000
AXPZ20 KNHC 010946
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 UTC FRI MAR 01 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 
0900 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 09N84W TO 05N90W TO 01N106W. THE 
ITCZ AXIS CONTINUES FROM 01N106W TO 04N120W TO 05N135W TO 
04N140W. SCATTERED MODERATE CONVECTION IS NOTED WITHIN 90 NM N 
OF AXIS BETWEEN 120W AND 135W. ISOLATED MODERATE CONVECTION CAN 
BE FOUND FROM 06N TO 08N BETWEEN 82W AND 87W...AND FROM 02N TO 
05N BETWEEN 95W AND 98W.

...DISCUSSION...

GAP WINDS...
GULF OF TEHUANTEPEC...THE 0906 UTC OSCAT PASS CONFIRMED THE 
PRESENCE OF GALE FORCE WINDS OF 30 TO 35 KT ACROSS THE GULF OF 
TEHUANTEPEC. GAP WINDS HERE WILL BE REINFORCED TODAY BY A 
SECONDARY COLD FRONT CURRENTLY MOVING ACROSS THE BAY OF 
CAMPECHE. THE GRADIENT WILL CONTINUE TO TIGHTEN TODAY INTO 
SAT...AND WINDS WILL FURTHER INCREASE TO STORM FORCE (50 KT) BY 
SAT AFTERNOON AND CONTINUING THROUGH EARLY SUN. GALE CONDITIONS 
ARE FORECAST TO PERSIST THROUGH SUN NIGHT. SEAS ARE EXPECTED TO 
BUILD TO AROUND 23 FT IN ASSOCIATION WITH THESE STORM WINDS. A 
STORM WARNING IS IN EFFECT THROUGH O3/0600 UTC. THIS WILL LIKELY 
BE THE THIRD STORM FORCE WIND EVENT ACROSS THE GULF OF 
TEHUANTEPEC THIS YEAR.

GULF OF CALIFORNIA...THE MOST RECENT OSCAT PASS CAPTURED STRONG 
NW WINDS S OF 29N IN THE GULF OF CALIFORNIA. MAXIMUM SUSTAINED 
WINDS SHOULD BE AS HIGH AS 30 KT IN THE CENTRAL GULF OF 
CALIFORNIA WITH SEAS TO 11 FT ACROSS THE LONG FETCH AREAS IN THE 
CENTRAL GULF WATERS. WINDS WILL GRADUALLY DIMINISH TO 20 KT OR 
LESS AND SEAS SUBSIDE TO LESS THAN 8 FT BY SAT MORNING. 

LOOKING AHEAD...EXPECT INCREASING WINDS AND BUILDING SEAS ACROSS 
THE GULF OF PAPAGAYO AND THE GULF OF FONSECA BY EARLY SUN. 
MARINE GUIDANCE SUGGESTS WINDS OF 20 TO 30 KT AND BUILDING SEAS 
OF 8 TO 10 FT COVERING THE AREA FROM 09N TO 13N BETWEEN 85W AND 
91W. WINDS ARE FORECAST TO ALSO INCREASE ACROSS THE GULF OF 
PANAMA LATER ON SUN. THESE GAP WIND EVENTS WILL BE ASSOCIATED 
WITH A VERY STRONG COLD FRONT MOVING ACROSS THE WESTERN 
CARIBBEAN FOLLOWED BY STRONG TO GALE FORCE WINDS.

A 1035 MB HIGH PRES LOCATED NEAR 35N130W EXTENDS ITS PRIMARY 
RIDGE AXIS SOUTHWESTWARD THROUGH 31N140W WITH A SECONDARY AXIS 
FOUND FROM THE HIGH TO 20N115W. ASCAT PASSES PROVIDED 
OBSERVATIONS OF FRESH TO STRONG NE TRADE WINDS OVER MUCH OF THE 
FORECAST REGION W OF 120W AND N OF THE ITCZ. A SURFACE TROUGH... 
REFLECTION OF AN UPPER LOW LOCATED JUST W OF THE AREA...LIES 
FROM 15N135W TO 08N135W TO 03N139W. THE 0610 UTC ASCAT PASS 
SHOWED N TO NE WINDS OF 20 TO 25 KT W OF THE TROUGH WITH E TO SE 
WINDS IN THE 20 TO 25 KT RANGE E OF THE TROUGH TO AROUND 136W.  
THE TROUGH WILL GRADUALLY WEAKEN AND MOVE NW. MEANWHILE...THE 
HIGH PRES WILL GRADUALLY WEAKEN THROUGH FRI AS A COLD FRONT 
APPROACHES FROM THE W. THE HIGH WILL REORGANIZE BEHIND THE FRONT 
ON SAT. TRADEWINDS WILL DIMINISH TO A STRONG BREEZE AND SHRINK 
WESTWARD TO THE REGION NEAR THE TROUGH TODAY AND SAT IN RESPONSE 
TO THESE CHANGES IN THE WEATHER PATTERN.

$$
GR