000
AXPZ20 KNHC 201529
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC FRI APR 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1500 UTC.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...
MONSOON TROUGH 8N83W 3N95W 5N125W. ITCZ 5N125W TO 3N135W. 
SCATTERED MODERATE TO STRONG WITHIN 200 NM N OF AXIS FROM 
114W-128W.

...DISCUSSION...
AN UPPER LEVEL ANTICYCLONIC CIRCULATION IS CENTERED NEAR 31N119W.
OTHERWISE MOSTLY ZONAL UPPER LEVEL FLOW IS FROM 10N-25N WITH AN 
80 KT JETSTREAM FROM 17N115W ACROSS SOUTHERN MEXICO. MODERATE TO 
STRONG SUBSIDENCE WITH DRY STABLE AIR AT THE MIDDLE AND UPPER 
LEVELS IS N OF 15N. IN THE DEEP TROPICS AN UPPER LEVEL RIDGE 
EXTENDS FROM PANAMA TO 12N101W. UPPER LEVEL DIFFLUENT FLOW IS 
ENHANCING CONVECTION N OF THE ITCZ FROM 114W-128W.

A 1024 MB HIGH IS CENTERED NEAR 31N138W. A COLD FRONT FURTHER W 
WILL APPROACH THE DISCUSSION AREA SAT NIGHT. NW WINDS ARE 
FORECAST TO INCREASE TO 20 KT W OF THE FRONT. ELY TRADES TO 20 
KT AROUND THE SOUTHERN PERIPHERY OF THE HIGH FROM 6N-20N W OF 
130W WILL DECREASE TO LESS THAN 20 KT BY SAT AS THE HIGH WEAKENS.

HIGH PRES WILL BUILD BEHIND A STRONG LATE SEASON COLD FRONT 
MOVING THROUGH THE GULF OF MEXICO. THIS WILL TIGHTEN THE PRES 
GRADIENT ACROSS SOUTHERN MEXICO RESULTING IN WINDS TO GALE FORCE 
THROUGH THE GULF OF TEHUANTEPEC SAT NIGHT.

$$
DGS