000
AXPZ20 KNHC 180930
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL
1005 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 0600 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0915 UTC.

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

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

...DISCUSSION...

A STRONG LATE SEASON COLD FRONT HAS MOVED INTO NORTHERN WATERS 
AND CURRENTLY EXTENDS ACROSS THE EXTREME NORTHERN GULF OF 
CALIFORNIA AND BAJA CALIFORNIA THROUGH 26N120W TO 22N132W. 
THE YUMA ARIZONA RADAR SHOWS A LINE OF SHOWERS AND THUNDERSTORMS 
ALONG THE PORTION OF THE FRONTAL BOUNDARY OVER SOUTHERN ARIZONA 
SATELLITE IMAGERY SHOWS SCATTERED MODERATE CONVECTION WITHIN 240 
NM E OF THE FRONT N OF 26N MAINLY OVER THE CENTRAL GULF OF 
CALIFORNIA AND NW MEXICO EXTENDING INTO ARIZONA. THIS FRONT WILL 
SWEEP SOUTHEASTWARD ACROSS BAJA CALIFORNIA OVER THE NEXT DAY OR 
SO. NW WINDS ARE FORECAST TO PEAK AT AROUND 30 KT 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 THROUGH TONIGHT. NORTHWEST 
SWELL ASSOCIATED WITH THIS FRONT WILL RESULT IN SEAS AS HIGH AS 
20-21 FT OFF THE W COAST OF BAJA CALIFORNIA NORTE LATER TODAY. 
THE PORTION OF THE FRONT OVER WATERS OFF BAJA CALIFORNIA SUR 
WILL DISSIPATE 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 1031 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 04N TO 20N W 
OF 130W AND FROM 06N TO 14N BETWEEN 123W AND 130W ACCORDING TO 
THE 0610 UTC ASCAT 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 NIGHT. 

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 EXTENDS 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 06N90W TO 04N97W. SCATTERED 
MODERATE WITHIN 150 NM S OF TROUGH BETWEEN 87W AND 92W AND 
WITHIN 60 NM N OF TROUGH BETWEEN 94W AND 96W. 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 INDICATED BY THE 0248 UTC ASCAT AND THE EDGE 
OF A 0500 UTC OSCAT 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. 

$$
COBB