000
AXPZ20 KNHC 131522
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON DEC 13 2010

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 
1400 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE AXIS IS ALONG 06N78W TO 
06N105W TO 07N115W TO 06N125W TO 08N140W. SCATTERED MODERATE 
CONVECTION IS WITHIN 180 NM S AND 120 NM N OF THE ITCZ AXIS E OF 
84W TO THE COAST OF COLOMBIA.


...DISCUSSION...

A WEAKENING 1023 MB SURFACE HIGH PRESSURE LOCATED JUST N OF THE 
AREA NEAR 32N129W EXTENDS A RIDGE OVER THE FORECAST WATERS 
COVERING ROUGHLY THE REGION N OF 15N AND W OF 110W. THIS RIDGE 
IS INTERRUPTED BY A WEAK DEEP LAYER INVERTED TROUGH THAT LIES 
ALONG 127W N OF 10N AND REFLECTS A TROUGH AT THE SURFACE FROM 
27N126W TO 21N123W. ONLY A SMALL AREA OF FRESH NE TO E 
TRADEWINDS OF 20 KT EXIST ON THE SOUTHERN PERIPHERY OF THE RIDGE 
OVER WATERS BETWEEN 09N AND 17N W OF 135W. THE SURFACE HIGH WILL 
MOVE TOWARD THE NW CORNER OF THE FORECAST AREA TUE AND THE 
PRESSURE GRADIENT WILL WEAKEN CONSIDERABLY ON WED AS A NEW LOW 
PRES SYSTEM APPROACHES THE NW CORNER OF THE AREA. A STATIONARY 
FRONT CURRENTLY NEAR 30N140W WILL REMAIN OUT OF DISCUSSION AREA 
BEFORE DISSIPATING LATER TODAY.

A SUBSIDING NW SWELL AFFECTS MUCH OF THE REGION S OF 15N W OF 
100W. THESE SWELLS WILL RELAX AND MOST OF THE FORECAST 
AREA...EXCEPT THE LOCATIONS IMPACTED BY GAP WINDS...WILL HAVE 
SEAS LESS THAN 8 FT AND WINDS LESS THAN 20 KT BY TUE.

GAP WINDS...
A STRONG COLD FRONT HAS MOVED ACROSS THE NW CARIBBEAN. WINDS ARE 
FUNNELING THROUGH THE CHIVELA PASS AND INTO THE GULF OF 
TEHUANTEPEC. AT 0800 UTC...SHIP C6FR3 MOVING ACROSS THIS GULF 
REPORTED SUSTAINED WINDS OF 59 FT VERIFYING THE PRESENCE OF 
STORM FORCE WINDS ACROSS THE GULF OF TEHUANTEPEC. IXTEPEC IN 
OAXACA MEXICO REPORTED SUSTAINED WINDS OF 45 KT WITH GUSTS TO 55 
KT AT 1200 UTC. WINDS THERE HAVE DIMINISHED TO 30 KT WITH GUSTS 
TO 40 KT AT 1400 UTC. A STORM WARNING REMAINS IN EFFECT FOR THIS 
AREA UNTIL 18Z. SEAS HERE HAVE LIKELY PEAKED AROUND 18 FT. GALE 
FORCE WINDS ARE EXPECTED TO PERSIST IN THE GULF OF TEHUANTEPEC 
UNTIL TUE AFTERNOON. 

NORTHEAST WINDS TO 20 KT HAVE BEGUN TO FUNNEL THROUGH THE 
CENTRAL AMERICAN PASSES AT THE GULF OF FONSECA AND PAPAGAYO AS 
THE COLD FRONT AND ASSOCIATED WIND SURGE CONTINUES TO MOVE 
SOUTHWARD THROUGH THE WESTERN CARIBBEAN. FRESH TO STRONG WINDS 
ARE EXPECTED OVER THE GULFS OF FONSECA AND PAPAGAYO THROUGH THE 
END OF THE FORECAST PERIOD ON WED. THE GULF OF PANAMA WILL SEE 
WINDS BUILD TO 25 KT BY EARLY TUE MORNING.

ELSEWHERE...WIDESPREAD CONVECTION IS LIMITED TO THE EASTERN EDGE 
OF THE ITCZ NEAR THE GULF OF PANAMA AND TO THE COAST OF COLOMBIA 
WHERE PRECIPITABLE WATER VALUES ARE ABOVE 2 INCHES. LOW LEVEL 
CONVERGENCE IS INCREASING OVER FAR NW SOUTH AMERICA BETWEEN THE 
EASTERLY TRADE WINDS OVER THE EASTERN CARIBBEAN...NORTHERLY 
WINDS OVER THE WESTERN CARIBBEAN...AND SOUTHWESTERLY FLOW ACROSS 
THE FAR EASTERN NORTH PACIFIC WATERS SOUTH OF THE ITCZ. WHILE 
THE PRECIPITABLE WATER VALUES ARE EXPECTED TO DECREASE SOME AS 
THE COLDER AND DRIER AIR MOVES INTO THE WESTERN CARIBBEAN FROM 
THE NORTH...THE SCATTERED CONVECTION CURRENTLY IN PLACE IN THE 
REGION IS EXPECTED TO CONTINUE FOR THE NEXT FEW DAYS UNDER A 
PERSISTENT UPPER RIDGE AND CONTINUED LOW LEVEL CONVERGENCE OF 
MOIST AIR TRANSPORTED BY THE SOUTHWEST WINDS IN THE PACIFIC S OF 
THE ITCZ.

$$
SCHAUER/GR