000
AXPZ20 KNHC 270335
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN JAN 27 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 
0030 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 06N77W TO 08N84W TO 
04N97W. ITCZ AXIS WAS ANALYZED FROM 04N97W TO 09N124W TO 
02N140W. NO SIGNIFICANT DEEP CONVECTION WAS NOTED.

...DISCUSSION...
A FLAT UPPER PATTERN WITH ZONAL FLOW ALOFT DOMINATES THE PACIFIC 
FORECAST AREA N OF 20N. THE TROUGH IN PLACE THE LAST FEW DAYS 
OFF THE BAJA CALIFORNIA PENINSULA HAS SHIFTED INLAND...BUT A 
PLUME OF TROPICAL MOSITURE TO ITS E CONTINUES TO SEND MAINLY 
MID-LEVEL CLOUDS AND WIDELY SCATTERED SHOWERS INTO THE CENTRAL 
MEXICAN COAST PRIMARILY FROM MANZANILLO TO MAZATLAN AND INLAND 
INTO N CENTRAL MAINLAND MEXICO. THIS TROUGH IS BEGINNING TO 
MERGE INTO THE LEADING EDGE OF A DEEPENING MID-LATITUDE TROUGH 
THAT WILL PUSH INTO THE NORTHERN PORTION OF THE FORECAST AREA 
OVERNIGHT TONIGHT. THIS DEEP-LAYER MID-LATITUDE TROUGH HAS 
ALREADY SENT A REINFORCING TRAIN OF NW SWELL THROUGH NW 
WATERS...WITH PERIODS AS LONG AS 20 SECONDS. SEAS IN THE 8-11 FT 
RANGE ARE ALREADY IN PLACE AND EXPECTED THE REMAIN OVER MUCH OF 
THE AREA W OF 120W THROUGH THE WEEKEND. THIS AMPLIFYING 
MID-LATITUDE TROUGH WILL PHASE WITH THE SOUTHERN STREAM UPPER 
JET BY MON. THE RESULTING MORE AMPLIFIED UPPER PATTERN WILL SET 
UP A STRONGER DEEP-LAYER RIDGE OVER THE FORECAST AREA BY MON AND 
BRING A RETURN OF STRONG NE TRADE WINDS OVER W WATERS GENERALLY 
BETWEEN 15N AND 25N WITH SEAS AT OR ABOVE 8 FT IN NW SWELL AND 
NE WIND WAVES FOUND N OF 06N W OF 112W BY MON EVENING. 

GAP WINDS...
GULF OF TEHUANTEPEC...1024 MB HIGH PRES IN THE NE GULF OF MEXICO 
CONTINUES TO SEND A RIDGE AXIS SOUTHWESTWARD TOWARD THE ISTHMUS 
OF TEHUANTEPEC...DIRECTING NORTHERLY FLOW INTO THE GULF OF 
TEHUANTEPEC. THE 1854 UTC OSCAT PASS SHOWED FRESH TO STRONG N-NE 
WINDS EXTENDING S FROM THE COAST TO 14N. ON SUN...THIS HIGH PRES 
SYSTEM IS EXPECTED TO BECOME ENGULFED IN STRONGER HIGH PRES TO 
ITS NE...WEAKENING THE RIDGING IN THE SW GULF OF MEXICO AND 
CUTTING OFF THE STRONG NORTHERLY FLOW THROUGH THE ISTHMUS OF 
TEHUANTEPEC. SEAS IN THE GULF OF TEHUANTEPEC SHOULD SUBSIDE 
BELOW 8 FT AND WINDS BELOW 25 KT BY SUN AFTERNOON AFTER THE 
MORNING DIURNAL MAXIMUM IN DRAINAGE FLOW OFF THE LAND DIMINISHES.

GULF OF PAPAGAYO...THE HIGH PRES OVER THE NE GULF OF MEXICO IS 
ALSO MAINTAINING MODERATE TO FRESH TRADE WINDS ACROSS THE SW 
CARIBBEAN THAT ARE FUNNELING INTO THE GULF OF PAPAGAYO. SHIP 
9HJI9 CONFIRMED THESE CONDITIONS AND REPORTED SEAS TO 9 FT AT 
1800 UTC AND THE 2254 UTC JASON1 PASS CAPTURED SEAS TO 8 FT SW 
OF PAPAGAYO. FRESH TO STRONG WINDS ARE EXPECTED TO CONTINUE HERE 
THROUGH THE MON WITH HIGH PRES TO THE N CONTINUING TO SEND 
EASTERLY FLOW FROM THE CARIBBEAN THROUGH CENTRAL AMERICA. A 
STRONG BREEZE WILL MOST LIKELY BE SEEN IN THE EARLY MORNING 
HOURS WHEN DRAINAGE FLOW IS AT A MAXIMUM. NE SWELL FROM PAPAGAYO 
WILL MIX WITH NW SWELL BETWEEN 90W-100W AND MAY INTERMITTENTLY 
GENERATE SEAS TO 8 FT. 

$$
SCHAUER