000
AXPZ20 KNHC 291602
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC WED FEB 29 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1415 UTC.

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

THE INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 02N100W TO 
THE EQUATOR NEAR 110W TO 01N130W TO THE EQUATOR NEAR 140W. 
SCATTERED MODERATE FROM 01N TO 04N BETWEEN 100W AND 108W. 

...DISCUSSION...

THE 1032 MB SUBTROPICAL HIGH LIES NW OF THE AREA NEAR 36N150W 
AND EXTENDS A RIDGE SOUTHEASTWARD TO THE SOUTHERN TIP OF BAJA 
CALIFORNIA. A TIGHT PRES GRADIENT LIES OVER BAJA CALIFORNIA 
BETWEEN THE EASTERN EDGE OF THE RIDGE AND TROUGHING OVER N 
CENTRAL MEXICO. THE 0406 UTC ASCAT PASS CAPTURED THE FRESH TO 
STRONG NW WINDS IN THE SOUTHERN GULF OF CALIFORNIA FORCED BY 
THIS PRES GRADIENT. 

A NEW COLD FRONT WILL ENTER NORTHERN WATERS LATER TODAY AND 
PASS THROUGH NE WATERS AND INTO THE NORTHERN GULF OF CALIFORNIA 
BY EARLY FRI MORNING. THE FRESH NW WINDS CURRENTLY ALONG THE W 
COAST OF BAJA CALIFORNIA N OF THE RIDGE AXIS WILL INCREASE TO 
STRONG AND POSSIBLY NEAR GALE FORCE BEHIND THE FRONT. 16-18 
SECOND PERIOD NW SWELL WILL PASS INTO NE WATERS BEHIND THE FRONT 
AS WELL...RAISING SIGNIFICANT WAVE HEIGHTS BEHIND THE FRONT TO 
10-14 FT BY EARLY FRI. 

S OF THE RIDGE AXIS...FRESH TO STRONG NE TRADE WINDS DOMINATE 
MUCH OF THE AREA W OF 120W AS SEEN BY THE 0544 UTC ASCAT PASS. 
LITTLE CHANGE IS EXPECTED IN THE STRENGTH OR POSITION OF THESE 
WINDS OVER THE NEXT TWO DAYS AS THE SUBTROPICAL RIDGE REMAINS 
NEARLY STATIONARY.

THE MEAN TROUGH ALOFT EXTENDS FROM 32N121W TO 15N140W. A 60-90 
KT SOUTHWESTERLY JET LIES ON THE LEADING EDGE OF THIS TROUGH. 
THIS JET IS TRANSPORTING TROPICAL MOISTURE NORTHEASTWARD FROM 
NEAR 10N130W THROUGH THE SOUTHERN GULF OF CALIFORNIA AND INTO 
THE RIO GRANDE VALLEY. AN AREA OF SCATTERED MODERATE CONVECTION 
IS NOTED FROM 09N TO 20N BETWEEN 119W AND 130W NEAR THE REAR 
RIGHT QUADRANT OF THE UPPER JET. ELSEWHERE...THIS MOISTURE IS 
MANIFESTED AS BAND OF MID TO UPPER LEVEL CLOUDINESS. 

AN ANTICYCLONE ALOFT LIES NEAR 07N95W AND EXTENDS A RIDGE 
SOUTHWESTWARD TO 00N105W. AN AREA OF SPEED CONVERGENCE AT THE 
SURFACE LIES UNDER ITCZ. MOISTURE CONVERGED IN THIS AREA IS 
BEING LIFTED BY THE DIFFLUENCE ALOFT...ENHANCING THE AREA OF 
SCATTERED MODERATE CONVECTION NEAR THE ITCZ DESCRIBED IN THE 
SECTION ABOVE.

GAP WINDS...

GULF OF CALIFORNIA...20-25 KT NW WINDS ARE IN THE SOUTHERN GULF 
S OF 28N EXTENDING S TO 19N E OF 110W. BY EARLY FRI 
MORNING...WINDS WILL BE LESS WILL BE TEMPORARILY LESS THAN 20 
KT IN THE GULF BEFORE THE NEXT COLD FRONT PASSES THROUGH LATER 
ON FRI.

GULF OF TEHUANTEPEC...THE 0402 UTC ASCAT PASS SHOWED WINDS TO 20 
KT WITHIN 45 NM OF THE COAST OF THE GULF OF TEHUANTEPEC. BY THIS 
AFTERNOON...WINDS IN THE WESTERN GULF OF MEXICO WILL TURN MORE 
SOUTHERLY. THIS WILL TURN OFF THE NORTHERLY FLOW THROUGH THE 
CHIVELA PASS. 

GULF OF PAPAGAYO...A STRONG PRESSURE GRADIENT ACROSS THE WESTERN 
CARIBBEAN AND CENTRAL AMERICA IS FORCING STRONG NE FLOW INTO THE 
GULF OF PAPAGAYO THAT IS EXPECTED TO CONTINUE FOR THE NEXT 48 
HOURS. IN ADDITION...MID LEVEL ENERGY EXTENDING DOWNWIND FROM 
PAPAGAYO IS ENHANCING NE WINDS AT THE SURFACE AS FAR W AS 105W. 
THESE WINDS WILL SLOWLY SHRINK IN AREA THROUGH THE PERIOD.

GULF OF PANAMA... NORTHERLY WINDS ARE EXPECTED TO INCREASE TO 20 
KT WITH SEAS LESS THAN 8 FT THIS EVENING. FRESH N WINDS WILL 
PERSIST UNTIL THE END OF THE PERIOD FRI.

$$
FORMOSA