000
AXPZ20 KNHC 020325
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                           
0405 UTC THU JAN 2 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...SPECIAL FEATURE...                                         
GULF OF TEHUANTEPEC STORM WARNING...A STRONG COLD FRONT WILL 
RACE SOUTHWARD IN THE WESTERN GULF OF MEXICO THU AND REACH THE 
ISTHMUS OF TEHUANTEPEC THU EVENING. HIGH PRES BUILDING BEHIND 
THE FRONT WILL PRODUCE A TIGHT PRES GRADIENT ACROSS SOUTHERN 
MEXICO THU NIGHT AND FUNNEL COLD AIR THROUGH THE CHIVELA PASS 
INTO THE GULF OF TEHUANTEPEC. STORM FORCE WINDS ARE EXPECTED IN 
THE REGION STARTING THU NIGHT AND CONTINUE THROUGH FRI MORNING. 
WINDS TO GALE FORCE ARE EXPECTED FRI THROUGH SAT MORNING. MAX 
SEAS GENERATED BY THIS HIGH WIND EVENT ARE PROJECTED TO BE 20 TO 
22 FT FRIDAY. LARGE SWELL WILL SPREAD DOWNWIND FROM TEHUANTEPEC 
REGION FRI THROUGH SUN...WITH 8 FT SEAS REACHING NEAR 110W.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...              
MONSOON TROUGH EXTENDS FROM 07N78W TO 07N86W TO 05N102W...THEN 
ITCZ AXIS TO 08N128W TO 08N140W. SCATTERED MODERATE TO STRONG 
CONVECTION IS WITHIN 30 NM OF AXIS BETWEEN 128W AND 137W.  

...DISCUSSION...                                                
A HIGHLY AMPLIFIED LONG-WAVE UPPER PATTERN CONTINUES OVER THE 
FORECAST AREA. A TROUGH ALONG 148W EXTENDS SOUTHWARD TO 10N. A 
TROUGH BETWEEN 107W EXTENDS DEEP INTO THE TROPICS TO NEAR 04W. 
BETWEEN THE TWO TROUGHS IS A RIDGE ALONG 130W. DIVERGENT FLOW E 
OF THE TROUGH ALONG 148W IS CRESTING OVER THE RIDGE ALONG 
130W...PRODUCING A LARGE AREA OF MID/UPPER LEVEL CLOUDS AND 
EMBEDDED SHOWER ACTIVITY N OF 10N W OF 125W. A PLUME OF MID 
LEVEL MOISTURE IS STREAMING NORTHEASTWARD AHEAD OF THE TROUGH 
AXIS ALONG 107W INTO SOUTH-CENTRAL MEXICO. A WEAK SURFACE RIDGE 
ANCHORED BY 1024 MB HIGH CENTERED NEAR 33N131W PREVAILS OVER THE 
NORTHERN PART OF THE AREA N OF 15N BETWEEN 110W-140W. MODERATE 
TO FRESH TRADE WINDS S OF THE RIDGE ARE FOUND PRIMARILY FROM 08N-
23N W OF 115W. DECAYING LONG-PERIOD NW SWELL DOMINATES WESTERN 
WATERS...AND MIXING WITH NE WIND WAVES ASSOCIATED WITH THE TRADE 
WINDS. STRONG TRADES IN W CARIBBEAN ARE BEING FORCED ACROSS 
MOUNTAIN GAPS INTO THE GULF OF PAPAGAYO. WINDS THERE PULSE TO 20-
25 KT ALMOST EVERY MORNING...ENHANCED BY MOUNTAIN DRAINAGE.

$$ 
MUNDELL