000
AXPZ20 KNHC 172141
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
2205 UTC SAT MAR 17 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 
1945 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 
30N120W TO 26N125W TO 25N140W. THE 1720 UTC AND 1900 UTC ASCAT 
PASSES SHOW WINDS TO 25 KT BEHIND THE FRONT S OF 30N WITH WINDS 
JUST BELOW GALE FORCE OVER THE FORECAST AREA N OF 30N NEAR 125W. 
THE SAN DIEGO CALIFORNIA RADAR SHOWS A LINE OF SHOWERS ALONG THE 
FRONTAL BOUNDARY APPROACHING TIJUANA MEXICO AROUND 2023 UTC. 
SATELLITE IMAGERY SHOWS SCATTERED MODERATE CONVECTION WITHIN 210 
NM EITHER SIDE OF THE FRONT N OF 27N. 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 31N151W AND IS 
ZONALLY ORIENTED ALONG 23N OVER THE FORECAST AREA. THIS RIDGE IS 
SUPPORTING A LARGE AREA OF FRESH TRADE WINDS FROM 05N TO 20N W 
OF 127W AND FROM 05N TO 11N BETWEEN 120W AND 127W ACCORDING TO 
THE 1726 UTC AND 1906 UTC ASCAT PASSES. THIS AREA OF TRADE WINDS 
WILL SHIFT SLIGHTLY FARTHER TO THE W 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 08N84W TO 05N89W TO 03N105W. 
SCATTERED MODERATE CONVECTION IS FOUND WITHIN 180 NM S OF THE 
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 1024 MB HIGH PRES 
OVER THE FLORIDA PANHANDLE AND THE AFOREMENTIONED TROUGH FROM 
08N84W TO 05N89W TO 03N105W CONTINUES TO SUPPORT FRESH NE GAP 
FLOW INTO THE GULF OF PAPAGAYO AS SEEN BY THE 1544 UTC ASCAT 
PASS. THE AREA OF FRESH WINDS IS EXPECTED TO SHRINK TO E OF 88W 
BY MON AFTERNOON AS THE SUPPORTING HIGH PRES SLOWLY SHIFTS 
NORTHEASTWARD. 

$$
SCHAUER