000
AXPZ20 KNHC 122143
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT JAN 12 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 
2100 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...

THE MONSOON TROUGH IS ALONG 03N77W TO 06N87W TO 06N95W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 06N95W TO 
08N113W TO 06N130W TO 07N140W. SCATTERED MODERATE CONVECTION IS 
S OF THE MONSOON TROUGH E OF 80W...AND ALSO WITHIN 120 NM EITHER 
SIDE OF A LINE FROM 08N128W TO 16N140W.

...DISCUSSION...

SHORT WAVE ENERGY IS ROUNDING THE BASE OF A MID TO UPPER LEVEL 
TROUGH EXTENDING FROM THE NORTHERN ROCKIES THROUGH SOUTHERN NEW 
MEXICO. ASSOCIATED SURFACE TROUGHING ALONG THE COAST OF THE BAJA 
CALIFORNIA PENINSULA IS SUPPORTING FRESH TO STRONG NW FLOW...
ALTHOUGH THE TROUGHING WILL WEAKEN THIS EVENING ALLOWING FOR THE 
WINDS TO DIMINISH. A SET OF NW SWELL ACCOMPANYING THESE WINDS 
WITH SIGNIFICANT WAVE HEIGHTS UP TO 13 FT AND PEAK WAVE PERIODS 
OF 14 SECONDS WILL QUICKLY SUBSIDE TO LESS THAN 8 FT BY SUN 
MORNING.

STRONG STATIONARY 1042 MB HIGH PRES IS CENTERED NEAR 39N141W 
WITH A RIDGE EXTENDING SE ALL THE WAY TO NEAR 13N105W. THE 
STRENGTH OF THIS HIGH PRES CENTER COMBINED WITH LOWER PRESSURE 
IN THE VICINITY OF THE ITCZ IS MAINTAINING A TIGHT PRES GRADIENT 
ACROSS THE W CENTRAL WATERS. THIS PATTERN IS SUPPORTING FRESH TO 
STRONG TRADES OVER MUCH OF THE AREA N OF THE ITCZ AND W OF 
110W...AS CONFIRMED BY AFTERNOON SCATTEROMETER DATA.

GULF OF CALIFORNIA...THE SURFACE RIDGE WILL BUILD FURTHER 
EASTWARD THROUGH SOUTHERN BAJA TONIGHT FOLLOWING THE PASSAGE OF 
THE MID LEVEL SHORT WAVE TROUGH. THIS WILL RESULT IN NORTHERLY 
WINDS INCREASING TO 20 TO 25 KT OVER THE SOUTHERN GULF OF 
CALIFORNIA THIS EVENING...PERSISTING THROUGH SUN. LOOKING 
AHEAD...STRONG HIGH PRES WILL BUILD OVER THE GREAT BASIN EARLY 
NEXT WEEK WHICH WILL RESULT IN STRONG TO NEAR GALE NW WINDS DOWN 
THE ENTIRE LENGTH OF THE GULF OF CALIFORNIA BEGINNING MON 
AFTERNOON.

GAP WINDS...THE GULF OF PAPAGAYO CONTINUES TO PULSE WITH FRESH 
TO STRONG WINDS DURING THE LATE NIGHT AND EARLY MORNING HOURS 
DIMINISHING TO 20 KT OR LESS DURING THE AFTERNOON HOURS. EXPECT 
THE WINDS TO STRENGTHEN ONCE AGAIN TONIGHT INTO EARLY SUN BEFORE 
DIMINISHING TO 20 KT OR LESS BY SUN AFTERNOON THROUGH MON 
AFTERNOON.

LOOKING AHEAD FOR THE GULF OF TEHUANTEPEC...A SURGE OF COLD AIR 
IS FORECAST TO ARRIVE BEHIND A COLD FRONT IN THE GULF OF MEXICO 
LATE TUE INTO WED. NORTHERLY WINDS WILL BE FUNNELED THROUGH THE 
CHIVELA PASS ACROSS THE GULF OF TEHUANTEPEC AREA...WITH GALE 
FORCE WINDS POSSIBLE BY MIDWEEK.

$$
LEWITSKY