000
AXPZ20 KNHC 180344
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC SUN MAR 18 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0315 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 HAS MOVED INTO NORTHERN WATERS AND LIES FROM 
30N116W TO 25N125W TO 23N140W. THE SAN DIEGO CALIFORNIA RADAR 
SHOWS A LINE OF SHOWERS ALONG THE FRONTAL BOUNDARY HAD MOVED 
THROUGH TIJUANA INTO BAJA CALIFORNIA NORTE AS OF 0042 UTC. 
SATELLITE IMAGERY SHOWS SCATTERED MODERATE CONVECTION WITHIN 180 
NM E OF THE FRONT N OF 26N. THIS FRONT WILL SWEEP SOUTHEASTWARD 
ACROSS BAJA CALIFORNIA OVER THE NEXT DAY OR SO. PEAK NW WINDS 
WILL REACHING JUST BELOW GALE FORCE IN THE GULF OF CALIFORNIA 
WHERE WESTERLY WINDS WILL FUNNEL THROUGH THE MOUNTAIN PASSES IN 
BAJA CALIFORNIA NORTE ALLOWING FOR LOCALLY STRONGER WINDS IN THE 
NORTHERN GULF THIS EVENING THROUGH SUN EVENING. NORTHWEST SWELL 
ASSOCIATED WITH THIS FRONT WILL BRING SEAS AS HIGH AS 20 FT OFF 
THE W COAST OF BAJA CALIFORNIA NORTE BY SUN. THE PORTION OF THE 
FRONT OVER WATERS OFF BAJA CALIFORNIA SUR WILL DISSIPATE BY MON 
AS THE REMAINDER OF THE BOUNDARY CROSSES EASTWARD THROUGH 
MAINLAND MEXICO.

THE FRONT IS SLICING INTO THE EASTERN EDGE OF THE SUBTROPICAL 
RIDGE WHOSE AXIS STEMS FROM THE 1030 MB HIGH NEAR 31N149W AND IS 
ZONALLY ORIENTED ALONG 22N OVER THE FORECAST AREA. THIS RIDGE IS 
SUPPORTING A LARGE AREA OF FRESH TRADE WINDS FROM 05N TO 20N W 
OF 130W AND FROM 07N TO 14N BETWEEN 125W AND 130W ACCORDING TO 
THE 1906 UTC ASCAT PASS AND 1948 UTC OSCAT PASS. THIS AREA OF 
TRADE WINDS WILL EXPAND TO THE E TO 120W TONIGHT AND THEN REMAIN 
RELATIVELY UNCHANGED THROUGH THE END OF THE PERIOD MON 
AFTERNOON. 

THE SOUTHERN STREAM UPPER JET IS FOUND ON THE LEADING EDGE OF  
BROAD DEEP-LAYER TROUGH ASSOCIATED WITH THE COLD FRONT OVER N 
WATERS. THE JET AXIS LIES FROM 00N135W TO THE TEXAS BIG BEND. 
THE JET IS TRANSPORTING TROPICAL MOISTURE IN THE MID AND UPPER 
LEVELS THROUGH THE SOUTHERN GULF OF CALIFORNIA INTO CENTRAL 
MEXICO AND 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 
UPPER TROUGH MOVES EASTWARD.

A SURFACE TROUGH LIES FROM 10N85W TO 07N87W TO 05N97W. SCATTERED 
MODERATE CONVECTION IS WITHIN 75 NM SE OF TROUGH BETWEEN 85W AND 
86W AND BETWEEN 94W AND 96W AS WELL AS WITHIN 270 NM S OF TROUGH 
BETWEEN 85W AND 91W. 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 PAPAGAYO...THE PRES GRADIENT BETWEEN HIGH PRES OVER THE 
FLORIDA PANHANDLE AND THE AFOREMENTIONED TROUGH FROM 10N85W TO 
07N87W TO 05N97W CONTINUES TO SUPPORT FRESH NE GAP FLOW INTO THE 
GULF OF PAPAGAYO AS SEEN BY THE 1808 UTC 0SCAT PASS. THE AREA OF 
FRESH WINDS IS EXPECTED TO DISSIPATE BY MON AFTERNOON AS THE 
SUPPORTING HIGH PRES SHIFTS NORTHEASTWARD AND THE PRES GRADIENT 
RELAXES. 

$$
SCHAUER