000
AXPZ20 KNHC 151525
TWDEP 

TROPICAL WEATHER DISCUSSION 
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC THU AUG 15 2013

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 
1500 UTC.
                                      
...INTERTROPICAL CONVERGENCE ZONE/MONSOON TROUGH...           
MONSOON TROUGH 10N86W TO 1008 MB LOW PRES 13N109W TO 14N115W TO
6N115W TO 6N135W. ITCZ 6N135W TO 7N140W. SCATTERED MODERATE TO 
STRONG WITHIN 120 NM S OF AXIS FROM 95W-102W AND WITHIN 150 NM N 
OF AXIS FROM 104W-107W AND FROM 9N-13N BETWEEN 107W-116W.

...DISCUSSION...                                                 
AN UPPER LEVEL TROUGH ACROSS THE NORTHERN PORTION OF THE 
DISCUSSION AREA EXTENDS FROM 32N135W TO 26N140W. MODERATE TO 
STRONG SUBSIDENCE WITH DRY AIR AT THE MIDDLE AND UPPER LEVELS IS 
N OF N OF 15N W OF 130W. A LARGE UPPER LEVEL ANTICYCLONIC 
CIRCULATION CENTERED OVER NORTHERN MEXICO NEAR 30N109W WITH A 
RIDGE EXTENDING SW OF THE ANTICYCLONE TO 12N122W. AN INVERTED 
UPPER LEVEL TROUGH IS SW OF THE RIDGE FROM CENTRAL MEXICO TO 
15N110W. IN THE DEEP TROPICS AN UPPER LEVEL CYCLONIC CIRCULATION 
IS CENTERED NEAR 9N136W. DEEP LAYER TROPICAL MOISTURE IS FROM 
9N-15N E OF 130W.  

A WEAK SURFACE RIDGE EXTENDS ACROSS THE NORTHERN PART OF THE 
AREA. THE MONSOON TROUGH EXTENDS ROUGHLY ALONG 10N EXTENDING 
FROM CENTRAL AMERICA TO NEAR 130W WHERE IT TRANSITIONS TO ITCZ 
AS MENTIONED ABOVE. THE PRESSURE GRADIENT BETWEEN THE RIDGE AND 
LOWER PRESSURE ASSOCIATED WITH THE MONSOON TROUGH AND IN THE 
VICINITY OF THE ITCZ IS MAINTAINING MODERATE TO FRESH 
TRADEWINDS. LINGERING SEAS TO 8 FT REMAIN OVER A SMALL AREA FROM 
16N TO 20N W OF 136W. THESE SEAS ARE EXPECTED TO DECREASE BELOW 
8 FT BY THIS EVENING. 

STRONG GAP WINDS IN THE GULF OF TEHUANTEPEC. THIS IS THE RESULT 
OF WIND FLOW AROUND A TROPICAL DISTURBANCE IN THE WESTERN 
CARIBBEAN INDUCING NORTHERLY FLOW THROUGH THE CHIVELA PASS INTO 
THE GULF OF TEHUANTEPEC. WINDS WILL CONTINUE TO PULSE TO NEAR 25 
KT OVER THE NEXT 24 HOURS AS THE TROPICAL DISTURBANCE MOVES INTO 
THE GULF OF MEXICO.

$$
DGS