000
AXPZ20 KNHC 021504
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU FEB 02 2012

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 1500 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1200 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH EXTENDS FROM 06N77W TO 04N98W. ITCZ EXTENDS FROM 
04N98W TO BEYOND 04N140W. NO SIGNIFICANT CONVECTION.

...DISCUSSION...
IN THE UPPER LEVELS...A SHARP TROUGH EXTENDING FROM 30N134W TO 
23N132W TO 18N136W IS LIFTING OUT TO THE NORTHEAST THIS 
MORNING.  WHILE THIS IS CAUSING NO SIGNIFICANT DEEP CONVECTION 
OVER THE SUBTROPICAL WATERS...THE TROUGH IS ADVECTING A 
SUBSTANTIAL AMOUNT OF HIGH CLOUDINESS NORTHEASTWARD...SOME OF 
WHICH IS REACHING BAJA CALIFORNIA.  

AT THE SURFACE...A MODERATE NORTH TO SOUTH PRESSURE GRADIENT IS 
PRODUCING FRESH NE TO E TRADEWINDS W OF 120W ALONG 10N.  THESE 
SHOULD CONTINUE WITH LITTLE CHANGE DURING THE NEXT TWO DAYS.  A 
COLD FRONT EXTENDING SOUTHWARD FROM A STORM-FORCE CYCLONE NORTH 
OF OUR REGION SHOULD REACH OUR NORTHWESTERN CORNER THIS 
EVENING.  WHILE THE GFS SUGGESTS THAT THIS WILL BE ACCOMPANIED 
BY 20 TO 25 KT NW WINDS BEHIND THE FRONT...THE REMAINING GLOBAL 
MODEL GUIDANCE INDICATES WINDS STAYING BELOW OUR 20 KT 
THRESHOLD...THUS THESE WINDS WERE NOT INCLUDED IN THE HIGH SEAS 
FORECAST.  REGARDLESS OF WHETHER THESE MODERATE WINDS WILL BE 
OBSERVED...CONTINUED LONG PERIOD NW SWELL FROM THE STORM-FORCE 
CYCLONE WILL PUSH ACROSS MOST OF OUR REGION.  HIGHEST 
SIGNIFICANT WAVE HEIGHT SHOULD REACH 12-13 FT THIS EVENING AND 
FRIDAY IN THE NORTHWESTERN CORNER OF OUR REGION...BASED UPON A 
BLEND OF THE GFS-BASED WAVEWATCH AND OTHER GLOBAL MODEL BASED 
GUIDANCE.

GAP WINDS...
FRESH TO STRONG EASTERLY TRADEWINDS OVER THE SW CARIBBEAN WATERS 
ARE FUNNELING THROUGH THE GAP IN TOPOGRAPHY OVER NICARAGUA INTO 
THE GULF OF PAPAGAYO. THESE GAP WINDS OF 2O TO 25 KT WILL 
CONTINUE THROUGH THE NEXT COUPLE OF DAYS. WINDS WILL PEAK DURING 
THE LATE NIGHT AND EARLY MORNING HOURS WITH THE ADDED COMPONENT 
OF NOCTURNALLY-DRIVEN KATABATIC WINDS. 

THE FRESH WINDS ARE ALSO FLOWING ACROSS THE ISTHMUS OF PANAMA 
AND INTO THE GULF OF PANAMA. THESE SHOULD DIMINISH THIS EVENING.

A MODERATE PRESSURE GRADIENT BETWEEN THE GULF OF MEXICO AND THE 
GULF OF TEHUANTEPEC IS MAINTAINING FRESH TO STRONG NORTHERLY 
FLOW THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC...AS 
NOTED ON A 0552 UTC SCATTEROMETER PASS FROM THE INDIAN OSCAT 
INSTRUMENT. THE RIDGE OF HIGH PRESSURE WILL WEAKEN AND SHIFT 
EASTWARD ON FRIDAY. THIS WILL LOOSEN THE PRESSURE GRADIENT AND 
WINDS OVER THE GULF OF TEHUANTEPEC WILL DIMINISH BELOW 20 KT BY 
FRI AFTERNOON. LOOKING AHEAD...THE NEXT ROUND OF STRONG GAP 
FLOW...POSSIBLY TO GALE FORCE...WILL BE LATE SUNDAY INTO TUESDAY 
AS A COLD FRONT PUSHES THROUGH THE SW GULF FOLLOWED BY STRONG 
HIGH PRESSURE.

NW WINDS WILL INCREASE TO 20 TO 25 KT OVER THE GULF OF 
CALIFORNIA BY FRIDAY AND INTO SATURDAY AS HIGH PRESSURE BUILDS 
OVER THE GREAT BASIN N OF THE AREA AND A TROUGH REMAINS ANCHORED 
OVER N CENTRAL MEXICO.  WINDS FORECAST ARE SLIGHTLY HIGHER THAN 
GUIDANCE GIVEN THE NARROW GULF IS NOT WELL-REPRESENTED IN THE 
MODELS...BUT THE PRESSURE GRADIENT FORCING DOES NOT APPEAR 
STRONG ENOUGH TO INDUCE A GALE IN THE AREA.

$$
LANDSEA