000
AXPZ20 KNHC 281556
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL 
1605 UTC SAT DEC 28 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH... 
MONSOON TROUGH EXTENDS FROM 05N77W TO 03N80W TO 03N83W THEN ITCZ
TO 09N120W TO 08N130W TO BEYOND 08N140W.  SCATTERED MODERATE
CONVECTION WITHIN 120 NM N OF AXIS FROM 102W TO 120W AND WITHIN
60 NM OF AXIS FROM 123W TO 133W.

...DISCUSSION... 
WELL DEFINED UPPER LEVEL CYCLONE N OF AREA AT 38N139W FLATTENS 
CREST OF MID-UPPER LEVEL RIDGE THAT DOMINATES PATTERN W OF 110W. 
NEGATIVE TILT UPPER LEVEL TROUGH FROM 22N140W TO 17N137W EXPECTED
TO DIG SE AND BE FORCE E BY BROAD INCOMING MID-UPPER LEVEL RIDGE.
TROUGH MAY DEVELOP ANOTHER CYCLONE AND SHIFT NE SUN OR MON. 

ANOTHER TROUGH AXIS EXTEND FROM SOUTHERN MEXICO TO THE GALAPAGOS
ISLANDS WITH VERY DRY AIR MASS NOTED E OF 100W. IF CYCLONE DOES
FORM THERE IS PLENTY OF TROPICAL MOISTURE AVAILABLE N OF 13N W 
OF 120W FOR CONVECTION.  

...ELSEWHERE AT THE LOWER LEVELS...
VIGOROUS HIGH PRES CENTER 1034 MB N OF AREA MAINTAINS MODERATE
TO FRESH NE TRADES AND SEAS TO 8 FT OVER REGION W OF 130W.  HIGH
PRES FORCED NE BY INCOMING STRONG LOW PRES CENTER 990 MB AND NE
TRADES BECOME LIGHT TO MODERATE LATE TODAY.   NW SWELLS PRODUCED
BY LOW PRES CENTER BEGIN IMPACTING NW CORNER OF BASIN LATE SUN.

GULF OF TEHUANTEPEC...STRONG TO NEAR GALE FORCE N WINDS LINGER
AFTER PAST GALE EVENT AND ARE EXPECTED TO DIMINISH TO A MODERATE
BREEZE BY LATE SUN...JUST TO RETURN BY LATE MON OR EARLY TUE AS
NEW COLD FRONT CROSSES GULF OF MEXICO FORCING COLD AIR ACROSS
THE CHIVELAS PASS INTO THE GULF OF TEHUANTEPEC. 

STRONG TO NEAR GALE TRADES OVER SW CARIBBEAN SEEP THROUGH
MOUNTAIN GAPS IN NICARAGUA INTO GULF OF PAPAGAYO.  STRONG E WINDS
LACK THE FETCH TO BUILD SEAS ABOVE 8 FT.  EVENT EXPECTED TO BE
OVER LATE TODAY AS CARIBBEAN BASIN PRES GRADIENT EASES. 

GULF OF CALIFORNIA...SIMILAR TO TRADES FURTHER W...GULF FRESH
NW BREEZE EXPECTED TO DIMINISH LATE TODAY AS VIGOROUS HIGH PRES
LIFTS NE...BUT RETURN IN MID WEEK AS HIGH PRES BUILDS OVER E PAC.

$$
WALLY BARNES