000
AXPZ20 KNHC 212124
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
2205 UTC FRI AUG 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 1800 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
2100 UTC.               

...TROPICAL WAVES...

A TROPICAL WAVE IS ADDED TO THE 1800 UTC ANALYSIS/SURFACE MAP 
ALONG 105W FROM 06N TO 15N. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS NOTED ON EITHER SIDE OF THE WAVE AXIS FROM 06N TO 
13N BETWEEN 100W AND 108W. THE WAVE IS REFLECTED IN A SURGE OF 
MOISTURE ON THE TPW SATELLITE IMAGERY AS WELL AS IN THE LATEST 
GFS 700 MB STREAMLINES AND 850 MB VORTICITY ANALYSIS.

A TROPICAL WAVE IS ALONG 115W FROM 06N TO 16N. SCATTERED 
MODERATE CONVECTION CAN BE FOUND FROM 08N TO 12N E OF THE WAVE 
AXIS TO 108W...AND FROM 03N TO 09N W OF WAVE AXIS TO 120W. 

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

THE MONSOON TROUGH EXTENDS FROM 10N83W TO 08N92W TO 10N100W. NO 
ITCZ IS PRESENTLY IDENTIFIED. SCATTERED MODERATE ISOLATED STRONG 
CONVECTION IS SEEN FROM 04N TO 09N E OF 92W TO THE COAST OF 
COLOMBIA...INCLUDING ALSO THE GULF OF PANAMA. 
 
...DISCUSSION... 

A 1009 MB AREA OF LOW PRES HAS DEVELOPED ALONG A TROPICAL WAVE 
AND NOW IS LOCATED NEAR 13N123W. THE CONVECTIVE ACTIVITY 
ASSOCIATED WITH THIS LOW HAS DIMINISHED DURING THE LAST FEW 
HOURS AND NOW IS PRODUCING A SMALL AREA OF DISORGANIZED SHOWERS 
AND TSTMS. SOME GRADUAL DEVELOPMENT OF THIS SYSTEM IS POSSIBLE 
OVER THE WEEKEND WHILE THE DISTURBANCE MOVES WESTWARD ABOUT 10 
KT. THIS AREA IS BEING MONITORED AND THE LATEST TROPICAL WEATHER 
OUTLOOK GIVES THIS LOW A LOW CHANCE OF DEVELOPMENT FOR THE NEXT 
48 HOURS. 

THE REMNANT LOW OF T.D. ELEVEN PERSISTS NEAR 31N132W WITH A 
CENTRAL PRES OF 1012 MB. A SURFACE TROUGH EXTENDS FROM THE LOW 
CENTER TO NEAR 28N138W. NO SIGNIFICANT CONVECTION OR WINDS ARE 
NOTED WITH THIS FEATURE. A SWIRL OF LOW CLOUDS IS STILL NOTED ON 
VISIBLE SATELLITE IMAGERY. THE LOW PRES IS FORECAST TO REMAIN 
NEARLY STATIONARY ON SAT AND FINALLY OPEN UP INTO A TROUGH ON 
SUN.  

A SURFACE RIDGE DOMINATES THE AREA N OF 17N W OF 112W WITH A 
WEAK 1017 MB HIGH NEAR 27N127W. PRES GRADIENT BETWEEN THE RIDGE 
AND A SURFACE TROUGH ALONG THE BAJA CALIFORNIA PENINSULA IS 
PRODUCING MODERATE TO FRESH NW WINDS OFF THE PACIFIC COAST OF 
THE BAJA PENINSULA. SCATTEROMETER DATA CONFIRMED THE PRESENCE OF 
THESE WINDS. FRESH TO LOCALLY STRONG SOUTHERLY WINDS ARE ALSO 
NOTED OVER THE NORTHERN GULF OF CALIFORNIA WITH SEAS TO 6 FT. 
THE HIGH IS FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT 
24 HOURS.
 
GAP WINDS...                                                     
AN EARLIER ASCAT PASS SHOWED FRESH TO LOCALLY STRONG GAP WINDS 
ACROSS THE GULF OF PAPAGAYO. THESE WINDS WILL RETURN OVERNIGHT 
TONIGHT INTO SAT MORNING WITH THE ASSISTANCE OF THE NOCTURNAL 
DRAINAGE FLOW WITH SEAS OF 6-7 FT. 

$$ 
GR