000
AXPZ20 KNHC 042204
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC FRI JAN 04 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH AXIS FROM 07N78W TO 07N84W BECOMES ITCZ TO 
07N107W THEN RESUMES FROM 07N112W TO 06N140W. SCATTERED MODERATE 
CONVECTION WITHIN 180 NM OF AXIS E OF 85W AND 180 NM N OF AXIS W 
OF 120W.

...DISCUSSION...
WEAK BROAD RIDGE SPREADS OVER BASIN W OF 115W WHILE LARGE 
AMPLITUDE LONGWAVE TROUGH COVERS BASIN FROM 95W TO 115W.  RIDGE 
BRINGS IN ABUNDANT MOISTURE ALOFT ON 70 KT JET CORE MOSTLY W OF 
130W.  MOSTLY DRY AND STABLE AIR N OF 20N E OF 115W.  VIGOROUS 
SHORTWAVE SLIDES ON W SIDE OF UPPER LEVEL LONGWAVE TROUGH AS IT 
DIGS SE JUST UPSTREAM FROM RIDGE.  THIS SCENARIO THREATENS TO 
BRING DETERIORATING WEATHER TO WESTERN E PAC JUST BEYOND 
FORECAST PERIOD.  

AT THE SURFACE...HEALTHY 1025 MB HIGH PRES CENTER 33N126W HAS 
RIDGE EXTEND SE TO 20N115W.  TIGHT PRES GRADIENT S OF RIDGE AND 
N OF ITCZ PROMPTS FRESH TO STRONG TRADE WINDS ACROSS W CENTRAL 
WATERS.  AREA OF STRONG TRADES EXPAND EARLY SUN AS COLD FRONT 
ENTERS NW WATERS.  LARGE LONG PERIOD NW SWELL UP TO 14 FT SPREAD 
ACROSS MOST OF BASIN E OF 100W. 

TIGHT PRES GRADIENT OVER GULF OF CALIFORNIA BETWEEN SURFACE 
TROUGH ALONG WESTERN COAST OF MEXICO AND ABOVE-DISCUSSED RIDGE 
FORCES FRESH TO STRONG NW WINDS AS FAR S AS 27N EXPECTED TO 
DIMINISH AS RIDGE WEAKENS.

GAP WINDS...GULF OF TEHUANTEPEC...GALE FORCE WINDS IN SW GULF OF 
MEXICO PULSE ACROSS CHIVELAS PASS INTO GULF OF TEHUANTEPEC... 
MOSTLY FORCE DURING LATE NIGHT AND EARLY MORNING HOURS THROUGH 
SUN.  REINFORCING NORTHERLY SURGE LIKELY TO ARRIVE LATE SUN.

GULF OF PAPAGAYO...DEVELOPING GALE EVENT IN SW CARIBBEAN 
INCREASE FRESH TO STRONG WINDS CROSS NICARAGUA MOUNTAIN PASSES 
AND ENTER GULF OF PAPAGAYO WITH SEAS BUILDING TO 10 FT BY EARLY 
SAT.  WINDS WEAKEN LATE SUN AS GALE EVENT ENDS IN CARIBBEAN.

$$
WALLY BARNES