000
AXPZ20 KNHC 310954
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC SAT DEC 31 2011

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.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...MONSOON 
TROUGH AXIS FROM 08N81W TO 04N96W THEN ITCZ TO 07N118W TO 
06N129W TO BEYOND 07N140W.  SCATTERED MODERATE TO STRONG 
CONVECTION WITHIN 90 NM OF AXIS FROM 120W TO 135W. 

...DISCUSSION...
WEAK HIGH PRES 1025 MB CENTER AT 31N133W WITH RIDGE AXIS 
EXTENDING SE TO 16N107W MAINTAINS PRES GRADIENT WITH ITCZ ENOUGH 
TO PRODUCE FRESH NE BREEZE FROM 10N TO 20N W OF 130W.  HIGH PRES 
WEAKENS AND SHIFT E LATE SUN EASING GRADIENT WHICH DIMINISHES 
COVERAGE AND STRENGTH OF TRADES.  COLD FRONT BRUSHES NW PART OF 
BASIN SUN BRINGING FRESH SW WINDS AHEAD OF IT AND FRESH TO 
STRONG NW BEHIND IT...BUT QUICKLY SHIFTS NE MAKING THE WIND 
IMPACT A VERY SHORT TIME.  ON THE OTHER HAND...LARGE LONG PERIOD 
NW SWELLS...AS HIGH AS 20 FT...BEHIND FRONT PROPAGATE SE INTO 
BASIN PEAKING MON. 

GULF OF PAPAGAYO...
FRESH TO STRONG TRADEWINDS WESTERN CARIBBEAN FLOW THROUGH 
NICARAGUA MOUNTAINS INTO GULF OF PAPAGAYO.  WINDS PEAK DURING 
LATE NIGHT AND EARLY MORNING COOL HOURS WITH MOUNTAIN DRAINAGE 
ADDING TO TRADES.  AREAL COVERAGE EXPANDS SUN AS FAR AS 90W 
AS CARIBBEAN WINDS INCREASE.

GULF OF TEHUANTEPEC...
WEAK TROUGH OVER YUCATAN PENINSULA FUNNELS AIR ACROSS CHIVELA 
PASS INTO GULF OF TEHUANTEPEC EARLY SAT WITH FRESH NORTHERLY 
WINDS IN PLACE LATE SAT.  WINDS INCREASE SUN AS STRONGER HIGH 
PRES BUILDS SOUTHWARD ACROSS MEXICO AND REACH GALE FORCE LATE 
SUN.  GUIDANCE SOLUTIONS HAVE BACKED OFF REACHING STORM FORCE 
WINDS...SO HAS FORECAST...BUT GUSTS TO NEAR GALE FORCE ARE A 
POSSIBILITY. GALE WARNING HAS BEEN ISSUED IN HIGH SEAS FORECAST. 
REFER TO AWIPS/WMO HEADERS MIAHSFEP2/ FZPN03KNHC FOR ADDITIONAL 
INFORMATION. 
     
$$
WALLY BARNES