000
AXPZ20 KNHC 200223
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL                         
0405 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 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 
0200 UTC.               

...TROPICAL WAVES...

A TROPICAL WAVE IS ADDED TO THE 0000 UTC ANALYSIS/SURFACE MAP 
ALONG 96W FROM 05N-12N. A CLUSTER OF MODERATE TO STRONG 
CONVECTION IS NOTED AHEAD OF THE WAVE AXIS FROM 07N-09N BETWEEN 
96W-100W. SCATTERED MODERATE ISOLATED STRONG CONVECTION IS 
BEHIND THE WAVE AXIS FROM 06N-09N BETWEEN 94W-96W. THE WAVE IS 
EMBEDDED IN A VERY DEEP MOIST LOW-LEVEL ENVIRONMENT AS OBSERVED 
ON THE TPW SATELLITE IMAGERY.

A TROPICAL WAVE AXIS IS ALONG 104W FROM 05N-13W MOVING W NEAR 15 
KT. THE WAVE SHOWS UP PRETTY WELL ON THE TPW ANIMATION AND 
SATELLITE DERIVED WINDS. ALSO...THE WAVE IS DEPICTED IN THE 
LATEST GFS 700 MB STREAMLINE AND 850 MB VORTICITY ANALYSIS. 
CONVECTION HAS DIMINISHED IN ASSOCIATION WITH THIS WAVE DURING 
THE LAST FEW HOURS. SCATTERED MODERATE CONVECTION IS NOW NOTED 
FROM 06N-10N BETWEEN 100W-104W. 

A TROPICAL WAVE AXIS IS ALONG 119W FROM 11N-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. SCATTERED MODERATE ISOLATED STRONG CONVECTION CAN BE 
FOUND FROM 12N-15N BETWEEN 114W-119W. SCATTERED MODERATE 
CONVECTION IS AHEAD OF THE WAVE AXIS FROM 12N-15N BETWEEN 119W-
122W.

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

CURRENTLY THERE IS NOT A WELL DEFINED MONSOON TROUGH OR ITCZ. 
MOST OF THE CONVECTIVE ACTIVITY IS ASSOCIATED WITH THE TROPICAL 
WAVES MENTIONED ABOVE.

...DISCUSSION... 

THE REMNANT LOW OF FORMER TROPICAL DEPRESSION ELEVEN-E IS 
ANALYZED NEAR 29N132W...WITH A CENTRAL PRESSURE OF 1011 MB. A 
TROUGH EXTENDS FROM 30N130W TO THE LOW CENTER TO 24N133W. 
ISOLATED SHOWERS ARE POSSIBLE WITH THE LOW AND TROUGH. AN 
ALTIMETER PASS INDICATED SEAS OF 7-8 FT WITHIN AROUND 90 NM NE 
QUADRANT OF THE LOW CENTER. SEAS WILL SUBSIDE TO 6-7 FT BY LATE 
TONIGHT. THE LOW PRES IS FORECAST TO MOVE NW REACHING A POSITION 
NEAR 30N133W BY THU EVENING...THEN WILL REMAINS NEARLY 
STATIONARY THROUGH SAT EVENING.
 
A WEAK NEARLY STATIONARY 1016 MB HIGH IS CENTERED NEAR 26N124W 
WITH A RIDGE EXTENDING SE TO 21N116W. THE PRESSURE GRADIENT 
BETWEEN THE RIDGE AND THE BAJA CALIFORNIA TROUGH IS EXPECTED TO 
INDUCE NLY FLOW OF 15-20 KT ALONG THE PACIFIC COAST OF THE BAJA 
PENINSULA THIS EVENING AND THU EVENING. SEAS WILL REMAIN 4-6 FT 
IN OFFSHORE WATERS. OTHERWISE...LITTLE CHANGE IS EXPECTED DURING 
THE NEXT COUPLE OF DAYS AS THE HIGH PRES REMAINS NEARLY 
STATIONARY.  

FRESH GAP WINDS WILL CONTINUE TO PULSE THROUGH THE GULF OF 
PAPAGAYO DURING THE OVERNIGHT AND EARLY MORNING HOURS WITH THE 
BENEFIT OF THE NOCTURNAL DRAINAGE FLOW WITH SEAS OF 5-6 FT 
DOWNSTREAM FROM GULF TO NEAR 90W. THESE SEAS COULD BUILD TO 6-7 
FT LATE THU NIGHT INTO EARLY FRI MORNING.
 
$$ 
GR