000
AXPZ20 KNHC 210231
TWDEP 

TROPICAL WEATHER DISCUSSION  
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 UTC TUE JUL 21 2015

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 
0230 UTC. 

...SPECIAL FEATURES...

A 1009 MB SURFACE LOW IS ANALYZED NEAR 13N110W AND IS MOVING NW 
AT 06 KT. SCATTERED MODERATE ISOLATED STRONG CONVECTION 
CONTINUES WITHIN 420 NM OVER THE NW QUADRANT WITH INTERMITTENT 
BANDING FEATURES. UPPER LEVEL NORTHEASTERLY WIND SHEAR HAS 
PERSISTED LONGER THAN EXPECTED AND PREVENTED THE ANTICIPATED 
TROPICAL CYCLONE FORMATION. THIS WIND SHEAR IS STILL FORECAST TO 
WEAKEN AND THERE IS A VERY HIGH PROBABILITY OF TROPICAL CYCLONE 
FORMATION WITHIN THE NEXT DAY OR SO. CYCLONIC 20-30 KT WINDS ARE 
OBSERVED WITHIN 150 NM OF THE CENTER. THE LOW...OR POSSIBLE 
TROPICAL CYCLONE IS FORECAST TO MOVE TO NEAR 15N115W 1007 MB 
LATE TUE WITH CYCLONIC WINDS INCREASING TO 30-35 KT MINIMAL GALE 
FORCE WITHIN 45 NM OF CENTER...WITH SEAS BUILDING TO 17 FT. THE 
LOW...OR POSSIBLE CYCLONE IS FORECAST TO REACH NEAR 16N116W 1003 
MB LATE WED WITH 30-40 KT GALE CONDITIONS WITHIN 75 NM OF 
CENTER...AND SEAS BUILDING 12-18 FT. SEE LATEST HIGH SEAS 
FORECAST UNDER WMO/AWIPS HEADERS FZPN03 KNHC/MIAHSFEP1 FOR 
ADDITIONAL DETAILS.

...LOWS AND TROPICAL WAVES...

THE REMNANT LOW PRESSURE OF DOLORES IS LOCATED NEAR 31.5N122W 
AND IS ANALYZED AS 1012 MB. THERE IS NO SIGNIFICANT CONVECTION 
AND ASSOCIATED SURFACE WINDS HAVE DIMINISHED TO 1FROM 12N120W TO 
09N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 180 NM OF 
LINE FROM 07N84W TO 07N95W...WITHIN 120 NM OF LINE FROM 07N96W 
TO 04N105W...WITHIN 90 NM OF LINE FROM 09N113W TO 03N131W...AND 
WITHIN 75 NM OF LINE FROM 08N133W TO 07N140W.0-15 KT. THE LOW 
WILL MOVE N OF THE AREA ON TUE.  

THE REMNANT LOW OF ENRIQUE IS ANALYZED AT 1010 MB NEAR 21.5N136W 
AND IS MOVING SLOWLY W-NW. SCATTERED MODERATE CONVECTION IS 
NOTED WITHIN 30 NM OF 21.5N135.5W. SURFACE WINDS OF 10-15 KT 
CONTINUE WITHIN 240 NM OVER THE NW QUADRANT WITH SEAS OF 6-8 FT 
PRIMARILY DUE TO MIXING SWELLS. THE LOW IS FORECAST TO MOVE W OF 
THE AREA ON TUE.
 
A TROPICAL WAVE IS ANALYZED FROM 07-17N ALONG 100W WITH ISOLATED 
MODERATE AND STRONG CONVECTION NOTED WITHIN 150 NM OF THE WAVE 
AXIS.
 
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...            

A WEAK SURFACE TROUGH ORIGINATES FROM A 1008 MB SURFACE LOW OVER 
NW COLOMBIA AT 10.5N74W AND EXTENDS WSW ACROSS THE SOUTHERN GULF 
OF PANAMA AND IS ACCOMPANIED BY SCATTERED MODERATE TO STRONG 
CONVECTION OVER AND WITHIN 60 NM N OF THE TROUGH AXIS.  
SCATTEROMETER WINDS INDICATE THAT THE ITCZ FORMS AT 2N120W AND 
EXTENDS SW TO BEYOND 09N140W. FROM 12N120W TO 09N140W. SCATTERED 
MODERATE ISOLATED STRONG WITHIN 180 NM OF LINE FROM 07N84W TO 
07N95W...WITHIN 120 NM OF LINE FROM 07N96W TO 04N105W...WITHIN 
90 NM OF LINE FROM 09N113W TO 03N131W...AND WITHIN 75 NM OF LINE 
FROM 08N133W TO 07N140W.

SCATTERED MODERATE ISOLATED STRONG CONVECTION IS OFROM 12N120W 
TO 09N140W. SCATTERED MODERATE ISOLATED STRONG WITHIN 180 NM OF 
LINE FROM 07N84W TO 07N95W...WITHIN 120 NM OF LINE FROM 07N96W 
TO 04N105W...WITHIN 90 NM OF LINE FROM 09N113W TO 03N131W...AND 
WITHIN 75 NM OF LINE FROM 08N133W TO 07N140W.BSERVED WITHIN 180 
NM EITHER SIDE OF A LINE FROM 07N84W TO 07N95W...WITHIN 120 NM 
EITHER SIDE OF A LINE FROM 07N96W TO 04N105W...WITHIN 90 NM 
EITHER SIDE OF A LINE FROM 09N113W TO 03N131W...AND OVER AND TO 
THE S OF THE ITCZ WITHIN 75 NM OF LINE FROM 08N133W TO 07N140W.

...DISCUSSION...

CROSS EQUATORIAL SOUTHERLY SWELL IS MIXING WITH NW SWELL  
RESULTING IN COMBINED SEAS OF 6-9 FT SEAS ACROSS THE TROPICS S 
05N BETWEEN 105-130W. THESE ENHANCED SEAS ARE EXPECTED TO MOVE N 
REACHING THE COAST OF CENTRAL AMERICA ON WED NIGHT THROUGH EARLY 
THU NIGHT.

GULF OF PAPAGAYO...GUIDANCE HAS BACKED OFF SOMEWHAT AND NOW  
EXPECT E-NE 15 KT DRAINAGE TONIGHT WITH SEAS TO ONLY 7 FT. 
DRAINAGE WINDS OF 15-20 KT ARE EXPECTED TO RESUME ON WED NIGHT 
RESULTING IN A SWATH OF 6-8 FT PROPAGATING WSW TO NEAR 10.5N90W 
ON THU MORNING.

$$ 
NELSON