000
AXPZ20 KNHC 161608
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI MAR 16 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 
1530 UTC.

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

THE INTERTROPICAL CONVERGENCE ZONE AXIS WAS ANALYZED SOUTH OF 
THE EQUATOR. NO SIGNIFICANT DEEP CONVECTION.

...DISCUSSION...

A STRONG COLD FRONT WILL BE ENTERING THE NW CORNER OF OUR REGION 
THIS EVENING.  THIS SHOULD SWEEP ACROSS WEST OF OF BAJA 
CALIFORNIA WITH PEAK NW WINDS REACHING 30 KT BY SUNDAY MORNING.  
CONDITIONS COULD REACH GALE FORCE...BUT AT THIS TIME...NONE OF 
THE MODELS ARE INDICATING THESE WINDS.  PEAK SIGNIFICANT WAVE 
HEIGHT SHOULD REACH 15-20 FT SUNDAY MORNING NORTH OF 26N BETWEEN 
117W AND 132W.  THE WAVE FORECASTS ARE A BLEND OF THE TYPICALLY 
MORE AGGRESSIVE GFS-BASED WAVEWATCH AND THE OTHER GLOBAL 
GUIDANCE.

A ZONALLY ORIENTED SURFACE SUBTROPICAL RIDGE ALONG 28N IS 
SUPPORTING A WIDE SWATH OF FRESH TRADE WINDS FROM 05N TO 15N W 
OF 122W ACCORDING TO EARLIER ASCAT AND OSCAT PASSES. THE TRADE 
WINDS WILL SHIFT W OF 130W BY THE END OF THE FORECAST PERIOD SAT 
EVENING. 

A SHEARED UPPER LEVEL TROUGH STRETCHED NE TO SW ACROSS THE 
FORECAST AREA GENERALLY FROM NORTHERN BAJA CALIFORNIA THROUGH 
22N130W TO 13N140W. THIS TROUGH WILL BEGIN TO PHASE WITH AN 
AMPLIFYING NORTHERN STREAM TROUGH IN ASSOCIATED WITH THE 
AFOREMENTIONED COLD FRONT BEGINNING LATER TONIGHT. NO 
SIGNIFICANT SURFACE FEATURES ARE ASSOCIATED WITH THIS SHEARED 
UPPER LEVEL TROUGH CURRENTLY.  THE SOUTHERN STREAM UPPER JET 
ALONG 12N W OF 130W SPLITS AS IT MOVES EASTWARD...WITH THE 
SOUTHERN BRANCH CONTINUING ALONG 10N AND THE NORTHERN BRANCH 
DIRECTED INTO NW MEXICO...TRACKING ONTO THE LEADING EDGE OF THE 
AFOREMENTIONED WEAK UPPER TROUGH TO THE N. THE NORTHERN BRANCH 
OF THE JET IS TRANSPORTING TROPICAL MOISTURE IN THE MID AND 
UPPER LEVELS THROUGH THE SOUTHERN GULF OF CALIFORNIA INTO THE 
RIO GRANDE VALLEY. THIS MOISTURE IS MANIFESTED AS A BAND OF 
MULTI-LAYERED CLOUDS ALONG THE JET AXIS. THESE CONDITIONS WILL 
CONTINUE OVER THE NEXT TWO DAYS AS THE ORIENTATION OF THE 
NORTHERN BRANCH OF THE JET IS NOT EXPECTED TO CHANGE 
SIGNIFICANTLY.

GAP WINDS... 
GULF OF TEHUANTEPEC...THE SURFACE RIDGING AND ASSOCIATED PRES 
GRADIENT OVER SOUTHERN MEXICO AND THE ISTHMUS OF TEHUANTEPEC 
WILL GRADUALLY WEAKEN BEGINNING LATER TODAY. FRESH TO STRONG N 
TO NE WINDS IN THE GULF OF TEHUANTEPEC REGION ARE EXPECTED TO 
DIMINISH TO LESS THAN 20 KT BY LATE SAT.

GULF OF PAPAGAYO...FRESH TO STRONG TRADES ACROSS THE CARIBBEAN 
SEA CONTINUE TO FUNNEL NORTHEASTERLY GAP WINDS OF 20 TO 25 KT 
INTO THE GULF OF PAPAGAYO EXTENDING WESTWARD TO 97W. PEAK WINDS 
SHOULD DECREASE AND AREA OF WINDS IS EXPECTED TO GRADUALLY 
SHRINK EASTWARD THROUGH SAT. 

GULF OF PANAMA...TRADES IN THE SW CARIBBEAN SEA WILL CONTINUE TO 
SUPPORT PULSES OF FRESH NORTHERLY FLOW ACROSS THE ISTHMUS OF 
PANAMA INTO THE GULF OF PANAMA. A JUST RECEIVED 1426 UTC ASCAT 
PASS SHOWS THAT THE WINDS HAD DROPPED BELOW OUR 20 KT THRESHOLD. 
THE WINDS SHOULD PICK UP AGAIN SLIGHTLY LATE THIS EVENING AND 
EARLY TOMORROW MORNING. SEAS ARE EXPECTED TO REMAIN LESS THAN 8 
FT OVER NEXT 48 HOURS.

$$
LANDSEA/COBB