000
AXPZ20 KNHC 201601
TWDEP 

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

...TROPICAL WAVES...

A TROPICAL WAVE EXTENDS FROM 04N TO 12N ALONG 99W. EXTRAPOLATION 
OF AN EARLIER ASCAT PASS AND LOW CLOUD MOTIONS SUGGESTED A LOW 
PRESSURE AREA HAS FORMED ALONG THE AXIS NEAR 08N99W. THERE IS NO 
SIGNIFICANT CONVECTION DIRECTLY ASSOCIATED WITH THE LOW PRESSURE 
AREA...HOWEVER SCATTERED MODERATE...BUT WEAKENING CONVECTION WAS 
NOTED FROM 05N TO 08N BETWEEN 94W AND 96W. THIS WAVE IS SITUATED 
NOT FAR FROM ANOTHER TROPICAL WAVE THAT IS NOW ESTIMATED TO BE 
ALONG 106W/107W FROM 05N TO 13N. ADDITIONAL ADJUSTMENTS MAY BE 
MADE TO THE ANALYSIS OVER THE NEXT 24 TO 48 HOURS AS THE 
TROPICAL WAVES INTERACT.

A TROPICAL WAVE AXIS IS ALONG 122W FROM 10N TO 16N MOVING W AT 
15 KT. THE WAVE REMAINS BROADLY APPARENT ON THE LATEST GFS 700 
MB STREAMLINE AND 850 MB VORTICITY ANALYSIS. THE TPW IMAGERY 
SHOWS A LARGE SWATH OF DEEP TROPICAL MOISTURE IN ASSOCIATION 
WITH THIS SYSTEM. OVER THE PAST SEVERAL HOURS SCATTERED STRONG  
CONVECTION HAS DEVELOPED FROM 12.5N TO 14N BETWEEN 117W AND 
120W. 

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

THE AXIS OF THE MONSOON TROUGH EXTENDS FROM 13N129W TO 12N140W. 
SCATTERED MODERATE CONVECTION WAS NOTED WITHIN 180 NM N OF THE 
AXIS W OF 130W. 
 
...DISCUSSION... 

N OF 15N E OF 120W...SHIP OBSERVATIONS AND DATA FROM AN 0512 UTC 
ASCAT PASS INDICATE MODERATE TO FRESH NW WINDS OFF THE PACIFIC 
COAST OF THE BAJA PENINSULA...BETWEEN 1016 MB HIGH PRES CENTERED 
NEAR 26N125W AND A SURFACE TROUGH ALONG THE COLORADO RIVER 
VALLEY INTO THE NORTHERN BAJA PENINSULA. RECENT ALTIMETER PASSES 
INDICATE SEAS ARE GENERALLY 5 TO 7 FT N OF 22N AND 4 TO 6 FT 
ELSEWHERE N OF 15N. THUNDERSTORMS OVER THE SOUTHERN PORTION OF 
BAJA CALIFORNIA AND THE GULF OF CALIFORNIA CONTINUE TO DIMINISH. 
WINDS AND SEAS OFF THE COAST OF  BAJA CALIFORNIA WILL DIMINISH 
THROUGH TONIGHT AS THE HIGH PRES WEAKENS AND DRIFTS WEST. 
MODERATE SOUTHERLY FLOW WILL PERSIST OVER THE NORTHERN GULF OF 
CALIFORNIA WITH SEAS TO 4 FT. NO CHANGES EXPECTED OTHERWISE 
THROUGH THE NEXT COUPLE OF DAYS.

S OF 15N E OF 110W...GLOBAL MODELS ARE IN GOOD AGREEMENT SHOWING 
SLOW DEVELOPMENT OF THE LOW PRESSURE CENTERED NEAR 08N99W. WINDS 
MAY BE REACHING 20 KT WITHIN 120 NM ON THE SE SIDE OF THE LOW 
LATER TODAY...BUT GENERALLY SCATTERED MODERATE CONVECTION WAS 
FROM 05N TO 08N BETWEEN 94W AND 96W. FRESH GAP WIND FLOW IS 
LIKELY PULSING THROUGH THE GULF OF PAPAGAYO THIS MORNING...A 
TREND THAT WILL CONTINUE OVERNIGHT FOR THE NEXT COUPLE OF 
NIGHTS...GENERATING SEAS TO 5 TO 7 FT DOWNSTREAM. ELSEWHERE SEAS 
ARE 4 TO 6 FT. LITTLE CHANGE IS EXPECTED OTHER THAN THE LOW 
DRIFTING WESTWARD SLOWLY.

ELSEWHERE...THE REMNANT LOW OF T.D. ELEVEN PERSISTS NEAR 29N132W 
WITH MSLP OF 1013 MB. NO SIGNIFICANT CONVECTION OR WINDS ARE 
NOTED WITH THIS FEATURE AND SEAS HAVE SUBSIDED BELOW 8 FT. THE 
LOW PRES IS EXPECTED TO WEAKEN AND NOT MOVE MUCH THROUGH THE 
NEXT 2 TO 3 DAYS. FARTHER SOUTH...DEVELOPING LOW PRES W OF 140W 
HAS BEEN GENERATING SW SWELL TO 9 FT. AN EARLIER ALTIMETER PASS 
INDICATED THIS HAS PROPAGATED TO THE EAST OF 140W...AND 
LINGERING SWELL TO 8 FT MAY EXTEND FROM 10N TO 13N W OF 138W. 
THIS SHOULD SUBSIDE TO BELOW 8 FT OVER THE NEXT 6 HOURS.
 
$$ 
COBB