARLY 
NEXT WEEK OFF THE N BAJA COAST.

SFC PRES GRADIENT IS TIGHTEST OVER THE FAR W PORTION...BETWEEN 
STRONG HIGH PRES OVER THE MID-LATITUDES AND WEAK TROUGHING 
WITHIN THE ITCZ ALONG 125W. THIS IS LEADING TO NE TRADES NEAR 20 
KT N OF 07N W OF 130W. THESE WINDS ARE EXPECTED TO WEAKEN OVER 
THE NEXT COUPLE OF DAYS AS THE RIDGE ERODES IN RESPONSE TO LOW 
PRES TO ITS W.

$$
CANGIALOSI