000
AXPZ20 KNHC 230957
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC WED JAN 23 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 
0930 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 03N77W TO 08N85W TO 05N92W THEN ITCZ 
AXIS TO 06N110W TO 15N119W.  SCATTERED MODERATE CONVECTION 
WITHIN 150 NM OF AXIS FROM 113W TO 116W.

...DISCUSSION...
SHARP NEGATIVELY TILTED UPPER LEVEL TROUGH EXTENDS FROM WELL NW 
OF AREA THROUGH 32N134W TO DEEP LAYER CYCLONE AT 24N131W.  WELL 
STACKED CYCLONE SUPPORTS STRONG...ALBEIT WEAKENING...SURFACE LOW 
PRES 1006 MB AT 23N132W AND SECOND SURFACE LOW PRES 1008 MB AT 
30N131W.  WEAKENING COLD FRONT EXTEND FROM SECOND LOW PRES SE TO 
20N126W THEN SW TO 07N138W.  WINDS ASSOCIATED TO THIS COMPLEX 
SCENARIO REACH NEAR GALE FORCE IN W SEMICIRCLE OF BOTH LOWS AND 
ON STRONG TO NEAR GALE FORCE ON EASTERN SIDE OF COLD FRONT 
WITHIN 300 NM.  UPPER LEVEL DIVERGENCE FROM INTERACTION BETWEEN 
UPPER LEVEL LOW PRES AND AMPLIFIED DOWNSTREAM RIDGE ENHANCES 
LARGE AREA OF CONVECTION WITHIN 480 NM N OF 19N E OF COLD FRONT. 

MODEL GUIDANCE WEAKEN BOTH LOW PRES CENTERS SO END OF FORECAST 
PERIOD IS LEFT MAINLY WITH LARGE LONG PERIOD SWELLS...UP TO 12 
FT...ACROSS WESTERN SIDE OF BASIN.  

...ELSEWHERE AT THE LOWER LEVELS...
COMPLEX SURFACE LOW PRES CENTERS WITH PREVIOUS GALE FORCE WINDS 
PROMPTS LARGE LONG PERIOD SWELLS...UP TO 17 FT...S-SE COVERING 
WATERS W OF 100W AND EVEN S OF EQUATOR.  

GULF OF TEHUANTEPEC GALE FORCE WINDS CONTINUE UNABATED PULSATING 
ABOVE AND BELOW GALE FORCE THRESHOLD AS HIGH PRES 1026 MB OVER 
SE CONUS MOVE S INTO NERN GULF OF MEXICO LATE IN THE WEEK.  
MODEL GUIDANCE MOVES HIGH PRES INTO SW N ATLC LATE SAT EASING 
FLOW ACROSS ISTHMUS AND BRINGING WINDS BELOW 20 KT BY THEN. 

N TO NE WINDS CONTINUE TO FUNNEL THROUGH GULFS OF PAPAGAYO AND 
PANAMA WITH SEAS TO 9 FT DOWNSTREAM GULF OF PAPAGAYO AND TO 8 FT 
IN GULF OF PANAMA.  WINDS EXPECTED TO PULSATE THROUGH FRI AS 
LOCAL DRAINAGE EFFECTS ENHANCE OR COUNTER E-NE WIND FIELD.

$$
WALLY BARNES