000
AXPZ20 KNHC 190316
TWDEP 

TROPICAL WEATHER DISCUSSION   
NWS NATIONAL HURRICANE CENTER MIAMI FL
0405 UTC THU JAN 19 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 05N78W TO 02N94W. THE ITCZ 
AXIS EXTENDS FROM 02N94W TO 06N116W TO BEYOND 04N140W. SCATTERED 
MODERATE CONVECTION WAS NOTED WITHIN 150 NM N OF AXIS BETWEEN 
115W AND 125W.

...DISCUSSION...
HIGH PRES 1030 MB IS CENTERED N OF THE AREA NEAR 33N125W WITH 
RIDGE EXTENDING SE TO NEAR 17N108W. THE PRESSURE GRADIENT 
BETWEEN THIS FEATURE AND LOWER PRESSURE IN THE VICINITY OF THE 
ITCZ IS MAINTAINING FRESH TRADEWINDS FROM 05N TO 20N W OF 110W. 
THE AREA OF HIGH PRESSURE WILL SHIFT SOUTHWARD INTO THE NORTHERN 
PART OF THE FORECAST AREA OVER THE NEXT 24 HOURS WHERE IT WILL 
REMAIN THROUGH THE REMAINDER OF THE FORECAST PERIOD. THIS WILL 
MAINTAIN THE LARGE COVERAGE OF FRESH TO STRONG TRADEWINDS 
THROUGH AT LEAST FRI EVENING. 

THE PROXIMITY OF THE AREA OF HIGH PRESSURE MENTIONED ABOVE AND A 
TROUGH OF LOW PRESSURE OVER MEXICO IS MAINTAINING A PRESSURE 
GRADIENT TO SUPPORT FRESH NW TO N FLOW OVER THE GULF OF 
CALIFORNIA S TO NEAR 18N. THE AREA OF HIGH PRESSURE WILL WEAKEN 
THROUGH THU NIGHT WHICH WILL LOOSEN THE PRESSURE GRADIENT ENOUGH 
TO DIMINISH WINDS BELOW 20 KT OVER THE GULF OF CALIFORNIA. 

GAP WINDS...
GULF OF TEHUANTEPEC...HIGH PRESSURE BEHIND A COLD FRONT OVER THE 
GULF OF MEXICO HAS INCREASED THE PRESSURE GRADIENT OVER THE SW 
GULF. THIS HAS RESULTED IN FRESH TO STRONG WINDS FUNNELING 
THROUGH THE CHIVELA PASS INTO THE GULF OF TEHUANTEPEC. WINDS OF 
30 KT CURRENTLY PREVAIL AND WILL REMAIN THROUGH THU MORNING. 
WINDS WILL START TO DIMINISH THU AS THE HIGH PRESSURE CENTER 
SHIFTS FURTHER EASTWARD ACROSS THE GULF OF MEXICO. THIS WILL 
WEAKEN THE PRESSURE GRADIENT...AND VEER WINDS OVER THE GULF OF 
MEXICO.,,WHICH WILL DIMINISH WINDS BELOW 20 KT OVER THE GULF OF 
TEHUANTEPEC BY FRI AFTERNOON.

GULF OF PAPAGAYO...FRESH TO STRONG TRADEWINDS OVER THE FAR 
WESTERN CARIBBEAN ARE FUNNELING THROUGH GAPS IN THE THE 
TOPOGRAPHY OF NICARAGUA AND COSTA RICA INTO THE GULF OF 
PAPAGAYO. THIS WILL CONTINUE THROUGH AT LEAST FRI EVENING WITH 
WINDS PEAKING DURING THE EARLY MORNING HOURS WITH THE ADDED 
COMPONENT OF NOCTURNALLY DRIVEN KATABATIC WINDS. MEANWHILE THE 
WINDS OVER THE SW CARIBBEAN ARE ALSO FUNNELING INTO THE GULF OF 
PANAMA PRODUCING FRESH NLY WINDS. THESE WINDS OVER THE GULF OF 
PANAMA ARE ALSO EXPECTED TO CONTINUE THROUGH THE NEXT 48 HOURS.

$$
AL