000
AXPZ20 KNHC 042146
TWDEP 

TROPICAL WEATHER DISCUSSION                                     
NWS NATIONAL HURRICANE CENTER MIAMI FL                          
2205 UTC SUN MAY 04 2014

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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC. 

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

THE MONSOON TROUGH EXTENDS FROM 06N77W TO 06N95W TO LOW PRES 
NEAR 09N111W 1012 MB TO 07N120W WHERE LOW LEVEL WINDS SUGGEST A 
TRANSITION TO ITCZ FROM WHICH EXTENDS TO BEYOND 06N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 90 NM S OF 
MONSOON TROUGH AXIS BETWEEN 95W AND 105W. SCATTERED MODERATE TO 
ISOLATED STRONG CONVECTION WAS NOTED WITHIN 120 NM S SEMICIRCLE 
OF THE LOW PRES NEAR 09N11W.

SCATTERED MODERATE TO ISOLATED STRONG CONVECTION WAS ALSO NOTED 
FROM 10N TO 15N BETWEEN 95W AND 110W.

...DISCUSSION...                                       

GULF OF TEHUANTEPEC...GALE FORCE WINDS THROUGH THE GULF OF 
TEHUANTEPEC HAVE LIKELY DIMINISHED A BIT AS HIGH PRES N OF THE 
AREA WEAKENS AND SHIFTS EAST...BUT SUSTAINED WINDS TO 30 KT WILL 
REMAIN A CONCERN THROUGH THE OVERNIGHT HOURS. SEAS TO 11 FT WILL 
GRADUALLY SUBSIDE STARTING TOMORROW AS WINDS DIMINISH. WINDS 
WILL FURTHER DIMINISH BELOW GALE FORCE BY THIS AFTERNOON...THEN 
TO 20 KT OR LESS BY MON AFTERNOON. 

AREAS OF CONVECTION CONTINUE TO FLARE THIS AFTERNOON FROM 10N TO 
15N BETWEEN 95W AND 110W. THIS IS IN PART DUE TO THE STRONG LOW 
LEVEL CONVERGENCE PROVIDED BY TEHUANTEPEC GAP WIND PLUME...BUT 
IS ALSO ENHANCED BY SOUTHERN STREAM JET DYNAMICS ALOFT. THE 
EASTERLY LOW LEVEL FLOW FROM THE GAP WIND PLUME ALONG WITH WEAK 
SOUTHERLY FLOW INTO THE MONSOON TROUGH FARTHER SOUTH IS 
ENHANCING ELONGATED CYCLONIC TURNING ALONG THE MONSOON TROUGH 
NEAR 100W. 

SPORADIC CONVECTION CONTINUES AS WELL IN THE VICINITY OF THE 
1012 MB LOW PRES NEAR 09N111W. THIS IS IN PART ENHANCED BY A 
NEGATIVELY TILTED SHORT WAVE TROUGH IN THE MID TO UPPER LEVELS 
OF THE ATMOSPHERE TO THE NORTHWEST OF THE LOW. WHILE THIS IS 
EXPECTED TO LIFT TO THE NE OF THE AREA TONIGHT...GLOBAL MODELS 
ARE IN GOOD AGREEMENT SHOWING A MORE AMPLIFIED UPPER TROUGH 
APPROACHING THE AREA FROM THE WEST. PROVIDED THIS WILL NOT 
IMPOSE SIGNIFICANT WESTERLY SHEAR ON THE CONVECTION AROUND THE 
LOW PRES...THE RELATED UPPER DIVERGENCE AHEAD OF THE TROUGH WILL 
ALLOW FURTHER CONVECTIVE GROWTH AND BETTER ORGANIZATION WITH 
REGARD TO THE LOW PRES. GLOBAL MODELS CONTINUE TO DEMONSTRATE 
DECENT AGREEMENT AND CONSISTENCY SHOWING THE LOW PRES DEVELOPING 
SLOWLY MOVING TO THE NORTH AND NORTHEAST.

AN ASCAT PASS FROM 1548 UTC INDICATED MODERATE TO FRESH GAP FLOW 
THROUGH THE GULF OF PAPAGAYO. THIS IN TURN SPARKED A FEW SHOWERS 
AND THUNDERSTORMS FARTHER DOWNSTREAM...BUT HAS SINCE DISSIPATED. 
THE GAP FLOW THROUGH PAPAGAYO IS EXPECTED TO REMAIN LIMITED 
THROUGH MID WEEK DUE TO FAIRLY WEAK HIGH PRES N OF THE AREA. 

FARTHER WEST...SCATTEROMETER DATA CONTINUE TO SHOW MODEST TRADE 
WIND FLOW INTO THE ITCZ TO THE SOUTH OF A WEAK SUBTROPICAL 
RIDGE. THE RIDGE IS EXPECTED TO BUILD OVER THE NEXT COUPLE OF 
DAYS. THE PRES GRADIENT SHOULD TIGHTEN SLIGHTLY BETWEEN THE 
BUILDING RIDGE TO THE NORTH AND THE DEEPENING LOW TO THE EAST 
ALLOWING FOR FRESH TRADE WIND FLOW BY MID WEEK.

ALTIMETER DATA FROM SEVERAL HOURS INDICATED SEAS TO 8 FT 
PERSISTING N OF 28N W OF 130W. THIS IS DUE TO LINGERING NW SWELL 
IN THE AREA AND IS EXPECTED TO DECAY BELOW 8 FT LATER TONIGHT. 
 

$$ 
CHRISTENSEN