000
AXPZ20 KNHC 061530
TWDEP 

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
1605 UTC MON AUG 06 2012

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 
1800 UTC.

...SPECIAL FEATURES...

1008 MB LOW PRES IS NEAR 12.5N107.5W WITH AN ATTENDANT TROPICAL 
WAVE EXTENDING N OF THE LOW AS IS DESCRIBED IN THE NEXT 
PARAGRAPH BELOW. SCATTERED MODERATE TO STRONG CONVECTION IS 
WITHIN 90 NM OF 12.5N109W. 20-25 KT WINDS ARE WITHIN 60 NM OF 
THE CENTER OF THE LOW WITH SEAS TO 8 FT...ALONG WITH A REGION OF 
8 FT SWELL AROUND THE PERIPHERY OF THE LOW FROM 05N TO 10N 
BETWEEN 95W AND 113W. ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE 
FOR DEVELOPMENT...AND THIS LOW HAS A MEDIUM CHANCE OF BECOMING A 
TROPICAL CYCLONE AS IT MOVES W-NW AT 10-15 KT DURING THE NEXT 48 
HOURS.

...TROPICAL WAVES...

A TROPICAL WAVE EXTENDS FROM THE 1008 MB LOW PRES NEAR 
12.5N107.5W AS MENTIONED ABOVE TO 19N107W. ISOLATED MODERATE TO 
STRONG CONVECTION IS FROM 14N TO 19N WITHIN 60 NM OF THE WAVE 
AXIS. THE TROPICAL WAVE ITSELF WILL BECOME LESS AMPLIFIED AND 
DEFINED AS THE BROADER CIRCULATION OF THE ASSOCIATED LOW BEGINS 
TO DOMINATE THE AREA.

A TROPICAL WAVE EXTENDS FROM 15N130W TO 09N128W. ONLY SCATTERED 
SHOWERS ARE OBSERVED ON EITHER SIDE OF THE WAVE AXIS. THE PRES 
GRADIENT BETWEEN THE SURFACE TROUGHING ASSOCIATED WITH THE WAVE 
AND THE SUBTROPICAL RIDGE SHOULD BE STRONG ENOUGH FOR FRESH TO 
STRONG WINDS TO BUILD NEAR THE WAVE OVER THE W CENTRAL WATERS 
DURING THE NEXT FEW DAYS.

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

THE MONSOON TROUGH IS ALONG 10N85W TO LOW PRES NEAR 08N99W 1011 
MB TO LOW PRES NEAR 12.5N107.5W TO 11N117W TO 12N129W. THE 
INTERTROPICAL CONVERGENCE ZONE AXIS EXTENDS FROM 10N130W TO 
09N140W. SCATTERED MODERATE AND ISOLATED STRONG CONVECTION IS 
WITHIN 120 NM OF A LINE 05N77W TO 08N93W...FROM 06N TO 11N 
BETWEEN 97W AND 105W...FROM 07N TO 12N BETWEEN 111W AND 122W... 
AND ALSO FROM 08N TO 10N BETWEEN 129W AND 137W. IN ADDITION... 
SCATTERED MODERATE TO STRONG CONVECTION IS WITHIN 75 NM OF A 
LINE FROM 14N99W TO 18N105W.

...DISCUSSION...

A WEAK SUBTROPICAL RIDGE EXTENDS OVER THE NORTHERN WATERS FROM 
1021 MB SURFACE HIGH PRES CENTERED NEAR 30N131W TO 21N116W. THE 
RIDGE WILL SLOWLY BUILD ACROSS THE DISCUSSION WATERS TODAY 
AS THE SUBTROPICAL HIGH CONSOLIDATES NW OF THE AREA NEAR 35N140W 
BY TUE NIGHT. NE-E WINDS OF 15 KT ARE ALONG THE SOUTHERN 
PERIPHERY OF THE RIDGE S OF 22N AND N OF THE MONSOON TROUGH/ITCZ 
AXIS PER RECENT ASCAT PASSES...WITH MAINLY 5-10 KT WINDS N OF 
22N.

CROSS-EQUATORIAL LONG PERIOD SOUTHERLY SWELL OF UP TO 18-20 
SECONDS CONTINUES TO IMPACT MOST OF THE WATERS N OF 15N. HIGHEST 
WAVE PERIODS ARE IN THE FAR NORTHERN WATERS N OF 22N...WHILE THE 
HIGHEST SIGNIFICANT WAVE HEIGHTS ARE ACROSS THE S CENTRAL WATERS 
WITH SEAS TO 7 FT. THE SWELL WILL CONTINUE TO GRADUALLY DECAY 
TODAY. ANOTHER SWELL EVENT FROM THE SOUTHERN HEMISPHERE WITH 
PERIODS IN THE 16-18 SECOND RANGE IS NOW CROSSING THE EQUATOR W 
OF 120W AND THIS SWELL TRAIN WILL CONTINUE TO PROPAGATE TO THE 
N-NE DURING THE NEXT FEW DAYS WHILE SIGNIFICANT WAVE HEIGHTS 
REMAIN JUST LESS THAN 8 FT.

GAP WINDS...FRESH TO STRONG NORTHERLY WINDS ARE EXPECTED IN THE 
GULF OF TEHUANTEPEC THROUGH TUE EVENING. THIS GAP WIND EVENT 
WILL BE INDUCED BY RELATIVELY HIGHER SURFACE PRES OVER INTERIOR 
SE MEXICO AND CENTRAL GUATEMALA...AND LOWER PRES TO THE S ALONG 
THE MONSOON TROUGH WHICH IS GRADUALLY DRIFTING NORTH AS T.S. 
ERNESTO IN THE NW CARIBBEAN SEA APPROACHES CENTRAL AMERICA AND
THE YUCATAN PENINSULA.

$$
LEWITSKY