000
AXPZ20 KNHC 010923
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
1005 UTC TUE JAN 01 2013

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W. THE FOLLOWING INFORMATION IS 
BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR...AND 
METEOROLOGICAL ANALYSIS.

BASED ON 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0900 UTC.

...SPECIAL FEATURE...                                         
GULF OF TEHUANTEPEC GALE...REPORTS FROM COATZACOALCOS ON THE 
NORTHERN END OF THE ISTHMUS OF TEHUANTEPEC...AND SALINA CRUZ ON 
THE SOUTHERN END OF ISTHMUS INDICATE AN 8 MB DIFFERENCE IN SEA 
LEVEL PRES PERSISTS...SUPPORTING WINDS TO GALE FORCE OVER THE 
GULF OF TEHUANTEPEC. AN 03 UTC ASCAT PASS SHOWED WINDS 
APPROACHING 40 KT...AFTER HAVING DIMINISHED SLIGHTLY IN THE 
AFTERNOON TO 30 KT. THE GALES WILL CONTINUE THROUGH EARLY 
MORNING...THEN DIMINISH AS THE PRES GRADIENT WEAKENS. AN 
ALTIMETER PASS FROM SEVERAL HOURS AGO SHOWED SEAS OVER 9 
FT...BUT THIS MISSED THE HIGHEST SEAS DOWNSTREAM OF THE GALES 
WHICH ARE LIKELY UP TO 13 FT. THESE SEAS WILL SUBSIDE BELOW 8 FT 
BY LATE AFTERNOON. LOOKING AHEAD...A STRONG COLD FRONT SWEEPS 
THE GULF OF MEXICO...BRINGING ANOTHER ROUND OF GALES TO THE GULF 
OF TEHUANTEPEC BY LATE THU...PERSISTING TO EARLY SAT.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
THE MONSOON TROUGH EXTENDS FROM 07N78W TO 06N90W TO 05N97W. THE 
ITCZ EXTENDS FROM 05N97W TO 07N105W TO 08N140W. NO SIGNIFICANT 
CONVECTION IS NOTED.

...DISCUSSION...                                               
THE UPPER PATTERN REMAINS HIGHLY AMPLIFIED WITH AN UPPER TROUGH 
E OF THE HAWAIIAN ISLANDS ALONG 150W...BROAD RIDGING ALONG 
135W...AND TROUGHING ALONG 110W. A SURFACE TROUGH ASSOCIATED 
WITH THE EASTERN TROUGH EXTENDS FROM NEAR MAZATLAN MEXICO TO 
14N110W. UPPER FORCING ASSOCIATED WITH THE SOUTHERN STREAM UPPER 
JET MAXIMA ON THE LEADING EDGE OF THE TROUGH IS SUPPORTING AN 
AREA OF THUNDERSTORMS ON THE SOUTHERN END OF THE SURFACE TROUGH 
FROM 13N TO 15N BETWEEN 108W AND 112W.

GULF OF PAPAGAYO...STRONG TRADES IN SW CARIBBEAN ARE MOVING 
THROUGH MOUNTAIN GAPS IN NICARAGUA INTO THE GULF OF PAPAGAYO. 
WINDS ARE PULSING TO 20-25 KT LATER THIS MORNING AND AGAIN THU 
MORNING...ENHANCED BY MOUNTAIN DRAINAGE.

FARTHER WEST...A 1026 MB HIGH PRES CENTERED WELL N OF THE AREA 
IS MAINTAINING MODERATE TO FRESH TRADE WIND FLOW MAINLY FROM 08N 
TO 20N W OF 115W. LONG PERIOD NW SWELL IS MIXING WITH SHORTER 
PERIOD SWELL GENERATED BY THE MODERATE TO FRESH TRADE WINDS OVER 
MUCH OF THE AREA FROM 07N TO 22N W OF 120W...WITH COMBINED SEA 
HEIGHTS REACHING 8 TO 10 FT. THE NW SWELL WILL GRADUALLY DECAY 
OVER THE NEXT COUPLE OF DAYS. SIMILARLY THE RIDGE N OF THE AREA 
WILL WEAKEN AHEAD OF AN ADVANCING TROUGH...ALLOWING TRADE WINDS 
TO DIMINISH THU INTO FRI.

$$ 
CHRISTENSEN