000
AXPZ20 KNHC 231527
TWDEP 

TROPICAL WEATHER DISCUSSION    
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON APR 23 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...
ITCZ FROM 6N89W 4N100W 6N110W 5N125W. SCATTERED MODERATE TO 
STRONG WITHIN 200 NM S OF AXIS BETWEEN 92W-103W. NUMEROUS 
MODERATE TO STRONG CONVECTION FROM 7N-11N BETWEEN 116W-123W.

...DISCUSSION...
UPPER LEVEL TROUGH OVER THE NW PORTION OF THE DISCUSSION FROM 
32N135W TO 20N140W. A BROAD UPPER LEVEL RIDGE IS E OF THE TROUGH 
FROM 15N-30N. A 75-100 KT JETSTREAM S OF THE TROUGH ENTERS THE 
AREA AT 11N140W TO 13N127W. A BAND OF BROKEN CIRRUS CLOUD IS 450 
NM S OF LINE 10N140W TO 23N125W. TRANSVERSE BANDING IS NOTED ON 
THE CIRRUS CLOUDS INDICATING POSSIBLE UPPER LEVEL TURBULENCE.
AN UPPER LEVEL CYCLONIC CIRCULATION IS OF THE SOUTHERN 
CALIFORNIA COAST WITH TROUGH SSE ACROSS CENTRAL BAJA CALIFORNIA.
A SHARP UPPER RIDGE IS OVER NORTHERN MEXICO. IN THE DEEP TROPICS 
AN UPPER LEVEL TROUGH EXTENDS FROM 7N116W TO THE EQUATOR AT 
108W. UPPER LEVEL DIFFLUENT FLOW BETWEEN THE TROUGH AND THE 
BROAD RIDGE IS ENHANCING CONVECTION FROM 7N-11N BETWEEN 
116W-123W. AN E-W RIDGE WITH AXIS FROM PANAMA TO 10N105W.

A 1016 MB HIGH PRES IS CENTERED NEAR 23N121W. THIS HIGH AND THE 
RESULTING PRES GRADIENT HAS BEEN WEAKENED BY THE TROUGHING ALOFT 
HAS RESULTED IN TRADE WINDS LESS THAN 20 KT OVER THE FORECAST 
AREA. THE PRES GRADIENT IS FORECAST TO TIGHTEN ENOUGH FOR A 
SMALL AREA OF 20 KT TRADES FROM 8N-15N BETWEEN 124W-128W TUE.

COLD FRONT ASSOCIATED WITH THE UPPER LEVEL TROUGH EXTENDS FROM 
30N130W TO 23N135W. SCATTERED LIGHT SHOWERS ARE ALONG THE FRONT. 
NW WINDS 20 KT W OF THE FRONT. THESE CONDITIONS WILL CONTINUE 
OVER NW WATERS BEHIND THE SLOW MOVING COLD FRONT OVER THE NEXT 
FEW DAYS...WITH SEAS BUILDING TO 12 FT IN NW SWELL. 

HIGH PRES OVER THE WESTERN GULF OF MEXICO BEHIND A STRONG LATE 
SEASON COLD FRONT HAS TIGHTENED THE PRES GRADIENT ACROSS 
SOUTHERN MEXICO RESULTING IN WINDS TO GALE FORCE THROUGH THE 
GULF OF TEHUANTEPEC. N-NE GALE FORCE WINDS TO 40 KT WITH SEAS 
11-14 FT WILL DIMINISH BELOW GALE FORCE BY TUE AFTERNOON.

THE COLD FRONT THAT BROUGHT THE HIGH PRES OVER THE WESTERN GULF 
OF MEXICO THAT INCREASED THE PRES GRADIENT OVER THE GULF OF 
TEHAUNTEPEC WILL DO THE SAME OVER THE GULF OF PAPAGAYO TUE AFTER 
THE COLD FRONT MOVES INTO COSTA RICA. ELY WINDS ARE EXPECTED TO 
INCREASE TO 20 KT TUE.

$$
DGS