000
AXPZ20 KNHC 200318
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC FRI JAN 20 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 
0300 UTC.

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

THE MONSOON TROUGH AXIS EXTENDS FROM 04N77W TO 03N80W TO 
04.5N87W TO 03N90W. ITCZ AXIS EXTENDS FROM 03N90W TO 02N97W TO 
06N116W TO BEYOND 04N140W. SCATTERED MODERATE CONVECTION WAS 
NOTED WITHIN 120 NM OF AXIS BETWEEN 115W AND 130W. SCATTERED 
MODERATE CONVECTION WAS NOTED WITHIN 60 NM S OF AXIS W OF 135W.

...DISCUSSION...

A MID AND UPPER CYCLONIC CIRCULATION IS CENTERED NEAR 22N126W. 
THIS CIRCULATION IS HELPING PRODUCE SCATTERED SHOWERS AND 
THUNDERSTORMS FROM 16N TO 22N BETWEEN 123W AND 126W. THIS 
FEATURE WILL DRIFT SLOWLY E THROUGH THE NEXT 48 HOURS ALONG WITH 
THE ASSOCIATED PATCH OF MODERATE CONVECTION. OTHERWISE THE 
PATTERN IS DOMINATED BY A 1024 MB HIGH PRES AREA CENTERED NEAR 
27N131W. THE PRESSURE GRADIENT BETWEEN THIS AREA OF HIGH 
PRESSURE AND LOWER PRESSURE IN THE VICINITY OF THE ITCZ IS 
MAINTAINING FRESH TO STRONG TRADE WIND FLOW FROM 06N TO 18N W OF 
115W. HIGH PRESSURE WILL CONTINUE TO PREVAIL OVER THIS REGION 
AND MAINTAIN THIS COVERAGE OF FRESH TO STRONG TRADE WINDS 
THROUGH AT LEAST SAT NIGHT. THE PRESSURE GRADIENT BETWEEN THE 
RIDGE OF HIGH PRESSURE AND A TROUGH OVER MEXICO IS PRODUCING A 
PRESSURE GRADIENT TO SUPPORT FRESH NW WINDS N OF 28N W OF THE 
COAST OF BAJA CALIFORNIA. THESE WINDS ARE ALSO EXPECTED TO 
CONTINUE THROUGH AT LEAST SAT EVENING. 

GULF OF TEHUANTEPEC...HIGH PRES OVER THE GULF OF MEXICO HAS 
SHIFTED E OF THE GULF WATERS. THIS HAS DIMINISHED THE PRESSURE 
GRADIENT OVER THE SW GULF OF MEXICO AND WINDS FUNNELING THROUGH 
THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. FRESH 20 KT WINDS 
CONTINUE OVER THE GULF OF TEHUANTEPEC...AND MAY REACH TO 25 KT 
DURING THE OVERNIGHT HOURS WITH THE ADDITION OF NOCTURNAL 
DRAINAGE FLOW. WINDS OVER THE GULF OF TEHUANTEPEC ARE THEN 
EXPECTED TO DIMINISH BELOW 20 KT BY FRI AFTERNOON. 

GULF OF PAPAGAYO...FRESH WINDS OVER THE SW CARIBBEAN ARE 
FUNNELING THROUGH THE GAPS IN TOPOGRAPHY OF NICARAGUA AND COSTA 
RICA ACROSS THE GULF OF PAPAGAYO. WITH THE FRESH WINDS EXPECTED 
TO CONTINUE OVER THE SW CARIBBEAN...THE FRESH FLOW OVER THE GULF 
OF PAPAGAYO WILL PERSIST AT LEAST THROUGH SAT EVENING. WINDS 
OVER THE GULF OF PAPAGAYO WILL PEAK NEAR 25 KT DURING THE EARLY 
MORNING HOURS WITH THE ADDED COMPONENT OF NOCTURNALLY DRIVEN 
KATABATIC WINDS. 

GULF OF PANAMA...FRESH WINDS FROM THE SW CARIBBEAN ARE FUNNELING 
ACROSS THE ISTHMUS INTO THE GULF OF PANAMA. THE FRESH WINDS OVER 
THE GULF OF PANAMA WILL CONTINUE AT LEAST FOR THE NEXT 48 HOURS.

$$
AL