000
AXPZ20 KNHC 262137
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT JAN 26 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 
2015 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
THE MONSOON TROUGH AXIS WAS ANALYZED FROM 04N77W TO 02N80W TO 
06N86W. ITCZ AXIS WAS ANALYZED FROM 06N86W TO 03N105W TO 08N122W 
TO 02N140W. NO SIGNIFICANT DEEP CONVECTION WAS NOTED.

...DISCUSSION...
A FLAT UPPER PATTERN WITH ZONAL FLOW ALOFT DOMINATES THE 
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 THROUGH THE 
SOUTHERN GULF OF CALIFORNIA AND INTO NW 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 8-10 FT RANGE ARE ALREADY IN PLACE AND EXPECTED THE 
REMAIN OVER MUCH OF THE AREA W OF 120W THROUGH THE FORECAST 
PERIOD. 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. 

GAP WINDS...
GULF OF TEHUANTEPEC...1025 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 1524 UTC ASCAT PASS CLIPPED THE EASTERN EDGE OF 
THE STRONG NORTHERLY FLOW HERE. 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. FRESH TO STRONG WINDS ARE EXPECTED TO CONTINUE HERE 
THROUGH THE WEEKEND 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. 

$$
SCHAUER