000
AXPZ20 KNHC 200245
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN MAR 20 2011

TROPICAL WEATHER DISCUSSION FOR THE EASTERN PACIFIC OCEAN FROM 
THE EQUATOR TO 32N...EAST OF 140W.

BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0300 UTC.

...ITCZ...

THE INTERTROPICAL CONVERGENCE ZONE IS CENTERED ALONG 09N84W TO 
03N96W TO 06N112W TO 04N121W TO 05N128W TO 04N140W. NO 
SIGNIFICANT CONVECTION.

...DISCUSSION...

A VIGOROUS UPPER LEVEL LOW OFF THE PACIFIC NW COAST OF THE U.S. 
EXTENDS A BROAD UPPER THOUGH INTO THE FORECAST DISCUSSION AREA 
NEAR 32N124W TO 24N130W TO W OF THE AREA AT 21N140W. A JET 
STREAM BRANCH ROUNDS THE BASE OF THE TROUGH WITH CORE WINDS OF 
80-100 KT IN THE EXIT REGION OF THE JET. THE UPPER LEVEL TROUGH 
WILL BE REINFORCED BY STRONG COLD AIR ADVECTION OVER THE NEXT 
1-2 DAYS. AS A RESULT THE ASSOCIATED SURFACE COLD FRONT WILL 
QUICKLY SWEEP SE AND MOVE INTO THE NW PORTION EARLY SUN MORNING 
WITH INCREASING SW-W WINDS AHEAD OF IT. ASCAT PASS AT 1930 UTC 
SHOWED WINDS ALREADY NEAR 30 KT BETWEEN 29N AND 30N...WHICH WILL 
INCREASE TO MINIMAL GALE FORCE IN THE NEXT 6 HOURS...WITH SEAS 
BUILDING TO 16 FT. WINDS BEHIND THE FRONT WILL BE W-NW AT 20 TO 
25 KT WITH SEAS TO 18 FT FROM LONG PERIOD NW SWELLS.

A WEAK UPPER RIDGE AXIS EXTENDS FROM AN ANTICYCLONE LOCATED NEAR 
17N103W TO 11N127W. A WEAKENING SURFACE TROUGH MOVING W AT 10-15 
KT ALONG 127W IS NOT ENHANCING GENERATING SIGNIFICANT CONVECTION.

HIGH PRES PREVAILS N OF 15N AND W OF 110W. FRESH TRADE WINDS S 
OF THE RIDGE AXIS ARE EVIDENT FROM ASCAT DATA FROM 06N TO 20N W 
OF 130W. THE RIDGE WILL SHIFT SOUTHWARD AND WEAKEN CONSIDERABLY 
AS THE COLD FRONT MOVES INTO THE REGION SUN. THIS WILL ALLOW THE 
AREA OF TRADES TO SHIFT S AND DIMINISH. A TIGHT PRES GRADIENT 
WILL CONTINUE THE NEXT 6 HOURS NEAR THE COAST OF BAJA CALIFORNIA 
WITH 20 KT NW WINDS EXPECTED TO CONTINUE TONIGHT.

A WEAK SURFACE TROUGH WITH AN EMBEDDED SURFACE CIRCULATION ALONG 
THE COAST OF COLOMBIA IS EXPECTED TO MOVE LITTLE OVER THE NEXT 
48 HOURS.

GAP WINDS...
GULF OF TEHUANTEPEC...N-NE WINDS OF 20-25 KT WITHIN 45 NM OF A 
LINE FROM 16N95W TO 15N95W ARE EXPECTED THE NEXT 2 DAYS WITH A 
DIURNAL MAXIMUM IN THE MORNING DRAINAGE FLOW THROUGH THE PASS.

GULF OF PAPAGAYO...A STRONG PRES GRADIENT IS EXPECTED TO CONTINUE
WITH LITTLE CHANGE EXCEPT FOR DIURNAL EFFECTS THROUGH MON WITH 
WINDS FUNNELING FROM THE CARIBBEAN THROUGH CENTRAL AMERICA.

GULF OF PANAMA...PERSISTENT PRES GRADIENT BETWEEN THE LOW/TROUGH 
NEAR THE COAST OF COLOMBIA AND HIGH PRES OVER CENTRAL AMERICA 
WILL SUSTAIN N WINDS OF 20-25 KT TO 5N BETWEEN 78W-81W WITH ONLY 
SLIGHT CHANGE IN WINDS AND SEAS EXPECTED THE NEXT 24-48 HOURS.

$$
MUNDELL