000
AXPZ20 KNHC 201521
TWDEP 

TROPICAL WEATHER DISCUSSION                                    
NWS NATIONAL HURRICANE CENTER MIAMI FL                       
1605 UTC SUN JUL 20 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 1200 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
1530 UTC.

...TROPICAL WAVES...                           

A TROPICAL WAVE EXTENDS FROM 16N109W TO 09N110W MOVING W 10 TO 
15 KT OVER THE PAST 24 HOURS. SCATTERED MODERATE CONVECTION IS 
NOTED AT THE SOUTHERN END OF THE TROPICAL WAVE ALONG THE ITCZ 
WHERE A 1009 MB SURFACE LOW IS NOTED NEAR 09N108W. ISOLATED 
THUNDERSTORMS ARE ALSO NOTED JUST AHEAD OF THE TROPICAL WAVE 
FROM 12N TO 15N BETWEEN 110W AND 115W. THIS IS IN AN AREA OF 
LIFT ON THE SOUTHEAST END OF A SHARP UPPER TROUGH EXTENDING 
ALONG 117W N OF 10N. GLOBAL MODELS INDICATE THE TROPICAL WAVE 
WILL MAINTAIN CONSISTENCY AS IT MOVES WEST AT LOWER LATITUDES 
THROUGH TUE.
 
ANOTHER TROPICAL WAVE EXTENDS FROM 14N129W TO A 1009 MB LOW NEAR 
10N130W TO 07N130W MOVING W 15 TO 20 KT OVER THE PAST 24 HOURS. 
THE TROPICAL WAVE IS IN AN AREA OF FAIRLY DRY AIR DUE TO 
SUBSIDENT NORTHERLY FLOW ALOFT ON THE EASTERN SIDE OF AN UPPER 
ANTICYCLONE. THEREFORE THERE IS NO SIGNIFICANT CONVECTION 
ASSOCIATED WITH THE WAVE. A RECENT ALTIMETER SATELLITE PASS 
INDICATED SEAS TO 7 FT ALONG THE WAVE AXIS...SLIGHTLY LOWER THAN 
PREVIOUS ESTIMATES. SEAS TO 8 FT ARE STILL POSSIBLE HOWEVER NEAR 
THE TROPICAL WAVE WITH ADDED INFLUENCE OF MIXED NE AND SE SWELL.

...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...  
 
THE MONSOON TROUGH EXTENDS FROM 09N84W TO 07N95W. THE ITCZ 
REACHES FROM 07N95W TO 10N110W TO 06N120W TO 10N130W TO BEYOND 
08N140W. SCATTERED MODERATE TO STRONG CONVECTION IS OBSERVED 
FROM 05N TO 07N E OF 83W. SCATTERED MODERATE CONVECTION IS 
OBSERVED WITHIN 60 NM SW SEMICIRCLE OF 1009 MB LOW PRES 
CENTERED ALONG THE ITCZ NEAR 09M108W. 
 
...DISCUSSION...                                                
AN UPPER CYCLONE IS CENTERED NEAR 31N130W...PROVIDING SUPPORT TO 
WEAK SURFACE TROUGHING N OF 25N BETWEEN 125W AND 135W. THIS 
BREAKS UP THE SUBTROPICAL RIDGE ALONG ROUGHLY 25N AND IS 
ALLOWING FOR FAIRLY WEAK TRADE WIND FLOW S OF 20N.

ANOTHER UPPER CYCLONE CENTERED NEAR 13N95W IS ENHANCING A LARGE 
AREA OF SCATTERED MODERATE TO STRONG CONVECTION FROM 12N TO 
15N BETWEEN 93W AND 95W. THESE THUNDERSTORMS ARE ALSO DUE IN 
PART TO MORNING DRAINAGE FLOW OFF THE COAST AND WILL LIKELY 
DIMINISH SLIGHTLY THIS AFTERNOON. 

STRONG TRADE WIND FLOW OVER THE SW CARIBBEAN WILL ALLOW PULSES 
OF FRESH TO OCCASIONALLY STRONG GAP WINDS INTO THE GULF OF 
PAPAGAYO THE NEXT FEW MORNINGS WITH SEAS TO 8 FT.

$$
CHRISTENSEN