000
AXPZ20 KNHC 162149
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2030 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 THE 
FORECAST AREA OVERNIGHT TONIGHT. THIS FRONT WILL SWEEP 
SOUTHEASTWARD ACROSS BAJA CALIFORNIA OVER THE NEXT FEW 
DAYS...WITH PEAK NW WINDS REACHING JUST BELOW GALE FORCE. 
WESTERLY WINDS WILL FUNNEL THROUGH MOUNTAIN PASSES IN BAJA 
CALIFORNIA NORTE ALLOWING FOR LOCALLY STRONGER WINDS IN THE 
NORTHERN GULF OF CALIFORNIA FROM SAT EVENING THROUGH THE END OF 
THE FORECAST PERIOD SUN AFTERNOON. NORTHWEST SWELL ASSOCIATED 
WITH THIS FRONT IS ALREADY INCREASING SEAS TO 10 FT OVER NW 
WATERS. SEAS BEHIND THE FRONT WILL REACH AS HIGH AS 20 FT IN THE 
OFFSHORE WATERS OFF THE W COAST OF BAJA CALIFORNIA NORTE BY SUN 
AFTERNOON.

A ZONALLY ORIENTED SUBTROPICAL RIDGE ALONG 27N IS SUPPORTING A 
WIDE SWATH OF FRESH TRADE WINDS FROM 06N TO 18N W OF 120W 
ACCORDING TO THE 1746 UTC AND 1926 UTC ASCAT PASSES. THE TRADE 
WINDS WILL GRADUALLY SHIFT W OF 130W BY THE END OF THE FORECAST 
PERIOD SUN AFTERNOON. 

A POSITIVELY TILTED UPPER LEVEL TROUGH IS STRETCHED NE TO SW 
ACROSS THE FORECAST AREA GENERALLY FROM NORTHERN BAJA CALIFORNIA 
TO 10N140W. THIS TROUGH WILL BEGIN TO PHASE WITH AN AMPLIFYING 
NORTHERN STREAM TROUGH IN ASSOCIATED WITH THE AFOREMENTIONED 
COLD FRONT BEGINNING LATER TONIGHT. THE SOUTHERN STREAM UPPER 
JET IS FOCUSED ON THE LEADING EDGE OF THE POSITIVELY TILTED 
TROUGH. THIS 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. THIS BAND OF CLOUDS 
WILL GRADUALLY SHIFT SOUTHWARD THROUGH MEXICO AS THE POSITIVELY 
TILTED TROUGH IS PUSHED EASTWARD BY INTRUDING NORTHERN STREAM 
TROUGH.

A SURFACE TROUGH LIES FROM 10N85W TO 05N89W TO 03N99W. SCATTERED 
MODERATE CONVECTION CAN BE FOUND WITHIN 210 NM S OF TROUGH 
BETWEEN 85W AND 93W. THIS CONVECTION IS BEING ENHANCED BY UPPER 
LEVEL DIFFLUENCE ASSOCIATED WITH THE REAR RIGHT QUADRANT OF THE 
SOUTHWESTERLY UPPER JET OVER THE CARIBBEAN SEA. 

GAP WINDS... 
GULF OF TEHUANTEPEC...FRESH TO STRONG N TO NE WINDS IN THE GULF 
OF TEHUANTEPEC WERE OBSERVED BY THE 1604 UTC OSCAT PASS. SURFACE 
RIDGING AND THE ASSOCIATED PRES GRADIENT OVER SOUTHERN MEXICO 
AND THE ISTHMUS OF TEHUANTEPEC WILL GRADUALLY WEAKEN TONIGHT... 
AND THESE WINDS WILL DIMINISH TO LESS THAN 20 KT BY SAT 
AFTERNOON.

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 96W ACCORDING TO 
THE 1604 UTC ASCAT AND 1720 UTC OSCAT PASSES. PEAK WINDS SHOULD 
DECREASE AND THE AREA OF FRESH WINDS IS EXPECTED TO SHRINK 
EASTWARD ON SUN. 

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 FOR NOW. WINDS IN THE GULF OF 
PANAMA ARE EXPECTED TO DROP CONSISTENTLY BELOW 20 KT BY SAT 
AFTERNOON.

$$
SCHAUER